19:45 Jimmy's fatherly concern for Ant is what makes Jimmy such a stand up man. The little things I notice bout each of you lmao. All amazing people stay safe out there and warm.
Same thoughts. Even with the gate open the turbo can spool up and make boost on the inlet side. Either increase the gate size or control the boost on the intake side with a blow off valve.
Had the same issue on my sr20det, I was hitting 15+ on a 6lbs internal gate. Ported the wastegate hole but that only kept it down 1-2 psi. Swapping to external gate was the only thing that fixed my issue. But if you got a bigger turbo exhaust housing laying around the shop that might help also before going external. SR IS GOOD!
Check to make sure the actual physical flapper on the gate is moving when open. Then you can rule out the turbo being the issue, plenty of people here in Aus have turbo na sr’s and have no issues with the stock ignition. But also doesn’t mean that yours is good! Just do smart coils and make sure the flapper is opening.
Yeah was gonna say, you guys in Aus and us here in NZ are pretty experienced with DE+T motors, SR or RB! Others have mentioned porting the manifold to get rid of the stepped bit which can help. Otherwise it might be external gate time which is kinda a pain but not too bad
Here's the thing with high compression engines and small frame turbos. The higher compression forces so much air through the exhaust manifold that the simple internal wastegate with its small dimensions cannot keep up no matter what. If you notice all of the big bad ass cars that are high compression running small or medium turbos have multiple external waste Gates on the system in the highest flowing areas of their exhaust manifolds. Some even have to go to the extreme of putting a wastegate on each exhaust runner just to manage their boost when they're compression is high. The trick for running a high compression engine with a turbo is to use a larger turbo, the larger turbo will negate the low end torque that destroys the engines and will stop the boost spiking as it will allow the boost to come in later in the RPM more controllable.
Yep, compression isn't the killer for boost. Could go for big singles but most do multiple smaller so you have better control over the flow, just take a little bit of work to put them in/if you have space for it.
I will say step by step diagnosis with a great explanation of each consideration is absolutely going to help so manny backyard bandits iron out their builds and I love to see it!
I love these videos/builds. Its probably boring to some but its a great experience to follow along and learn and read the comments and see everyone working together to figure out the issue.
This is a similar issue that happens with turbo ii rx7’s. When you increase boost, you need to port the exhaust manifold so that the internal wastegate can operate more efficiently. This will eliminate the boost creep. Not sure if it’s the same with sr20 manifolds as well but it’s worth a look
Jimmy, these guys may know what’s up. I had the same experience with my Turbo II when I had mine. You may end up porting the wastegate and then welding a bigger door on the flap.
But you guys are talking about increasing boost… that engine is at low boost and it’s going up on pressure because of the creep… i think that the most plausible cause could be the wastegate flapper that broke off the actuated lever and it stays stuck closed… i dunno😕
@@lorenzodicosmo2708 even some stock boost level cars can experience boost creep(again speaking for rx7’s). It just has to do with the efficiency/flow of the wastegate. The more power you make, the more significant the boost creep will be. Remember, stock hp on the turbo sr20 is around 220hp (crank) and Jimmy made way more than that, to the wheels.
I wonder if the flapper is getting stuck or is loose on the arm? Is the initial downpipe elbow at all restricting the gate flow? Also not a bad idea to replace the distributor cap and rotor.
I think most wastegate actuators are welded on and then held on with a circlip at the flapper inside the manifold. As unlikely as it could be, I still had the same thought - maybe the flapper inside the manifold is just not opening all the way (or at all). Could be clogged with carbon? Or as I commented below, on rx7 turbos the wastegate port is just too small from factory, so it needs porting.
I just looked at a past video and the isr elbow he used has an oval pipe to the flange to accommodate the wastegate. Interesting detail though is that he never shows the elbow being off of the turbo so it's hard to determine what it's like inside.
I also had the thought that maybe he had a rag or paper tower in an exhaust port that got sucked into the wastegate vs getting shredded in the turbine. It's a stretch at best but maybe haha
If you attach the ramps to the dyno with a hinge you can mount scissor jacks to the ramps to make it easier to level the cars. If you get the type with the bolt head you can just run them up and down with an impact.
The lever that connect to the flap is broken so it’s staying closed the whole time. Hence building all the boost no matter what position you try. Hope that helps and keep up the good works guys. Killer videos!!! A cool obs Chevy regular cab short box build with a turbo LS would be sick to see and something a little different you can put your twist on.
According to some sources I can find, the rods and pistons are actually the same. The head combustion chamber is what makes the compression ratio different. The bottom end can generally handle quite a bit, but obviously you have to avoid knock.
Try a divorced turbo elbow. It has a piece to keep the exhaust gasses from over powering the waste gate gasses. Had to do the same on a KA with a GT2876.
