I took a run to Glocs on the weekend. Went in the morning about 10:00 a.m. and I new it was going to be warm so I set up a thermocouple in the i/l, post i/c.

Temps before starting engine (in garage) were 20 degs and off boost was steady 30's, this is on std MY00 i/c.

On boost temps quickly rose to high 40's and even 50's.

Slowing for roundabouts brought down the temps to 30's again, but traffic lights saw rising 40's on heat soak - better watch the drag from lights!

Knocklink in morning only light first 2 greens on gear change.

In the afternoon, the weather was hotter. Returned at about 4:00 p.m. and read the temp guage BEFORE starting engine at 50 degs

On the move this settled to mid 30's again and even at 100 *ph off boost you can steady the temp at 33ish degs.

But the outside temps had grown and now on boost, I saw high 60's and even 70's on boost. This manifested itself as greens and then flickering red on the knocklink on mild boost at 100 *ph. I didn't want to see if it was anything more than flickering/transient red!

The car didn't feel slow but without the knocklink then I wouldn't have known and backed off.

The car was running optimax and is in a mild state of tune. The AFR seemed to be OK as did boost levels.

So what I'm trying to say is that in this extreme weather TMIC's are having trouble coping. Even mild boost can send temps soaring and your knocklink flashing. Unfortunately I didn't have water spray so I can't tell you if would've made a difference (but I will get it now).

Anyone else experienced the same?

F

 

70C in road use in the UK (even though it is very hot) suggests there is a problem such as a boost leak, or that the boost is just too high for the cooling capability. Unfortunately 99/00 ECU does not know the charge temperature, if it did you would want it to drop the boost in these circumstances. Retarding the ignition further or adding fuel will not really cure the problem, need to drop the boost or improve the intercooling.

Samco intercooler hoses can help in this situation if not already on the car. The lower pressure drop gives a lower compressor discharge temperature for a given manifold pressure. Water spray may reduce the temperatures by 5-10C in these circumstances.

Obviously better intercooling and/or water injection help, but at a price, as would a larger turbo, less restricted exhaust to lower EGT etc.

 

I'll try another temp gauge just incase this one is over reading!

I'll also have a good check over the plumbing. The i/c looks fine though with no bent fins and just a couple of fly's.

F

 

I also noticed knock in this hot weather on settings that were not knocking earlier in the week..

Worst was sitting in queuing traffic.. induction kit obviously sucking in air off engine.. pulled off in first.. on boost...
knock knock.. whose there? Mr Det...... rather than debt.. makes a change..

Doh..



Bigger intercooler calling...

JGM

 

What were the ambient temps on these hot days over there?

Cheers,

George.

 

andyF was reading over 50 degrees charge temp after the intercooler on the start line for the handling track yesterday and he has a decent front mount intercooler, so it is concievable you were seeing those temps today with a top mount.

 

I gather Andy's high temp was heatsoak whilst sitting there stationary after a hard run. I believe his temperature on the move was low 30s under full boost.

If Floyd's was 33 on cruise I would not expect 70 + with boost if you were doing 100 *ph

At Knockhill, with a complete lunatic driving, you hit the highest temperatures at the beginning of the main straight, about 52 after five laps on a similar setup to Floyd's and it is down into the high 30s by the bridge just under about 1/4 mile later when you are doing 110ish. This is with ambients of about 10 C lower than the recent hot spell in the South. 70 C still seems remarkable to me on basically the same spec of car. I don't think your gauge is out Floyd, otherwise it should not have lit up your knocklink if the temps were in the 50s.

If it is 70 in road use in this weather and there are no leaks, the boost has to be turned down.

[Edited by john banks - 7/15/2003 9:28:11 AM]

 

Where do you get your temp stuff from ?

Am interested in fitting something to mine, is it just a probe somehwere near the intercooler, and a relevant gauge

Cheers

Steve

 

With fmi(680x270x88mm) no water spray
On my97 with motec readouts from inlet air sensor:
Norm driving, max +3 above ambient
Idling ,max +7 and dropping as above once moving
On boost (1.4bar) +8 at first stabilizing to +5 above ambient.

