Actually, a 3" system sacrifices a little low end for an extra tic or two on the top end. So an entire 3" system may not be his answer if he's looking for quicker spool-up and less lag. Now... a slightly smaller dp with the rest of the system being 3" could work.

 

That's only true for a N/A vehicle, which uses some exhaust back-pressure to create low-end torque, but with a turbocharged car the benefit of expelling the gasses as quickly from the turbocharger as possible via 3" piping which greatly decreases spool-up time far outweighs any benefit of a little bit of back pressure. Back pressure just slows down the turbine which is neither good for high-end HP OR low-end torque. I'd definitely go 3" all the way.

 

I know-I know............ I've heard Garret argue this a million times over... BUT I disagree from my experience........ not that it's a huge difference... and I agree that this is more applicable for N/A vehicles.... but it still plays in on a turbo car. I've driven both (smaller vs. larger dp) on numorous occasions and can DEFINITELY feel the difference.... being that the 3" dp causes a tad more low end TQ loss... but with a little more at the top end as a tradeoff. This point has been argued MANY X before so we should probably just disagree and be done with it.

 

No prob.

 

Well it's a moot point because if you wanted a car with superfast spoolup you shouldn't have bought a car with a 16g on it. Didn't you test drive it first?

It's a high-powered turbo car. If you have no lag, you have no turbo. Easy as that.