can anyone tell me what's the different between 2.75" and 3" DP?? i heard that smaller DP give your more Torque but you loose a little HP. thanks

 

A quarter of an inch

Seriously, there is no measureable difference in power between the two. You will be limited to 600 HP with the 2.75" DP.

I assume you are considering the Espelir DP.

 

i know that, by the way RRE quoted that. anyway i just wanted to see what people have t say about it,

 

Take a look at this thread:

https://www.evolutionm.net/forums/sh...=inch+downpipe

 

I have a 76mm (2.75 inches) Tanabe DP running into a full 3" exhaust. The car's been flashed and dyno tuned. Power down low is awesome! With the 76mm DP, my tuner told me I would sacrifice a little top end HP for a little low end TQ. The top end is dramatically improved and there is now plenty of usable power before 3k RPM's. The craziest thing though is that the low end torque around 3.4k RPM's is explosive...really explosive. The car is scary quick around town now. If you're like me and like the feel of a power band where torque figures are significantly higher than horsepower figures (like 320wtq and 290whp for example), then the 76mm may be the way to go.

 

any backpressure after the turbo is bad, bad, bad. You will not gain torque by having backpressure after the turbo, but you will lose top end. With that being said, the 3" will produce the same torque but more hp than a 2.75" dp. At power levels around 300 whp or less, I doubt they'd be a measurable difference.

 

3" all the way, eliminate as much back pressure as possible.

 

i really don't think it makes much difference. with my car, with an hks 2.75" dp, consistantly made more tq on dyno days than most cars there that day, those cars having identical mods but w/3" dp. but my car may just make most tq... don't know. i don't think .25" diff in pipe diameter would cause that much back pressure and may actually aid in exh. scavaging... eg. tapered (increasing) diameter exhaust headers to do just that. i am not an expert in thermal dynamics just sayin zall.

 

Just get the 3".

 

Man sorry but do a search this has been beat to Death ...................

 

76 mm = 3.00 inches.

 

Oops...I should have said 70mm.