CTSC Dyno today

[cristo555]

Had my '91 dyno done today. Hot and humid here in Baltimore today-- I have taken dyno's at stock/ header only/ and now header and CTSC only. Went from 228hp/171tq to 237/175 with the header (cooler and less humid day) and now to 304/213 -- So the header and CTSC added 76 hp so far. The mechanics at Agile Performance felt that opening up the exhaust would make up the other 20-25 hp that Comptech claims. Any opinions ? I don't really want a LOUD exhaust but for 25 hp I would do it. I tried posting the graphs from today but I can't figure out how -- boost was peaked at close to 6000 rpm at 6.2psi with a slow curve from 5psi at 3800 returning to 5.2 at redline. The A/F concerned me.... staying between 12.4 and 12.8 until around 5000rpm then it drops to 11.3 then starts back up at 7000 rpm to end back at 12.8 at redline. The HP curve was almost a straight line from 95hp/2500rpm to 304hp/7700rpm. The guys at Agile felt that the F/A was OK and noted that the engine went towards lean only when the boost was around 5 psi or lower...they felt it was safe. Also the car runs very well--smooth and powerful. By the way -- not having the aftermarket exhaust does have one bonus--you can hear the CTSC whine very clearly as you drive.. It reminds me of a jet engine when accelerating and when slowing down....very cool. Sorry this was such a wordy post but It's tough describing a graph.

 

[NSXTASY_MD]

Cristo, get an aftermarket exhaust....its your biggest bottle neck at this point...not only preventing you from realizing your set-ups potential, but the high back-pressure of them pee-sized 1 and 7/8 inch exhaust pipes are adding a lot of thermal stress on your engine & engine area that can be avoided.


I can't comment on which exhausts are quietest, but have personally experienced several that weren't objectionable by any measure...particularly if used with cats (as you would most likely do)



PS: How much did Agile charge you for the CTSC install ??

 

[cristo555]

Agile charged $840 for the install......
So far the best sounding video clips that I've heard are the Paddock Magnaflow (great low tone -but loud) and the Anytime. Do you know of any exhausts that have a deep sound but are not real loud? I don't care for most of the exhaust notes (if you can depend on sound clips) since they are too raspy or tinny.

 

[Zipy]

Go for the flowmaster! I've got one and I love the way it sounds. I would describe it as nice and low, and medium loud at full throttle. I used 2 1/2" pipe in and out and pilot resonated tips.

 

[Racerxjling]

I have CTech throughout. I personally wanted something a bit tamer. I am so impressed w/ the welds in the headers that I wanted the same in the exhaust. Car sounds just the way I wanted it. I also have a mesh engine cover so the SC sounds nice/mean.

92 CTSC/I/H/E

Jeff

 

[donwon]

My A/F did the same. I'd like to see the dyno to see if its in the same place. Please post when you can.

 

[Racerxjling]

I too was concerned w/ some lean spikes so I went w/ the AEM ecu and fpr. I also did the RC550 injectors and Walbro HP fuel pump. My last dyno showed a very flat a/f curve.

Jeff

 

[cristo555]

I too was concerned w/ some lean spikes so I went w/ the AEM ecu and fpr. I also did the RC550 injectors and Walbro HP fuel pump. My last dyno showed a very flat a/f curve.

Jeff

Are you running the standard or 9lb pulley? Any major benefit in HP or is it just a safety factor?

Jim

 

[donwon]

Here are Cristo's graphs:

 

[donwon]

Your A/F dips and gets rich in exactly the same place as mine did. Mine was going into the 9's. When I fixed it I got a good chunk of power in the band, but saw minimal HP increases

I have a 3.2 and initial dyno on hi boost kit was 320/236 I/H/E, so from that point of reference, sounds about right. (seen other people running 340-360 on a standard kit, even higher like racers on AEM)

Im at 340 now, going to go next week for another try.

I know what you mean about the sound, it sounds meachanically evil, in a cool way.

 

[Racerxjling]

Cristo555

I am running the 9lb pulley (aka "hi boost"). The aem/fuel etc. was run for safety purposes. Next up is a big bore throttle body within the next 2 weeks.

My #s/facts on the car are here:

http://www.nsxprime.com/forums/showthread.php?s=&postid=324579#post324579

Jeff

 

[ScienceofSpeed]

The factory exhaust is quite restrictive, even on a N/A car. A car we tested with headers installed gained 22 rwhp with an exhaust alone (TAITEC JGTC). We've seen similar gains with the TAITEC GT Lightweight on an otherwise bone-stock 3.2L NSX (18+ rwhp) and good gains with the Anytime exhaust alone (12+rwhp).

take care,
-- Chris