update - just ordered Asura Exhaust and have decided to increase my boost so no doubt will I increase HP



So I currently have a 60mm exhaust and Minitoyota will be building me a custom 3" with two mufflers, plus recirculating my wastgate as it's open now. So what do you think my power increase will be after my retune. I'm hoping to get over the 500hp mark without increasing boost. I should also note I'm running a IP 3mm hg, 1000cc injectors, 255 walboro.

 

i wish i could get my wastegate recirculated

so you're pushing around 426 with a 60mm...i'm sure with a better tune and that bigger exhaust you should be closer to 460-470 i assume.

But just remember when welding that dump toob into the exhaust and recirculating, your gonna lose power again.

i'm a lil confused on the graph as to why its not so smooth.

 

I bet you gain at least 30 hp..

 

It depends on the tune I'd guess 30hp+. I have 255 fp and 1000's also. The fr manifold and 3" exhaust is a good combo for power.

 

im kinda hoping to break the 500hp mark sounds like that may not happen on 15psi....tempted to go up but also longevity

 

ur not gonna gain 75whp on a 3" exhaust upgrade and a recirc of wastegate downgrade. you may gain 20whp thruout rev band at best. your gonna need more boost.

 

I'd really like to see the end result. Your the only other person that I can think of that has an equal length, GT30R, and a 3mm on an AP1

 

With a recirc dump and a much less restrictive exhaust, you'll probably make another 10-20 hp at the same boost pressure. Maybe more depending on how much timing is added and if you can increase wastegate duty cycle at higher RPMS (if it starts to drop PSI). Also, how far down the DP and at what angle the dump is recirculated into the downpipe will have an affect on power. Honestly, if you are getting a loud 3inch single exhaust, why recirculate the dump? It seems illogical to get a 3inch exhaust and then throw the dump back into the downpipe. I don't see how a external dump will make a 3inch single any louder than it already is.

 

I'm actually going with a 3" dual, and the hope is that it's not going to be too loud. Jeff seems to think he can make it so it's not that loud, but it is obviously going to be louder then what I have now. I'm pretty dissapointed with everyones guestimates. I was really hoping for a big increase in power.

So how about taking things the other way, any guess what my power would drop to if I kept my current exhaust and had the wastgate recirculated into that?

 

theres a thread somewhere in FI where deadzero went to a 3" dual. he went from 580ish to 616ish. your not gonna gain rediculous power upping the exhaust. but the more power you make, the bigger the gain it will give.

but recirc will just kill power, and kill spool. DONT DO IT!