2.5 inch system

[DJones]

Anyone got any ideas of what the power limit is for a 2.5 inch system (single box no cats)?

Cheers

[Corey]

Would be quite restrictive, I'm going 3" on my ur.

[caterpillar]

i use the 3" for my ride too ....and the sound too.....AAAAH!!

[Silverboy]

I guess the question was what the limit on the 2.5" system was, not how great a 3" system is

To answer the question: it depends, on bends, construction, silencer etc etc, and how optimal you want it, and when you set the mark on where it has "reached its limits.." .I've seen 281WHP dynopacked on a 20VT quattro with 2.5" system...

[4WheelDrifter]

Here's some wise words from Marco.

IMHO good ID exhaust sizes for various engine outputs could be:

- Ø 62mm up to 310 hp;
- Ø 66mm up to 360 hp;
- Ø 72mm up to 430 hp;
- Ø 76mm up to 480 hp;
- Ø 85mm up to 600 hp;
- Ø 95mm up to 800 hp;
........

[DJones]

Thanks guys - more money.....

[Silverboy]

according to A. Graham Bell and his great book "forced induction performance tuning " the tailpipe and exhaust system for blown and nitrous engines are
2,25: 140-185hp
2,5: 180-220hp
2,75: 210-265hp
3,0: 250-320hp
3,5: 280-360hp

for turbo engines it would be
1,3-1,6litres 2,25-2,5 (in)
2,0-2,3litres 2,75-3,0 (in)
2,5-3,0litres 3,5 or 2x2,5 (in)
on road engines developing 120-150hp/litre, on competiton engines developing 200-250hp/litere pipes sizes 0,5-1,0in larger should be used..

So.. it all depends what you meen by "limit"..

[coupegt]

but the Miltec alot of the user on this board seem to be very pleased with is "only" 2.75" dont know how much power they´re putting out though.

Im considering buying the costom auto craft SS 2.5" system, as the price seems very competetive, only thing putting me off, is im a little worried about limiting my upgrade route with to small an exhaust system.

[Silverboy]

the 281whp engine with 2.5" exhaust was a 3b engine, with stock manifold, 26/27 turbo, stock downpipe, stock injectors, higher fuel pressure and rs2 IC.. not to bad on just a 2.5" system in my opinion.. on a dynopack