Puzzled by the whp gain after ITB

[NA1/2-R GT]

Hi Tanto,
As I stated on my later post, no hard feelings no harms done.
I really have no knowledge in all technical and engineering information to say here. All I can tell you all is my car felt a lot faster (noticealbe faster) and walked away from my friend's subaru withh 329 WHP. Now I know how's feel to have torque in an NSX.
Besides, there aren't that many ITB setups out there yet!!!
My setup has 48mm TBs.
I will say this again, any TUNER can claim that they can tune ITBs on an NSX but few ever succeed!!!
The only way we can truely answer to skepticism is to have Tony @ UMS tune Tae's system. Only then we know exactly wether tuning is really that important!!!
But yes, anyone can come by and test drive my car and decide for themselves. I offered test drive to local NSX owners, and if they can chime in they can tell you the difference in my setup and a typical N/A setup.
Some of you may know my attitude on fellow car enthusiast test driving my car. I let people drive my car like it's just another Honda... wait, it's just a Honda..

Dan- Since i was apparently one of those that you feel insulted you, i should comment further. No one was questioning you about the numbers you believe you gained. But with ANY dyno numbers that are not repeated on say three cars are going to be questioned. There are just too many variables on the dyno for us to believe one result, especially when it just sounds too good to be true. Again, in your case the numbers may be totally valid, but until someone like SOS tells us they have seen 41 hp on more than one car, we just have to be skeptical. Again not of your honestly, but of some variable that possibly skewed the result.
I don't know how long you've been around, but the early NA Comptech engines told us that it's REALLY hard to get HP out of this engine NA. They did not have ITB's, but they had bigger cams, valves, head porting, increased compression, and probably several treaks we didn't know about. While many were saying these eingines produced around 360 flywheel, One of the their big boys told me that 345 was optimistic and that was on 100 octane. I took that as meaning 325 was probably a realistic number. I remember more than one owner who spent 30k with Comtech and only got a couple a dozen HP and 3 tenths in acceleration. Point being, veterans will always be questioning excellent numbers. Certainly no "hate" intended. Peace.

 

[greenberet]

NA1/2-R GT: Another way to double-check how much the ITBs and custom-tuned engine management system got you would be to put your NSX and another NSX on the same dyno on the same day, making sure the operator measures the rpm from the ignition signal and enters the actual gearing and tire sizes into the computer. To better simulate on-road conditions, you could leave the engine compartment glass (or Lexan) closed and position fans at the openings to the engine compartment instead.

If the reference car were a bone-stock NA1 you’d see how much all your mods netted. If the reference car had headers, cat delete pipes, and a sports muffler like yours plus a big bore throttle body, sports air filter, low-restriction intake snorkel, and had its PGM-FI chip custom programmed on a dyno, you’d get a feel for how much the step up to ITBs and the AEM netted. In any case, you have some beautiful mods on your car!

 

[NA1/2-R GT]

Well, since Tae's setup and mine are almost the same (excepts the exhaust) I am going to download my tune for Tae then he can upload it into his AEM so that should make a difference. If it does make a difference, that goes to show that TUNING is very important! We shall wait and see.:wink:

 

[greenberet]

That’s a great idea and if it’s not too much trouble, maybe FD3SNSX could load your tune at a dyno facility and do a before / after test. Maybe even with another NSX tagging along as a baseline.

In any case, it’s definitely true that the engine will only be able to deliver all of its potential with the proper fuel and ignition maps.

 

[sparky]

Good stuff. It would be great to have a standard ITB map available for AEM - are you both using the AEM 30-1042 CPU? (i.e.not the early one, and not the new Series 2)

 

[NA1/2-R GT]

I have Ver.2 which is supposed to be the best version so far (according to AEM)

 

[FD3SNSX]

Thanks again Dan !

I also have AEM Ver2. This will be very interesting. I will do another pull with my current calibration than a few more after loading up Dan's calibration on a same day/same dyno. So stay TUNED guys !!! :biggrin:

Tae

 

[sparky]

But I understand the AEM CPU "Series 1" was:
30-1002 = version 1
30-1042 = version 2

but recently they released the "Series 2" CPUs which have further improvements, and a completely revised user interface software.

So I'm still unsure, do you have version 2 or Series 2 ?

thanks

 

[NA1/2-R GT]

1042 Vers. 2 just like this:
http://scienceofspeed.com/products/engine_performance_products/NSX/AEM/EMS/default.asp

 

[jde]

Well, since Tae's setup and mine are almost the same (excepts the exhaust) I am going to download my tune for Tae then he can upload it into his AEM so that should make a difference. If it does make a difference, that goes to show that TUNING is very important! We shall wait and see.:wink:

I believe the tuning plays a big role in this, I'm about to install my ITB's, I would be interested to test your tune in my setup too, have similar specs. Then we are 3 cars with similar specs that can compare dyno charts.

jde

 

[Ponyboy]

Wow, how did I miss this thread. I can't believe (actually I can) the people giving Dan and Tae grief about the lower than expected ITB numbers and dismissing the intake altogether.

