nzevo8

hey guys iv got an evo 8 and Ive got boost issues not being able to pass 20psi.


exhaust is not blocked
intercooler is not blocked nor leaking
i have brought a brand new waste gate actuator
will have a new turbo
replaced boost control solenoid

any ideas what it could be or where i could look?

any help would be much appreciated

sparky

iTrader: (1)

What do you mean...."will have a new turbo."? Have you already installed a new turbo? What particular turbo are you going to install/have installed? Is the WGA already installed and functional on the car? What WGA? Is it a stock factory actuator?

viprez586

iTrader: (3)

Start with a boost leak test, soapy water and a spray bottle.

It really helps to have a decent size air compressor and a regulator to adjust how much pressure your testing at.

nzevo8

When i had the car on the dyno for the first time during my ownership it would not boost more then 20psi though the previous owner already had it tuned on 20psi low boost and 24psi high boost.

it had a stock evo 8 actuator on the Map ef3 which was installed incorrect as the EF3 needs a evo 9 actuator. i could see the actuator rod had been rubbing against the bracket. thinking that we had found the issue it was replaced with a Kinugawa waste gate actuator where my tuner had it set to the correct preload. He then ran it up on the dyno and it still didn't pass 20psi. he said the spring in the waste gate is likely to just be a 10pound spring and thats most likely why it won't boost pass 20psi it was the last waste gate actuator he had in stock so there was nothing else we could do on the day.I left the workshop with it tuned at 20psi and would return in a month with higher pressure spring.

Month later i got a 1.2bar spring. Along with it i decided i will do some more mods to extract more power. so i brought the following:

Tomei Cams
Kelford TX272 type L camshafts (10mm intake & exhaust lift)
GSC lifters
K&N intake
EF3 turbo (reconditioned)

I then returned for a retune and hoping that i would now achieve my power goal, but once again it still would not boost 20psi even with the 1.2 bar spring. so the next thing my tuner looked at was the boost control solenoid so that was replaced with a new unit and once again that was not the fault.

He then called the tuner who had previously tuned the car and was told the Map ef3 are quite common to go faulty (though i had just reconditioned it.......?????)

once again i left the shop, this time thinking the fault is the turbo. A new turbo will boost pass 20psi. I decided enough is enough and splashed out on a FP green DBB. I sold the ef3 where it was then installed on a evo 6. The evo 6 managed to boost pass 20psi no problems and made more power then what I'm after.

i spoke to the guy who rebuilt my turbo and we agreed if the turbo was faulty then that evo 6 should also not be able to boost pass 20psi.

So now my car is current apart waiting for the FP green DBB (which is still in the build Q after 5 weeks!) while waiting i decided i will pull apart the exhaust and intercooler and check for leak or blockage. I found no leaks & no blockage.

CONCLUSION:
*New waste gate actuator (not the problem)
*New 1.2 bar Spring (not the problem)
*New boost control solenoid (not the problem)
*Reconditioned MAP EF3 turbo (was not the problem)

New parts I'm going to have for it is, FP green DBB turbo, Curt brown ported OEM manifold, and changing lower intercooler pipe & possibly upper intercooler pipe (not that these parts were the problem)

After all these changes I'm still not sure what the problem is!!!!! & not sure what else it could be. I'm hoping i will put the car back together with the new parts and it will magically boost pass 20psi! , if not I'm not sure what else to look at.

leemaster

I just --->

nzevo8

thank you for your help, back on topic

slowsrt4:(

iTrader: (13)

really??

Reborn624

what kind of boost controller are you using?

nzevo8

ECU controlled, Link G4 plug in ecu with a Mac 3 port boost control solenoid

novem

iTrader: (2)

Bypass the EBC setup and borrow a MBC! You should able to turn it up past 20psi. If you have any missing bolts on the o2 housing or any gap, you will loose boost. I would go with bigger upper/lower ICP's also.

N.

nzevo8

iv already got 3" pipes as it is, and I'm looking at changing back to 2.5". iv asked my tuner about trying a MBC which he suggested in the last tune but unfortunately he was out of stock. This time he has said if boost doesn't go up "boost controllers MBC or EBC isn't the problem" I'm a bit puzzled why he would suggest it last time but now has changed his mind. either way i thought i will give him a call once the cars back together and get to the bottom of it.

im a little suspicious of the B.O.V (HKS) early in the year i was driving and it came off the flange. when i went to put it back together i noticed the rubber seal had gone missing since it had come off. i managed to get another rubber seal and put it back on and hasn't came off since.

my plan is to:

*put the car back together, test drive and see if the problem still exist.
*boost leak test (will be sure to check around the B.O.V & flange)

while I'm waiting for my turbo to arrive, I'm taking the time to do some research and check over the car to try find the issue.

evo8426

iTrader: (27)

First thing you should've done was a boost leak test

sparky

iTrader: (1)

Can you replace the HKS with an OEM, MR metal DV?

nzevo8

its had boost leak test done prior tuning, both times

my pipes got a welded on HKS flange, i need to do a boost leak test and determined weather it is the B.O.V first. but I'm considering down sizing pipes and possibly changing to a tial Q B.O.V anyway.
i do see on here a lot of guys use/recommend the metal evo 9 B.O.V?

viprez586

iTrader: (3)

The OEM metal 9 and 10 MR Bypass valves are quite superior since they've been proven to hold high amounts of boost pressure, especially when crushed properly.