I built and raced v-twin engines for 30 years,last five years running top fuel harleys. I owned a harley all in house engine machining and dyno tuning shop for 10 years afte i quit racing. I spent hours in a controlled environment , with well established baselines tuning on small to large cubic inch engines.The davinci,yost power tube or any other so called fuel atomizer on S&S carbs is horseshit.A bead blast finish inside the intake manifold will produce positive results.A Thunder Jet will produce positive results.Velocity stacks only work at wide open throttle,a S&s teardrop air cleaner with no element makes the most power on street bikes. Straight pie exhaust systems of any diameter,even stepped diameters hurt mid range performance on any v-twin engine under 4 inch bore.Thunder headers and cycle shack m pipes are king up to around 100 CI inch bore and up stepped diameter rag pipes or 2 into 1, are great power makers. RB racing exhaust are some of the finest around.I tested every damn pipe around in controlled settings,even making stepped diameter pipes just for dyno testing. Retarded tining 3 to 5 degrees makes mre horse power easier starts, and cooler running use the T-JET TO PUT THE low end back in the engine.K&N filters make @ 1.5 more horse power. But hell what do i know in 1994 i was runnin 160 MPH 1/8 mile ET's and 195 MPH 7.0 sec 1/4 mile passes. I even had a guy standing beside the dyno open a NOS bottle a second just to let the bike pull a lil in the air cleaner,course i jetted a lil fat first. 103 octane gas makes more power .It takes 16 to 1 compression to burn 110 octane. Ya'll Think About It Mr. Chris.
What do you mean "S&s teardrop air cleaner with no element", no filter element? Ofc its best to run a filter for street use considering birds and babys can be pulled into the carb. But Thx for the Timing advise, got a 84 hot stroker SS kit (4.1/2'' stroke, stock bore cyl) for my FLH76, 2-1 RB lsr, and a ss-e carb teardrop. Its a bitch to start and to kick but runs strong, and with 0.295 int/68 main it shouldn't be too rich, but carbon fouls the plugs when at idle. But the retarded timing is worth a try and the lean it out on the fuel mix screw. Thx Oldtimer Chris!
A guy named, I think, was Chris Forrest actually drilled a super E bowl for me to have the fuel drain installed a little while back. Wonder if this is the same guy of Forrest Fire Performance. I appreciate this knowledge because I've figured a lot of it on my own where this guy's already forgotten more than what I know already lol. I run a super E with a thunderjet, bomb sight, and a 1" spacer on an 88 sportster with a Hammer 1250 kit and a set of V2s. I had that crappy Turbulator on it and like you said, those atomizers are garbage, that is true in my opinion too.. One thing I know is I also glad to hear I'm not the only one whos run a tear drop air cleaner with no element. I run drag pipes because we all know how much a thunderheader is lol Haven't gotten there yet but on the list. That thunderjet cleared up a lot of my low end issues I had running a straight super E and cv with those pipes. I don't even use the accelerator pump on my set up now and the bike turns on around 2000-2500rpms with the mild cams. I have put about 5000 miles on it this year that way with no issues so far. This isn't advice, this is knowledge this guy is passing on here...
Ever test this at the track? Im running a G on my 106 stroker twin cam dyna. Trying to break into the 10s. Best run has been an 11.0 and 6.90 in the 1/8th. Its fun!
good info! I saw an fxr with the super G taz and the 1" spacer the other day, guy says it makes a huge difference in throttle response and performance. He is also running a wideband commander tuner for easy on the fly adjustment. I am definitely ordering one for my fxr 124"
Hi Chris and thanks for watching! The XXX carb work is expensive and hopefully it pays off. I will be testing soon. I just installed it yesterday. I will attempt to give an update. Thanks again...Mark
I'm just curious as to what up range that would be for and what it would take to say get something like that to work on say a 88ci twin cam with screaming eagle heads and a makuni on it right now I just don't feel like I've quite got the power I want out of the makuni I may be doing something wrong with the makuni but it's ither alot of power down low but to lean on top end with a smaller main jet but when I bumped it up to fatten it up a lil it's like it doesn't have the power it did out of the hole
love the setup on this but there a bitch to tune... Those thunder jets are tricky.. U have to get all the 3 jets working with eachother and still i haven't found that swwwt spot
Hi and yes tuning with all carburetor models can be tricky and I have spent many, many hours changing jets and reading plugs. Most often it can be easier with the new injected models but you either need a self tuning ignition and/or a dyno which can be costly. I am old school and prefer to tune carbs on my own but it sometimes takes time, skill and patience to get them right.
