I built a rear mount turbo 1994 Infiniti Q45 years ago and it all depends on proper sizing of the turbine AR. Same turbo front vs rear of course it will spool a bit faster up front. Just need to properly size the turbo for the application. You will use a smaller AR for a rear mount. I hit full boost faster than many of my friends with front mounts when they had large turbos and around the same as most typical turbo vehicles. One friend had an 86 Porsche 930 Turbo, I hit full boost about 2000 RPM sooner than he did... I'm a huge fan of rear mounts. Thanks for sharing your build, been fun to watch your progress.
Thats awesome SIX SPEED JONES! I've rechipped many stock ECUs for the VH45 for NA or boost applications. A stock ECU is fine but I can extract some more power by modding the ECU. Remove speed limiter, increase recline, update timing and fuel maps, etc. I shared alot of build info on NICO Club forums if you want to track it down. Look for posts from "qsiguy".
I'm gladly surprised that your boost threshold is as low as 3200 rpm. The displacement of your Z definitely contributes to the boost threshold being at a much lower rpm than a turbo 4 cylinder. Even the ugly duckling Honda K, the K24Z, with the "big block 2.4L" and the widely hated integrated exhaust manifold, made full boost at 3600 rpm when Tuning By Nick made a turbo K swap into his Porsche 911 997. (435 whp @ 7450 rpm, 335lb-ft wtq at 5830 rpm, ~300lb-ft at ~3800 rpm) Modern turbos have reduced turbo lag and boost threshold significantly with better and lighter materials, and optimized manufacturing techniques. Still have to properly size your turbo, like what you did. Boost threshold will be higher on a rear mount vs. a traditional front mount (by a couple hundred rpm). Boost threshold = threshold (in rpm) where you get boost Turbo lag = the lag between throttle and boost, when you're above boost threshold
Small edit: Nick said on a more recent video about his swap that the turbo fully spooled at 3600 rpm, which is even more mind-blowing. All hail the boost boost!
As with pretty much everything there's pros and cons, a rear mount will take a little longer to hit peak boost, that's just a fact, so you're losing out on some low end "meat", but peak power should be exactly the same. The good thing is with a stock engine that's going to actually increase longevity which is why I think they're so popular. With a built engine however that goes out the window and there's zero reasons to run a rear mount, you'd want as fat of a powerband as possible.
@@PostMortemor it doesn't. It doesn't matter where your power is. If you use too much power too many times, your bearings, valves, ... Might suffer. If you have low end grunt and you floor from say standstill a lot, yes, your gearbox and crankshaft get beaten a lot. But if you have no low end grunt and thus elevate your rpm tondo the same, .... It's the same. Hope you get what i mean?
All I got to say is that I have a full engine bay and an empty bed on my truck. If i did this it might be called a mid mount turbo lol. right behind the cab in the bed. Thanks for sharing your experience on this subject.
@@blackpearlmedia7797 Well the biggest pro is that I might just have to re route some cheap exhaust pipe up through the bed, if i don't like it i can re weld the pieces i cut out back in. My biggest concern with a turbo is over crowding the engine bay. and that might be worth a little turbo lag maybe lol.
@@davidcraft4909 if you choose the right brand of turbo and size I bet you will be pleasently surprised at home much lag there isn't. I have a Borg Warner and it's a dog of a turbo. Slow as it gets and I still hit boost at 3700
There is no turbo lag if you size your turbo correctly, just like if it was mounted next to the engine. Catastrophic turbo lag because it’s a rear mount, It’s a myth!
586whp on stock internals? That's a scary number for a stock VQ block. lol Hopefully going rear mount myself before too long, and appreciate your videos!
Apparently the HRs can handle quite a bit more horsepower than I thought and it's more about the torque numbers. My guys over at limp mode tuning said you don't want to be too much above 420 to 450 ft lb of torque and I'm at about 420. Running good and strong for the last 6months. And 400whp for 6months before that. Next year will be the biggest test!
Throwing in a larger final gear can help in a way. Actually learning about rear mounted turbos. So would it be beneficial to skip usuall headers and exhaust upgrades in order to maximize back pressure to spool the turbo?
Idk if you know yet or caved to the norm but the only "back pressure" you want is from the exhaust pipe. Unless your oem headers are restrictive there isn't really a need for new ones and if you need new headers go with shorty headers with a small collector. There should be 0 cats 0 resonators and 0 mufflers before the turbo they will really reduce overall performance if you want a muffler do it after the turbo.
Not necessarily exhaust flow still matters. Most aftermarket’s designs smooth out the path compared to oem. Not to mention some headers have cats. Most of the exhaust will be custom might as well make headers for your application.
The only other rear mount turbo setup I've seen on a front engine car was 10yrs ago by Nutnfancy on his 350Z as well. Has anyone else tried this on another platform?
I built a rear mount turbo 1994 Infiniti Q45 years ago and it all depends on proper sizing of the turbine AR. Same turbo front vs rear of course it will spool a bit faster up front. Just need to properly size the turbo for the application. You will use a smaller AR for a rear mount. I hit full boost faster than many of my friends with front mounts when they had large turbos and around the same as most typical turbo vehicles. One friend had an 86 Porsche 930 Turbo, I hit full boost about 2000 RPM sooner than he did...
I'm a huge fan of rear mounts. Thanks for sharing your build, been fun to watch your progress.
That's sick! And thanks for following along man, just learning as we go! Haha
I'm building a Vh45 300zx! I'd love to hear from your experiences!
Thats awesome SIX SPEED JONES! I've rechipped many stock ECUs for the VH45 for NA or boost applications. A stock ECU is fine but I can extract some more power by modding the ECU. Remove speed limiter, increase recline, update timing and fuel maps, etc.
