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Puzzled by the whp gain after ITB

Joined
3 March 2011
Messages
304
Location
MD
I got my car (92 3.0L with 30k miles) tuned today after the SOS ITB installation and I am kind of disappoined with the whp gain. ONLY 20 WHP ??

Dyno1.jpg


My base run was with CT headers/Exhaust/SOS test pipe/DF AIS.

Could anyone out there with the SOS ITB w/o the stroker kit share theie map with me ?? My tuner and I want to compare the two and see if there's something wrong. I already sent an email over to Dan to see if he would since we have a very similar setup

My email add is [email protected]

Thanks
Tae
 
Wow, I was close to pulling the trigger on the itb's myself, but thought to myself $5k more and i can get a supercharger. I hope you can squeeze more HP out of your kit, its a waste for only 20hp.
 
I'm disappointed because Dan picked up 41whp with a similar setup. 41 vs 20 is a big difference

This is Dan's dyno for comparison
 

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Ouch. That's a lot of $$$ for so little "go". That's what I was afraid of looking at this mod. :frown:

i heard they are hard to set-up, kinda like tuning carbuerators.

Wow, I was close to pulling the trigger on the itb's myself, but thought to myself $5k more and i can get a supercharger. I hope you can squeeze more HP out of your kit, its a waste for only 20hp.

I'm not saying the ITB setup only produce 20whp gain. I'm just confused because I was expecting ~40whp gain after seeing Dan's build. I'm looking for other tune maps to see if theres something I/or my tuner missed. I would've called SOS directly but by the time we were done, it was too late to contact them.
 
are you sure Dans setup is exact to your yours,and don't forget the inherent variability of the dynos themselves.
 
The dyno sheet you posted doesn't show A/F ratio. Any idea how that was doing? Sounds like you might have room to run a little leaner or with a little more agressive timing.
 
is the dyno calibrated correctly?

I mean I have heard people getting the stats of your car from
example dyno A=300hp
and then the same car drives to dyno B and has 260hp

less recorded HP than dyno A

does your car feel like it has more HP than before?
 
290+ hp at the rear wheels is nothing to sneeze at. I see you have CT headers. What kind does Dan have? Seems like you don't really make any more hp up until vtec kicks in.

I agree that perhaps your tuner needs to consider timing and fuel. Modifications like these are going to take a while and a lot more customers using them before all of the kinks are worked out and tweeks are learned.
There could be unrelated issues such as a weak fuel pump.
All in all I think if you can pull 300rwhp out of an unopened 3.0, you are doing great.

Just a few years ago SC and Turbo applications were netting out an additiona 75 rwhp for the average Joe and now the can easly add double that on a stock motor.

I personally think the ultimate setup for the NSX is 400rwhp stroker motor with ITB's.

This video and the sound absolutely blows me away and I get chills just watching it. Mad driving skills!!!!
http://www.youtube.com/watch?v=P1Z7ZlAQs5o
 
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With published ~40whp gains on a stock NA1 I just assumed everyone buying the system was looking for the throttle response and sound.
 
are you sure Dans setup is exact to your yours,and don't forget the inherent variability of the dynos themselves.

Yes our cars are almost identical. At the time Dan tuned his car, he was running DC headers with ARC ti exhaust while I'm running the CT headers with Pride V2 exhaust

For $5,000; I'd want alot more than 20-40 HP.

I will be completely happy with additional 40whp gain :biggrin:

The dyno sheet you posted doesn't show A/F ratio. Any idea how that was doing? Sounds like you might have room to run a little leaner or with a little more agressive timing.

My tuner tried going both routes, going rich and going really lean to see if he can push out more power.

is the dyno calibrated correctly?

I mean I have heard people getting the stats of your car from
example dyno A=300hp
and then the same car drives to dyno B and has 260hp

less recorded HP than dyno A

does your car feel like it has more HP than before?

Dyno is clibrated properly. My tuner uses dynojet while Dan's car was done using dynapack, which usually pulls lower numbers than dynojet. If you look at Dan's build thread (page 4), he mentioned that his baseline pull using a dynometer was at 276 compare to the baseline number of 233 when he used the dynapack.


290+ hp at the rear wheels is nothing to sneeze at. I see you have CT headers. What kind does Dan have? Seems like you don't really make any more hp up until vtec kicks in.

I agree that perhaps your tuner needs to consider timing and fuel. Modifications like these are going to take a while and a lot more customers using them before all of the kinks are worked out and tweeks are learned.
There could be unrelated issues such as a weak fuel pump.
All in all I think if you can pull 300rwhp out of an unopened 3.0, you are doing great.

Just a few years ago SC and Turbo applications were netting out an additiona 75 rwhp for the average Joe and now the can easly add double that on a stock motor.

I personally think the ultimate setup for the NSX is 400rwhp stroker motor with ITB's.

This video and the sound absolutely blows me away and I get chills just watching it. Mad driving skills!!!!
http://www.youtube.com/watch?v=P1Z7ZlAQs5o

He was using the DC Sport headers. I know 292rwhp is a great number for an unopened engine. However, when seeing other ITB setup gained over 40whp w/over 60flywheel lbft tq while I only gained 20whp/16lb tq, I have to wonder if something is wrong.
 
With published ~40whp gains on a stock NA1 I just assumed everyone buying the system was looking for the throttle response and sound.

