2.5 inch open downpipe comparable to 3 inch downpipe full exhaust?
 

Finishing up my Stock turbo GSR, ramhorn Garrett t3/t4e 57 trim, blah blah, nothing you guys haven't seen before. I will be retaining AC, so I will be using my 2.5inch downpipe. I plan to run this open underneath the oil pan during events, so I was wondering if this is comparable to a full 3 inch downpipe/exhaust? Will I see any significant difference?

Power goals are 330whp. Thanks guys!

Re: 2.5 inch open downpipe comparable to 3 inch downpipe full exhaust?
 

for 330whp, no real point. what about just running a 3" downpipe with an e-cutout instead if you want to make all that noise?

Re: 2.5 inch open downpipe comparable to 3 inch downpipe full exhaust?
 

UOTE="TheShodan;49449]for 330whp, no real point. what about just running a 3" downpipe with an e-cutout instead if you want to make all that noise?[/QUOTE]

The 2.5" downpipe is going to connect to a 2.25 fujitsubo exhaust for daily driving. During track events I plan to run the downpipe open because I already have a 2.5" downpipe that fits my setup. Don't really want to make "Noise", but was just wondering if running an open 2.5" downpipe would be comparable to a full 3" setup powerwise

Re: 2.5 inch open downpipe comparable to 3 inch downpipe full exhaust?
 

Also, I've ran electriccutouts in the past and they've always broken within 2-3 months daily driving. I'm gonna connect the downpipe to an exhaust using a test pipe and will remove the test pipe during events to open up the downpipe

Re: 2.5 inch open downpipe comparable to 3 inch downpipe full exhaust?
 

My meager contribution..as a mere layman;

I remember at least one thread with , Iirc..dyno results, testing different downpipe sizes and I think some exhaust variation.
Of course the gains will vary at different power levels and turbos surely,
but I can't qoute the results.

"significant?" will depend on one's definition I guess.