My eventual goal is like 450bhp and with the 2.5l and a 321t, the torque should be 450 ft/lbs and over hopefully. I was avised to keep my 2.5" exhaust system, as it makes for a much torquery and responsive car.

 

Personaly I dont think that is good advice. Swapping to a 3in exhaust is a very good idea. Because at the 400plus level you are aiming for the 2.5in becomes constrictive. You can hear it in actual fact.

321t should be 450hp, max torque - now this is a guestimate on my part 470-480ish. Certainly you wont see such a big percentage gap between the power and torque at that power level as you do lower down.

Cheers
steve

 

The advice I was given was from a very reliable source. Also, I know of someones car running around 480bhp on a 2.5" system. I'm well aware that many peolple and tuning companies say 3" for above a certain level, but I'm going with my giving advice.

 

On a turbo car the last thing you need is back pressure. I know 2.5 inch exhausts can run at 500 bhp or getting close to that but this business about needing back pressure for more torque from a smaller diameter exhaust is a complete and total misconception on a turbo charged car.

 

Not sure on the protocol regards quoting myself

the above is the mods an power etc for my car as it stands.

What torque is a VF28 capable of putting out?
Im thinking about a Hybrid gt FMIC or an Sti 8 TMIC conversion then a remap an was wondering if I left the spec as is only changing the intercooler would the torque gain be worthwhile? I realise the turbo and injectors are probably producing as much reliable power as the can at 334bhp. its torque im after.

Or do i need to consider a full decat, ported headers an up pipe to get the turbo spooling quicker to raise torque? I have a set of magnex headers in the garage an was going to sell them........

sorry if ive hi jacked the original post

 

Well my tuner said that he got over 500 Nm (about 370 ft/lbs I think?) from my car on E85 but restricted it to 460 Nm to spare the gearbox and rods. 460 Nm on Vpower.