Evan's 444whp HTA Green Evo 8.5
#1
Evan's 444whp HTA Green Evo 8.5
Evan had an unfortunate escapade in the ice a few years ago that left his 2006 Evo IX MR totalled but left his desire for a fast car. After locating a low mile 2003 BBY shell, he had us do a full IX swap including the 6 speed and ACD into the new shell. Initially it was still a stock turbo car with some HKS272s and the normal bolt ons which made decent power for what was done to it-
It didnt take too long before the speed bug had bit and the need for a few more parts became a necessity.
Mods-
Forced Performance HTA Green
Forced Performance Silicone intake
FIC 950cc injectors
HKS272s
Walbro 255
Tomei Expreme Manifold
Invidia 3" O2 housing
AEM Tru Boost
AMS FMIC (cast end tanks) and piping
3" TBE
At this point the car was still on a stock MAF and made good power but seemed like something wasn't quite there-
Compared to another HTA Green car we had done around the same time it seemed to be missing 60whp. Was it the stock intake manifold vs the Magnus of the other car or was it the S2s vs the HKS272s? Evan drove the car for almost 2 years before he decided to come at it again but based on what him and I had talked about his plan of attack was simple. Match the other car's modifications and make the same power.
New mods-
Magnus V5 Intake manifold
GSC S2 camshafts
ETS 1.5" stock turbo header
ER SD Tune
After getting all the parts on and the baseline done it was obvious that the new parts had helped spool tremendously compared to where it had been but power seemed to be relatively unchanged-
Sure it spooled 300rpm faster and was making more power above 6500 but it wasnt what it should be. After checking preload on the turbo, which appeared to be fine, a second boost leak check, we compared it Brett's car (the other car mentioned before) and could see that for whatever reason Evan had a bunch of boost taper that Brett bypassed.
Easy solution, wire the Tru Boost solenoid to the ECU for some 3 port action and let it eat-
444whp was what the doctor ordered. I left the torque a little lower than where it had been before in the interests of keeping the now older stock bottom end happy.
Before and after-
The 3 ports ability to keep boost taper away and allow the HTA Green to do some work solved this particular car's power needs. Will it be another 2 years before we have another installment? Hopefully not but in the meantime I am sure that Evan will enjoy the new found power.
Aaron
It didnt take too long before the speed bug had bit and the need for a few more parts became a necessity.
Mods-
Forced Performance HTA Green
Forced Performance Silicone intake
FIC 950cc injectors
HKS272s
Walbro 255
Tomei Expreme Manifold
Invidia 3" O2 housing
AEM Tru Boost
AMS FMIC (cast end tanks) and piping
3" TBE
At this point the car was still on a stock MAF and made good power but seemed like something wasn't quite there-
Compared to another HTA Green car we had done around the same time it seemed to be missing 60whp. Was it the stock intake manifold vs the Magnus of the other car or was it the S2s vs the HKS272s? Evan drove the car for almost 2 years before he decided to come at it again but based on what him and I had talked about his plan of attack was simple. Match the other car's modifications and make the same power.
New mods-
Magnus V5 Intake manifold
GSC S2 camshafts
ETS 1.5" stock turbo header
ER SD Tune
After getting all the parts on and the baseline done it was obvious that the new parts had helped spool tremendously compared to where it had been but power seemed to be relatively unchanged-
Sure it spooled 300rpm faster and was making more power above 6500 but it wasnt what it should be. After checking preload on the turbo, which appeared to be fine, a second boost leak check, we compared it Brett's car (the other car mentioned before) and could see that for whatever reason Evan had a bunch of boost taper that Brett bypassed.
Easy solution, wire the Tru Boost solenoid to the ECU for some 3 port action and let it eat-
444whp was what the doctor ordered. I left the torque a little lower than where it had been before in the interests of keeping the now older stock bottom end happy.
Before and after-
The 3 ports ability to keep boost taper away and allow the HTA Green to do some work solved this particular car's power needs. Will it be another 2 years before we have another installment? Hopefully not but in the meantime I am sure that Evan will enjoy the new found power.
Aaron
Last edited by JohnBradley; Feb 6, 2013 at 03:40 PM.
#2
Evolved Member
iTrader: (9)
Really cool. Who would have thought addition of a v5 and tube mani would allow improve in spool? Car responded very well to 3port boost as well. That's a wild improvement. I don't think I saw fuel listed. If these results came from anywhere else I would say no way its pump...esp your 92...but we're constantly seeing surprising results from you so I'm curious. I suspect its e85 tho...power seems right for e85 and boost is about where a 255 would force you to stay. Wonderful chart tho...prefect stock block setup with ultra safe tq, good spool and great top, all with moderate boost level. Very impressive
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Aaron
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Intake manifolds on stock appearing turbos can be 25-45whp depending on how large the turbo is and how large the motor is. Exhaust manifolds we are on the fence. Reason is we only ever test them on e85 it seems and it was 8whp on a car that made 581whp going from ported to an inch and half. Gasoline may be a little different because of exhaust temp and resultant density.
#14
EvoM Guru
iTrader: (50)
Not specifically other than we always run larger ID tube headers. We did the testing on small runner stuff vs the larger runner stuff awhile back with MRfred. Since we didnt notice any difference with the brands he tested, we just always go straight to the 1.5" and call it a day.
Aaron
Aaron
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The reason why I ask is because the ETS stock replacement manifold calls for a 1.25" if you're under 600hp and 1.5" if you're over 600 hp. Someone on Tri-State Evo put the 1.5" on their stock IX turbo and it actually made the car laggier, thus why I'm surprised that the 1.5 was used in this case and ran fine.
I'll add that while peak power was relatively the same between 1.25" and 1.5", oddly the off-boost responsiveness was noticeably better with the 1.5" piping. This was with no other changes to my Evo. My suspicion is that it had less to do with the pipe diameter and more to do with the steep transition in size from the exhaust port size (roughly 1.4" tall and 1.8" wide) to the 1.25" tubing diameter. Most headers force this transition over a distance of only 0.5".