as355f1

Hi,
just after a bit of advice, i bought a turbo 2000 with a fooked head gasket, i stripped the engine and sent both heads off for a light skim, when i collected the heads i was told they were both badly warped and had to have 10 thou skimmed off both, i rebuilt the engine using all genuine Subaru gaskets and ran it in for 100 miles.
So tonight thought right time to give it some beans and test it out, the car pulls strong through all the gears but under hard acceleration between 4500-6000 rpm i am getting slight pinking, apart from that everything seems fine the car is standard apart from the exhaust but according to the boost gauge its boosting to 1.2 bar, i don't have any other history for the car so not sure if someone has been messing with it or had a remap
any help would be appreciated as to why it may be pinking
Thanks
Jim

best_quality03

hi skimming the heads reduces the compresion ratio. turbo charged engines need a low compression ratio so that the turbo can force more air/fuel in giving more power. i would think that you may have to change the head gaskets for thicker ones thus lowering the compression ratio. i would be very carefull in running the car with detonation this can kill engines faster than bush can kill iraqs

as355f1

yes i know how quick it will die if its detonating had one go on me before, just not convinced its to do with the skim, was hoping someone else had a similar prob after a rebuild

best_quality03

i would say it has everything to do with the skim 10 thou will up the compression enough to cause your problems

GazJenno

shouldnt be boosting to 1.2BAR if its standard should it!?

best_quality03

i don't know but you have just rebuilt it maybe you missed a vac hose or maybe crossed 2 over. just have a good check over. A small split in the actuator vac hose can cause real problems with overboost or any vac hose for that matter

as355f1

hoses are perfect, triple checked them, might try turning the boost down

GazJenno

Yea probs something to do with the overboosting caused by mixed up vac hoses, splits, missing restrictor....suprised you havent hit the fuel cut though when its reaching 1.2BAR

1.2 BAR from that poor little TD04 will just be hot air I would have thought and too much of it for the fuel system to cope with too.....would fit in with the rev range your seeing the Knock at too.

GazJenno

so its on a manual boost controller? How are you avoiding fuel cut? not the safest set up if using a boost controller and FCD

as355f1

the hoses have been replaced from where they were removed but that does not mean they were originally in the correct place, does anyone have a diagram as to the correct position of the vac hoses also where is the restrictor in my car thanks
Jim

as355f1

no its all standard but i can fit a bleed valve to turn it down to see if that works

GazJenno

yea but thats cheating ....there must be something wrong for it to be boosting at 1.2BAR because it should be 0.9BAR as standard.

as355f1

need a diagram of vac hoses to check

as355f1

just had another thought to adjust the boost would slackening wastegate rod lower the boost ?, also does a 99 turbo 2000 have the adjustable rod ?
thanks

jim

jd5217

did you rebuilt the bottom end aswell or just the heads?

PeeVee

iTrader: (1)

10 thou shouldn't make any difference, the factory allow 12.

I would be more focused on the excess boost coupled with maybe a mixture problem. If your pipe work is correct & your sensors are all ok then more boost should not make it det, the system should cope with it.

Another thing to consider is that the battery was probably disconnected & the Ecu has been reset, so the ign curves will be advanced. Did you just hear the det once or does it re occur. In theory your Ecu should be listening for det and should retard Ign until the det stops. If det is bad then you end up with no Ign advance & a very slow engine.

Phil

dj219957

agree, 1.2 bar (17.4psi) sounds like it overboosting to me and that would be main cause of det. I think anything over 16 is a bad idea without proper map/mods. I dont think a standard 99 uk2000 should be running anywhere near that.

as355f1

no only head gaskets

OK think i have sorted this, i wound the actuator bar out 2 turns and this has lowered the boost to .9 det has now stopped and car still pulls strong.

only other problem i had was as i was braking down the slip road from a highish speed run one of my goodridge braided flexi hoses burst
to say i nearly shat myself is an understatement
another job to sort in the morn