Id pull off the downpipe and see the wastegate move. I had t25 turbo do 15psi on a fwd b15 sr20 using the oem wastegate with a manual boost controller. It’s still alive.
Jimmy, I just went through all of this with my rb25neo de+t. Put it on e85, no knock anymore. So we could then advance the timing as per normal. And the boost was controllable. Not to mention the gains on e85 with a high compression head.
I always put the wastegate on the exhaust housing, 44-60mm gates never had boost creep like this, but yes higher compression is def enough on a 4cylinder, they want to breathe so you got to give them bugger manifolds downpipes etc for them not to want to boost creep
I tried everything on my r32. I’d just weld internal Wastegate shut and weld Wastegate flange to stock manifold. Your boost will be on point. Only thing that worked for me
There's already been comments about it, but this is a major issue on small turbos with IWG's! Port the wastegate hole and get a bigger flap, then it will be OK or you can go external gate, but then do a oversized one, that's how you controll small turbos on high comp and high displacement engines
I had a similar issue with my 2jge+t build. Had a 14 psi spring in it and it was going to 19psi by the end of the run with an external gen v turbosmart gate. The theory was that cause it’s a 10:1 motor it creates so much gas pressure before that it couldn’t get enough out. It didn’t level out till 22 psi
ok this is goin to drive me bonkers. the ramps for the dyno, square stock steel across the end of the ramps and a perunamtic bottle jack lifting on the bar thus lifting the ramps. 12 ton at napa. go get it. square u bolts are at O'Reilly on the sales floor. 🙃 that air filter is asking for trouble.
YOU HAVE 3 OPTIONS: 1) Port the internal wastegate. Maybe will work but not a guarantee. 2) Make you exhaust MORE restrictive (not less) so the turbo doesn’t spool as fast and encourages gasses to flow through the wastegate more and the turbine less, again not a guarantee. Adding a cat would be you best shot with this option. 3) Just get an external wastegate that is 1000 times better at controlling boost levels, plus screamer pipe, because who doesn’t love that. BONUS EXPENSIVE OPTION: Get a higher quality turbo with a better internal wastegate design.
I agree with lots of the comments saying what i think too. Porting the waste gate out may help, id also make sure that the wastegate is functioning as it should on the inside. A larger turbo would spool slower, and decrease the low end torque but up the hp on the top end. For some reason i love a t04e.
For future reference, exhaust restriction will reduce boost creep. It's common on a lot of 2J based cars to install a restrictor flange in the mid pipe to control boost creep. Less flow= turbo can't spin as fast= less boost
As other comments are suggesting u might wanna check the wastegate flap inside the exhaust housing, so that the flap is actually opening as it should. The arm might be broken off of the flap or something, and the flap might be stuck.
going thru this with my son's turbo L28 Datsun... the hole behind the wastegate flapper was too small to relieve boost, we tried running it with the gate rigged open and it was still hitting boost cut. We are machining out the gate opening before we go to a turbosmart actuator
Jimmy pull off the turbo and check the actual wastegate hole under the flap. They can be EXTREMELY too small for the size of the turbo sometimes and you need to drill em out/port them so they can actually flow enough when the gate is open. Theres a reason why people dont use internal gates anymore.
Jimmy. Theory is actually backwards on the backpressure issue. If you exhaust was restricted your boost would be lower. Like having a clogged cat. I had the same issue on mine. We were trying to target 28psi on my car and would only hit 17 and was super lazy. Found out cat was failed. Ended up gutting the cat and then we turned the gate duty down and hit 36psi and was overboosting and having creep issues. You need to port the inside of the hotside where the flapper is.
I've done this swap personally. Regardless of what engine turbo combo always achieve a linear boost curve.... imo waste gate flap damage and or the dump pipe is stopping the flap open correctly. The latter I have seen personally on s14 with a aftermarket dump pipe. Sr is good.
Good video Jimbo 👍🏽 Same issue is common on the 1JZ (In stock chassis - JZX) with stock Turbo(ct15b) when you Decat it starts to boost creep/spike, this also gets worse with a 3" exhaust, instead of factory boost 13psi it goes up to 15-20psi. Decat/3" exhaust Creates too much flow, that the Wastegate can't overpower the flow through the turbo housing. *But in reality the waste gate port/hole is just too small, so external gate is probably the best fix for this problem. (Ps I had the same issue on my JZX) I hope this helps, and I look forward to watching the fix for this 🙂👍🏽
Think stock is more like 10 well on mine and multiple mates jzx and since decat and 3" it's around 12-13 you could have a worn vacuum diaphragm on the iwg though which could explain it haha
I had a s14 sr20det in a 180 doing this with a 2871 and a disco potato the lowest boost I got was 18 and kept going up near 300hp no matter what I did including an external gate!! Put a stock 2560 on and it got sensible 🤷♂️
Path of less resistance it’s building pressure inside the exhaust housing as the 20mm internal gate can’t flow the exhaust gas enough. Had my spec R tuned last week has a 10psi internal gate spring makes 10psi controllable until 5500-6000rpm then the flow through the exhaust housing internal gate isn’t enough to stop it building boost so at 6500-7000rpm it makes 18psi which is holdable.(brand new gtx2871r)
2 things. Timing ok from crank and cams? And check if the turbo gate internaly is ok. I hade a guy that had mounted it wrong. When actuated it closes instead of opening. The waist gate was working backwards.