I shared alot of build info on NICO Club forums if you want to track it down. Look for posts from "qsiguy".
@@shanesdiy that’s amazing!! I’m super interested in checking out the forum. Thanks!! I’ll keep in touch, sir!
I'm gladly surprised that your boost threshold is as low as 3200 rpm. The displacement of your Z definitely contributes to the boost threshold being at a much lower rpm than a turbo 4 cylinder. Even the ugly duckling Honda K, the K24Z, with the "big block 2.4L" and the widely hated integrated exhaust manifold, made full boost at 3600 rpm when Tuning By Nick made a turbo K swap into his Porsche 911 997. (435 whp @ 7450 rpm, 335lb-ft wtq at 5830 rpm, ~300lb-ft at ~3800 rpm)
Modern turbos have reduced turbo lag and boost threshold significantly with better and lighter materials, and optimized manufacturing techniques. Still have to properly size your turbo, like what you did. Boost threshold will be higher on a rear mount vs. a traditional front mount (by a couple hundred rpm).
Boost threshold = threshold (in rpm) where you get boost
Turbo lag = the lag between throttle and boost, when you're above boost threshold
Small edit: Nick said on a more recent video about his swap that the turbo fully spooled at 3600 rpm, which is even more mind-blowing.
All hail the boost boost!
As with pretty much everything there's pros and cons, a rear mount will take a little longer to hit peak boost, that's just a fact, so you're losing out on some low end "meat", but peak power should be exactly the same. The good thing is with a stock engine that's going to actually increase longevity which is why I think they're so popular. With a built engine however that goes out the window and there's zero reasons to run a rear mount, you'd want as fat of a powerband as possible.
How will it increase longevity? I'm just curious. I'm thinking about it on a Lexus is200
@@PostMortemor it doesn't. It doesn't matter where your power is. If you use too much power too many times, your bearings, valves, ... Might suffer.
If you have low end grunt and you floor from say standstill a lot, yes, your gearbox and crankshaft get beaten a lot. But if you have no low end grunt and thus elevate your rpm tondo the same, .... It's the same.
Hope you get what i mean?
I'm pleasently surprised how quickly your rear-mount turbo lights off.
Y'all built the system well.
Thank you! Yeah I like it but it could be faster!
All I got to say is that I have a full engine bay and an empty bed on my truck. If i did this it might be called a mid mount turbo lol. right behind the cab in the bed. Thanks for sharing your experience on this subject.
I say send it! Bed mount say whattttttt!
@@blackpearlmedia7797 Well the biggest pro is that I might just have to re route some cheap exhaust pipe up through the bed, if i don't like it i can re weld the pieces i cut out back in. My biggest concern with a turbo is over crowding the engine bay. and that might be worth a little turbo lag maybe lol.
@@davidcraft4909 if you choose the right brand of turbo and size I bet you will be pleasently surprised at home much lag there isn't. I have a Borg Warner and it's a dog of a turbo. Slow as it gets and I still hit boost at 3700
Very informative thank you!
Glad you got some value from this!
There is no turbo lag if you size your turbo correctly, just like if it was mounted next to the engine.
Catastrophic turbo lag because it’s a rear mount, It’s a myth!
Yes!
586whp on stock internals? That's a scary number for a stock VQ block. lol Hopefully going rear mount myself before too long, and appreciate your videos!
Apparently the HRs can handle quite a bit more horsepower than I thought and it's more about the torque numbers. My guys over at limp mode tuning said you don't want to be too much above 420 to 450 ft lb of torque and I'm at about 420. Running good and strong for the last 6months. And 400whp for 6months before that. Next year will be the biggest test!
What is the A/R of the the turbine housing on your turbo?
Love the scenery, what part of CT are you in?
This was in Mexico!! New Hartford, Mexico
on my setup its neglagable . when i roll against my friends twin turbo 370 im ahead from the get go, its all in the setup
100% agree
Throwing in a larger final gear can help in a way.
Actually learning about rear mounted turbos. So would it be beneficial to skip usuall headers and exhaust upgrades in order to maximize back pressure to spool the turbo?
Idk if you know yet or caved to the norm but the only "back pressure" you want is from the exhaust pipe. Unless your oem headers are restrictive there isn't really a need for new ones and if you need new headers go with shorty headers with a small collector. There should be 0 cats 0 resonators and 0 mufflers before the turbo they will really reduce overall performance if you want a muffler do it after the turbo.
Not necessarily exhaust flow still matters. Most aftermarket’s designs smooth out the path compared to oem. Not to mention some headers have cats. Most of the exhaust will be custom might as well make headers for your application.
Can you rear boost a diesel car? I mean, one front, one back?
The only other rear mount turbo setup I've seen on a front engine car was 10yrs ago by Nutnfancy on his 350Z as well. Has anyone else tried this on another platform?
Wait a minute. I knew he had a turbo 350Z. I was a fan of his back in the day for his knife reviews but I had no idea it was a rear mount
@@blackpearlmedia7797 yeah it was the first I've ever heard of it and I was just watching his reviews on knives, guns, and gears lol.
@@blackpearlmedia7797 th-cam.com/video/tBMpkapcLTc/w-d-xo.html
@@future_phonk huh, no kidding!
Auto mafia racing for the 3.7 mustangs
I still gotta hear this car in person
Yes you do!
Can’t wait till my z is boosted 🔥
Me either bro! I demand Dyno videos when you do!
Looking forward to doing it to a 350z vert
Awesome! It would be great to have a very in the group!
I want to boost my G35 this way, any tips? :)
Lots! Here take a look at this pros and cons video I put together. I'll but putting out a lot more on the subject as well
th-cam.com/video/XZiEKdrfWQo/w-d-xo.html