overboosting to 18-20psi

hiya

i just brought a 89 legacy rs r with all the gear out of a 97 wrx with a td05 turbo. its has no boost tap or controller but has been boosting between 18-20 psi, i ask the owner whos a subaru mechanic and he has said because its been sitting for so long ( been a unused track car with a kill switch setup that cuts all power from the battery) it should go back to factory after some k's because the ecu will adapt to it. it did drop down to 15-16 for a little while but then went back up again. so i am wondering if this could be from it sitting for a long time and the wastegates sticky or if its to do with the actual set up. any help or idea's would be great thanks

p.s after driving a na diesel ute for 5 months its nice to be thrown back in my seat again haha

Put up pics of the boot lines associated with turbo and wastegate and pics of the car too.

Welcome to the forums dude.

took some pics but my cousin took my phone cord to ragland and the inter cooler piping and turbo guard thing is in the way, will get some proper ones tomorrow also should have mentioned its got a front mount instead of a top and i think the owner said the waste gate had been bored out? probably has something to do with it. also is there any real benefit to a front mount apart from the added size goes hard on boost but takes a while to spool up. thank you Mr vice president

Front mount doesnt heatsoak and better cooling properties. The spool thing is neglible tbh.

Wastegate being bored wont change boost level somethings amiss.

You racing it? Need to wack up a garage thread keep us posted.

the spool is just coz big ol tdo5 on a stabdard ol motor .

first things first what brand is your boost gauge ?

stock ecu ?

does that car actually run alright ? if 18psi then i doubt it . if it does run aight then i doubt 18 psi

if you look on trade me you will find that 18 psi is "factory boost " lol

well i just went for a drive to get some milk and gas ( so distracted i drove off without putting it in lol) and on the way in it hit about 16-17 in 3rd then on the way back went well past 20 before i could let off the gas, its an auto gauge gauge which im pretty sure is not the best brand but im reasonably sure its not the gauge, it also surge 3 times on the way back with a fuller tank under boost. its got a sti ecu with a organge airflow meter and red injectors (i think)

yup its been running good apart from a bouncy idle, but the owner said there had been some oil in the intake and i notices a little bit of oil splattered around the Bov so maybe that could have something to do with it. haha my old wrx only boosted 9psi without a controller so im ****ting myself in this.

i was planning on caging it and using it for my first gravel rally car but it handles bloody well on the road so it seems a bit of a waste when ill probably end up taking it into a ditch, so it will probley stay a road/track car now if it doesn't pop

also would a boost tap solve it or would it only be able to increase it if its doing this without one cheers

Need to see how boost lines are routed before ill pass judgement. Short answer is you cant turn it down with a controller or tap only up.

Should have yellows.

Also i would recommend staying off the happy pedal till its sorted otherwise it will turn to sad panda pedal.

With a boost tap you can wind it down to 7psi if you wanted. It could be that the boost control strategies in the ecu are not keeping up with the td05 turbo and wastegate.

To be clear tho a tap wont turn it down if its not plumbed correctly or has a sticky gate etc.

Easy way to tell is run a line direct from comp to wastegate and see if it holds 7psi solid. If that works then you can add a tap or ebc to get the boost to where you want it.

thanks for your help but least of my problems now, after owning the legacy for a total of a day and a half i had dccd in the lowest setting and manage to slide it off the road into a ditch and then into a retaining wall, i think i should just stick to my diesel ute..... and if anyone has a rolling body of a legacy or a v 1-3 wrx for sale let me no

Ouch. If it's any consolation, you aren't the first to be bitten by a DCCD, and you won't be the last. You might get lucky; caged WRX rolling bodies pop out of the woodwork now and then on trademe and through local clubs.