fast lane

I was told that the car stopped gaining power at that point and after the install it gained power through 6000 rpm.

Coochas

That's odd. The owner's manual shows the HP increasing close to redline.
Believe me I do appreciate your taking the time to do the experiment but I think that your mechanic really should have dynoed the engine to higher revs to make this more scientifically sound.

fast lane

I agree it's odd. All I can really say is that the extra hp is very noticeable there is a night/day difference with the car. I'm very happy with the system. As far as the dyno goes I really don't know how to explain it. Just relaying the information I was given.

Pugnacious

The fact that you are happy with the results is all that should matter.

However, when I look at your dyno results I see a net loss in both torque (close to 30 ft. lbs.) and hp after the modifications from 4,000 rpm to around 5,500 rpm where the pre-modification run stops. I can’t explain why he would stop the first test at around 5,500 rpm but even the post modification run shows a dip in hp at that rpm; but the simple fact that it does stop at 5,500 rpm means that that dyno run is meaningless as to peak hp differences. The only part of the power band that was improved was from 3,250 to 4,000 rpm and those are nice improvements in the lower part of the mid range but the rest of the power band is worse off.

gpjli2

Just catching up with this. I have noted the fact that blipping the throttle is more difficult. To me it seemed like the throttle mapping was off but it may just be a lack of responsiveness. The loss on the low end caused by the headers really bothers me. Where the engine would break the rear wheels loose in first, it now hooks up. While that is not a problem it does give you an idea of what is going on in terms of bottom end. The car seems to pull on top, but that may be the result of the losses below. To be honest with you, I am thinking at this point that Porsche knew what they were doing with those crappy looking, short primary tube, uneven length headers. There is a big danger in "gaining x# of hp" at a given rpm and not looking at the big picture.

Chris C.

Without diving too deep into the numbers, I would say this speaks to the need to buy a tuned system from one vendor designed to provide better all-around performance - headers, exhaust and intake combined with software, optimized to use the high flow cats.

Getting a high peak horsepower is great if that's where you use your car's power delivery and if that's what you were seeking.

gpjli2

Let me advise the board members that Chris C is my son and he is using my distress as an opportunity to post a picture of his new GT3 Looks beautiful Chris. You have yet to tell me when I can expect to drive this beast. Btw, I have an exhaust for you..........

gpjli2

To follow up, discussion on other forums indicates that these sort of losses are inherent in exhaust mods. To regain Tq and readjust HP curve it is necessary to reflash the ecu. Either that or replace the oem system. Gerry