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NSteXpo 2002 Dyno Day Report - now available!

Originally posted by cojones:
Chris, if you send EDR your data points (500 rpm intervals should be fine), he should be able to get these plotted on the same comparo graph, so we can get a sense for relative magnitude as well as slope/shape.


What I'd need is the original ".001, .002, .003, etc." file from the Dynojet computer. I'm using the Dynojet viewer to make those graphs. Just send it in an email and I can overlay the data and post the result.

EDR
 
Here is the dyno graph I was refering to:

dyno_042202.gif


Cheers,
-- Chris

[This message has been edited by ScienceofSpeed (edited 18 May 2002).]

[This message has been edited by ScienceofSpeed (edited 18 May 2002).]
 
Mike --

That equation holds true only for a car dynoed with a 1:1 gear ratio. The NSX does not have a 1:1 gear ratio. The factory gear ratios are 1st (3.0), 2nd (1.7), 3rd (1.2), 4th (.96), and 5th (.75). Common practice for the NSX is to dyno in 3rd gear, as the gear ratio is closest to 1:1.

BTW, a big kudos to the guys at Factor X Motorsports. My experience with this group has been fantastic. If anyone in the SoCal area is interested in dyno or tuning work, I'd highly recommend you check them out:
www.factorxmotorsports.com

Regards,
-- Chris

Originally posted by grippgoat:
Chris, I think you've got a problem with your numbers. The torque figures don't quite match the HP figures in some cases (BBSC is way off). Below is the calculated torque figure working from hp.

Torque = 5252 * hp / rpm

Chris's torque numbers are in parentheses.

GMSC:
280 @ 6000 = 245 (250)
325 @ 7500 = 227 (225)

CTSC:
270 @ 6000 = 236 (240)
325 @ 7500 = 227 (235)

BBSC:
325 @ 6000 = 284 (220)
370 @ 7500 = 259 (245)

So I don't know if you were reading the graphs separately and which is more correct (your hp or torque figures), but you're definitely way off on one or the other for the BBSC and the CTSC's 7500rpm figure.

-Mike

[This message has been edited by grippgoat (edited 01 May 2002).]



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SoS_logo.gif
 
Hi Eric --

I e-mailed the .djr file to you for your review.

Cheers,
-- Chris

Originally posted by erobbins:

What I'd need is the original ".001, .002, .003, etc." file from the Dynojet computer. I'm using the Dynojet viewer to make those graphs. Just send it in an email and I can overlay the data and post the result.

EDR




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SoS_logo.gif
 
CTSC (Vehicle #14):
6000 RPM RWHP - 270
RWTQ - 240

7500 RPM RWHP - 325
RWTQ - 235

***************

Those of you in Dallas at the dyno day, perhaps noticed the look of perplexion on my face after the pulls. I was expecting a solid 20 more RWHP. In fact, the dyno event was a bit of a confirmation that my 64k mile engine is indeed getting tired. Subsequent engine diagnostics substantiate my concern - rebuild is in the future. Yes, there are a couple of "secret" mods that support my expectation of the additional HP that Saint did not deliver.
 
The relationship between the HP and Torque hold true for any ratio gear. Unless each measurement are taken in different gear, which I don't believe the case.

Simple math:

Torque = 5252 * HP/rpm

If both are measured by certain ratio gear let's say X. Both side of the equation will need to be multiplied by X factor.

Torque * X = 5252 * X *HP/rpm.

Divide both by X you still come up with the same equation.


[This message has been edited by Andrie Hartanto (edited 02 May 2002).]
 
From my observation of the graph:

GruppeM (#12)
229 RWHP @ 5000 rpm
285 RWHP @ 6000 rpm
329 RWHP @ 7600 rpm (peak)
322 RWHP @ 7800 rpm

CTSC (#14)
232 RWHP @ 5000 rpm
275 RWHP @ 6000 rpm
320 RWHP @ 7600 rpm
322 RWHP @ 7800 rpm (peak)

BBSC (#13) with 4lb pulley
166 RWHP @ 5000 rpm
222 RWHP @ 6000 rpm
342 RWHP @ 7600 rpm
360 RWHP @ 7800 rpm (peak)

BBSC (SoS claim #)
325 RWHP @ 6000 rpm
370 RWHP @ 7500 rpm

If I have to make an educated guess.

If the BBSC makes 380RWHP @ 7800rpm, it shall make around 290RWHP @ 6000rpm


I include 7600 rpm cause the gruppeM peak at that rpm and the comptech pretty much flat. The 7800 rpm is relatively inaccurate, cause Dyno machine tend to give spike at the time you let go the gas. But seem to be good number with BBSC, since it is increasing linearly.

disclaimer:
I'm not trying to say that Chris is not right. My numbers is strictly an educated guess taken from observing the 4lbs graph. He maybe right and I maybe wrong. I'm open to that possibility. Since I have no data of the actual dynograph.



[This message has been edited by Andrie Hartanto (edited 02 May 2002).]
 
Looking at the dyno plot Chris posted, I think he looked at the wrong scale for torque and horsepower. I think the correct numbers are:

BBSC:
235 ft-lbs @ 6000 = ~270hp
255 ft-lbs @ 7500 = ~365hp

-Mike
 
You're right. I got confused looking at a graph in black and white (original is in color). I'll try to get a separate plot tomorrow as well as have Eric post a plot on the same graph.

