NSteXpo 2002 Dyno Day Report - now available!

[Yellow Rose]

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

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

The a/f mixture on the Comptech was the smoothest of the three superchargers. Throughout the entire RPM range, it varied by only one point. I don't recall the range exactly, it was either 12:1 to 13:1 or 13:1 to 14:1.

 

[Rubber Chicken]

Great thread overall, very informative.

A few things...

Originally posted by mdoan300:
Turbo wastegates are used to prevent over-boosting and blow-off valves are used to keep turbos spooled between shifts.

Actually I believe that the primary function of the BOV is to prevent damage to the compressor when the compressed air has nowhere to go once the throttle plate is closed suddenly. (ie during shifts)

Most OEM turbo'd cars have BOV's that vent into the intake stream to keep the turbo spooled and to prevent the system from running rich.

Aftermarket Turbo Kits usually just vent the BOV into the atmosphere, and deal with that last bit of richness.

At least that's how I understand it.


Also, for the benefit of all, I kinda played around in photoshop with the BBSC dynograph from the PDF and the BBSC dynograph from the SoS website.

Found here and here, respectively:
From NSX Dyno Day

From SoS's Site

And I came up with the following graphs.

Take it with a grain of salt, because these were two dyno's under different conditions.

But with that grain of salt also consider that the thick blue and red lines (from NSX Dyno Day) were with the 4 lb pulley and 9 lb ECU Map, and the thin well defined red and blue lines were from SoS (which I presume came from BB themselves?) at a 5 lb pulley which I also assume was well tuned, but supposedly with no other bolt on's.

The Torque graphs differ by quite a bit actually, in fact the stock torque graphs, which ought to be very similar really have to be taken loosely. (again with a grain of salt)

I would venture to guess that the difference in the graph's of a 4psi SC and a 5psi SC would be quite close to simply a vertical translation on the y-axis (horsepower/torque) Yet what we see in the graphs is a little different, In fact the 4psi setup with the 9psi ECU seems to be sluggish under 5000 rpm, then it seems to match the 5psi after that engine speed.

I can only surmise that the incorrect ECU tuning is responsible for the loss in low end, but you never really know.

Hope this helps.

Ken


[This message has been edited by Rubber Chicken (edited 15 May 2002).]

 

[nsx1164]

Originally posted by nsx1164:
Comparing the two CTSC cars:

#14 (Saint?): RED 95 3.0 with 9# CTSC
- i/h/e (RM exhaust)

#16 (PO'd guy

): YELLOW 01 3.2 with 6# CTSC
- i/h/e (all CT)

#14 consistently out performs #16
- is there some "secret-mod" with #14 (tuning, larger injectors, better chip program) ??
- is either one yielding more "typical" results ... from earlier anecdotal evidence, it seems that most CTSC setups perform like #16

As shown in separate threads, car #14 (Saint) has the high-boost CTSC setup (~8-9 lb boost) and has been tuned by Mark Basch... this explains some of the performance increase.

 

[aaronb]

Car #1 = Mine!

Most HP, Non-Modified!

1997, 79,500 Miles

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[true]

Does anyone have the compressor flow map's for the forced induction applications? (basch sc, comptech sc, gruppem sc, bell tt) I'd like to take a look. Please let me know or post them if you have it. Thanks.

------------------
jack of all trades, master of some.

 

[Russ]

Rubber Chicken's graphs inspired me to combine the BBSC, Comptech, GruppeM and stock graphs from the Dyno Day report. This shows at a glance the advantages of each SC compared to stock, as well as to each other.

------------------
Russ
'91 black/black

 

[true]

Originally posted by Russ:
Rubber Chicken's graphs inspired me to combine the BBSC, Comptech, GruppeM and stock graphs from the Dyno Day report. This shows at a glance the advantages of each SC compared to stock, as well as to each other.

Thanks Russ, very nice graph, but that's not what I'm looking for. The comptech and gruppeM are torque beats..loving that torque curve. Assuming your graphs are accurate, the basch sc doesn't come near touching them till 7000RPM. It's actually lower then stock up untill 5200rpm!! Peak HP doesn't mean jack. Also i was trying to find the comptech flowmap yesterday and came across nsxflorida.com page that had brochure info for the sc..and it said the comptech brochure said 12.6 sec 1/4. Can anyone confirm?

I'm looking for the compressor flow map.

For example..

Here is a t04e compressor flowmap:

<img src=http://www.turboneticsinc.com/comp_maps/Fig13.gif>

[This message has been edited by true (edited 17 May 2002).]

[This message has been edited by true (edited 17 May 2002).]

 

[NetViper]

It looks to me like to really enjoy the BBSC, you have to be on the track... The other two look like more fun on the street. Hopefully thier prices will come down with the intro of the BB.. but who knows..


