ROSSCNEW

Has anyone fitted a Dawes Device to their Sti, if so ,Did you have any problems.

Is it worth while fitting ?

Is there any noticable power gains

Cheers

Ross

ROSSCNEW

anyone

Dougster.

What sti??

And probably the answer is no, don't do it.

Ken Ross

Yes a STI 2

Apart from getting carried away @ Knockhill and blowing the Intercooler off (twice)

No problems

ROSSCNEW

Sti version 4

clubby

I've got one on my STI7. It was fitted before I bought the car, so no idea what it was like before. It was fitted to stop boost spikes caused by the Magnex exhaust w/full decat. It seems to work okay, but I've never driven the car without it so who knows.

Ken Ross

Give Dave @ AWD (Perth) a call, he should know, most likely he's fitted one.

01738 633336

john banks

IMHO, you need to check all or most of the following:

Detonation with det cans or knocklink or similar
Fuel pressure
Air fuel ratio ideally on wideband
Turbo compressor map
EGT
Charge temperature
Injector duty cycle

If you are not doing all this IMHO you are not doing it properly and are taking a risk with holing a piston, breaking a ring land or other detonation related damage to your engine. These engines can run phenomenal power relatively safely if you pay attention to the above, if you do not and it fails, it will be most likely because it was detting and you did not realise, hence Subaru engines have an (IMHO unfair) reputation for being made of chocolate.

With many UK cars you can put a Dawes and run most of them as high as fuel cut without issues, just with a boost gauge, because so many of them have been tested. For MY99/00 I have data on all the above for using a Dawes with a decat and fuel cut lifter up to 19 PSI on the standard turbo and 22 PSI on a hybrid.

Clubby, your car was terribly badly setup with the Dawes when I looked at it and I don't think your engine would have lasted.... case in point.

Boost is not everything guys, and just wacking it up on an STi is the last thing that should be done. Yes I remap ECUs, but I can't do anything for an STi4, so you know I am not biased here as I am not trying to sell you something you don't need.

If you are going to set it up properly then fine, but unless you are skilled with engine management leave it alone IMHO.


[Edited by john banks - 2/3/2003 5:32:41 PM]

ROSSCNEW

Im going to take it to star performance and let them fit it and set it up. Should i still worry even if they set it up?

Thanks for all input

Ross

john banks

I think Star or any specialist worth their salt seeing the little list of things above would be well advised to run a mile from a job like this.

I know some specialists think I am ultra cautious with my tuning, but none of the specialists in Scotland actually remap the ECUs themselves which I do for all of them.

Recently an overboosting STi which had half of the correct fuel pressure over 5000 RPM had a Dawes device fitted to it by a specialist. It had a lambda voltage of zero (ie leaner than 14.7:1) at 6000+ RPM at 19 PSI with no active knock correction (the ECU doesn't listen up there) and no way for the ECU to pull boost with no knock monitoring. This had been setup and the specialist had no idea what the engine was actually doing. Don't do it, and don't let anyone else do it either. STis are too near the edge already. I say this from experience looking at several examples which have failed and that have been near to failing again.

john banks

When I say all this there are notable exceptions like Andy F, but he is effectively mechanically remapping his ECU with the mods he does and IS monitoring all of the above. If you have his skills to do this then don't let me put you off.

ROSSCNEW

Thanks John,

I think i'll give it a miss.

ROSSCNEW

John,

I had my car rolling road tested, the boost peaked at just above 1 @ 5500rpm and dropped below 1 upwards.

The guy at star reconed the boost should stay constant above 5.5k if i get dawes fitted.

What do you recon ?

Thanks

Ross

john banks

Yes it would stay flat at that sort of boost level, but the ECU has inappropriately advanced ignition timing to do so with any margin of safety. Also the boost on the rollers would be lower than it would be on the road.

clubby

JB

Thanks again for sorting out the Dawes issue on my car. It had been overboosting in the colder weather recently, so we (Brian Downie)adjusted the Dawes again. It's not getting near 1.4bar now, and I gather 1.4 is what the standard car runs? Should I get it checked regularly on Delta Dash, I know someone who has it now -Santa couldnt stretch to a laptop and DD!

Clubby

john banks

Ian Litchfield recommended 1.2-1.3 bar IIRC. Speak to him about it.

clubby

Jb
Ok, I'll reset my boost guage to alarm at 1.25 ish, we'll see if it reaches that. Cant see me getting to press the loud pedal much in this weather!

I may just invest in Delta Dash, I need to learn more about the set up, I feel like a right thickwit knowing next to nothing about it. I worry it's going to go bang on me, which would be affa sare.

kevy1975

John,
I am in the Aberdeen area, have a Sti5 with minor engine mods, SS backbox and magnex decat centre as well as a Blitz LM induction kit fitted.
I do run the car on Optimax everytime but do worry incase there is "Knock". The car only has 13K on it but would you recomend a re-map or any precautionary measures, to give me peace of mind ?

Regards,
Kevin.

john banks

Use octane booster as well as Optimax, also get a knocklink and your car will be safer. A remap is a totally separate issue I am not trying to sell you one.