Here is a comparison of turbo's I have run on my my car I started out with a vf34 and then got a PE1820 clone (Deadbolt vf22) right now I have a 20g but that is about to change. The vf34 was run on pump gas the other turbos were run with 93 + meth. A front mount and headers were also added with the 20g. I am sure that added some to the lag. The curve keeps getting higher but sadly is moving to the right. The PE1820 on a 2.5 would make a kick ass autocross car. It spooled as fast as the vf34 but made quite a bit more power.
Very impressive. What kind of numbers you shooting for with the S turbo? Can it be more than the 20G? Any plans on running meth inj. with the new setup?
I don't know. It keeps moving Hopefully it will be pretty close to 500 with the S and meth. And with a 3" exhaust hopefully it won't drop off as much. I was going to sell the meth kit but I think I would give up at least 70hp and would have to run race gas to get it back. A meth habit is a lot cheaper than a c16 habit so I am going to keep it.
Do you think the 2.5 exhaust is the only reason it is dropping off so much? I am coming from a the NA world where the tapering off usually means header restriction or heads restriction. What engine set up are you running currently?
If he's still running WRX heads, those will be a bottleneck at higher HP goals. This is a great comparison for reference on turbos on a 2.5 swap. Do you have 1/4mile times for each setup?
The restriction is a combination of heads and exhausts. I am trying to find a 3" catback to eliminate the exhausts portion. Built heads will have to wait a while. vf34 13.02 @ 108 1.78 60' pe1820 (no meth) 12.72 @ 111.11 1.72 60' pe1820 (meth) 12.40 @113.3 1.73 60' 20g 12.33 @ 115.27 1.92 60' I only had 4 runs on the 20g and in between the pe1820 and the 20g I added a 6 speed to the mix. Better shifting and a 1.7 60 and I would have had 11's on the 20g.
I would think that some free flowing headers, some port work could really help the top end quite a bit. Again this is from my NA experience. I had the same issue on a 63 Chevy II SS and some long tube headers and port work to the heads really helped things out. The other thing I can think of that will cramp things is the intake. At some point the turo will e able to shove more air through the engine than is possible. Again some port work or an intake swap could proably help. Throttle body, same thing. This is, after all, one ig air pump. I read a comparison on a supercharged mustang where they actually compared upping the boost with making it flow better. First they upped the boost by 5 psi. Did a dyno recorded everything. Next they swapped out the headers, CAI intake, heads with ported and polished models and throttle body. They were actually able to make 50 more hp with 5 psi less boost. Their findings were that by making everything flow better they did not have to boost as high...same compression , everything else the same.