Official ITB Reference Thread

[integrals]

While I know there aren't a ton of us ITB owners out there, I thought it would be nice to have a reference of engine / mods / results to keep all this conversation in one place.

Simple format..

Engine:
ITB Kit:
Supporting Modifications:
Tuner:
Fuel:
Results Before and After:
Misc:
Dyno Plot:


Engine: 3.0L
ITB Kit: Science of Speed
Supporting Modifications: Comptech USA Header, SOS Exhaust, with Catalytic Converters, 370cc RC Injectors, AEM Series II
Tuner: UMS Tuning
Fuel: 91 octane
Results Before and After: 251whp and 199lb/ft tq - 275whp and 214lb/ft tq
Misc: Engine has 151,000 miles on it, car is heavily tracked, totally stock internals, no engine hatch on it yet, using the SOS airbox. Fuel economy is about 19mpg city and 26mpg highway. Initially had low load drivability issues but this was smoothed out via tuning.
Dyno Plot: Coming soon.

 

[L_RAO]

Great idea for a thread.

Do you have any dyno plots to post as well? That would show us if the "total area under the curve" changed dramatically as well, for better or for worse.

 

[integrals]

Great idea for a thread.

Do you have any dyno plots to post as well? That would show us if the "total area under the curve" changed dramatically as well, for better or for worse.

Oh man I totally forgot. I do have some, I jsut haven't got them digitized or digital versions yet. It was a good gain, i'll definitely add that!

 

[ScienceofSpeed]

Engine: ScienceofSpeed Stage 3 3.5L, 12.5:1 static CR, Toda Type-C Camshaft Set
ITB Kit: ScienceofSpeed 50mm
Supporting Modifications: more details are car / engine here: http://www.nsxprime.com/forum/showthread.php?t=166522
Tuner: Tony Szirka
Results Before and After: do not have a comparison with factory manifold, however, best guess based on similar engines built with stock manifold is 20-30 hp difference with individual throttle bodies
Dyno Plot: 400.2 whp, 307.6 lb/ft wheel torque
http://scienceofspeed.com/revolutio...SX/1992_Grand_Prix_White/dyno/SOS_35L_ITB.gif

cheers,
-- Chris

 

[gsrboy]

^ Fuel is E85

 

[gsrboy]

Engine: 3.2L, 12:1 compression, web cams,
ITB Kit: Jenvy 52mm ITBs
Supporting Modifications: My build http://www.nsxprime.com/forum/showthread.php?t=128469
Tuner: HPF
Results Before and After: ????
Misc:
Dyno Plot:

Going ITB Turbo now. If I was going go back all NA I would do the SOS 3.5L 13.5:1, Toda Type C and E85.

 

[Nero Tenebre]

Great idea for a thread.

Do you have any dyno plots to post as well? That would show us if the "total area under the curve" changed dramatically as well, for better or for worse.

+1
I would like to see the plot on a stock motor with bolt-ons and not modified/built motors which may have a compounding effect on their benefit.

 

[integrals]

+1
I would like to see the plot on a stock motor with bolt-ons and not modified/built motors which may have a compounding effect on their benefit.

That is EXACTLY what mine is.

Bone stock internal 3.0L with ITB's and Header / Exhaust vs an IHE Bone stock 3.0L.

I'll try to get the overlay posted asap.

 

[austrian type-R]

I would like to know your MPG value before and after the ITBs. 1 litre Gasoline 95ROZ is 1,50 Euro and 98 or 100ROZ already 1,60 Euro overhere, so it does matter if my NSX needs 11 ltr/100km or 17 ltr/100km. 25+whp is not worth 6ltr/100km+ fuel consuption.

 

[integrals]

I have been able to achieve 26mpg freeway and 18mpg city driving. I have had it FINELY tuned beyond the initial dyno tune as well though.
With IHE stock, I was achieving 29-30mpg freeway and 22mpg city.

 

[dablackgoku1234]

Engine: 3.2L, 12:1 compression, web cams,
ITB Kit: Jenvy 52mm ITBs
Supporting Modifications: My build http://www.nsxprime.com/forum/showthread.php?t=128469
Tuner: HPF
Results Before and After: ????
Misc:
Dyno Plot: I should get it from my tuner. Its 345whp I forgot the torque. 91 pump

Going ITB Turbo now. If I was going go back all NA I would do the SOS 3.5L 13.5:1, Toda Type C and E85.

