pt76jon

Hey I was just wondering if anyone could tell me where i can get a 5 inch to 3.5 inch exhaust reducer for a downpipe. I can find 5 - 4 inch reducers but cannot find a 5 to 3.5 inch anywhere. The turbo that I have is a gt4788 t6.
Or do you think that 3.5 inch is not enough to support 1400 crank hp?

Thanks

smokinHawk

iTrader: (48)

you probably will have to get a 5-4 then a 4-3.5
for 1400 crank hp id go as big as i could, as it will be easier to make the power, then to restrict the exhaust

IMD

iTrader: (10)

3.5 is way too small. it will work...technically, but at that hp level, you're probably leaving at least 50 hp on the table.

bgblockelcamino

iTrader: (9)

i have used exhaust tips for reducers before they are cheaper and have more sizes just a thought

Drew04GTO

iTrader: (1)

Dr. Gas makes a 5-3.5" reducer if you're stuck with space limitations. I agree though that you'll be leaving power on the table, I'd go 4". Switching from 3.5" to 4" will be an increase of almost 630cfm (estimate). There was an article a while back in Popular Hotrodding on exhaust tech and according to them 1sq in is roughly 215cfm capable. You need 2.2 cfm exhaust flow per 1hp according to them for a 0 loss exhaust system, 4" is a bit small for your needs if you follow their guidelines.

*edit* Just looked at that GT4788, just because on the outer edge of the compressor map itll flow 1400bhp worth of air doesnt mean youll be making 1400hp. With a 4" exhaust you should have enough exhaust flow for everything that turbo can throw at it.