My DE+T on the dyno, was unhappy on 91 (pre-ignition?) Fuel was changed to 98 & it ran a lot better. Because of a boost creep issue caused by a small rear turbo housing, the boost is set at 8psi. The wastgate on my turbo is an adjustable Turbosmart IWG. I also have stock plugs,leads & distributor. The exhaust on my car consists of a tubular manifold, 2.5 inch stainless exhaust with 200cpi cat & Vibrant rear muffler.
Im from NZ had a few mates have similar issues with internally gated turbos, in the end the wastegate hole the flap closed on needed to be ported as the hole was ridiculously restrictive. Had it happen with an Rb25det series 2 and Rb25det neo. we also replaced dump as they're pretty restrictive too
Check the actual flapper of the waste gate. You wouldn’t see it from the outside, but the lever may be “engaged” on the outside but it must closed or not fully open on the inside. Turbo seems fine. Vacuum source is fine. Timing is fine. Must be that mechanical issue. New manifold would likely fix it.
As frustrating as these sorts of problems are, they are the ones where you genuinely learn something new. You'll get it dialed, and it'll seem obvious in hindsight. 👏👏👏👍
Perhaps the size or lack of, in the runners of the exhaust manifold, coupled with the higher compression, and potentially not enough flow through the flap of the gate in comparison to the efficiency of the turbo are just making boost too easily, changing one thing clearly wasn't working so maybe it wasnt just one thing that was causing it? Lot of the Barra guys over here in aus port the wastegate flap if staying internally gated because it quickly becomes difficult to control boost. Or like a lot of other people are suggesting maybe the flap itself isn't rotating with the shaft
Had the same issue on my s13 rally car with a 11-1 compression SR with the same 2860 turbo. Had the internal gate machined out and a gt30 waste gate flap fitted. Pulled it from 13-14psi minimum back down to 8-9.
if the gate has been wired opened or whatever and its still making all the boost the only answer is the wastegate is to small.. strange just that tad more compression would make such a difference but it seems the only answer.. either port the gate hole or change the housing.. if all else fails its worth a try just to find out
Port the wastegate! I've had these same problems on my Eunos Cosmo, it started overboosting as soon as I put a more free flowing exhaust on it. Ported the internal gate out a bit and now she's miiint.
Had to port my internal gate in my turbo to stop boost creep, its usually to do with the manifold Design even thought the stock manifolds are fine up until about 350hp ish. bigger rear housing can help aswell
You need to add back pressure if you want your current setup to work. Otherwise you need to port the wastegate but need to do that correctly or you'll have other issues also.
Could be faulty CAS (camshaft not crank) behind your distributor, pretty sure it’s the same as rb30et’s (straight 6, 3L turbo engine) Easy fix. Same kind kind of thing happens to our turbo RB30et’s in Australia in our VL turbos. Even though it isn’t an SR, they run a distributor on both n/a and turbo models, this kind of rb didn’t come with coil from factory.
fairly common to plug internal wastegates to avoid cracking early, I'd pull the exhaust housing and make sure the wastegate flap is actually doing something
you'd almost assume that the flap has been wielded shut in the turbo for it to still be making that kind of jam, when i fitted a 2871 to my det i pinned the gate open to drive to get tuned and could barely get 2psi at like 6k rpm. i'd take the elbow off and look at the gate operation
This is purely a mechanical issue- the wastegate opening in the exhaust housing needs to be ported a bit bigger. Even factory 20dets have a bit of boost creep from factory and the slightly higher compression of the NA motor will exacerbate this trend. 20 minutes with a fir grinder and you can make a massive improvement. It's also very important to smooth the flow into the wastegate port from the manifold side
Pull the turbo off and check that the wastegate actuator is actually opening and closing the internal wastegate, it seems like the arm has broken off inside, that's the only thing that makes sense now and I have seen it happen before
If any GT28 size turbo, if the compressor able to flow 400hp, if the exhaust housing is 0.64 AR, I port and enlarge each and every wastegate hole to make sure it won't over boost
I am using the same turbo on a built Honda D-series with 11:1 compression and having the same issue. (Tuned on the link Honda standalone) we think that the internal wastegate is too small to control the turbine speed and ended up adding a 38mm external wastegate. Getting tuned tomorrow so hopefully it works.