Regards,
-- Chris

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SoS_logo.gif
 
Car #4 had some MAJOR fluctuations in air/fuel mixture during the dyno. I stood there and watched it jump all up and down during the runs. It would go lean then rich all of a sudden. I don't know what the problem was but the car had some issues making smooth power across the range.

As for who will do DC AND NOS...I think Doug tried that and blew the engine!
wink.gif
Then again he was pushing 390 something from some hardcore tuning before he hit the NOS. If I remember right that is.
 
It seems that based on a friend's impression after driving the BBSC car and from the numbers we can SEE...is it fair to assume that the GM and CT SCs are more linear and make more useable power over the complete range? I mean for the track/street, which one seems like the best use of power and application? Not taking price into factor of course.

Can anyone who has driven each tell how they FEEL to drive and what the major pros and cons are? Aside from the numbers what are the impressions?
 
Originally posted by AndyVecsey:
CTSC (Vehicle #14):
...
I was expecting a solid 20 more RWHP.
...
Yes, there are a couple of "secret" mods that support my expectation of the additional HP that Saint did not deliver.
9 # boost upgrade ??
biggrin.gif
 
Originally posted by scottjua:
It seems that based on a friend's impression after driving the BBSC car and from the numbers we can SEE...is it fair to assume that the GM and CT SCs are more linear and make more useable power over the complete range

The BB SC (or any SC for that matter) setup can pretty easily make more usable power at lower RPMs. One way to do this is to use a smaller pulley on the blower to spool it up more quickly, working in cooperation with a blow off valve to control boost in the upper RPM range. This how the GMSC does it.

See http://www.nsxprime.com/ubb/Forum1/HTML/001074.html


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Russ
'91 black/black
 
Ok,

I'm not an expert on Turbo and SC. But I believe, the blow off valve is intalled on the intake side (after the SC and before the throotle body to reduce build up when you let go of the gas. To bleed using this, means it should open after certain pressure, thus making noise at that rpm range and throughout. I'm not sure if the blow off valve capable in doing this effectively. I know Turbo uses wastegate for this.

Anybody expert on Turbo or any FI can comment on this?
 
On the Gruppe M kit, the bypass/relief valve is just after the throttle body, but before the induction side of the supercharger.

Its bypass chamber leads straight to the intake, bypassing the supercharger entirely.

-B
 
quote:
--------------------------------------------------------------------------------
Originally posted by scottjua:
It seems that based on a friend's impression after driving the BBSC car and from the numbers we can SEE...is it fair to assume that the GM and CT SCs are more linear and make more useable power over the complete range
--------------------------------------------------------------------------------


I don't get to the track very often so the powerband of the current BB unit isn't exciting enough for me. I'm sure it would be awesome at a constant high speed where RPMs are always above 5500. It would drive me nuts to not feel anything around town until high RPM. It's not about racing, just about fun factor.
I come from owning three vettes and am used to the instant torque on demand. That's why I enjot the more street friendly power band of a Comptech. They are all great setups. It just depends on your personal preference.
To say any one is clearly better than another is oversimplified.


[This message has been edited by ilya (edited 02 May 2002).]
 
Proves once again that there is no substitute for cubic inches (or cubic centimeters). Let's hope the next gen NSX is at least 3.5L, hopefully 4.0L.
Bryan Zublin
 
That was very informative. Thanks for putting this together.

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2001 QuickSilver Corvette Coupe. - Not Bone Stock :D

2002 Black Acura 3.2 TL/S
 
Originally posted by Andrie Hartanto:
I'm not an expert on Turbo and SC. But I believe, the blow off valve is intalled on the intake side (after the SC and before the throotle body to reduce build up when you let go of the gas. To bleed using this, means it should open after certain pressure, thus making noise at that rpm range and throughout. I'm not sure if the blow off valve capable in doing this effectively. I know Turbo uses wastegate for this.

Anybody expert on Turbo or any FI can comment on this?

Turbo wastegates are used to prevent over-boosting and blow-off valves are used to keep turbos spooled between shifts.

Michael.
 
Just got a chance to checkout the reports. Wow erobbins.. excellent write up. Good stuff.. I'm impressed at how much torque gruppem makes at such a low rpm (2500)...and it's sustained. torque is what is actually 'felt' hp doesn't really mean a thing... _especially_ peak HP. It's calculated by the torque values anyways. If I had a choice of any combo tested (not including nos) it's the gruppem sc..it has the most usuable daily driving torque values. It will win on the street everytime. :]

Too bad the a/f didn't work right..i'd love to see comptechs...their dyno is almost perfectly smooth. Get what ya pay for.

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jack of all trades, master of some.
 
Originally posted by true:
Just got a chance to checkout the reports. Wow erobbins.. excellent write up. Good stuff.. I'm impressed at how much torque gruppem makes at such a low rpm (2500)...and it's sustained. torque is what is actually 'felt' hp doesn't really mean a thing... _especially_ peak HP. It's calculated by the torque values anyways. If I had a choice of any combo tested (not including nos) it's the gruppem sc..it has the most usuable daily driving torque values. It will win on the street everytime. :]

Too bad the a/f didn't work right..i'd love to see comptechs...their dyno is almost perfectly smooth. Get what ya pay for.


Well said....
 
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