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NetViper -= 100% Stock EBP 2000 Civic Si =- Still looking to get an NSX, but at least I can live life at 8,000 RPM!

 

[Jimbo]

Of course, the only value in these dyno test results can be found in the comparison between the Comptech and the Gruppe M.

If you're looking to make an informed decision about the BBSC then these numbers and charts are worthless.

Why?

Because the BaschBoost supercharged vehicle was utilizing a pulley designed to provide about 4 lbs. of boost, yet the ECU software (fuel map, etc.) was expecting 9 lbs. of boost.

It will be interesting to see the final production dyno charts for the BBSC.

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords

 

[true]

Originally posted by Jimbo:
Of course, the only value in these dyno test results can be found in the comparison between the Comptech and the Gruppe M.

If you're looking to make an informed decision about the BBSC then these numbers and charts are worthless.

Why?

Because the BaschBoost supercharged vehicle was utilizing a pulley designed to provide about 4 lbs. of boost, yet the ECU software (fuel map, etc.) was expecting 9 lbs. of boost.

It will be interesting to see the final production dyno charts for the BBSC.

-Jim

The ECU does not know the difference between 4PSI with a max of 9, nor 4 PSI max. That is, unless they have 2 2 different fueling values for 4psi on both pullys which wouldn't make much sense. Also, I guess Jim is right in the fact that the numbers ALL could be skewed since I remember reading nobody utilized the same or a standard boost gauge. Who really knows how much boost everyone was pushing.

I don't know if i would call the numbers and charts worthless. The graphs give a general overview of the compressor's characteristics. If one of these runs at 10PSI it will probably make more power, but the direction of the torque curve probably wont change much...just get bumped up a little... (assuming compressor efficiency doesnt go out the window)


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jack of all trades, master of some.

 

[nsxlr8]

POWER UNDER THE CURVE.

Give me the Comptech ANY day against BBSC. I know I love max power. But Like I've ALWAYS said. It's the whole Chart. Shifting brings you down to 4900 rpms. The Comptech should beat the BBSC. (supposed 4psi kit that is) -

 

[Jimbo]

I agree that's it's the area under the curve that's important.

That's why I want to see the real final production data for the BBSC.

You can't draw any informed conclusions from the BBSC data that has been presented so far in this thread.

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords

 

[BryanZublin]

Originally posted by Rubber Chicken:
(snip) But with that grain of salt also consider that the thick blue and red lines (from NSX Dyno Day) were with the 4 lb pulley and 9 lb ECU Map, and the thin well defined red and blue lines were from SoS (which I presume came from BB themselves?) at a 5 lb pulley which I also assume was well tuned, but supposedly with no other bolt on's. (snip)

The dyno graph "thin lines" dated 12-Oct-2001 (SN 945) is my 1992 NSX. The BB SC configuration at that time was with the rising rate fuel pressure regulator, stock injectors, and stock ECU chip (ie. stock timing). Since that time, the BB SC design has been changed to use stock fuel pressure, higher flow injectors, and modified ECU chip (ie. modified fuel flow and timing). I wouldn't compare the October 2001 dyno data with recent data since the October data does not represent the production BB SC configuration. I believe that the pulley used for the October data was 3.5 or 3.75 inches and the production version will use a 4 inch pulley.

Regards,
Bryan Zublin

------------------
Zublin Engineering
http://www.zublin.com

 

[Yellow Rose]

The Comptech should beat the BBSC.

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

Not necessarily - I've driven both, each in various stages of "tuning". It depends on what you are looking for.

I personally do not subscribe to the "area under the curve" concept. That is silly. What if you like to spend your day at redline, do you suppose you will select a SC with a lower HP value at 8000 RPM that has more area under the curve? Of course not. You will select a SC that has a higher HP in the 6-8000 RPM, even if has less performance at lower RPM.

Because the opposite is equally true, one size does not fit all.

[This message has been edited by AndyVecsey (edited 17 May 2002).]

 

[true]

Originally posted by Jimbo:

You can't draw any informed conclusions from the BBSC data that has been presented so far in this thread.

-Jim

Keep telling yourself that. Maybe they will change the actual supercharger unit and start producing power at driving RPM.

I'm not disagreeing that their final dyno will be generate more power, but to say you cant make an informed conclusion on what their final will look like is goofy unless they change their compressor.

------------------
jack of all trades, master of some.

 

[Lud]

Originally posted by AndyVecsey:
I personally do not subscribe to the "area under the curve" concept. That is silly. What if you like to spend your day at redline,

You need to look at the area under the curve FOR YOUR INTENDED DRIVING.

If you do not care about 1000-4000 RPM, ignore it.

If your concern is soley 6000-8000 RPM, then look just at that part of the curve.

If you want to be able to punch it in high gear while crusing on the interstate and have gobs of power, you need to look at the lower RPM end of the curve.