Smooth out the harsh edge of the wastegate port where the exhaust gas flows to exit through the flapper. The smoothing would be performed on the turbine side. Use a carbide burr bit. Usually helps with boost creep. Also SR’s suck.
I used to have a 5th subaru legacy GT that had the same issue, no matter what we did it would always overboost when I put a 3 inch downpipe on it. Not sure what kind of downpipe you're using but theres a good chance there isnt enough restriction in the exhaust and too much restriction in the wastegate itself. You either need to enlarge the wastegate port or run a an external gate, anything else would be a bandaid fix.
I think the last thing everyone is thinking is if the lever is actually opening the port inside the turbo elbow but if it's moving the wastegate from exhaust gasses flowing through the port then that shouldn't be the case
could it be the cam overlap, i know N\A engines have a overlap intake/exhaust so that the gasses flow better which is not needed on turbo engines since the turbo is creating enough flow, so in theory if there is too much overlap on this srDE it means that it blows boost into the exhaust which keeps the turbo boosting since it is exhaust driven,could be wrong and it could be something else but just helping to brainstorm here.Hope this helps👍✌️👉
Port that wastegate hole mate!! Also, you don't need to wire the flap open when testing the wastegate port. Just simply unhooking the actuator arm is enough. The gases will smash that flap open. My disco potato(GT28/60 RS) on my RB20det has a similar problem although mine is less effected. Spikes to 19psi but drops back down to 17ish, that's with a 14psi actuator. So if I port the wastegate it would be fine but that's around the boost I wanna run so I left it. Also 2 step will ruin that stock NA sr, just so you know.
![[#2024MAMA] BIGBANG (빅뱅) - 뱅뱅뱅 (BANG BANG BANG) + FANTASTIC BABY | Mnet 241123 방송](http://i.ytimg.com/vi/EQsYfiPR9uM/mqdefault.jpg)
19:45 Jimmy's fatherly concern for Ant is what makes Jimmy such a stand up man. The little things I notice bout each of you lmao. All amazing people stay safe out there and warm.
@@CANDY-in9js Can a carrot fix are boy Jimmy’s issue?
@Lucifer Sorry i don't speak Egg roll
Boost Creep......Port wastegate in exhaust housing to encourage the gases to go through the gate rather than straight through the turbine 👍
+1, I remember skid factory doing this on chinese turbos, looks like the same issue here.
Or get rid of the shitty internal waste gate and get a quality external waste gate... Or say fuck it and turn up the boost cut
Same thoughts. Even with the gate open the turbo can spool up and make boost on the inlet side. Either increase the gate size or control the boost on the intake side with a blow off valve.
Or get rid of the shitty internal waste gate and get a quality external waste gate... Or say fuck it and turn up the boost cut
@@givman2004 no blow off valves!
Had the same issue on my sr20det, I was hitting 15+ on a 6lbs internal gate. Ported the wastegate hole but that only kept it down 1-2 psi. Swapping to external gate was the only thing that fixed my issue. But if you got a bigger turbo exhaust housing laying around the shop that might help also before going external. SR IS GOOD!
SR IS GOOD is the message an auto enthusiast cult leader would spread to gain followers
Check to make sure the actual physical flapper on the gate is moving when open. Then you can rule out the turbo being the issue, plenty of people here in Aus have turbo na sr’s and have no issues with the stock ignition. But also doesn’t mean that yours is good! Just do smart coils and make sure the flapper is opening.
Yeah was gonna say, you guys in Aus and us here in NZ are pretty experienced with DE+T motors, SR or RB!
Others have mentioned porting the manifold to get rid of the stepped bit which can help. Otherwise it might be external gate time which is kinda a pain but not too bad
Yep, nothing wrong with a little port job, some are really bad and others only need a little trim.
Anyone buy yugioh cards from jimmy shops and they come with random merch? I think it’s pretty cool
Got my DBZ card and some wild 90s junk air fresheners.
I bought that shirt for Bhalls build and it came with a card LOL
I bought bhalls shirt and some stickers and didn't get a card. I was actually looking forward to seeing what random card I got ha
Here's the thing with high compression engines and small frame turbos. The higher compression forces so much air through the exhaust manifold that the simple internal wastegate with its small dimensions cannot keep up no matter what. If you notice all of the big bad ass cars that are high compression running small or medium turbos have multiple external waste Gates on the system in the highest flowing areas of their exhaust manifolds. Some even have to go to the extreme of putting a wastegate on each exhaust runner just to manage their boost when they're compression is high. The trick for running a high compression engine with a turbo is to use a larger turbo, the larger turbo will negate the low end torque that destroys the engines and will stop the boost spiking as it will allow the boost to come in later in the RPM more controllable.
Yep, compression isn't the killer for boost.
Could go for big singles but most do multiple smaller so you have better control over the flow, just take a little bit of work to put them in/if you have space for it.