ITBs a backwards novelty item and not a serious power mod? What a completely idiotic statement. If a race series allows ITBs, you'll see them installed. There is so much engineering and science behind tuning ITBs that using them has the potential for over 100% volumetric efficiency at peak. I could go on.

ITBs not getting better throttle response than stock? BS. It's the very nature of having ITBs to have better throttle response (both on and off throttle). The factory "razor's edge" makes due with a single throttle body and takes time to pressurize the plenum. ITBs don't have that restriction and make that "razor's edge" seem about as sharp as a broadside of a mallet. Again, I could go on.

Tae, as others have stated, the biggest drivers in determining the difference in yours and Dan's numbers are:

• Dyno - diff. dynos have a profound effect on the final number (ie Mustang vs dynojet/et al.). Not to mention diff. climate conditions.
• Tuning - one tuner may be or may not be as skilled as another with a specific engine or mod.
• Mods - especially in a tuned NA engine, different mods will play a big part in differing hp levels.

All of the above is fairly obvious. I think the issue is mostly tuning, your two graphs are generally similar in shape except for the downward spike in the middle of your graph (kinda concerning). The spike issue and tuning are what, IMHO, should be addressed first if you choose to chase the issue.

FWIW, although altogether different engines, Tony at UMS tuned mine as well - both w/ and w/o ITBs.

 

[BD]

I remember reading a JDM NSX related articles talking about ITB HP gain with HIE is about max 340 ~ ish HP to the crank, that's how they advertised it with a slight RPM increase to 7500 with NA1 engine. DBW was not offered and converting back to cable is not recommended.

NA power increase is very expensive when compare to simple FI, but that is the JDM culture. You rarely see FI NSXs in Japan.

Good luck on your ITB project, hope all turn out well.

 

[NA1/2-R GT]

I believe the tuning plays a big role in this, I'm about to install my ITB's, I would be interested to test your tune in my setup too, have similar specs. Then we are 3 cars with similar specs that can compare dyno charts.

jde

Once I downloaded the map for Tae, I am sure he can share that with you for your set-up too.

Regards,

Dan

 

[TURBO2GO]

ITBs a backwards novelty item and not a serious power mod? What a completely idiotic statement.

I think the point was that for the same or less money you can have a whole lot more HP, be emissions legal with some systems, and not need all this tuning. Nevermind not sucking unfiltered air into your engine. I'm not sure I'd call someone an idiot because they tried to point that out.

 

[Ponyboy]

I think the point was that for the same or less money you can have a whole lot more HP, be emissions legal with some systems, and not need all this tuning. Nevermind not sucking unfiltered air into your engine. I'm not sure I'd call someone an idiot because they tried to point that out.

Well, then you need to learn to communicate better. B/c what you wrote and the statement in quotes above have entirely different meanings.

Even so, considering your logic and the psycho idea that you can actually buy an SC or turbo system for under 5k as remotely valid, you should also be bitching about those who buy headers, or test pipes, or exhausts as those don't produce "a whole lot more HP." And for just a couple of grand more, they could have hp, be emissions legal, and not need tuning.

I think you have to realize that some people don't want forced induction in their sports car and that the challenge of producing big NA power is particularly attractive to them.

 

[Mac Attack]

I think a few folks need to step back and relax. Don't worry about justifying your expenditures - if you're happy then fine. There's good and bad in this world due to not everyone thinking the same way :wink:

I thought long and hard about doing ITB's. Kits can be had for as little as $1500k (obviously not Jenveys) which is more reasonable. Thought about roller barrel throttlebodies, dual injector per cylinder setups (which is now possible with the new AEM EMS), and a simple two-step vacuum-controlled variable length system (despite my previous posts in another thread how useless I used to think that was).

Good luck with the tuning - here's hoping you can squeeze a few more ponies out of it!

Dave

 

[kookoo4nsx]

It's all about exploring different techniques to achieve higher HP. There is no one perfect solution.

Evolution takes time.

 

[FD3SNSX]

Ok guys, here are the results. These runs were done on the dynojet. We first ran with my map, then ran again after loading Dan's map w/o making any changes. We did this multiple times and the results were pretty same.

