under or over diff exhaust.

[Apolan]

lets talk abot the width of the exhaust too.. what would be best suited for a stock to moderately modded 4a-g? 50mm? 2inch?

[JonAE86]

I plan on running headers, then 2.5" exhaust. Will be building and tuning my other engine to put in it later, dream about 180 horses.

Over the diff is better for me i guess, since we have lots of HUGE speed bumps(read mountains) and bumpy roads.

[lasse]

speed bump, and underdiff exhaust, should not be a problem, because the lowest part on the exhaust is where the wheels are. the ground clearence will be the same as youre wheel size. does this make any sense at all lol
I am going for a underdiff exhaust, it is much easier to make, and it has a better flow.

i stole this pic from another tread muhaha.
http://i22.photobucket.com/albums/b301/b..._01672.jpg

Lasse

[Denmark]

I was just last week looking at a rallycar here en Denmark,and he had made a 2,5inch overdiff,that had no problems hitting the diff or anything,

This is what i will make for my silver AE86,then when you have to take the rear aksel down,i dont have to take off the exhaust.

My car will not have over 350 hp :wink: ,so the flow issue is no problem for me,maybe you what a lot more Lasse


Regards,
Skassa

[lasse]

Denmark Wrote:My car will not have over 350 hp :wink: ,so the flow issue is no problem for me,maybe you what a lot more Lasse


Regards,
Skassa

But a underdiff exhaust looks cool lol


lasse

[Denmark]

Yes it does.

I had it on the red one,but that was mostly , becourse it was easyer to make a underdiff exhaust


Skassa

[Ivan141]

Just remember that 2,5" is overkill for NA 1.6 engine's....for turbo it is perfect.

[JonAE86]

Ivan141 Wrote:Just remember that 2,5" is overkill for NA 1.6 engine's....for turbo it is perfect.

i know.

But when you can only get made exhausts with press bends, you go for slightly larger cuz the bends get crushed a little.

There is no1 here that can make mandrel bends for the exhaust.

Going for 2.5" exhaust = getting ok bends, about 2.25" i guess.

Going for 2.25" exhaust = about 2" bends

[NoHachi]

Jon, dunno, but you could try and use the following trick that we used to use for our dyno-exhaust setups..Instead of dropping the money on expensive mandrel bent pipes, we would just grab a piece of pipe, weld one end closed and stuff it with sand. The whole thing would go into the bending machine and we would heat up the outer curve section of pipe with a simple gas-torch.
While not exactly mandrel bent, the end result was good enough. Maybe 1% less performance then true mandrel bent.

[AEsuperG]

my first under diff exhaust i just took one pipe and cut and welded. the bends were never less than 135 degrees. and there were only two bends. turned out fine. until some jackhole sawed off my APEXi muffler and ran away.