that is the exact Y pipe i have john BUT, it is not stock... i dunno if it will matter but it came with the greddy exhaust and when it did i installed the greddy Y-pipe. the greddy evo II is a 3 piece exhaust 2 canisters which bolt up after the axle and the new y-pipe which bolts up at the b pipe i think its called

i didnt notice much a little rumble but not much else till i got my exhuast leak fixed then the butt dyno showed some improvement....i wasnt looking for alot though

when you say "IT may cause some low response"are you thinking i should pick up some low end then?

 

The Greddy "Y-pipe" shown is not the FIRST Y-pipe. The first Y-pipe is the critical one from the catalysts to the single center pipe. After that point you could use a single exhaust or use another Y pipe (such as the Greddy or the stock one) to split it back into duals. Again, it is the FIRST Y-pipe that I have been discussing and is what I am referring to when I say STOCK Y-pipe.

What is important to understand is that for MOST of the RPM range of the engine the stock exhaust is BIGGER than necessary for the VOLUME of flow.

PEAK flow is 300hp that requires flowing 300hp of exhaust volume. This is at +-6000rpm. Peak torque of 310tq occurs at 4000rpm and that equals 236hp. So, at 4000rpm the exhaust is flowing about 80% of its flow at 6000rpm. At 3000rpm it is only flowing 166hp or 55% of the exhaust capacity. At 2000rpm it is about 30%.

This flow is NEVER smooth. It is non-stop pulsing with every exhaust cycle of the 8 cylinders. Each pulse creates a pressure wave away from the engine in the exhaust system which is followed by a pressure rebound wave back towards the engine when each pulse ends.

What is wanted is a system that allows EACH pressure pulse to move easily away from the engine while limiting the rebound pressure wave back towards the engine. Small pipes, velocity, catalysts, collectors and more tend to do this. Larger tubes and removing parts lowers velocity and makes it EASIER for the rebound pressure waves to return to the engine. This reduces power and response. Of course too small or restrictive of a system will limit peak flow and hurt peak power.

The factory Y pipe has a specialized design that allows peak flow but restricts reverse flow.

 

OHHHHHHH ok, now i gotcha. thanks

 

^100% agreed. oem-sized exhaust components are plenty adequate for a car with even mild to moderate engine mods. It's not until you are really pushing more CFM into the engine (i.e. turbo or supercharger) where then it REQUIRES larger exhaust components to properly expel the exhaust due to the higher output of power.

 

The way Im starting to look at things is like this how much time do you spend down low vs mid n upper rpm range after launch might be a worthy sacrifice if there is more mid to upper just my opinion.

 

Hey airbender is the car running any better? Does it still feel like its missing at idle?

 

It's alot better today at a light the rpm bounce on me again but this has nothing to do with the install It happenend before once or twice only after tm plugs I'm going bck to ngk still not what I expected but maybe because I'm not stock I think if I can accomplish a tune it will make up what I'm looking for .

 

Nice...any dyno figures yet?

 

Anyone else installed theirs yet? Mine is coming soon, but I can't install it due to other projects.

 

Why not run the stock Denso iridiums? Mine still looked ok after 160k miles.

 

well i got my headers in....it appears some slag is around the O2 bung and it looked rough so i took a file and smoothed them down, one place in one of the tubes has some minor slag to i wonder if it will affect anything?

 

Nice! I'm jealous. Now get to work, install them and make a DIY.

BTW got any more pics?

 

who and how do i order theses lookin for the y pipe also, please PM if u can help thanks

 

Since groupbuy is over, you'll have to buy them at regular price

http://www.ppeengineering-onlinestor...?categoryId=32

 

Well my dyno is off until i figure this out got my first engine check light on the car here are all the codes (p0441 evaporative emission control system incorrect flow detected) (po446(pd) evaporative emission control system vent) control circuit po455(pd) po455 evaporative emission control system leak detected large leak and p2418(pd) undefined code.