I will say step by step diagnosis with a great explanation of each consideration is absolutely going to help so manny backyard bandits iron out their builds and I love to see it!
I honestly preferred this outcome, if it went smoothly first pull we wouldn’t have learned as much 🔥
Thanks for showing this Jimbo, actually learned a lot about turbos today.
I love these videos/builds. Its probably boring to some but its a great experience to follow along and learn and read the comments and see everyone working together to figure out the issue.
Jimmy got Brian back with the 2 step 😂 Donnie almost dying from Brian’s 2step from his mk2 is still my favorite Clip of all time
This is a similar issue that happens with turbo ii rx7’s. When you increase boost, you need to port the exhaust manifold so that the internal wastegate can operate more efficiently. This will eliminate the boost creep. Not sure if it’s the same with sr20 manifolds as well but it’s worth a look
I had this issue. Ended up having to make the wastegate port like 2.5x wider to prevent boost spikes.
Jimmy, these guys may know what’s up. I had the same experience with my Turbo II when I had mine. You may end up porting the wastegate and then welding a bigger door on the flap.
But you guys are talking about increasing boost… that engine is at low boost and it’s going up on pressure because of the creep… i think that the most plausible cause could be the wastegate flapper that broke off the actuated lever and it stays stuck closed… i dunno😕
@@lorenzodicosmo2708 even some stock boost level cars can experience boost creep(again speaking for rx7’s). It just has to do with the efficiency/flow of the wastegate. The more power you make, the more significant the boost creep will be. Remember, stock hp on the turbo sr20 is around 220hp (crank) and Jimmy made way more than that, to the wheels.
@@CANDY-in9js sup natalie
I wonder if the flapper is getting stuck or is loose on the arm? Is the initial downpipe elbow at all restricting the gate flow? Also not a bad idea to replace the distributor cap and rotor.
Turbo elbow is likely restricting waste gate flow. Needs a divorced turbo elbow.
I think most wastegate actuators are welded on and then held on with a circlip at the flapper inside the manifold. As unlikely as it could be, I still had the same thought - maybe the flapper inside the manifold is just not opening all the way (or at all). Could be clogged with carbon? Or as I commented below, on rx7 turbos the wastegate port is just too small from factory, so it needs porting.
we had a similar issue with a celica Gt4, but in the end it was the distributor cap
I just looked at a past video and the isr elbow he used has an oval pipe to the flange to accommodate the wastegate. Interesting detail though is that he never shows the elbow being off of the turbo so it's hard to determine what it's like inside.
I also had the thought that maybe he had a rag or paper tower in an exhaust port that got sucked into the wastegate vs getting shredded in the turbine. It's a stretch at best but maybe haha
If you attach the ramps to the dyno with a hinge you can mount scissor jacks to the ramps to make it easier to level the cars. If you get the type with the bolt head you can just run them up and down with an impact.
Nobody:
JimmyO: "Check out the throw on my wastegate rod"
Plot twist, What Jimmy thinks is open is actually closed
Lmao I actually researched the turbo to see if this was the case. Stock turbo shows wastegate arm point down from exhaust inlet
My first engine was a s14 sr20de in a s13. Awesome seeing what these things can do. I was never very confident in it so I swapped to det.
The lever that connect to the flap is broken so it’s staying closed the whole time. Hence building all the boost no matter what position you try.
Hope that helps and keep up the good works guys. Killer videos!!! A cool obs Chevy regular cab short box build with a turbo LS would be sick to see and something a little different you can put your twist on.
Port the waste gate out! Make it flow as much as possible 😜💥💯
According to some sources I can find, the rods and pistons are actually the same. The head combustion chamber is what makes the compression ratio different. The bottom end can generally handle quite a bit, but obviously you have to avoid knock.
This conveys a great message, even if you think a car build is going to be "easy", it won't. Lol. That's just how it goes.
Watching old Jimmy videos boom Jimmy uploads great moment🤌🏽
Try a divorced turbo elbow. It has a piece to keep the exhaust gasses from over powering the waste gate gasses. Had to do the same on a KA with a GT2876.
Agreed
Id pull off the downpipe and see the wastegate move. I had t25 turbo do 15psi on a fwd b15 sr20 using the oem wastegate with a manual boost controller. It’s still alive.
Brian looking stylish today with those glasses 🤘🏻😂
Has the wastegate seized shut and the lever broken off so it moves ? That’s the only thing I can think of
This was my thought
they tried 2 wastegates tho
@@fredrikandersson3885 they tried the actuator, not the wastegate itself. The wastegate is built into the turbo
There talking about lever connected to opening valve at manifold
First thing I thought of. Need to see the thing moving to make sure it isn't cracked and stuck mostly closed.
Love how you now got a clean zenki and it’s only gonna get better
Jimmy, I just went through all of this with my rb25neo de+t. Put it on e85, no knock anymore. So we could then advance the timing as per normal. And the boost was controllable. Not to mention the gains on e85 with a high compression head.
