sti-spec-a

Fitted a TD05H turbo to the car

The cars a 95 WRX STI with a Scoobyecu type thing mapped for decat and induction. After i fitted the replacement turbo the car i was seeing boost levels of 1.4+ bar, i lifted before it climbed any further to stop her going BANG also the car was trying to "shut down" at these boost levels, it wasnt hitting fuel cut as it was still trying to rev albeit very mutedly

The scoobyecu is mapped for 98ron fuel and boost target of 1.2bar, hence my concern

The plugs are PFR6B's, are these being "blown out" would PFR7B's be better over a bar of boost

I have wired the compressor output to the wastegate and it is seeing a max of 0.5bar

I have fitted a replacement Boost control solenoid exact same boost results on both 6K and U8 ecu

I have fitted a std U8 ecu and seeing boost of 1.1 bar before hitting fuel cut

I have also checked to see if the wastegate is jammed it is not

There is NO Dawes Device fitted

I fitted NEW boost pipework from compressor nipple to solenoid and solenoid exit to wastegate

Can the actuator on a scoob be loosened?

Will fitting the 7B's deal with the "shut down" syndrome on load?

Any suggestions greatly recieved

Thank you

vulnax999

iTrader: (7)

What Turbo have you replaced with the TD05 turbo ... the ScoobyECU's are programmed for certain ECU's and Turbos ... if you got a higher flowing or boost pressure capable turbo then the ecu loses it it and you get extra air / pressure and then det!

Fancy a Diesel?

Why did the ECU allow 1.4 bar ... fuel cut should be between 1.05 and 1.15 bar unless changed ?

Higher boost would try to blow out the plug spark, depending on condition of plugs ( age, wear, gap ) and coil pack condition.

Turbo outlet to wastegate shows the wastegate is working at about the right relief pressure.. If you put in new pipework for compressor / solenoid/wastegate, did you refit the restrictor in the same line?? That may explain the over boosting situation?

NotoriousREV

Have you plumbed the boost solenoid correctly. I've managed to get it plumbed the wrong way and seen boost of 1.7bar+. It was fast though

sti-spec-a

AFAIK the pipework is OK

Can somebody post a link/pic to how the boost pipework should be connected as i might have made an **** of it

If the restrictor in the pipework is missing will the turbo overboost this much?

Previous turbo was a VF28 but the Scooby ecu is mapped for a TD05, the ECU ran fine in the prev owners car which is equipped with a TD05 so in theory it should be stable at 1.2bar

Cheers Grant

Turbo_Steve

I'd stick a dawes on it as a diagnostic tool to start with. If that fixes the problem then you know you need to look at the solenoid plumbing. Do you have a restrictor in the bottom pipe? (It sounds like you don't) you should have a small brass restrictor to limit the boost bleed to the intake. Would suggest you are either missing one, or it needs to be smaller.

R19KET

Or, get a map designed for a TD05 !

Mark.

TheSquirrel

The map on the scoobyecu is designed for a TD05

Fitted a U8 ecu which is standard and mapped from the factory for a TD05

Grant@work

StickyMicky

fit a dawse IMO

TheSquirrel

Where in the line should a Dawes Device go on a 3 port boost solenoid

A. From compressor output nipple to top solenoid input?

B. From Middle soleniod output to wastegate input?

C. From bottom solenoid output to induction intake?

Thank you

Turbo_Steve

Dawes replaces the 3-port solenoid, dude.
You can use more complicated installations, but for the purposes of diagnosing your problem, it just goes between the compressor nipple and the wastegate actuator.

You may just want to stick with the dawes once you've fitted it...but if you DO want to go back to the ECU control, you need to look at the restrictor size, as chances are this is going to be the cause of the problem.

Just out of interest, are you using the hoses that came with the car, or have you replaced them...in which case there will be no restrictor at all...hence the problem

R19KET

I assume this means "hosed" ?

If so, it proves that the turbo/actuator are fine. So it's either down to the hosing/solenoid, or the map.

My previous post was worded poorly. I meant to say get the ECU correctly mapped for your set up, with the TD05.

Generic maps can be unreliable, since the cars can vary so much.

At best they have to be conservative, and should use the lowest common denominator to be safe, at worst you can have anomalies, causing boost, det, or fuelling problems.

Mark.

scoobydobydoo

Yes, there are different sizes of restrictors to each model of car, but if the restrictor is missing it will cause you to loose boost not over boost!

TheSquirrel

In what pipe should the restrictor be?

Top from compressor nipple

Middle to wastegate

Bottom to induction

sti-spec-a

Anyone answer the above question.

Where in the loop does the pipe with the resrictor go

Compressor output to top solenoid input

Middle output to wastegate

Bottom output to air intake

I want the ECU to control the boost instead of a Dawes but i cant remember where the restrictor pipe goes back in.

Thank you

sti-spec-a

Anyone answer the question above the that one up there.

Please

Grant

sti-spec-a

Where does the restrictor go.

Top, Middle or Bottom

Grant

sti-spec-a

Bttt for someone who might be passing

vulnax999

iTrader: (7)

I think the restrictor goes in the line to the wastegate actuator .. I don't seem to have one so cannot confirm!
So off the lower side pipe off the 3 port boost control solenoid.

Try it and see.

Turbo_Steve

In mine it was in the bottom pipe, I believe to control the -ve pressure back to the intake. However, mine had been played with, but a lack of restrictor in bottom pipe will result in too much boost.

Is your 'bottom pipe' restricted?