If you want power evenly throughout the RPM range, look at the whole thing.

But that doesn't change the fact that peak HP is irrelevant compared to the area under the part of the curve you are interested in.

Nobody spends all day at 8000 RPM redline unless they never shift and never accelerate or decelerate.

 

[Jimbo]

Thanks for the commment "true."

I'll stand by my comments that the dyno plots and data in this thread do not represent what the final, real, production BBSC is capable of producing.

I'll leave the speculation and extrapolation to you...I'll wait for the actual data.

-Jim

PS: On the subject of "area under the curve", let me amend my statement by saying that for me and for the type of driving I do most of the time in my NSX that the area under the curve is what catches my eye and interest. I don't drive at 8K all day long, nor do I drive at the track every day either. I do realize that for some, peak HP at redline is important.

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords

 

[ScienceofSpeed]

I agree with Jim on this comment. If you look at the dyno of the production system dyno, you will note that not only is there higher peak power, but the power curve shifts to lower RPMs. While the nature of the power delivery remains the same (linear power gain over RPM) you'll note that the power is lower in the RPM band significantly changes the way the car feels on the road.

At upshift points, the BBSC still nets higher HP gains than the other blower systems.

Comment above about "one size does not fit all" is 100% correct (props to Andy)

Cheers,
-- Chris

Originally posted by Jimbo:
Thanks for the commment "true."

I'll stand by my comments that the dyno plots and data in this thread do not represent what the final, real, production BBSC is capable of producing.

I'll leave the speculation and extrapolation to you...I'll wait for the actual data.

-Jim

PS: On the subject of "area under the curve", let me amend my statement by saying that for me and for the type of driving I do most of the time in my NSX that the area under the curve is what catches my eye and interest. I don't drive at 8K all day long, nor do I drive at the track every day either. I do realize that for some, peak HP at redline is important.

------------------

[email protected]
http://www.ScienceofSpeed.com

 

[Jimbo]

I can see where the curve might be quite similar for the final production BBSC...but it's also entirely possible that the entire curve could be shifted higher (as in the speculation above) when the proper pulley and the other production changes are finalized.

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords

 

[8000RPM]

Originally posted by AndyVecsey:
Because the opposite is equally true, one size does not fit all.

Well then, so why did you state that you thought the concept of "area under the curve" was silly again?

How else would one know which size fits the best if one had no access to "area under the curve" data?

You seem to have contradicted yourself in your own post.

[This message has been edited by 8000RPM (edited 17 May 2002).]

 

[Number9]

This is from a supercharger FAQ I found on the web, but conforms well with empirical data Eric compiled:

"Typically, a centrifugal supercharger will make it's maximum boost at the engine's redline rpm and nearly nothing at 1500-2000 engine rpm. Boost builds exponentially with engine rpm, meaning that boost comes on very quickly in the upper half of the powerband."

So it looks like the GruppeM and high-boost CTSC are essentially equivalent and bring on boost much sooner (in effect, acting like a larger displacement engine) than the BBSC and are both therefore clearly better than the BBSC for street applications.

Once the BBSC is sorted and optimized however (I'm assuming that the narrow 1K RPM band where the BBSC is better could be broadened to encompass 3K at the high end), it should have much better peak HP at any given boost level compared to the GruppeM/BBSC (because it's more efficient, hence it heats the air less and therefore provides a denser air charge at any given boost level).

So it seems pretty clear - pure track cars will probably want to run BBSC whereas pure street cars will want to run GruppeM/high-boost CTSC (and those in between will have a VERY tough decision to make). BTW, I'm assuming cost isn't an issue - if it is, then definitely BBSC, if it isn't, then forget the SC and go talk to David!

[This message has been edited by Number9 (edited 17 May 2002).]

 

[Sig]

$5,000 price differential makes the decision much easier for me.

 

[Jimbo]

I'm not sure one can make the blanket statement about centrifigual blowers and engine RPM.

Since you can use different sized pulleys it would seem that there's some flexibility in what engine RPM range gives the optimum blower RPM.

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords

 

[Number9]

Originally posted by Jimbo:
Since you can use different sized pulleys it would seem that there's some flexibility in what engine RPM range gives the optimum blower RPM.

Not true. You're constrained by the peak boost you select. If you go with a smaller SC pulley than that, you'll blow up your engine like an E46 M3 on a track day. The nature of the centrifugal blower is such that it'll never have a torque curve like the roots or whipple, unless you do something really degenerate like tiny pulley and wastegate. It's not bad, it's just different - better efficiency for more high-end HP but sucky boost at low/mid.

 

[Jimbo]

9,

I'm not sure I follow you.

I understand that the pulley size determines the peak boost and that in order to get peak boost at lower RPM some sort of wastegate would be needed.

But in the positive displacement air pumps don't you also have that problem?

-Jim

------------------
1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords