I know that you have to have a good amount of backpressure for your car to run good but i was wondering what makes you have too little back pressure. I am going to get a full custom exaust (from the headers back) 2.5'' will this still have enough back pressure or will this be not enough? I just want to know what the best setup would be.
Thanks for all input

 

now if you said 3" then it would be a different story. there won't be any loss w/ 2.5", but there will be increased noise levels! what brand parts you gonna get(muffler, Y-pipe, cat conv., etc.)??

 

I wouldn't worry too much if your going to be putting everything back on like the converter, glass pack, and a new exhuast. You'll have plenty of pressure. I don't have any headers, but I've got straight pipe all the way back with the exception of a glass pack in the oem location. It's a little loud but no biggy. I'll do muffler later. Only loss noticed was just a little in low end. I used to have it split in the back, now that was loud!

 

I am going to be getting a custom y pipe, high flow cat.,and i still havent decided on the muffler