I didn't know Jenvey had an ITB kit for the NSX, more details?

 

[NA1/2-R GT]

Here's mine:

Engine: 3.0 L stock CR stock internal
ITB: SOS 48mm
Supporting mods: Headers, straight pipes, & exhaust, AEM EMS
Tuner: Tony @ UMS Tuning
Before: 233 whp
After: 274 whp 219 ft/lbs torque (love the torque)

 

[docjohn]

your white car looks great...what air filtering option do you use with the sos kit?I know he was working on a filter to sandwich between the trumpets and the heads.

 

[greenberet]

Here's mine:

What’s amazing about your dyno chart is more torque at every rpm. The chart you posted above shows your torque increased by about 20% between 3000 and 5000 rpm despite losing the VVIS resonance.

FD3SNSX’s ITB installation is very similar to yours. In case FD3SNSX doesn’t see this thread, a description of his ITB build can be found here. http://www.nsxprime.com/forum/showthread.php?t=152851

Here are both of your before and after horsepower curves shown in one chart. Since your tests were carried out on different dynos on different days, the absolute numbers generated aren’t really comparable, but they’re interesting to look at anyhow.

 

[NA1/2-R GT]

Thanks for the graph greenberet.
What I felt with big difference is the torque under VTEC.
I think the test pipes let the ITBs breath alot better then cats.

 

[integrals]

I still want to remove my cats and see if any difference is made.

 

[L_RAO]

I was at a dyno shop this week and saw a ITB'd K24 pick up 6 wHP from 5000 RPM+ when they went from 45 psi to 85 psi . The car was running ID1000 injectors.

 

[Nero Tenebre]

Wow that's a lot of added pressure, is that safe to run?

 

[L_RAO]

Yes, but that particular owner had a pretty beefy fuel system (pump, etc.) as a whole.

 

[greenberet]

The chart you posted above shows your torque increased by about 20% between 3000 and 5000 rpm despite losing the VVIS resonance.

What I felt with big difference is the torque under VTEC.

Yeah, at VTEC your chart shows a 24% gain in torque but the biggest gain is before VTEC kicks in. At 5500 rpm, your chart shows a 39% increase! Since FD3SNSX’s torque curve shows a hump at 5500 rpm as well, there must be some resonance in the ITBs at that point. Resonances are good (which is the whole point of the VVIS). If you put an airbox over the ITBs, you could calculate its volume to resonate and boost torque further at specific rpm. And if you inhaled cool air from outside the engine compartment while driving on the road, you could get an even denser intake charge.

 

[johnjohn]

Has anyone heard when SOS will be offering a Air filter box assembly to fit over their ITbs? And on the mean time is there anywhere that makes cheesecloth type "socks" to fit over the individual horns?

 

[austrian type-R]

gsrboy: Is your 3.2 engine a sleeved/bored C30 engine or a stock C32 engine? If it is a C32 engine, what pistons are used? thanks

 

[gsrboy]

I didn't know Jenvey had an ITB kit for the NSX, more details?

I can't find anything about it anymore. Its looks very similar to the SOS ITBs though.

gsrboy: Is your 3.2 engine a sleeved/bored C30 engine or a stock C32 engine? If it is a C32 engine, what pistons are used? thanks

Mine is a 3.0 engine that has been sleeved and bore out to 93mm. I am using CP pistons 12:1.

 

[johnjohn]

I saw this (http://honda-tech.com/showthread.php?t=2639894&page=5) and then was surprised not to see it on SOS's site. But after doing some more hunting i think two smaller ones (http://www.borla.com/products/induction/airbox.htm) that join to a single CAI would look better. Chris/SOS can you weigh in on what SOS will be doing?

 

[Jeff@Carbon6]

Has anyone heard when SOS will be offering a Air filter box assembly to fit over their ITbs? And on the mean time is there anywhere that makes cheesecloth type "socks" to fit over the individual horns?

You can buy micro-screen style filters for them at Pegasus Racing. Search "horn filter".
https://www.pegasusautoracing.com/home.asp
They also have some they may not list on the site. The diameter varies depending on the length of horn you have. I used theirs for a little while before I build my air box.