Hi HD racing, have you had the opportunity to test the carb yet..? I'm curious to know how the power delivers now with the throat of the carb bored out. Have you noticed a drop in Tq..? Thanks
Hi Dale! I installed the XXX modified carburetor on my 90 inch XL last week but I have not had the chance to test it. This XL ran a 10.7 ET in the 1/4 miles last year so it is going to be hard to tell unless I get it to the track again because it will be hard to gauge those types of numbers and speeds unless I can see numbers on a time slip. My dyno numbers with this bike at the beginning of last season were 109 HP and 103 TQ. However changes were made throughout the season that were nor recorded on a dyno so I am not sure where I was at for the 10.7 at 123 MPH run or before the carburetor modification. The other difficulty I am having with this possible track test is that I am in the middle of building a different XL drag only bike that I am going to be almost totally focused on at the track for at least the beginning of this season. Consequently, I am going to gear up my XXX carb 90 inch and ride it on the street some so I may not be getting any testing times soon. Thanks for asking and watching Dale. If and when I do get any results I will truy to post it.......Mark
Hey Dale I tested the carb on my 90" Sportster the past couple of days and it feels very strong. It needs a little tuning now. I run and air/fuel gauge to help me with tuning and it is running rich on the low to mid end so it needs some leaning or smaller low end jets. I think the accelerator pump mod may have been a little too much so I have to adjust. I came around a corner and shifted into 2nd gear and it pulled the front wheel of the ground about a foot and held it there through the shift to 3rd so it is strong. That is a great feeling on an HD that can just hold the front wheel off the ground about a foot all the way through 2nd gear, without balance wheeling, and just motor! You see the guys do it at the flat tracks and road tracks. Big fun!
HD Racing i see that you use both S&S and Mikuni,and seen in another video where you say you like mikuni for street.Do you feel either of these are that much better than the CV40 for the price?
Hello MS and thanks for watching! I like all 3 carbs but my preference is toward the S&S and Mikuni. There is a tune-up kit that can be bought for the CV40 that really helps a lot for the cost of around $45 and a small amount of work. There are also people who can rework the CV40's who swear by their performance. I do prefer carbs over injection because I can tune myself without a dyno which can cost as much as $300 plus now-a-days. Thanks again!
Hi sidestreetways16! I like bot the S&S E and the HSR42 and use them both on my street bikes. The Mikuni HSR42 better all around response for a street bike but for my drag bikes I use the S&S.
Hey Ed! My performance bikes are 77 CI, 90 CI and 95 CI sizes so I found the S&S D to be too big for those motor sizes so the bored out G may be the answer for the 90 and the 95 cubic inchers. Both my 90XL and 95FXD have extensive head, piston and cam modifications and I am still driving them on the street so I like the G's accelerator pump and hoping that one or both of those bikes will be able to accommodate the additional capacity of the XXX mods. The D is the proven drag bike carburetor which I have struggled with in street/strip applications but had great success with on a drag strip only bike. There are virtually endless opinions on carburetor modifications and applications according to motor size and use which can lead to many hours of discussion and debate. Thank you for your comments Ed on this interesting topic!
i have a 124 with b 2 heads with a super d,runs great on the dragstrip,it has no accelerator pump and it sucks on the street, pops cracks,wish i had a fuel injection on mine for the street
I built and raced v-twin engines for 30 years,last five years running top fuel harleys.
I owned a harley all in house engine machining and dyno tuning shop for 10 years afte
i quit racing. I spent hours in a controlled environment , with well established baselines
tuning on small to large cubic inch engines.The davinci,yost power tube or any other so called fuel atomizer on S&S carbs is horseshit.A bead blast finish inside the intake manifold
will produce positive results.A Thunder Jet will produce positive results.Velocity stacks only work at wide open throttle,a S&s teardrop air cleaner with no element makes the most power on street bikes.
