NA mods and results?

G

gmonsen

New Member
Joined
9 April 2011
Messages
6
Location
Southeast Pennsylvania
Hi... I'm a new member here and not an owner. I am interested in how I could modify an NSX to have a bit more power and remain naturally aspirated. I would expect to put on a good exhaust (does Tubi make one?) and air intake, plus changing out the cams and cam adaptors. Can someone tell me who makes good cams for the car? Also, any idea what a motor would make with cams, exhaust, intake, and some retuning (chips, I would assume, can be found to deal with the cam changes? Or, do I need an aftermarket ecu?)?

Anyway, I don't want to go with a blower, since I prefer NA motors. I currently drive an Rx7 with a 3 rotor NA motor... :) So, no blower.

Thanks for any advice.

Gordon
 
Last edited:
Welcome Gordon! Glad you made it over. I'm sure you'll get the answers you're looking for!

I'm sure everyone will be curious about your other vehicles too :smile:
 
I'll start. It seems most are putting down between 260 whp - 295 whp with basic bolt on's. I'm not sure how much power you'll gain by cams. I'm sure the pro's will chime in and spill the beans.

Rynees put down 295 whp with Intake, Headers and Exhaust.


ryneen said:
Year: 91
Mileage (on motor/after rebuild):95,000
Motor (internals): Stock
Displacement:3.0
Intake: Cantrell cold air intake
Header: Comptech
Exhaust/muffler: Taitec Lightweight
Wheel/tire size and model: 235/17 front 275/17 rear. Technomagnesio wheel and Toyo R888 tires
Clutch: Stock
Motor builder & tuner: Stock
ECU: Stock
Fuel injectors: Stock
FI- No
Supercharger make and boost level: None
Turbo compressor&turbine size and boost level: None
Gear dynoed in: 2nd
Ambient temp & humidity during dyno: 80F
Click to expand...

8zpem9.png
 
Note: I wasn't using cats. I had straight pipes for what it's worth.

EAC said:
I'll start. It seems most are putting down between 260 whp - 295 whp with basic bolt on's. I'm not sure how much power you'll gain by cams. I'm sure the pro's will chime in and spill the beans.

Rynees put down 295 whp with Intake, Headers and Exhaust.




8zpem9.png
Click to expand...
 
check with CT engineering which is the new old comptech.they also come up for sale used from time to time.
 
ryneen said:
Note: I wasn't using cats. I had straight pipes for what it's worth.
Click to expand...

do you know how much hp you were making before the mods?
just wondering how much they added.
 
EAC... Is that the hammer? Thanks. Glad to be here as well.

docjohn... Thanks. I gather cams are not readily available anymore from Comptech? Science of Speed makes some cams still? Will check them out.

Ryneen... Does your car pass emissions without the cats? Not that it can't be gotten around. I don't run cats on my Rx7 and my local guy has some way of getting it inspected successfully. I'm pretty close anyway and could probably retune to pass. I love the sound with straight pipes as well as the power gain. Would you have a link to the sound of your motor?

greenberet... I will read it and thanks for pointing me in the right direction.
 
Ive got the Tubi exhaust... Looks are awesome. Sound is *really* awesome. Weight isnt so hot, neither is power.

My car (99 3.2L) was dynoed by previous owner with intake, CT headers, CTSC and both the CT and Tubi exhausts. The CT exhaust made a bit more power (I think it was 10rwhp)

A few years on it was dynoed again, however, with intake, CT headers, CTSC and Tubi exhaust and the results came in much better. But it was different day, different dyno, so unfortunately not comparable.

I think its possible that the Tubi exhaust gets more efficient over time, but overall I think that with the Tubi on the NSX you are trading a bit of power and weight (vs the most efficient exhausts) for the look and sound.

To me, the difference of a few rwhp or a few lbs here or there (esp since its still a nice improvement over stock) is worth the tradeoff for the awesome sound (which, IMO, is much better than any other exhaust)

I think as a general rule its fair to say that both the 3.0L and 3.2L benefit from headers/exhaust, but the 3.0L sees a bigger benefit since the headers were really nicely redesigned for the 3.2L so there is less room for gain.

Ive yet to hear of a chip update being worthwhile and I dont think the aftermarket air intake systems have a big effect either.

The wiki results look pretty accurate to me as general guidance. Dont be fooled by the #s on the CTSC. I can tell you that the dyno results from my 99 are about that 355 rwhp # and it feels *far* faster than any non FI 3.2L Ive ever ridden in and *is* a lot quicker. GPS timings have put me at around 4.2-4.5 0-60. I've never gotten near that with a non-FI 3.2. More like 5-5.1
 
afaik 4th is the norm.
 