Blue is with Dan's map tuned by Tony/UMS
Red is my map tuned by Ray/PFSupercars

Engine cold

Engine hot (after many runs)

Here are the data
Dynojet Research Inc.
Run Name: C:\DynoRuns\HONDA\NSX\Tae\RunFile_016.drf
Run Title:
Run Notes:
Run Date: 9/29/2011 7:45:22 PM
RunFile_016.drf: 88.72 °F 29.47 in-Hg Humidity: 21 % SAE: 1.01 Average Gear Ratio: 53.74
s RPM x1000 hp ft-lbs Air/Fuel
0.39 2.75 11.64 22.17 14.27
1.36 3.00 100.35 175.68 13.01
2.31 3.25 108.53 175.39 11.62
3.21 3.50 123.60 185.47 12.02
4.12 3.75 129.85 181.86 12.33
5.00 4.00 146.20 191.97 13.02
5.88 4.25 151.64 187.39 12.25
6.73 4.50 172.41 201.23 12.48
7.56 4.75 182.18 201.44 12.78
8.39 5.00 191.04 200.67 12.30
9.24 5.25 207.82 207.90 11.77
10.02 5.50 223.09 213.04 12.46
10.84 5.75 224.81 205.34 12.28
11.66 6.00 235.16 205.85 12.21
12.47 6.25 252.51 212.19 12.73
13.25 6.50 267.19 215.89 12.77
14.06 6.75 267.42 208.08 12.61
14.92 7.00 265.16 198.95 12.47
15.81 7.25 270.06 195.64 12.53
16.69 7.50 278.78 195.22 12.66
17.58 7.75 284.54 192.83 12.79
--------- --------- --------- --------- ---------
MAX: 17.58 7.75 284.54 215.89 14.27
MIN: 0.39 2.75 11.64 22.17 11.62
--------------------------------------------------------------------------------
Dynojet Research Inc.
Run Name: C:\DynoRuns\HONDA\NSX\Tae\RunFile_017.drf
Run Title:
Run Notes:
Run Date: 9/29/2011 7:58:26 PM
RunFile_017.drf: 88.64 °F 29.47 in-Hg Humidity: 20 % SAE: 1.01 Average Gear Ratio: 53.78
s RPM x1000 hp ft-lbs Air/Fuel
0.75 2.75 91.13 174.05 12.68
1.69 3.00 102.12 178.78 13.70
2.60 3.25 112.24 181.39 12.89
3.49 3.50 124.69 187.11 13.09
4.40 3.75 129.53 181.41 13.15
5.28 4.00 146.46 192.30 13.56
6.16 4.25 151.83 187.63 13.02
7.00 4.50 171.87 200.60 13.28
7.83 4.75 182.89 202.23 13.42
8.65 5.00 192.80 202.52 12.85
9.49 5.25 207.58 207.66 12.48
10.27 5.50 225.61 215.44 13.43
11.07 5.75 227.58 207.87 13.10
11.89 6.00 236.64 207.15 12.86
12.69 6.25 253.50 213.03 13.08
13.47 6.50 268.15 216.67 13.49
14.28 6.75 271.03 210.89 13.46
15.13 7.00 267.62 200.80 13.24
16.00 7.25 270.10 195.67 13.17
16.88 7.50 280.97 196.75 13.17
17.78 7.75 286.22 193.97 13.27
18.69 8.00 289.73 190.21 13.28
--------- --------- --------- --------- ---------
MAX: 18.69 8.00 289.73 216.67 13.70
MIN: 0.75 2.75 91.13 174.05 12.48

Multiple runs were done but the results were same and the highest WHP gained using my map was 296whp, which is 29whp difference compared to my base.

I was surprised/glad to see how the results from two different maps were almost identical because that proves there was nothing wrong with the tune itself. Overall, I am very happy with the result. The throttle response/sound/more tourqe makes the drive 1000x better/fun.

 

[sparky]

+ ~30rwhp is a very useful gain. The perfect sequel would be to do exact same as above, but on the other NSX. e.g. the short sudden plunge in the mid range remains curious and may be unique to your car.

 

[FD3SNSX]

+ ~30rwhp is a very useful gain. The perfect sequel would be to do exact same as above, but on the other NSX. e.g. the short sudden plunge in the mid range remains curious and may be unique to your car.

I thought the mid range plunge was due to passover to VTEC ? no?? While driving, I don't feel any power loss in that range.

 

[sparky]

According to NSX manual (p5-7) VTEC comes in between 5800 - 6000rpm, check out the power surge after that in your chart. The down spike in your case is nearer 5,100rpm.

 

[whrdnsx]

Another thing to consider is wheel weights & the type of dyno.

We've seen 40HP difference in a wheel change on the dyno back to back.

also a Hub dyno will show a greater figure than a rolling dyno obviously cause it's not turning any wheels.

 

[sparky]

whrdnsx I assume the better hp result was with lighter wheels?

 

[TURBO2GO]

This is exactly what I expected. For there to be little to no difference. That is still a healthy gain, although I do wonder what closing it off with a filter will do. Have you dyno'ed that at all? I am assuming all these runs are unfiltered?

 

[Caustic]

And did you still have the restrictive exhaust on?