I always put the wastegate on the exhaust housing, 44-60mm gates never had boost creep like this, but yes higher compression is def enough on a 4cylinder, they want to breathe so you got to give them bugger manifolds downpipes etc for them not to want to boost creep
Needs some ca18det on the channel 😄
I tried everything on my r32. I’d just weld internal Wastegate shut and weld Wastegate flange to stock manifold. Your boost will be on point. Only thing that worked for me
There's already been comments about it, but this is a major issue on small turbos with IWG's! Port the wastegate hole and get a bigger flap, then it will be OK or you can go external gate, but then do a oversized one, that's how you controll small turbos on high comp and high displacement engines
I had a similar issue with my 2jge+t build. Had a 14 psi spring in it and it was going to 19psi by the end of the run with an external gen v turbosmart gate. The theory was that cause it’s a 10:1 motor it creates so much gas pressure before that it couldn’t get enough out. It didn’t level out till 22 psi
ok this is goin to drive me bonkers. the ramps for the dyno, square stock steel across the end of the ramps and a perunamtic bottle jack lifting on the bar thus lifting the ramps. 12 ton at napa. go get it. square u bolts are at O'Reilly on the sales floor. 🙃
that air filter is asking for trouble.
Had this problem on my E30. Port the gate. Helps a lot. I wasn't totally comfy with it through, so I went external for simplicity sake
YOU HAVE 3 OPTIONS:
1) Port the internal wastegate. Maybe will work but not a guarantee.
2) Make you exhaust MORE restrictive (not less) so the turbo doesn’t spool as fast and encourages gasses to flow through the wastegate more and the turbine less, again not a guarantee. Adding a cat would be you best shot with this option.
3) Just get an external wastegate that is 1000 times better at controlling boost levels, plus screamer pipe, because who doesn’t love that.
BONUS EXPENSIVE OPTION:
Get a higher quality turbo with a better internal wastegate design.
Brian looks like he is about to perform rocket man for you in the shop
I agree with lots of the comments saying what i think too. Porting the waste gate out may help, id also make sure that the wastegate is functioning as it should on the inside. A larger turbo would spool slower, and decrease the low end torque but up the hp on the top end. For some reason i love a t04e.
For future reference, exhaust restriction will reduce boost creep. It's common on a lot of 2J based cars to install a restrictor flange in the mid pipe to control boost creep. Less flow= turbo can't spin as fast= less boost
Had to do the same on a 2.2l eco tech with high compression and a small turbo.
Ant has progressed soo much with his confidence on camera that he has highkey became more entertaining as a person 😂💯
As other comments are suggesting u might wanna check the wastegate flap inside the exhaust housing, so that the flap is actually opening as it should. The arm might be broken off of the flap or something, and the flap might be stuck.
SR may be good, but KA all day baby
Best automotive TH-camr hands down!
Pull the turbo, and port the internal wastegate to match the valve seat. If you see any pressure drops, change the back housing.
Sometimes the port in the housing for the wastegate flap is too small and causes boost creep/ spike. Porting open that hole may help with flow.
The thumbnail is everything
going thru this with my son's turbo L28 Datsun... the hole behind the wastegate flapper was too small to relieve boost, we tried running it with the gate rigged open and it was still hitting boost cut.
We are machining out the gate opening before we go to a turbosmart actuator
Keep the internal!!! Port it and put a bigger flapper!
Jimmy pull off the turbo and check the actual wastegate hole under the flap. They can be EXTREMELY too small for the size of the turbo sometimes and you need to drill em out/port them so they can actually flow enough when the gate is open.
Theres a reason why people dont use internal gates anymore.
Donny with the goofiest line of all time I love it 😂😂
Jimmy. Theory is actually backwards on the backpressure issue. If you exhaust was restricted your boost would be lower. Like having a clogged cat. I had the same issue on mine. We were trying to target 28psi on my car and would only hit 17 and was super lazy. Found out cat was failed. Ended up gutting the cat and then we turned the gate duty down and hit 36psi and was overboosting and having creep issues. You need to port the inside of the hotside where the flapper is.
I've done this swap personally. Regardless of what engine turbo combo always achieve a linear boost curve.... imo waste gate flap damage and or the dump pipe is stopping the flap open correctly. The latter I have seen personally on s14 with a aftermarket dump pipe. Sr is good.
I can never miss a jimmy oaks upload😮💨
Good video Jimbo 👍🏽
Same issue is common on the 1JZ (In stock chassis - JZX) with stock Turbo(ct15b) when you Decat it starts to boost creep/spike, this also gets worse with a 3" exhaust, instead of factory boost 13psi it goes up to 15-20psi.
Decat/3" exhaust Creates too much flow, that the Wastegate can't overpower the flow through the turbo housing.
