Thread: Which down pipe should I get?

Originally Posted by bluegtp91

True, N/A cars probably don't NEED a 3" Downpipe...but is it going to hurt? No.

False. Exhaust velocity is what gives you the scavenging effect, giving you a lot more low end. Too big and you may gain on the high end, but you end up with no low end to get you there. The exhaust system needs to be balanced, which is why saying that every car should run a 3" DP is just ignorant.

Originally Posted by Ragefear

thank you! Someone who understands and doesn't insist on just throwing the biggest exhaust available at the car.

An exhaust that doesn't scavenge is a motor that has to work harder. Depending on the type of boost and how much, it still can be a factor.

I don't insist on throwing on the largest exhaust available. I understand his side of it. I am just stating that it is all personal preference...up to you whether you want a bigger downpipe or not...the market is there and you can buy it if you like. If you don't want to harm the back pressure of your N/A car then get a 2.5".

BTW...there was no Boost...we were talking N/A's last time I checked...

Originally Posted by Scimmia

False. Exhaust velocity is what gives you the scavenging effect, giving you a lot more low end. Too big and you may gain on the high end, but you end up with no low end to get you there. The exhaust system needs to be balanced, which is why saying that every car should run a 3" DP is just ignorant.

Just wondering...so you're telling me if you were to line up 2 GT GP's one with a 2.5" DP and one with a 3" DP...you're saying the outcome would easily be in the favor of the 2.5" DP'ed GT? I honestly doubt that your velocity claims make THAT much difference. The Torque the 3" DP guy loses from the larger Dp will make it up with less wheelspin. Same concept with a GTP with headers vs. a GTP with PEM's. Go test it and I'll side with you on your theory...

Some people would like more top end, others want torque. It is based on personal preference anyways IMO.