scooby2004Lee

iTrader: (1)

Posted a theard last night that my car held back on the motorway and the engine manangement light came on! Here is the full story as of present. Last night on the way back from the ace cafe i was cruising the motorway at 80mph, and when i saw a lovely open road i planted my right foot but the car held back quiete aggresively. The engine management light came on straight away. I therefore took it to "Tourque of the devil" this morning and they plugged it into the computer and the fault read "Overboost". Apparently in the colder weather i may get a form of overboost. My car is a 2004 wrx, however it has these mods:
STI TMIC (Brand new) , VF35 TURBO (STI Brand new), Walbro fuel pump, 565 Pink injectors, flat panel green filter, Full decat up and down pipe, blitz nur spec r, remapped ECUTEK to 331BHP (All these parts where brand new 2000 miles ago when i fitted them).
What should i do in order to stop any overboost, or should i upgrade more parts in order to get better power more securely??

alex_00s

iTrader: (18)

Just heard back from my mapper and he reckons my car is over boosting and that does seem as like what its doing coz on gentle throttle it goes up through the revs, but put my foot down and it boosts high and cuts out and all sorts.

I think one trip to the ECU doctor and she'll be cured. Just weird it happened from unpluggin the dash clocks, but I must have caused a feedback when messing with the terminals and triggered sumin to go wrong, DOH!


ps: 3 port boost solenoid for your car mite do the trick?

Tidgy

i'd take it back to the mapper and get him to take a look or possibly get it on the dyno, will show what the problem is ratehr than chasing it round the enigne bay.

WRX Blues

One of my classic STi's suffered with overboost and used to hit fuel cut - felt like I'd run into a brick wall! It had a full de-cat and when the weather got colder it was at it's worst. I almost chucked it in the biffa as I couldn't get it cured until someone suggested fitted a duel solenoid boost controller set at a peak boost below fuel cut.
I duly did this and got the car checked on the RR to make sure it wasn't running lean. Never missed abeat after this - nailed 1.3bar every time and held well through rev range.
My new ages have always been re-mapped but I have never had a problem with overboost - at least not to the extend where it hits fuel cut?
Suggest you go back to mapper - I would have thought this could be cured

scooby2004Lee

iTrader: (1)

Well as mine only happend once, last night in the really cold 6degrees lol, he said that it could just be the weather! I drove it back at a good pace and it was fine 1000000%. Full boost ect. I just want to do everything an STI would have to make sure the car is safe! My mapper said if it continued he would tweak it and turn the boost down, in order to stop overboost, (TURN IT DOWN...I WANT MORE LOL).

Fat Boy

Very common in cold weather, it's a fuel cut due to temp overboost- 3 port boost solenoid and tweak will sort it

alex_00s

iTrader: (18)

there's been a few floating around in the sale section recently - definately worth fitting

nug172

I had this problem after fitting a full system. took it to get remaped and it cured it no problem. im now getting 23psi of boost with no cutting out.

andyxros

mine is getting more boost now its colder but when i had it mapped he said he had liffted everything up so i have (or not felt) fuel cut and prob never will if its lifted enough and i dont even have a rev limiter anymore
so it prob just needs a tweek or put a slightly bigger restrictor pill (from a TD04 should do) in the boost pipe will take it down maybe 2 psi approx, i know this cos i had it mapped with TD04 pill still in and put the vf35 pill in and got 2 psi more

scooby2004Lee

iTrader: (1)

Thanks for all the help guys!! As i say it only happened once and my mapper said if it continues he would tweak it so that it doesnt do it, however it meant turning it down and losing 5bhp!! I dont want to do that and i dont see why i should. surely a 3port boost solenoid and a tweak will work? Am i right in saying that the reason this happend is because my map is to 1.5bar of boost and when in cold weather it is boosting more hence the term overboost, so the car holds back because it is acheiving too much??

alex_00s

iTrader: (18)

Dont worry Lee, keep an eye on it and if it doesnt do it again happy days... but if like me you get it allllllllllllllllllllllllllllllllllllllllll day long its map tweek time

scooby2004Lee

iTrader: (1)

Lol thanks alex, but my BBBIIIIGGGG question is, if i have to have a tweak why does he have to turn it down!!!!!??????????? Surely if it can boost more let the turbo boost more and tweak it up to 1.7bar or sumin??

Splitpin

Lee, with the best will in the world you're starting to waste both your time and ours asking questions that can only be answered properly by your mapper, or someone else with their head under the bonnet of your car (or in front of a laptop connected to it).

Alex, myself, and everyone else who have commented can only guess or go on personal experience that may not be relevant to your car.

There is no certainty that the boost may need to be turned down to cure the overshoot. It may simply be that a small change to the boost dynamics will fix it. May be, as said elsewhere, that a different solenoid or porting the wastegate might be the answer.

As for reasons why it can't be "turned up", maybe it can be, but maybe this is as much as you can run without it detting like a tw*t. Again, we can't tell you so go find someone who can.

bluenose172

iTrader: (2)

You'll could be in danger of detting while over boosting so it's not just about raising the limit. The way he could do it and reduce the effect in normal temp conditions is to tweak the the wastegate compensation tables for temp(IAT etc), I'm sure they'll be available on ECUTek.

Imran21

iTrader: (5)

I had over boosting problems in my Version 3 type R. I fitted a Hallmans manual boost controller and set it to 1.3 bar and it now holds at that through the whole rev range and gears (except 1st of course, in which i get 1 bar flat).
This mbc bypasses the OE boost solenoid (vacuum line).
Just thought i'd put in my experience with a similiar issue if its helpful.
Cheers,
Imran

phil739

iTrader: (30)

i dont have a restrictor pill but am running a 3 port from my vf35