*But in reality the waste gate port/hole is just too small, so external gate is probably the best fix for this problem. (Ps I had the same issue on my JZX)
I hope this helps, and I look forward to watching the fix for this 🙂👍🏽
Think stock is more like 10 well on mine and multiple mates jzx and since decat and 3" it's around 12-13 you could have a worn vacuum diaphragm on the iwg though which could explain it haha
@@darren_irvine yep you're right, forgot to mention I've got a JZX110 Fortuna and it's about 13 factory. But same issue either way 👍🏽
I haven't watched Jimmy o in a while and was so shocked when ant said more than a word 😳 good to see him on camera seems like a good lad!
I had a s14 sr20det in a 180 doing this with a 2871 and a disco potato the lowest boost I got was 18 and kept going up near 300hp no matter what I did including an external gate!! Put a stock 2560 on and it got sensible 🤷♂️
Path of less resistance it’s building pressure inside the exhaust housing as the 20mm internal gate can’t flow the exhaust gas enough. Had my spec R tuned last week has a 10psi internal gate spring makes 10psi controllable until 5500-6000rpm then the flow through the exhaust housing internal gate isn’t enough to stop it building boost so at 6500-7000rpm it makes 18psi which is holdable.(brand new gtx2871r)
2 things. Timing ok from crank and cams? And check if the turbo gate internaly is ok. I hade a guy that had mounted it wrong. When actuated it closes instead of opening. The waist gate was working backwards.
My DE+T on the dyno, was unhappy on 91 (pre-ignition?) Fuel was changed to 98 & it ran a lot better. Because of a boost creep issue caused by a small rear turbo housing, the boost is set at 8psi. The wastgate on my turbo is an adjustable Turbosmart IWG. I also have stock plugs,leads & distributor. The exhaust on my car consists of a tubular manifold, 2.5 inch stainless exhaust with 200cpi cat & Vibrant rear muffler.
Im from NZ had a few mates have similar issues with internally gated turbos, in the end the wastegate hole the flap closed on needed to be ported as the hole was ridiculously restrictive. Had it happen with an Rb25det series 2 and Rb25det neo. we also replaced dump as they're pretty restrictive too
Check the actual flapper of the waste gate. You wouldn’t see it from the outside, but the lever may be “engaged” on the outside but it must closed or not fully open on the inside. Turbo seems fine. Vacuum source is fine. Timing is fine. Must be that mechanical issue. New manifold would likely fix it.
You have a spot in the middle of your lens coming through on the video, little purple dot, maybe from recording welding arc?
fun to watch you try & diagnose stuff. your vids teach me a lot.
Had this problem as well. Was only able to fix it with external waste gate. Was on the ecotech 2.2l and not a sr but thats my 2 cents
As frustrating as these sorts of problems are, they are the ones where you genuinely learn something new. You'll get it dialed, and it'll seem obvious in hindsight. 👏👏👏👍
Perhaps the size or lack of, in the runners of the exhaust manifold, coupled with the higher compression, and potentially not enough flow through the flap of the gate in comparison to the efficiency of the turbo are just making boost too easily, changing one thing clearly wasn't working so maybe it wasnt just one thing that was causing it? Lot of the Barra guys over here in aus port the wastegate flap if staying internally gated because it quickly becomes difficult to control boost.
Or like a lot of other people are suggesting maybe the flap itself isn't rotating with the shaft
Had the same issue on my s13 rally car with a 11-1 compression SR with the same 2860 turbo.
Had the internal gate machined out and a gt30 waste gate flap fitted.
Pulled it from 13-14psi minimum back down to 8-9.
Also running a stock manifold.
I just can't wait to see all of the s-chassis all running and together!
Same thing on my 3sgte. Wastegate port is way too small on these turbos. I had the same issue with 2860rs. Port it, it’ll help a ton
if the gate has been wired opened or whatever and its still making all the boost the only answer is the wastegate is to small.. strange just that tad more compression would make such a difference but it seems the only answer.. either port the gate hole or change the housing.. if all else fails its worth a try just to find out
Loving this S14 fix & DE+T episodes makes me want to do a EJ204+T to my Impreza ....U'll figure it out Jimmy & give us top content doing it😎😎😎
I’m the same, been wanting to +T my ej251 for a while now and this is just feeding that want even more.
@@UsedLegacy9 try 'home brew subaru' on TH-cam he's done eg2.5+T stuff ages ago on his channel
Check the gasket at the downpipe. It might have have the spot for the exhaust to go when the flap is open.
Look at the wastegate port in the turbine housing. It may need cleaning out even porting (especially if it's a Chinese housing)
I have a 2860rs on my sr20det, I had to port my internal gate and install a bigger flap to get it to control the boost spiking
Port the wastegate! I've had these same problems on my Eunos Cosmo, it started overboosting as soon as I put a more free flowing exhaust on it. Ported the internal gate out a bit and now she's miiint.
