overboost??

[GAZ-MAN]

hi all, im new to the evo scene, i got this couple of weeks ago it goes amazing but the guy told me that it would do 150+ and since he fitted the evo 8 turbo i get to 130 and the car stops like theres no acceleration then it comes back on up to 130 again then stops? overboost maybe? the car boosts perfect in every other gear

 

[madmilligan]

What does it say on boost gauge at that speed my nine turbo on a 6 engine drops to about 1.3 bar at that speed but hold to 150 Max really due to gearing

 

[GAZ-MAN]

ive not got a guage mate

 

[madmilligan]

What about a boost controller what's evo and what's the spec? Mine holds higher boost in 4th and 5th

 

[GAZ-MAN]

sorry its an evo 7 bud with an 8 turbo unit, every gear is fine even in 5th till it hits near 130 then its like the revs cut out i pump the accelerator and theres nothing it slows down to about 120 and comes back again and does the same all over again

 

[GAZ-MAN]

its a uprated fuel pump, full exhaust system, bigger front mount and remap so previous owner told me always ran on v power im getting it serviced tomorrow so was hoping maybe plugs mite be needing changed?

 

[madmilligan]

Need a diagnostic plug in etc and boost leak test

 

[GAZ-MAN]

my pal said he has mitubishi software so when its in for service tomorrow al get him to plug it in and see what fault codes are and ill stick them up here and see if anyone can help

 

[dan2926]

First thing i would do would be fit a boost gauge see what you are running when it happens then you can work out of its fuel cut or something else, this would probably also tell you if it has been mapped aswell

Do you have any receipts for getting mapped, i wouldnt take someones word.

I would guess that the parts have been fitted and car is not set up for the mods.

Im collecting parts for mine just now and will be fitting them all at the same time then takin for a remap. I fitted some parts when i got them and had strange issues with boost so removed them for just now.......

Good luck M8

 

[GAZ-MAN]

who will be doing your remap mate?

 

[dan2926]

I have always used Wallace Performance in Aberdeen but beleive they have changed hands since i was last there. There is a guy on here who does mapping pretty local to me his website is here:

HTDevelopments

Cheers Danny

 

[GAZ-MAN]

Well was out in the car there it gets to bang on 120 it's pulling amazing then stops car slows down to 110 comes back on hits 120 again and stops back down to 110 them comes on again tried it a few times, maybe cause its an import maybe a limiter?

 

[dan2926]

Limiter comes in @ 112mph on jap imports m8, normally removed when speedo converted to mph. I had a impreza that used to fuel cut at top end of 5th turned out to be overboost, but that was fuel cut yours almost sounds like limp mode. Fit a boost gauge m8 and rule it out thats the cheapest option.

 

[GAZ-MAN]

When at 120 the car stops boosting when I'm pressing the accelerator there is nothing and it hits bang on 110 and comes into life again up to 120 and does it all over again it's a bit of a weird one

 

[RsvRob]

If it's boosting fine then I would say it's a speed limiter not overboost/fuelcut....

You would still get fuelcut in lower gears and lower speeds aswell. If it's only when you hit 130mph then it's a limiter problem.....

Remove vac pipes from solenoid and plumb straight from actuator to turbo. That way you will only get actuator pressure of 0.7bar. This will determine if your actuator is knackered or the solenoid. Or if it is still a limiter issue. Do all this then take for test drive and roll onto throttle do NOT stamp the pedal to the floor, coz if it's fuelcut you'll likely boost far to much. Rolling onto throttle will still build boost until fuelcut.