I'm considering a replacement for the stock headers & crossover pipe on my '05 LGT. I'm curious if anyone has seen data comparing the same car on the dyno with before & after numbers, with all other factors remaining static. The car is making around 400 awhp & 400 ft/lbs at 20 psi on e85. I've heard an opinion that the car will lose low end grunt for a minimal top end gain. Would, say, a Grimmspeed crossover pipe yield worthwhile results? Or perhaps the header/crossover pipe combination? Anyone care to share their experience and/or side by side comparison data?
I like my Grimmspeed PnP Exhaust Manifold/Crossover pipe on my '04 WRX. It gave me good numbers and my butt dyno is happy. I have no before and after that would be meaningful since I did a bunch of stuff at the same time. Is there a problem with your setup or just a mod itch?
Nothing wrong with the current setup - I'm just wondering if I've left some power on the table using the stock header & crossover pipe setup while pushing this much air through the motor. The more I investigate, the more I think the Grimmspeed PnP manifold/crossover is probably the best bang for the buck. And perhaps just a slight itch...
when you're at that much power, a set of good headers that don't crack will allow more flow to make a few more ponies.