i have a hks carbon Ti muffler that has a 3in inlet and i dont want it to go to waste, there is a shop in the area that can bend 3in as well, and im planning to boost very soon, but one of my friends said " isnt 3in a little overkill even with a turbo??" well thats why im here, can the hahn stage 2 make full use of a 3in and what knid of power loss am i lookin at until i get boost??? i need help ASAP b/c if the 3in is gonna really kill my ponies then ill just use 2.5 and put a converter just before the muffler to go up to 3 but if its not gonna suck that bad then ill just suffer with a little less go until i get boost, not to mention i know skwirl has a 3in and he's N/A, i dunno please help and quick.
many changes in the making
my favorite part about doing bodywork,.......... bondo bugers
3" for N/A is overkill. I run 2.5" and even that is pushing it. 2.25" is more widely accepted as the perfect size for a relatively stock engine with jsut bolt-ons. Once you go boost, yeah 3" is great. The more you uncork the turbo the faster it'll spool and the happier it will be. I have an HKS muffler off a JDM Silvia exhaust that I had weld to my 2.5" with an expansion fitting and it's fine. That way I can use the same muffler when my turbo goes in, which will be 3" fromt he downpipe back.
well what kind of power loss are we talkin here??
many changes in the making
my favorite part about doing bodywork,.......... bondo bugers
It's not really power loss so much as it is a lack of torque. The engine will in all reality make the same amount of power, it jsut won't be able to use it. Running 3" pipe on this small of a motor N/A takes away a lot of exhaust velocity needed for scavenging and what not. It'd be about as bad as running the car open header. For a turbo it's fine because of how a turbo uses that exhaust energy. For N/A engines it's a different story. However, you can get away with 2.5" pipe with the engine the way it is now, and then keep the 2.5" when you go turbo. For a street car, even boosted, 2.5" would still work given the turbo is sized properly.
