Tim's Evo 9 SE build. From Stock to 2.2themoon
Watched 2X
Feb 24, 2017, 04:06 PM
#77
Tomei Version 2 downpipe going on in the next few weeks.
Its a 3" DP vs the 2.75" Version 1. The 02 housing is also larger. Its still pretty amazing I was able to make the power I did on a small downpipe. Combination and tuning are everything!
FWIW I measured back pressure on my stock engine/cams and it was 38psi at 30lbs of boost. You really want to avoid a 2:1 ratio as this can lead to excessive heat, knock and other undesirable things.
I don't know if it will pickup much at the top end of things since I'm near the end of the Red but we will see. I've been totally happy with Tomei products, performance and fitment. Back when my car was stock I bolted on the full system and lost 50lbs of weight, and picked up 50 whp /50 Tq on the same tune . Dynojet runs the same week.
http://www.tomeiusa.com/_2003web-cat...ponent_v2.html
Also have another change in the works.
Its a 3" DP vs the 2.75" Version 1. The 02 housing is also larger. Its still pretty amazing I was able to make the power I did on a small downpipe. Combination and tuning are everything!
FWIW I measured back pressure on my stock engine/cams and it was 38psi at 30lbs of boost. You really want to avoid a 2:1 ratio as this can lead to excessive heat, knock and other undesirable things.
I don't know if it will pickup much at the top end of things since I'm near the end of the Red but we will see. I've been totally happy with Tomei products, performance and fitment. Back when my car was stock I bolted on the full system and lost 50lbs of weight, and picked up 50 whp /50 Tq on the same tune . Dynojet runs the same week.
http://www.tomeiusa.com/_2003web-cat...ponent_v2.html
Also have another change in the works.
Feb 24, 2017, 04:16 PM
#78
EvoM Guru
iTrader: (1)
I wonder if it will get rid of the weird torque/boost plateau from 4-4500ish.
Mar 25, 2017, 10:11 AM
#84
We did run it harder then before. I thought it was maxed out before looking at other Red data. We didn't just ask for 40 off the hit to make a number. Its important to look at the powerband not just the peak numbers. The dyno graph on smoothing 0 also tells you how well the engine is running.
I didn't measure back pressure on the built engine but going off the dyno graph you can tell that its the limiting factor. I can say that it used to make 530whp in cool/dry weather at 27psi and made 555whp at 28psi last night in 77* weather with humidity so the larger downpipe helped some.
When you are running any turbo hard you want to try and lower backpressure. I was perfectly happy with the smaller DP but since the car has made good power before I wanted to upgrade it incase it lowered backpressure even a small amount.
The 58mm wheels crammed in a twinscroll housing can only do so much, its tapering and no real reason to run it past 7600-8000 . I'd still prefer this housing since it responds so well and makes Great low end grunt.
Also, I have no interest in an 02 dump and in this case I'm running the turbo hard so the gate is shut anyway.
Sidenote, for wheel size reference I've seen a PTE Evo 5858 dyno graph at 40psi and it made 700whp and tapered . I'm totally happy with the powerband and quickspool my setup has. It sounds better then a T3 IMO and has lowend grunt.
I didn't measure back pressure on the built engine but going off the dyno graph you can tell that its the limiting factor. I can say that it used to make 530whp in cool/dry weather at 27psi and made 555whp at 28psi last night in 77* weather with humidity so the larger downpipe helped some.
When you are running any turbo hard you want to try and lower backpressure. I was perfectly happy with the smaller DP but since the car has made good power before I wanted to upgrade it incase it lowered backpressure even a small amount.
The 58mm wheels crammed in a twinscroll housing can only do so much, its tapering and no real reason to run it past 7600-8000 . I'd still prefer this housing since it responds so well and makes Great low end grunt.
Also, I have no interest in an 02 dump and in this case I'm running the turbo hard so the gate is shut anyway.
Sidenote, for wheel size reference I've seen a PTE Evo 5858 dyno graph at 40psi and it made 700whp and tapered . I'm totally happy with the powerband and quickspool my setup has. It sounds better then a T3 IMO and has lowend grunt.
Last edited by Abacus; Mar 25, 2017 at 10:51 AM.
Mar 25, 2017, 03:51 PM
#86
Congrats, that really is a great power band! I'd guess it's super easy to drive both on the street and track.
What tuning changes do you make for track days?
Thinking about doing an exhaust dump, like RRE or English? That's about all you've got left to reduce back pressure.
What tuning changes do you make for track days?
Thinking about doing an exhaust dump, like RRE or English? That's about all you've got left to reduce back pressure.
Mar 25, 2017, 07:05 PM
#87
Thanks. The car is a blast with the 4.11 gearing. Broad power band and just moves out .
For track days I just adjust the boost target to what I want. I'm going to get a trim knob to interface with the ecu for power settings. There is a BTI gauge coming out that will interface thru can-bus and that can adjust power.
To my knowledge my car is making the most power on an MHI Red,has a fat powerband and the graph is smooth not wavy. Now, I've got alot of dyno time and my tuner knows the standalone well so My setup is pretty well dialed in.
I won't do an exhaust dump for a few reasons. I built a powerful street car that is relatively quiet and sounds good IMO. I drive it pretty hard and don't need any more attention that a dump would bring.
A true divorced or separate 02 dump won't really help when the wastegate is shut and the turbo is trying to make all of it. If you notice on cars that have them the dump gets quiet as boost goes up. I've got no interest in that unless I'm making over 900-1000whp.
For track days I just adjust the boost target to what I want. I'm going to get a trim knob to interface with the ecu for power settings. There is a BTI gauge coming out that will interface thru can-bus and that can adjust power.
To my knowledge my car is making the most power on an MHI Red,has a fat powerband and the graph is smooth not wavy. Now, I've got alot of dyno time and my tuner knows the standalone well so My setup is pretty well dialed in.
I won't do an exhaust dump for a few reasons. I built a powerful street car that is relatively quiet and sounds good IMO. I drive it pretty hard and don't need any more attention that a dump would bring.
A true divorced or separate 02 dump won't really help when the wastegate is shut and the turbo is trying to make all of it. If you notice on cars that have them the dump gets quiet as boost goes up. I've got no interest in that unless I'm making over 900-1000whp.
