[bluerayone]

I have a thread in the Gen 5 forum http://www.camaro5.com/forums/showthread.php?t=463992
thought I check with here with you Gen 6 owners too.. granted we don't have same type of NPP system, however its a similar design and your cars have the built in capability to easily toggle between exhausts modes so you may have more insight in what I am looking for: the perceive power difference (or better yet, dyno pull results to track time sheets) running between stealth and track. Is there a great power difference between the two or is it just a noise maker as some suggest and perceived power increase is a panacea effect from the louder more powerful sounding exhaust

[parish8]

I am going to the dyno tomorrow to get some baseline numbers. I will make 3 runs. Open, closed, then open.

[SSDan]

Originally Posted by parish8

I am going to the dyno tomorrow to get some baseline numbers. I will make 3 runs. Open, closed, then open.

I predict the difference will be so minor it will be in the statistical noise thus making it inconsequential.

[parish8]

Originally Posted by SSDan

I predict the difference will be so minor it will be in the statistical noise thus making it inconsequential.

I agree.

[Jeb114]

Noise Maker,

[13vertss]

My guess about 2-3 hp and tq.

[Maiden Rush]

Track mode has better throttle response and stiffer steering. That's all I can tell you off the top of my head.

[vtirocz]

Originally Posted by SSDan

I predict the difference will be so minor it will be in the statistical noise thus making it inconsequential.

I agree. This is the feedback that I got from the GM intake / exhaust development engineer at the Camaro Fifty event. From a flow vs. delta P standpoint, it goes stock, then GM PP (Borla), then NPP while bypassing (in terms of lowest deltaP at high flow). However, he mentioned there was such little difference in power with the GM PP and NPP setups, that they would only be advertising the pressure drop and sound benefit.

This is one reason I was hoping NPP would be optional on the upcoming 1LE (in addition to the Recaros).

[jdasnt3]

A wonderful noise maker.

[bluerayone]

For the Corvette GM cited a 5hp gain with NPP over a stock exhaust setup. I have not seen any such HP claims for Camaros equipped with NPP.
There is also an unanswered question here, what is the power output on NPP system with flaps closed. The simple answer would be 5 or 3hp less; I'm not so sure.

Someone in a corvette forum posted their RWHP/TQ numbers from a Z06 Vett equipped with NPP showing two pulls: valves open and closed. The closed pulls showed a big drop in power, HP/TQ (45-50 hp loss).

If the Dyno test is to be believed it would infer NPP is not designed to run on two pipes (valves closed ) beyond start up and modest driving around town. Also NPP is more restrictive than stock when straight pipes are closed.

A few question I had on the above dyno test, since they were using a dash logic device to close the flaps through the ODBC 2 connector and ECU perhaps in overriding the computer they also overrode other variables that impacted performance accounting for such a decrease in power). Another factor, the Vett was SC, surely every exhaust setup has its limits and the more HP I would suspect the greater the exhaust flow and more likelihood they could hit the limit on two pipes.

I am very interested in the poster a few posts back who is doing a couple of DYNO Pulls: open (TRACK) and closed (STEALTH) and posting his results. Regardless of the debate, empirical evidence like dyno result and track sheets are compelling and the proof is in the pudding as they say.

[parish8]

all runs in 6th gear(a8) on a dynojet, damn that is a long pull but it should help once it is boosted.

run 1 open, run 2 closed, run 3 open.

only about 5 minutes between runs, you can see it lost power each run and the closed cut out didn't seem to have much of an effect.

[Richard0nee]

Originally Posted by parish8

all runs in 6th gear(a8) on a dynojet, damn that is a long pull but it should help once it is boosted.

run 1 open, run 2 closed, run 3 open.

only about 5 minutes between runs, you can see it lost power each run and the closed cut out didn't seem to have much of an effect.

Yeah not sure NPP really gained any additional hp/torqe.. I wondered what competitive mode yields vs track/sport.

On an unrelated topic, If the peak of HP if before 6k rpm and peak torqe is at 5200 rpm wouldn't it make sense to shift at 5200-5500 rpms? Why waste time hitting redline if after 6k the power especially torque will drop?

Just one of the things I wondered.

[parish8]

Originally Posted by Richard0nee

Yeah not sure NPP really gained any additional hp/torqe.. I wondered what competitive mode yields vs track/sport.

On an unrelated topic, If the peak of HP if before 6k rpm and peak torqe is at 5200 rpm wouldn't it make sense to shift at 5200-5500 rpms? Why waste time hitting redline if after 6k the power especially torque will drop?

Just one of the things I wondered.

what is this competitive mode? i see the stealth, sport, track, snow. does an a8 have this?

to figure out best shift points you have to look at the delivered tq to the rear wheels. to do this you have to look at the multiplication of the transmission in each gear. you have to shift well past peek tq in 1st because once you shift to 2nd you loose some gear multiplication going into the next higher gear.

an easier way to do it is with a GTECH and see what your g's are through the shifts. there shouldn't be a big jump or loss of gforce between shifts(not counting during the actual shift).

can we even adjust the shift points? today on the way home from the dyno i played with a hopped up audi. i just let the car shift itself and it shifted down way too aggressively into a gear that put it at 6400rpm and then it just hung there a sec before shifting to the next gear. the guy was 2 cars in front of me before my car started taking off. i understand i need to get it in the right gear before hand for that kind of thing.

[Richard0nee]

Originally Posted by parish8

what is this competitive mode? i see the stealth, sport, track, snow. does an a8 have this?

to figure out best shift points you have to look at the delivered tq to the rear wheels. to do this you have to look at the multiplication of the transmission in each gear. you have to shift well past peek tq in 1st because once you shift to 2nd you loose some gear multiplication going into the next higher gear.

an easier way to do it is with a GTECH and see what your g's are through the shifts. there shouldn't be a big jump or loss of gforce between shifts(not counting during the actual shift).

can we even adjust the shift points? today on the way home from the dyno i played with a hopped up audi. i just let the car shift itself and it shifted down way too aggressively into a gear that put it at 6400rpm and then it just hung there a sec before shifting to the next gear. the guy was 2 cars in front of me before my car started taking off. i understand i need to get it in the right gear before hand for that kind of thing.

Ahh got ya.. yeah might be more complicated so I'll just shift at 6k if I want to rip it..

Yes you have competition mode as well. Start the car and once you are in sport/track mode hit the traction control button twice and you should be in competitive mode.

http://www.camaro6.com/forums/showth...mpetitive+mode