Guys, I'm just starting my thinking about all this, so I've got a lot of catch up to do. However, it seems to me that -- so far -- I don't see much in the way of cars that have aftermarket engine management systems. Is that true? I think I was looking at docjohn's dyno results and noticed the AFR's going down to the low 12's toward 6000 and then getting leaner, but back to the same AFR's that were shown from 3000-5500 or so. At first, I was wondering if the motor liked being a little richer around 6000 or what. It seems that this is running the stock ecu, maybe? If this is right, why don't people use aftermarket ecu's? I'll keep reading.

In any event, it seems relatively easy to get to 300-ish whp with bolt ons and that should be pretty good power for the car, though 350 is what I would prefer for the weight. Someone said (and I can't find it) that they thought their porting only added 5 whp, which also seems a bit strange on first blush. I would have expected much more given my experience with somewhat similar motors. However, 300 whp should be fine in the NSX.

Gordon
 
go to www.scienceofspeed.com, or alternatively check with autowave in southern california. both have excellent reputations for service and product. My only personal experience is with Science of Speed. Stellar service. Nothing else i could say would improve on that statement.
 
If you don't want to increase discplacement and bore /stroke then 300 is a good target for na. My car ran its oem ecu when that dyno run was made,and being a 96 has all the obd-2 nannies.The guys with stroker motors may be running after market ems, you may want to peruse the stroker club threads. The best advice though is to buy the best nsx you can afford and drive it as is so you alone can determine how powerful it is.BTW we have seen some folks complain about the nsx lack of power only to find that those folks don't rev the car to redline, and shift before vtec engagement,kinda sad.
 
docjohn... Thanks. I will check out the stroker guys. Stroking isn't one of my favorites, since it often changes the character of the power delivery. Motors generally have a sweet spot relative to bore and stroke and going outside that can really change the engine. (Oh, and since I drive an NA 20b 3 rotor powered Rx7 and a full tilt boogey E30 M3, I love high revving NA motors. :))

Gordon
 
Gordon now that you mentioned it again, since EAC also hinted that your 20b powered car is pretty bad ass, would you mind showing it? I know it is off topic from this thread, also how much power does it make NA? My friend is building a 20B FD as well and I'm curious to see what kind of numbers he will be pushing.
 
s14_tat... My FD is not "bad ass" really. It was meant to be an evo "grand touring" version of the FD. As much effort went into the interior as it did the motor for instance. It makes 350 whp, but has an extremely broad power band. Makes more than 200 foot pounds from 2000-8000 rpm and pulls to 10,000 rpm. Full race NA 20b motors today make 430+ whp but are a bit less civilized... Here's a few videos and a thread describing the car. (Thread's VERY long and lots of pictures.)

Gordon


http://www.youtube.com/watch?v=sLQQxOqYyug

http://www.youtube.com/watch?v=Q0DBQQVPlzU&feature=related

http://www.youtube.com/watch?v=ceOeVw6wWz0&NR=1

http://www.rx7club.com/showthread.php?t=937174
 
Gordon, I may have missed it but I didn't see what year NSX you have. Regardless, welcome to the community.

If you talk to Chris at SOS, he may get you interested in the SOS individual throttle body kit they have. Looks like a truely streetable, easy to drive setup that could get you closer to your HP goals. Once they get a filter system worked out for it, it seems like it would be perfect for a na daily driver.
 
gmonsen said:
s14_tat... My FD is not "bad ass" really. It was meant to be an evo "grand touring" version of the FD. As much effort went into the interior as it did the motor for instance. It makes 350 whp, but has an extremely broad power band. Makes more than 200 foot pounds from 2000-8000 rpm and pulls to 10,000 rpm. Full race NA 20b motors today make 430+ whp but are a bit less civilized... Here's a few videos and a thread describing the car. (Thread's VERY long and lots of pictures.)

Gordon


http://www.youtube.com/watch?v=sLQQxOqYyug

http://www.youtube.com/watch?v=Q0DBQQVPlzU&feature=related

http://www.youtube.com/watch?v=ceOeVw6wWz0&NR=1

http://www.rx7club.com/showthread.php?t=937174
Click to expand...

That looks/sounds awesome.
 
I've seen seen someone take an RX7 as far as you have. Amazing Gordon. I can only imagine what you could do to a NSX.

gmonsen said:
s14_tat... My FD is not "bad ass" really. It was meant to be an evo "grand touring" version of the FD. As much effort went into the interior as it did the motor for instance. It makes 350 whp, but has an extremely broad power band. Makes more than 200 foot pounds from 2000-8000 rpm and pulls to 10,000 rpm. Full race NA 20b motors today make 430+ whp but are a bit less civilized... Here's a few videos and a thread describing the car. (Thread's VERY long and lots of pictures.)

Gordon


http://www.youtube.com/watch?v=sLQQxOqYyug

http://www.youtube.com/watch?v=Q0DBQQVPlzU&feature=related

http://www.youtube.com/watch?v=ceOeVw6wWz0&NR=1

http://www.rx7club.com/showthread.php?t=937174
Click to expand...
 

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