Straight pie exhaust systems of any diameter,even stepped diameters hurt mid range performance on any v-twin engine under 4 inch bore.Thunder headers and cycle shack m pipes are king up to around 100 CI inch bore and up stepped diameter rag pipes or 2 into 1,
are great power makers. RB racing exhaust are some of the finest around.I tested every damn pipe around in controlled settings,even making stepped diameter pipes just for dyno testing.
Retarded tining 3 to 5 degrees makes mre horse power easier starts, and cooler running
use the T-JET TO PUT THE low end back in the engine.K&N filters make @ 1.5 more horse power.
But hell what do i know in 1994 i was runnin 160 MPH 1/8 mile ET's and 195 MPH 7.0 sec
1/4 mile passes. I even had a guy standing beside the dyno open a NOS bottle a second just to let the bike pull a lil in the air cleaner,course i jetted a lil fat first.
103 octane gas makes more power .It takes 16 to 1 compression to burn 110 octane.
Ya'll Think About It
Mr. Chris.
Thanks for the info Chris! I have thought about those topics many a times! I love trying to get all the HP's I can out of them!
Wow...great comment!!
What do you mean "S&s teardrop air cleaner with no element", no filter element? Ofc its best to run a filter for street use considering birds and babys can be pulled into the carb.
But Thx for the Timing advise, got a 84 hot stroker SS kit (4.1/2'' stroke, stock bore cyl) for my FLH76, 2-1 RB lsr, and a ss-e carb teardrop. Its a bitch to start and to kick but runs strong, and with 0.295 int/68 main it shouldn't be too rich, but carbon fouls the plugs when at idle. But the retarded timing is worth a try and the lean it out on the fuel mix screw.
Thx Oldtimer Chris!
A guy named, I think, was Chris Forrest actually drilled a super E bowl for me to have the fuel drain installed a little while back. Wonder if this is the same guy of Forrest Fire Performance. I appreciate this knowledge because I've figured a lot of it on my own where this guy's already forgotten more than what I know already lol. I run a super E with a thunderjet, bomb sight, and a 1" spacer on an 88 sportster with a Hammer 1250 kit and a set of V2s. I had that crappy Turbulator on it and like you said, those atomizers are garbage, that is true in my opinion too.. One thing I know is I also glad to hear I'm not the only one whos run a tear drop air cleaner with no element. I run drag pipes because we all know how much a thunderheader is lol Haven't gotten there yet but on the list. That thunderjet cleared up a lot of my low end issues I had running a straight super E and cv with those pipes. I don't even use the accelerator pump on my set up now and the bike turns on around 2000-2500rpms with the mild cams. I have put about 5000 miles on it this year that way with no issues so far. This isn't advice, this is knowledge this guy is passing on here...
Ever test this at the track? Im running a G on my 106 stroker twin cam dyna. Trying to break into the 10s. Best run has been an 11.0 and 6.90 in the 1/8th. Its fun!
good info! I saw an fxr with the super G taz and the 1" spacer the other day, guy says it makes a huge difference in throttle response and performance. He is also running a wideband commander tuner for easy on the fly adjustment. I am definitely ordering one for my fxr 124"
Hi Chris and thanks for watching! The XXX carb work is expensive and hopefully it pays off. I will be testing soon. I just installed it yesterday. I will attempt to give an update. Thanks again...Mark
It’s called an annular booster -the purple ring. Just like a Holley HP carb has
Bad ass carb.old school.
Love those S&S carbs!
So boring from 44mm to 47mm will slow down the intake charge velocity, isn’t this going to increase the likelihood of puddling?
Interesting and informative as always.
Thank you for watching Gary! Just trying to share some specialized hot rod Harley information. I appreciate your comments!
I'm just curious as to what up range that would be for and what it would take to say get something like that to work on say a 88ci twin cam with screaming eagle heads and a makuni on it right now I just don't feel like I've quite got the power I want out of the makuni I may be doing something wrong with the makuni but it's ither alot of power down low but to lean on top end with a smaller main jet but when I bumped it up to fatten it up a lil it's like it doesn't have the power it did out of the hole
I like the S&S on a big HD and I think an S&S G or E should work good. I had them on my ** and they worked good.
