I am pretty sure this topic has been discussed before, but anyways this is my situation. Currently i am running Injen SES on my Z 5at, matter of fact i have only three mods..Stillen intake, Crawfordz HFC & offcourse the injen exhaust. I have this exhaust for last 5 month to be honest i love the way it looks & sounds. But ever since i got this exhaust it totally took away my low end torque. I already spoke to Injen according to them there exhaust is made for h-end torque. And so, now i am thinking about getting rid of these exhaust and perhaps get the HKS H-power Ti

Therefore i now need advice do you think it's a wise decision to sell the Injen & get the HKS because my main reason of getting a new exhaust is simply trying to gain low end torque.

 

you lost your tq because you don't have enough exhaust back pressure. the injen 2.5" TD flows too much for the mods that you have. if you go to another 2.5" TD exhaust, you'll have the same problem.

get a piggyback ecu and get your setup tuned.

 

I would be interested in seeing the before and after dyno charts. Thanks.

 

Did you swap out your 3.2 for the 3.5 final drive ? best mod to make up for the low end tq loss in the 5at after opening up the exhaust, and if you do not plan on going F/I sell the 3.2 and get your money back for the cost of the 3.5...after all was said and done this mod only cost me $150.00... it was very hard for me to keep the tires from spinning all the way thru first gear and part of second, but the more you drive, the more you will learn how to launch with minimal spin...and +1 on the tune.

 

High back pressure is detrimental to power. The reduced exhaust velocity due to the oversize piping is what killed his low end. Typical low end (cheap) systems lose power because they simply up the pipe size. Quality systems which have the R&D behind them flow better, have less backpressure, and make more power. Having said that, I will admit that for our cars and pocketbooks, we have to accept compromises.

 

Your mods are not major, and you may like the Fast Intentions exhaust system. You wont loose bottom end with the system...check out the dyno's and reviews from those who have bought it on this and the G35Driver forum...

www.fastintentions.com

Rick

 

Oh I see.