3in exhaust to small for 6765?
i thought the same thing at first but it doesnt seem like like valve float. when i turn the boost down to 28-33psi i the surging goes almost completely away
I thought the same thing but why would the turbo surge if theres valve float? i ran 40psi on my 6262 and never had a surging issue and i was reving the car to 9k
I say just try it and report back with the results! 
Every car is different... just because the Supra benefit from the 4" doesn't necessarily mean our cars will too. If you're trying to suck out every last horsepower then try out the 3.5" and see what happens. Try an exhaust with less bends...
Every car is different... just because the Supra benefit from the 4" doesn't necessarily mean our cars will too. If you're trying to suck out every last horsepower then try out the 3.5" and see what happens. Try an exhaust with less bends...
Correct. This has been tested to death by me and others. I know that corking it is never the answer. Just because you "can" run 3" and make 800whp doesnt mean its the best way to go. I know that at 660whp and 26psi I started losing power the more boost I added on my 3.5 when I changed from a straight pipe more or less to a 3.5" Magnaflow muffler. I added a 60mm dump on it and the power came right back.
After I complete the LS2 coil swap I am going to a 3.5" exhaust starting ~8.0" off the turbo and my ultimate hp goal is 600hp@wheels. Even though it can be done with a 3" exhaust it is a question of efficiency.
A quote from the previous article provided...
While many turbo cars out there use 3-inch exhausts, we've proven that a hefty amount of horses are left in the stable when doing so. In fact, with just the 3.5-inch rear section, 20-whp gains started as low as at the 300-whp level and kept climbing.
A quote from the previous article provided...
While many turbo cars out there use 3-inch exhausts, we've proven that a hefty amount of horses are left in the stable when doing so. In fact, with just the 3.5-inch rear section, 20-whp gains started as low as at the 300-whp level and kept climbing.
Evolving Member
Joined: Sep 2002
Posts: 198
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From: Italy
As personal experience i can say that, swapping from a 3.5" complete exhaust to a 4" shortest route, on my evo with a BW s400sx 76 mm ( about a gtx45R ), i gained 60 hp and 480 rpm of spool, a surprise for me..... As note, the tuning past 5000 rpm had to be modified a lot, but gains are great, only downside is that a 4" short exhaust is really loud, i don't think it's possible to run it on the road.....