OH i forgot that Davinci is a booster out of old school auto drag racing carbs,not a v-twin engine with a short turn radius intake head ports. zlol
Thanks for the comment Chris!
love the setup on this but there a bitch to tune... Those thunder jets are tricky.. U have to get all the 3 jets working with eachother and still i haven't found that swwwt spot
Hi and yes tuning with all carburetor models can be tricky and I have spent many, many hours changing jets and reading plugs. Most often it can be easier with the new injected models but you either need a self tuning ignition and/or a dyno which can be costly. I am old school and prefer to tune carbs on my own but it sometimes takes time, skill and patience to get them right.
Hi HD racing, have you had the opportunity to test the carb yet..? I'm curious to know how the power delivers now with the throat of the carb bored out. Have you noticed a drop in Tq..? Thanks
Hi Dale! I installed the XXX modified carburetor on my 90 inch XL last week but I have not had the chance to test it. This XL ran a 10.7 ET in the 1/4 miles last year so it is going to be hard to tell unless I get it to the track again because it will be hard to gauge those types of numbers and speeds unless I can see numbers on a time slip. My dyno numbers with this bike at the beginning of last season were 109 HP and 103 TQ. However changes were made throughout the season that were nor recorded on a dyno so I am not sure where I was at for the 10.7 at 123 MPH run or before the carburetor modification. The other difficulty I am having with this possible track test is that I am in the middle of building a different XL drag only bike that I am going to be almost totally focused on at the track for at least the beginning of this season. Consequently, I am going to gear up my XXX carb 90 inch and ride it on the street some so I may not be getting any testing times soon. Thanks for asking and watching Dale. If and when I do get any results I will truy to post it.......Mark
Hey Dale I tested the carb on my 90" Sportster the past couple of days and it feels very strong. It needs a little tuning now. I run and air/fuel gauge to help me with tuning and it is running rich on the low to mid end so it needs some leaning or smaller low end jets. I think the accelerator pump mod may have been a little too much so I have to adjust. I came around a corner and shifted into 2nd gear and it pulled the front wheel of the ground about a foot and held it there through the shift to 3rd so it is strong. That is a great feeling on an HD that can just hold the front wheel off the ground about a foot all the way through 2nd gear, without balance wheeling, and just motor! You see the guys do it at the flat tracks and road tracks. Big fun!
Great news, sounds like its flowing well. Once you get the jetting cleaned up it should prove to be a great set-up.
HD Racing i see that you use both S&S and Mikuni,and seen in another video where you say you like mikuni for street.Do you feel either of these are that much better than the CV40 for the price?
Hello MS and thanks for watching! I like all 3 carbs but my preference is toward the S&S and Mikuni. There is a tune-up kit that can be bought for the CV40 that really helps a lot for the cost of around $45 and a small amount of work. There are also people who can rework the CV40's who swear by their performance. I do prefer carbs over injection because I can tune myself without a dyno which can cost as much as $300 plus now-a-days. Thanks again!
Was looking for email but no dice
for someone that wants to make 70ish hp from a 91 1200 what carb would you recommend an s&s super e or something like a hsr42 or what do you prefer
Hi sidestreetways16! I like bot the S&S E and the HSR42 and use them both on my street bikes. The Mikuni HSR42 better all around response for a street bike but for my drag bikes I use the S&S.
What are you putting this on and are you going to dyno it, for a dragbike I use S$S D model carbs....
Hey Ed! My performance bikes are 77 CI, 90 CI and 95 CI sizes so I found the S&S D to be too big for those motor sizes so the bored out G may be the answer for the 90 and the 95 cubic inchers. Both my 90XL and 95FXD have extensive head, piston and cam modifications and I am still driving them on the street so I like the G's accelerator pump and hoping that one or both of those bikes will be able to accommodate the additional capacity of the XXX mods. The D is the proven drag bike carburetor which I have struggled with in street/strip applications but had great success with on a drag strip only bike. There are virtually endless opinions on carburetor modifications and applications according to motor size and use which can lead to many hours of discussion and debate. Thank you for your comments Ed on this interesting topic!
i have a 124 with b 2 heads with a super d,runs great on the dragstrip,it has no accelerator pump and it sucks on the street, pops cracks,wish i had a fuel injection on mine for the street