exhaust systems

[philthepill_389]

would a twin back box system like 2x 3inch back boxes either side make my car run **** or lose bhp compared to 1x 3inch back box


thanks

[loggyboy]

Back box alone will make sod all difference. maybe 0.5 bhp either way.

[big gra]

i noticed a big increase on my 1.2 when i changed the backbox from standard to a cherry bomb, but a twin exhaust will make no difference to a single!

[loggyboy]

i noticed a big increase on my 1.2 when i changed the backbox from standard to a cherry bomb, but a twin exhaust will make no difference to a single!
I dont believe you, its called the placebo effect.

[Adam]

Lol, are you sure it didn't just "sound" faster

[philthepill_389]

sorry i worded my post wrong i have a 1.6 8v gsi with a full 2 inch 1 box system 4 branch cam etc etc running 120bhp proven. i have been wanting a dual system on my nova as i seen a cavy gsi the other day with 2 x3inch back boxes and it looked spot on i was just wondering will it make my car lose bhp adding another back box

thanks

[philthepill_389]

so dose any one know if a dual system will make it lose power

[Sirnixalot]

dual exhausts on anything but a V engine or less than 6 cylinders is just extra weight.

there are some packaging exceptions mind you.

Dual exhaust on an inline 4 = ghey

as for loosing power it depends on how the split is done, if its like a Y then you might lose a little low end, if its done like a T you will lose a little from the whole rev range.

by the way the 3"/4"5/" measurment you are quoting is the diameter of the tip which makes no real difference, the diameter you need to pay attention to is the inlet and interior pipe diameter

[Stuart]

if its split more than say 2 foot from the end of the manifold then its going to make NO difference.

[philthepill_389]

i know the size of the tip dont make a differance. i was just saying i seen 2x 3inch boxs on the cavvy. my system is 2inch from block to start of the back box with 1 3inch sports silencer with a 2.5inch back box with a 3 inch tip.

so stuart if i split it say 5 inchs fron the 4 branch and run 2 pipes dow the car it will be fine

thanks

[craig green]

They arent 3" boxes. They are 3" tailpipes.

The tailpipe will make next to no difference. If you want tailpipes at either side of the bumper, then a split system may well decrease the power output. Its not ideal nor is it a performance benefit. (Therfore Chav)

Best left to Mondeos.

[Stuart]

just run a std system to the back and split out jsut before the back box...