Exhaust size question

[EVOCPE]

1 of my mates is wantin to get a full exhuast system on his DAILY 63T powered GSR but doesnt know what size, 2.5" or 3"

He doesnt track or race the car, he just wants it to have abit more "GO"

At the moment he's running a 20G turbo, EVO1 dump pipe and running 1 bar boost off a chipped ECU, 720cc inj, Walbro pump

I notice all the aftermarket dumps these days have 2.5" outlet, so would it really effect the performance much running a full 2.5" zaust + high flow cat (staright as posible to the back)

Only asking is the workshop he usually takes the car do only has a 2.5" bender, and the other workshop can do a 3" system but quoted him $1500 for complete system including cat, resonator and muffler

Does anyone know what size the EVO1/2 dump outlet is and what size the EVO3 outlet is?

I searched the forum and havnt seen anything posted about this

And if anyone is using a 2.5" system please let me know how the performance is like and power

 

[khubner1]

not sure man i got mine done in 3" from the std dump back. i have heard somthing about as you step up to larger pipe dimensions you have a scavenging effect but how much or if this makes any difference im not sure.

imo i'd go with whoever offer the cheapest. as on a street car the difference would be bugger all

 

[CYBORG-X]

the evo 3 dump is 2.5in outlet, but can be opened to 2.75in by porting the outlet.
for the 2ltr you will only need 2.5in system, but im assuming your friends exhaust shop has a press bender which is bad =( he needs mandrel bent in 2.5in and straight through mufflers for the best flow.

the factory exhaust is 2.5in (evo) but its press bent and poor designed for max flow

 

[BMGTZ]

I have a 2.5 inch mandrel bent on one car.....and a 3 inch mandrel bent on the other. They both have similar tunes now but the 2.5 has 18 psi and eats the other car easily as it runs stock boost....what ever that is

2.5 in =evo two engine and all hardware

3.0in = evo one and all hardware.

with the 2.5 boost seems a bit earlier

 

[7zark7]

I have a full S/S custom 3" system from the turbo, high flow cat (flanged so I can de-cat ) and an X-Force cannon with 3" inlet and 5" outlet. It cost around $1000 mark but i admit that was "Mates-Rates".
Best thing I ever did

 

[lozza]

I don't think 2.5" offers much of a reduction in power and torque at that mod level. But it would be best to get 3" now for the little extra to allow for mods later when you will need it.

 

[forged93]

from what my friend's experience, by changing to full 3inch exhaust system may suffer at low rpm... however, the feel / power at mid n top end rpm is definitely better... and as what you mentioned, 20g (assume that the turbine wheel was changed / bigger too) in the set up.... thus IMO, 3inch should be better and of course... future for upgrade too... :thumbsup:

 

[Gianni]

^
I've got 3" on mine. Still need a tune but I'll let you know what we get. Hopefully next weekend

 

[EVOCPE]

Its all goo. We all know what 3" exhaust can do. Was just wondering if anyone had a 2.5" and what power

I think we just gonna go 3" with a quiet muffler