What do you want from it? Power, noise, looks? for me it's the 3" as it looks better and I'm running a 3"decat too
I have 3" turbo back, sounds great loud outside but I am inside so not bothered The smaller one is ment to be louder
Sorry to hijack thread but does anyone run a full 3" straight through system? Going to get a custom exhaust made up and would like to know how this would sound. Cheers
You dont need backpressure on a car. The idea is to get rid of the gas. Pressure will be created in the exhaust manifold before the turbo anyway.
Hmm..Ok. Ive always used 3" straight through stainless systems that have been custom made. Il ask the guys at the centre whether a box will be needed, wouldnt be too hard to drop one in if im loosing power.
What Renault with the F4R have zero boxes? Try to test one with one rear box and another with NO boxes....In a dyno or loggin. You'll see the diference especially in midrange rpm.
Less back pressure will decrease spool time - hence why a decat car the turbo spools quicker. Do you have any traces to compare ?
On a turbo car lower back pressure post snail to increase spool time. The theory of back pressure needed is a non starter. Why wouldn't you want to get rid of waste gas once it has passed the useful turbo area? What purpose does it achieve ? The only reason I can work out for not having zero back boxes is noise. However , having said that I am unsure of the pulse from the meg downpipe which might affect the output which is what mr RSRacing was talking about. Without back to back traces being overlaid tho ?
I have a 3" turbo back straight through k-tech system, it can be as quite or as loud as you want it to be, on a steady run its quite quiet but as soon as you hammer it its really loud sound nice!
Was talking to the exhaust guys yesterday and he said that most of their race exhausts that they build are full 3" turbo back exhausts with NO boxes, sometimes a backbox depending on what type of noise the customer wants. Will be going to get mine done in March after the MOT then will get a Decat, should be loud and a bit more powerful
I was thinking about the custom route as the company near me has a very good repuation and their price's are very good. I was looking to go towards a 3" turbo back with a sports cat, and probs resonated as I had a non-res 3" inc sports cat cobra exhaust on my VXR and that was stupid loud. It showed subaru's up sound wise lol :cool:
