ScoobyJawa

Righto, Len traced the fault to the wastegate. The actuator and rod are fine but where the rod meets the turbo and to the wastegate itself there is a fault. Its opening ok but doesn't close properly and so the wastegate is rattling/turning.

He's fitted the brand new TD04 turbo and all is well . Well almost .

Driving it home in 5th on the motorway and I gradually pressed the throttle and it went up to 1.4 The car is TEK2.5 and was running around 1.2-1.25 before the overboost to 1.6 incident last week. Car also has full decat, K&N induction and boost hoses.
I came off the motorway and tried 3rd gear. Boost went up to 1.3, which I never saw in 3rd before. Now this is far too high.

Any thoughts? I'm going to reset the ECU tonight and try cleaning the boost solenoid. I also have a Dawes for the time being to keep boost to 1.25 and prevent overboost until I can get a 3 port solenoid and remap. However, I'd really like to find out why the boost is getting so high on the new turbo before I fit the dawes. As I said, other than the tek, hoses, exhaust (and a VTA DV) nothing else is changed and the turbo is brand new TD04 straight from Subaru.

Advice/Thoughts most welcomed.

P20SPD

iTrader: (1)

The actuator on this turbo could be set too tight.

ScoobyJawa

Even though its brand new? Its got the paint all over it etc so that you don't tamper with it...........

Pete Croney

I suspect that your Tek 2.5 was mapped to suit the knackered wastegate on the old turbo.

I would carefully take it across to Merv/John and let him rework his magic.

P20SPD

iTrader: (1)

YES even though it is marked.

Just because it is marked, does not mean it is right, just means thats where they decided to put the paint

Get someone to pressure test it and see when it cracks open

ScoobyJawa

Pete - the TEK is simply the bog standard TEK 2, all they have done is substitute the 16PSi boost target for 17PSi, otherwise it is the same plug and play between cars TEK2 that you can buy.

P20SPD - Ta! can't believe that they don't check it in the factory!

Thanks for the answers guys. Better get the Dawes on as a stop gap then to keep the boost down at 1.25 until I can get it checked.

BugEyed

I think the advice that you have got from both the above is spot on. Your boost control would have been mapped for the old actuator, and the new one is different. Whether or not the new one was set correctly by Subaru it is different to the old one, and hence not correct for the map.

My advice is to do as Pete says, drive the car carefully back to the mapper and get them to adjust their map for you. If you want to avoid the overboost plumb the line from the turbo outlet straight into the actuator and this will mean that you only get about 7lb of boost til you get the map sorted.

Duncan

Edited to add - the good news is that your new turbo is obviously more efficient than the old one, so when you get it sorted you should have better response.

[Edited by BugEyed - 12/17/2002 3:03:55 PM]

ScoobyJawa

Hi Duncan - See above though re the map its a generic, not specifically tailered to my car!!! I can either do the 0.7 or use the Dawes to keep boost down so OK there.

I'll pressure test the actuator myself tonight hopefully. What should it crack open at?

Cheers
Neil.

ScoobyJawa

BTW - what makes you say the turbo is more efficient?

ScoobyJawa

BTT - anyone know what pressure the TD04 actuator should crack open at? 1 bar, less?

Thank you!

nom

Half a bar, I think!

Edited as I pressed the wrong button
The Dawes nor the solenoid disconnection will reduce the boost if the actuator is wrong - it'll just go to where it wants to & that's that! But should be easy(ish) to adjust, as long as your boost gauge is accurate

[Edited by nom - 12/17/2002 5:24:15 PM]

Pete Croney

The TD04 for the 01/02 is different (so Subaru tell me) but I've not compared the too.

I do know that when you map a 99 its a real struggle to get more than 1.1/1.2 bar out of it.

An 01/02 will run at 1.4 bar (don't try this at home).

I suspect that your new turbo is a shiny new 01/02 version.

john banks

I have found it easy and appropriate to get about 1.25 bar out of the MY99/00 TD04 in the midrange, and they have been known to make 1.7 bar (rather illadvisedly with a Superchip, but the turbo did last a few months before it let go). Sounds like the WRX turbos are better at the top end, where the MY99/00 cannot really hold much over 1-1.1 bar at 6000 RPM.

EvilBevel

Pete, would make sense. I read the same about the MY01 TD04L ... probably slightly bigger exhaust section ?

ScoobyJawa

So you think there is a chance I have a turbo from an MY01? Is there any way to tell the difference? I have the old one off my MY99 and the new one on the car to compare if I know where to look. Would the MY01 turbo boost to 1.4 if fitted to my sort of car with my sort of mods on the MY99...? WOuld it fit the MY99 up-pipe and downpipe without any mods?

I've been running 1.2-1.25kg/cm for the last 6 months and the defi gauge I have seems pretty accurate.

BTW - anyone got a step by step on how to pressure test the actuator?

ScoobyJawa

N.B. - Also spoke to Merv at PE on email earlier. He said he would be suprised if there was a problem with the actuator on a brand new turbo from subaru, but I'd like to check anyway. Do the MY01 TD04s crack open at a different pressure?
He recommended I cleaned out the boost piping with the restrictor in it (this was supplied with the turbo) and clean the boost solenoid and also leave the battery disconnected all night to reset the ECU.

If I have been supplied a TDO4 from the MY01, then is the restrictor size different as this would surely make a difference too? The MY99 had a 1.2 IIRC?????

Cheers.

Bob Rawle

The TD04 in itself is a limit to run boost but I have never had a problem getting one to spool to any boost ...

You have a new turbo and that is clearly different to the old one ... the boost response needs adjusting to suit, if that turbo had been on the car when you first had your ecu upgrade then the same thing would have been required.

The MY01's use different boost control pipework and are much harder to spool to 1.2 bar than the earlier cars.

Bob

ScoobyJawa

Thanks Bob,

Thats what I thought re the turbo, if I'd had the chip with this one fitted it would still need playing with!
I'm going to test the actuator strength at lunch to see what point it opens at. I may also put the old piping/restrictor from the old turbo on to try that.

So, anyone know the differences between the TD04 MY99 and the MY01+ and how to tell, just to make sure........

[Edited by ScoobyJawa - 12/18/2002 10:15:02 AM]

ScoobyJawa

Right - I've checked the wastegate tension and its opening at 0.6-0.65kg/cm (0.59-0.65bar, 8.5-9.5psi) ish on the defi gauge which I know is pretty accurate. Boost was holding at 0.6kg/cm but peak indicator on the gauge showed about 0.65 or just a tad more. Now this is about right for the TD04 (merv said about 10psi and others here have said slightly less) so it would appear the reason for high boost lies elsewhere.

I've checked the restrictors from my old turbo and on the new one, and they appear identical(except ones a bit more shiny ), or as near as I can tell with the naked eye, an engineers ruler and something to hold them together in line! So it doesn't appear to be them.

Tonight I'm going to try cleaning the 2 port boost solenoid and I'm going to unplug the ECU overnight to reset it. See what occurs tomorrow. (BTW, boost solenoid - cleaning is just connect green connectors under dash, ignition to position 2 and then spray in some brake clear in both pipes?)

Any other thoughts gladly received!