I know mandrel is better but my said he could do a 2.5" header back for 150 bucks, single with a apexi n1 muffler. Problem is he would have to press bend it. Is press bending that big of a flow difference where more than 5hp is affected?

 

you could ask if he could cut sections of pre bent pipes and weld them together instead.

 

If it is not mandrel, then you are throwing your money out the window. The stock would be better. There are some great examples of the reduction in flow from this on the web.

 

but with just little bends would it matter that much? like the biggest bend would be 35 degrees

 

first of all if it's press bent it's not going to be stainless. Stainless has a rockwell hardness of 87 and can only be mandrel bent. First reason why OEM would be better.

second of all, you're going to be reducing flow by a substantial amount. OEM 2 3/8" piping (before the y-pipe) is mandrel bent very well and is nearly the same as the original piping diameter. Again, OEM would be better (up till the y-pipe in this case). The two 2" pipes are bent very well as well.

You're far better off buying 2.5" Stainless mandrel bent sections, cutting those to the correct angles, and welding everything together. u can find them at www.verociousmotorsports.com.

Either make the whole thing out of new stainless piping, or if you want to make it easier on yourself and save some fabrication money, cut the OEM before the y-pipe and run a 2.5" stainless section out to a single muffler.

Crush bent (approx 35-40 degrees):



Mandrel bent (about the same angle):



much better flow, don't ya think?

 

quick google search brought this up:

http://www.bobsmuffler.com/dyno.htm

 

sharptech..checked many duals and i didnt like any one of them as they made much less power than single..

so i thought to my self..spend a shit load of money or spend 100 bucks for a custom?

I went for a custom with an HKS hi power muffler..did it as a header back type..theres only 1 small bend and for the sharp degree's i have cut and welded an arm ( as we call it here)

its light and has great flow although pretty noisy but alot better than my ex dual or any dual i have driven...plus i didnt want to spend much so i went for a custom if you dont want to spend much go for it but first check if the place you wanna do it in is a pro and not just any noob with pipe bending machine.
from what SoCalIsMyLife posted thats a really bad bend that is not worth to bother with, so check with the garage first if their good enough, i got a pic of my custom if your interested let me know ..

 

304L Stainless is only $11/foot for 2.5" OD, $15 for a 90 degree bend, will last you much longer, looks better, and has a much higher resale value should you decide to get something else later

 

Excellent illustrations, thanks guys.

 

you should buy one of Socal's exhausts