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reliable 450whp build

33K views 16 replies 12 participants last post by  mheyman  
#1 ·
Hi eveyone,

I currently have a 2006 wrx making 366whp and 400wtq. I would like to get it to a reliable 400-450whp daily driver. I am running E85. The car has 1000cc injectors, walbro 255 fuel pump, aem intake, 3 in turboback, one step colder spark plugs if that makes any difference, 3 port boost controller. I am debating on whether to buy a cosworth short block or if i should let my tuner just build my block. When comparing the two options both consist of cosworth pistons, sleeves, and the forged rods which seem to be the most important for a reliable motor. In your opinions would forged pistons, forged rods and sleeving the motor be reliable? An STI 6-speed will be swapped in as well along with the rear diffs at the same time. Front mount and a GTX35r will be used with the new build.

Open to all of your suggestions.
 
#2 · (Edited)
If you are running E85 and you want 400-450whp....

-You dont need to sleeve the block
-Cosworth or CP pistons are a great choice, personally I would up the compression ratio slightly, I run 10:1 but that isn't for everyone.
-Manley H-beams are fine for that power level or even Eagle H-beams, although if you want total overkill, go for a nice set of Manley I-beams :tup:


A GTX35r is big, you don't need that for 400-450whp. You would be much happier with a GTX3076 or even a GTX3071. Both will definetly do 400whp+ on E85 with 23+ psi of boost and will provide the best response and less of a lag fest. You could get away with a build like http://www.iwsti.com/forums/gd-members-journals/173437-illestuknow-04-jbp-gtx3071.html
and have great response with practically 430whp. That would be a blast to drive around everyday. Or even take it to more extreme levels with the 3076 and be like http://www.iwsti.com/forums/gr-memb...s/158083-bschweigs-08-ast-4150-cosworth-benson-racing-sleeves-gtx3076-63-a.html with 503whp.

Heck if you want the best car all around and kill it on the road course or streets, get an EFR7163, save a crap load of cash and reproduce this setup: Next Gen is here: Full-Race/Borg-Warner EFR7163 in stock location. 440whp/443wtq - NASIOC

Just look at those numbers, and that spool!
 
#3 ·
^^agree with above

Add in killerB oil pickup while you have everything out. I would let the same shop build, install, and tune so less blame if something goes awry plus they are more likely to offer a warranty for their work.
 
#4 ·
I am doing, essentially the same thing. I was at ~430 whp on the stock long block but started lifting a head. I had/have full confidence I could have made the stock motor last, however, I wasn't expecting the head to lift (I ended up with great spool and a lot of low end torque giving really high cylinder pressures). The motor needs head studs and since these motors have to come out to do this... \/

What I am in the process of doing: Just ordered a brand new OEM 08+ short block. Once the motor comes in, I will be ordering Manely A/B drop-in pistons and some head studs. I will size the rings, swap in the pistons, install the head studs, have the heads skimmed, and put it back together with OEM head gaskets and pretty much keep the rest of the build as close to OEM as possible (still have my TGV's :) ) I may replace valve stem seals, but at 34k miles, the heads shouldn't really need anything.

The turbo is a 20G @ 23 PSI with ELH, EWG, 3" TBE, CAI, and silicone inlet. The stock 34k mile clutch started slipping at 430wtq. Also running E85, ID1000's, Walbro 450 (<- you'll want this), and base pressure at 50 PSI.

Compression on the Manely A/B pistons is bumped up a couple points (8.5:1, IIRC).


This is an 'unfinished' tune due to the clutch slipping. I didn't plan to raise the boost anymore, but I had a bit more timing I could have added. My goal was to keep the fun factor/spool of the VF39, but gain more power and hang onto it better up top... It's pretty fun.
Image


Here is a graph comparing my buddies ported VF39 vs my Blouch 20G. Literally, all our other mods are the same.

Image



I can't comment on shops... I build and tune my own cars.












My buddies 2006 WRX STi wagon (VF39 and full STi drivetrain swap). He just removed the turbo and is planning on a 2.5XT-R shooting to beat my numbers. I also tune this car.
 
#6 · (Edited)
I have a 2010 STi, lifted a head at 46500 miles during extreme driving. since the motor was coming out, I did a basic build ( I was on E85 and synergy 20g turbo 410/425 tq, synergy 340 fuel pump, ID1000, header, dp, exh)

after the build i decided to do TGV delete as well, also with the following mods (most of the stuff I already had, just changed up the turbo to blouch 20G XT

New stuff:
JE Forged pistons
Scat H beam rods
ACL main/rod bearings
ARP head studs
air pump delete
Motive autowerks composites tgv
aeromotive FPR
setrab 19row oil cooler (with thermostat)
forged motorsport by pass valve
-------------------------------------
stuff already have:
ID1000 injectors
South Bend SS TZ clutch (rated at 600 wheel tq)
synergy 340 lph fuel pump
ngk 1 step colder
grimmspeed 3 port ebcs
koyo rad
kill b pick up n baffle tray
crawford v2 aos
Blitz Nur-spec exh
GT spec equal length exh manifold
GT spec uppipe
aem intake
invidia catted downpipe

Image


E85: 423 HP/ 450 Tq to the wheels, tuned by yimisports SoCal, target boost 24 psi taper to 20 .

Image
 
#8 · (Edited)
I have a 2010 STi, lifted a head at 46500 miles during extreme driving. since the motor was coming out, I did a basic build ( I was on E85 and synergy 20g turbo 410/425 tq, synergy 340 fuel pump, ID1000, header, dp, exh)

after the build i decided to do TGV delete as well, also with the following mods (most of the stuff I already had, just changed up the turbo to blouch 20G XT

New stuff:
JE Forged pistons
Scat H beam rods
ACL main/rod bearings
ARP head studs
air pump delete
Motive autowerks composites tgv
aeromotive FPR
setrab 19row oil cooler (with thermostat)
forged motorsport by pass valve
-------------------------------------
stuff already have:
ID1000 injectors
South Bend SS TZ clutch (rated at 600 wheel tq)
synergy 340 lph fuel pump
ngk 1 step colder
grimmspeed 3 port ebcs
koyo rad
kill b pick up n baffle tray
crawford v2 aos
Blitz Nur-spec exh
GT spec equal length exh manifold
GT spec uppipe
aem intake
invidia catted downpipe

Image Link


E85: 423 HP/ 450 Tq to the wheels, tuned by yimisports SoCal, target boost 24 psi taper to 20 .

Image Link
Nice numbers! How much boost was that (disregard, I'm blind)? I wish my clutch held because I know it would have been up in the 450-460 wtq range. Always next year I suppose. :)

I still think the 20G is just a really fun turbo!
 
#12 ·
These are impressive builds guys and this is what I'm looking to do with my dd 04 STI this summer. The motor has 120k on it and I was thinking of a built race block like those from builtej or awdtuning but not sure if that's the beat bang for the buck. Would it be better to just do an ams advanced rebuild kit? Money isn't really the issue. I'm just thinking if I can save 2 grand on the motor I can use it for other parts.
 
#17 ·
Pre 2015 breaking 400 was a kind of big deal. Its gotten easier. Everything is figured out. You just need good skills or a good shop/mechanic. That saifd breaking 400 on still crosses the line from from a fun street car to the very very bottom of a "big build" . . .
 
owns 2020 Subaru STI
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