Had to port my internal gate in my turbo to stop boost creep, its usually to do with the manifold Design even thought the stock manifolds are fine up until about 350hp ish. bigger rear housing can help aswell
You need to add back pressure if you want your current setup to work. Otherwise you need to port the wastegate but need to do that correctly or you'll have other issues also.
Could be faulty CAS (camshaft not crank) behind your distributor, pretty sure it’s the same as rb30et’s (straight 6, 3L turbo engine) Easy fix. Same kind kind of thing happens to our turbo RB30et’s in Australia in our VL turbos. Even though it isn’t an SR, they run a distributor on both n/a and turbo models, this kind of rb didn’t come with coil from factory.
Easy fix there bud! Throw some bigger injectors at it to support some corn and ignore the creep. Problem solved. It'll live at 20psi....😎
fairly common to plug internal wastegates to avoid cracking early, I'd pull the exhaust housing and make sure the wastegate flap is actually doing something
Connect the external boost gauge to ensure it matches the ecu map sensor
May need to “port” the wastegate port on the rear housing, I had a similar sized turbo on my rb20 and had over boost issues and that helped a bit!
Not gonna lie I’ve been learning about turbo a lot better watching you guys thank you 🙏🏿
higher compression could be causing you to get boost creep compared to lower compression. might need to do external or bigger downpipe and exhaust.
you'd almost assume that the flap has been wielded shut in the turbo for it to still be making that kind of jam, when i fitted a 2871 to my det i pinned the gate open to drive to get tuned and could barely get 2psi at like 6k rpm. i'd take the elbow off and look at the gate operation
This is purely a mechanical issue- the wastegate opening in the exhaust housing needs to be ported a bit bigger. Even factory 20dets have a bit of boost creep from factory and the slightly higher compression of the NA motor will exacerbate this trend. 20 minutes with a fir grinder and you can make a massive improvement. It's also very important to smooth the flow into the wastegate port from the manifold side
Pull the turbo off and check that the wastegate actuator is actually opening and closing the internal wastegate, it seems like the arm has broken off inside, that's the only thing that makes sense now and I have seen it happen before
never get tired of that outro 👌👌👌
If any GT28 size turbo, if the compressor able to flow 400hp, if the exhaust housing is 0.64 AR, I port and enlarge each and every wastegate hole to make sure it won't over boost
made 280rwkw on stock manifold with a GTX2867r on 22psi. take the dump off see if the flap is fully openiing
Try dremel the internal waste gate outlet on the hot side of the turbo so the waste gate can flow more air.
Port internal wastegate hole, spray paint with flapper closed and port right out using paint as a guide.
you can try to port the wastegate flow path in the exhaust housing so u have less pressure
I am using the same turbo on a built Honda D-series with 11:1 compression and having the same issue. (Tuned on the link Honda standalone) we think that the internal wastegate is too small to control the turbine speed and ended up adding a 38mm external wastegate. Getting tuned tomorrow so hopefully it works.
Smooth out the harsh edge of the wastegate port where the exhaust gas flows to exit through the flapper. The smoothing would be performed on the turbine side. Use a carbide burr bit. Usually helps with boost creep.
Also SR’s suck.
Make sure the downpipe flange is not blocking the wastegate port.
I used to have a 5th subaru legacy GT that had the same issue, no matter what we did it would always overboost when I put a 3 inch downpipe on it. Not sure what kind of downpipe you're using but theres a good chance there isnt enough restriction in the exhaust and too much restriction in the wastegate itself. You either need to enlarge the wastegate port or run a an external gate, anything else would be a bandaid fix.
I think the last thing everyone is thinking is if the lever is actually opening the port inside the turbo elbow but if it's moving the wastegate from exhaust gasses flowing through the port then that shouldn't be the case
could it be the cam overlap, i know N\A engines have a overlap intake/exhaust so that the gasses flow better which is not needed on turbo engines since the turbo is creating enough flow, so in theory if there is too much overlap on this srDE it means that it blows boost into the exhaust which keeps the turbo boosting since it is exhaust driven,could be wrong and it could be something else but just helping to brainstorm here.Hope this helps👍✌️👉
Port that wastegate hole mate!! Also, you don't need to wire the flap open when testing the wastegate port. Just simply unhooking the actuator arm is enough. The gases will smash that flap open. My disco potato(GT28/60 RS) on my RB20det has a similar problem although mine is less effected. Spikes to 19psi but drops back down to 17ish, that's with a 14psi actuator. So if I port the wastegate it would be fine but that's around the boost I wanna run so I left it.
Also 2 step will ruin that stock NA sr, just so you know.
NA high comp probably pushing a lot of gases too.
Its a higher compression engine and internal gate has a small exhaust exit I had a similar problem on my subaru. Put a external gate and be done