$5,000 for sound? Should have spent $20 on whistle tips.
 
Guys, I have a real hard time understanding how on earth ITB's can add 40HP to a 250 RWHP motor. It just is illogical since you are not going forced induction or increasing displacement. Nor are you changing compression. You are, simply, freeing up the intake as much as possible. Getting rid of a restriction on the intake side and expecting 40 HP out of that seems unlikely to me.
 
Also, look at Dan's dyno graph. Both baseline and final pulls were done on the same dynapac/same location/different day/different environment condition. But he gained almost 40 whp and 20 lbs tq right off the line while my dyno shows no significant gain until 4500 rpm.
 
Guys, I have a real hard time understanding how on earth ITB's can add 40HP to a 250 RWHP motor. It just is illogical since you are not going forced induction or increasing displacement. Nor are you changing compression. You are, simply, freeing up the intake as much as possible. Getting rid of a restriction on the intake side and expecting 40 HP out of that seems unlikely to me.

you have a point...my 3.0 motor with the old comptech IEM package which included cams got me to 292-298 rwhp...that was with the uniflow and usual EHI mods.
 
Ditto Turbo2Go. I"m not an ITB expert, but i have read Hot Rod dyno tests for around 45 years and most involve intakes. On a relatively stock motor 3 liter, i would be surprised to see even a 15 HP increase, and your tuning would have to be perfect to get that. And i would NOT expect a better throttle responce than stock. I"ve modded a lot of iron 8's and bikes, you always lose just a bit of that factory "razors edge" throttle responce. The OEM's spend lots of time getting this right. I'm just talking that first 1/4" of pedal movement. Then rationalization sets in and the increased power and noise cause one to sense something that isn't there (?). Not that losing that edge is a deal breaker. And hopefully your tuner can get you so close you won't fret about it. We were all pulling for you as i hope ITB's are in my future (w/stroker) also. I fear that 41 HP result set an unrealistic goal for you. Personally i see the ITB's as mated with a stroker and cams. And then i see them more as a sound issue vs a HP gainer. I hope to get to drive one myself sometime to see if the different sensations are a plus or minus for me personally. I"ve had engines where the sucking sounds were so loud it was distracting. Sorry for the off thread comments.
 
Please don't take this the wrong way, but as nice as the Pride exhaust is, and it is nice, there are better exhaust choices for HP gains.
 
Please don't take this the wrong way, but as nice as the Pride exhaust is, and it is nice, there are better exhaust choices for HP gains.

Does the Pride give any hp gains? Its a pretzel exhaust isn't it?

If you are going to test, you might as well take the exhaust off just to see.
 
you have a point...my 3.0 motor with the old comptech IEM package which included cams got me to 292-298 rwhp...that was with the uniflow and usual EHI mods.

Guys, I have a real hard time understanding how on earth ITB's can add 40HP to a 250 RWHP motor. It just is illogical since you are not going forced induction or increasing displacement. Nor are you changing compression. You are, simply, freeing up the intake as much as possible. Getting rid of a restriction on the intake side and expecting 40 HP out of that seems unlikely to me.

Ditto Turbo2Go. I"m not an ITB expert, but i have read Hot Rod dyno tests for around 45 years and most involve intakes. On a relatively stock motor 3 liter, i would be surprised to see even a 15 HP increase, and your tuning would have to be perfect to get that. And i would NOT expect a better throttle responce than stock. I"ve modded a lot of iron 8's and bikes, you always lose just a bit of that factory "razors edge" throttle responce. The OEM's spend lots of time getting this right. I'm just talking that first 1/4" of pedal movement. Then rationalization sets in and the increased power and noise cause one to sense something that isn't there (?). Not that losing that edge is a deal breaker. And hopefully your tuner can get you so close you won't fret about it. We were all pulling for you as i hope ITB's are in my future (w/stroker) also. I fear that 41 HP result set an unrealistic goal for you. Personally i see the ITB's as mated with a stroker and cams. And then i see them more as a sound issue vs a HP gainer. I hope to get to drive one myself sometime to see if the different sensations are a plus or minus for me personally. I"ve had engines where the sucking sounds were so loud it was distracting. Sorry for the off thread comments.

I agree with all of you guys. Gaining 40whp/60lbft tq by just adding less restrictive intake system seemed very odd, but after seeing the real numbers, I thought "hmmm maybe it is possible ??" My tuner also advised me before I purchased the ITB not to expect that much gain as it is irrogical to obtain such significant gain by simply changing the intake system alone.

I actually gained a total of 25whp (baseline corrected number was 267 and 292 is already corrected number). If I had not seen Dan' gain, I would've been really happy with the 25whp.

It is also possible that the engineering of stock NSX intake box is far less restrictive than the aftermarket ones. Dan was using aftermarket intake box while I was using OEM during my base run and my base run number was lot higher than his but our end results were pretty close.
 
Does the Pride give any hp gains? Its a pretzel exhaust isn't it?

If you are going to test, you might as well take the exhaust off just to see.

makes sense. engine is sucking in more air than it can expel. should try test pipes too. if that doesn't free up more power, it'll sound really REALLY good at least. :biggrin:
 
FWIW I made more HP switching from my GT-Rom 5.0 to an ARC ti. I miss the sound a bit but the ARC has a nice tone of its own. If you have ITB's your exhaust should STFU anyway because it is now the worse singer in the chorus.
 
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