Kosh

Ok, putting dual exhausts on an i4 robs the engine of torque because of too much exhaust flow and too little back pressure. Thats why its safe to stay single exhaust.

question 1: If you have a 3 in single exhaust. Is it equivalent to having two 1.5 in duals?

I ask because I want to put dual exhaust on my i4 accord that has a turbo kit. I have a 2.5 in exhaust right now. Most of the piping is going to be 2.5 in(actually until the axle at the back) Then I want to split it to make it dual exhaust. Perhaps 1.5 - 2 in piping.

Thanks for your thoughts.
Kosh

Fryd_Up

ok, correct me if I'm wrong, but you cant do TRUE dual exhaust on a I4 since theres only one downpipe... but you can do a y-pipe which splits the exhaust from one pipe to two... this is what my cars got factory, but I'm pretty sure that will rob you of power... since your turbo I'd say your best bet is to do single exhaust 2.75 - 3 inch all the way back.

95AccordEXR

sure you can, the exhaust manifold goes from 4 to 2 and then from 2 to 1 right? well, instead of going from 2 to 1, just do 2 all the way back.

this doesn;t apply for the turbo of course, since all four go to 1 then into the turbo. the turbo only has 1 outlet, so for a dual exhaust, you'd have to go from 1 to 2

however, if you got the $$$ you can twin turbo the I4, the outer tqo cylinders feeding one turbo, and the inner two feeding a second. with two turbos you have two outlets and thus a true dual exhaust. why anyone would want to do this I dunno.

Nightshade

2.75 - 3" exhaust is too big

Unless yuou are boosted don't go larger than 2.25 - 2.5 or you lose back pressure which hurts your bottom end numbers.

Kosh

ok, what I was talking about was a dual exhaust setup like the v6 accord'ss or the TL-S's. I guess thats really called a T. Would this T hurt toque on a boosted i4? I guess that is my real question.

I hear most people prefer the single turbo over the twin design. People with supra's remove thier twin turbos for a single BIG turbo. So, ditto, I don't know why anyone would want a twin setup.

Latterz
Kosh

Nightshade

Hmmm...well your comment drifted a bit here but...

The dual exhaust is more of a looks thing than anything ese and doesn't help the car in any way other than looks. It does however add unnecessary weight to the car thereby hurting it in the end.

As for the dual turbo setup.....Singles are efficient and the reason they swap out for the single is because they are usually smaller sequential turbos. If you can have one larger turbo boosting once it is more efficient for the engine and has the potential to create much higher pressure. Besides synchronizing a dual turbo engine in a sequential stage setup is a pain in the ass.