bsbllfit7

Hey everyone I have recently swapped from my stock Evo 8.5 turbo to a MAP EF4 in hopes of close to 500whp that was somewhat safe on the stock drive train. When I first ran the turbo it was at wastegate pressure or roughly 15psi. This generated a evoscan horsepower of roughly 284whp 250wtq. I have since upped the boost searching for more power and am currently at 31 psi. At 31 psi I started to see slight knock so I have back off to 30 psi and removed a degree of timing. Afr is 11.5 at peak torque and goes to 11.1 at redline. The problem I am seeing is the car is struggling to make 400whp with 30 psi on a ef4. This does not seem correct given the size of the turbo. Compression test was all around 145 or so and boost leak confirmed bo severe boost leaks, one super small once at the iac valve and the boss screw which will be fixed soon. Blow off valve is holding strong to 35 plus. What do you folks out there could be the issue here, am I seeing valve float which is hindering the engine from producing more power? Mods list that are important to this are below.
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Walbro 255hp
Pte 1050cc injectors
Full 3 inch turbo back

e_kobz

iTrader: (36)

What’s the condition of the turbo? The MAP EF series are notorious for failing.

bsbllfit7

Brand New only a few hundred miles on it now. Both wheels look perfect and no shaft movement.

bsbllfit7

And most of the failures attributed to those turbos were due to improper oiling just like the FP series turbos before they mandated oil feed from the oil feed housing as well as a restrictor inline.

e_kobz

iTrader: (36)

It was also the use of crappy non OEM turbine housings and wasegate flap components.

e_kobz

iTrader: (36)

What are you revving to? Also post a dyno chart or logs if you are able to

bsbllfit7

Revs to 7500 because of stock valve springs. I did find that the wastegate preload backed off which explained the decreased spool up all of a sudden. Will take another log here momentarily. I also am going back down to 25psi to see if that stock springs handle that better.

Furthermore on the ef4, I plan on going fp's stainless housing with external wastegate once all other necessities get completed.

e_kobz

iTrader: (36)

That’s gonna make a laggy turbo even laggier on a stock block 2.0L

CurseDSM

iTrader: (3)

Check inside the housing. Take it off the turbo mine was eaten up by the junk casting and the bearing cover was destroyed.

bsbllfit7

I've had the turbine housing off a few times and it still looks good as new on there. I'm creating boost just not power.

CurseDSM

iTrader: (3)

Trust me it will end up like this. The cast rating on a cold side should be around a 4 or 5 is what mitsu uses, they used a 2 according to my turbo rebuild guy. I was making 30 plus lbs of boost when this happened decided to get a new wheel make it a little smaller. Well long story sort this is what we found. Now I have the same chra, Evo 9 hotside being mine was cracked, and a 25g cover. Long story short I still don't make the power I want and its coming off.

Bladey

are you on factory cams? cause that will play a big part in not making the numbers...

bsbllfit7

Per original post kelford 272 with stock springs. After talking to gsc and kiggly as well as kelford in likely being severely held back by the springs given my boost/cam/valce spring setup currently. I am going to drop the boost to 25 psi or so until I can get springs installed. In the mean time it gives me time to tune my 3 port I just installed today.

dookgvr4

iTrader: (14)

Forgive my ignorance but how do the valve springs hold you back?

ronaldo9

iTrader: (2)

He will need more boost and revs to make the power he wants. He is at risk of valve float on the stock springs.