Cheers

 

Low 30s are very cool summer days for us over here. Imagine what our poor scoobs go through when the average summer day temps are above 36 and we get quite a few days in the 40s as well.

I have recently refitted my Blitz electronic boost controller to lower my boost down to 1bar for the 40 degree days, just to be on the safe side.

Cheers,

George.

 

Will running the A/C make any difference the fueling/timing when on boost? Just seem to show more activity on the knock link when I have the A/C on than off on these hot days, just for reference the car is a STI5 with a BRD3, APS FMIC and full decat.

Paul

Edited because I am a ****e speller

[Edited by pban - 7/15/2003 11:31:58 AM]

 

Hi John,

Ok to pick your brain ?

With my Sti7 PPP if the ambient temperature goes above 27/28
degrees the boost seems to be limited to .5 of a bar worst case.

Normally boost is 1.2/1.3 bar.

Do you reckon that its just the ECU pulling the boost down by
design or maybe something sticking due to it all just being to
damn hot ?


Cheers

Dan

 

Steve,

I know you can buy thermocouples and digital thermometers from Maplins. Not sure if the guys are using specific gauges or just these.

Stefan

 

Steve

The expensive way is fit a SPA gauge with thermocouple

Paul

 

Dan it is probably dropping the boost in response to detonation.

You should get the dealer to check it. Although it does not surprise me knowing the contents of the STi 7 ECU and the fact that the boost is just increased on the STi 7 PPP with no other alterations, I don't think that a Subaru approved setup should shut down the boost like this - it is obviously very close to the edge/over the edge - that is assuming there are no faults on your car.

Check the current situation on the fuel pumps for STi 7 PPP, and also I suggest you get a knocklink. I suspect it might make Floyd's look rather mild

[Edited by john banks - 7/15/2003 11:57:22 AM]

 

Cheers

Any Maplins Part codes? or a cheap alternative


Also I take it running a Dawes in this weather is not a good idea ?


Steve

 

Cheers John,



Looks like I'll have to take it round to them again...

Last time they couldn't find anything...but the temperature had
dropped from the previous day.

Is the Sti7 PPP really just a boost hike ? wow

 

The PPP has only been on for about a month and a half...

And it does indeed have an uprated fuel pump.

Looks like it'll be coming off...cos other than lowering the boost
I don't see what they can do

 

Re the Dawes, if your ears are not used to listening for knock or you don't have a knocklink best to turn it down. It is better to lower the boost in this weather, performance will probably not be lost that much.

Re the PPP - get is checked out. If nothing is found then almost certainly there is or the ECU thinks there is det which is why it is shutting down the boost.

 

Thanks John

I do have a knock link, and it is quiet as a mouse, but then I have been keeping off boost too (at least until I get the Dawes off)

 

Pban,

If you have the aircon on, the engine is working harder to drive the pump and also the water temp may be a little higher due to heat from the aircon radiator. This may explain the extra lights on the KN.

Les

 

FYI I have a K type thermocouple placed in the mouth of the inlet manifold, post i/c. It is connected to a Fluke measuring instrument. You can purchase these from Maplins (or similar devices) or RS etc. The thermocouple is just a piece of wire so it can easily be slipped between hoses and pipes to measure temps inside.

I measured the temps again on the way into work (7:00ish). Ambient 20 degs, i/l temp before start 20 degs. Cruise saw 24 average, on boost - mid to high 30's with peaks of 45. I could see 45 sitting in traffic easily. No knock activity other than normal greens on gear change.

I really don't think that anything is wrong with the car, just a case that the TMIC can't cope with the boost at high ambients. So, I either turn the boost down with a dawes or improve the cooling somehow.

It seems that with normal ambients (20's) the TMIC can cope, but raise it a little more and on boost temps rise in a non linear way (ambient 20degs = 45degs on max boost, ambient 30 = 60/65 or more). Perhaps the TMIC just can't lose enough heat to recover between acceleration runs? The heat builds up cumulatively?

My post was really to warn of potential dangers in this hot weather if you don't have a knocklink, and are running more than std boost or possibly even if you're not.

F

 

Les

Might explain it, car is certainly not a lively with the A/C on

Paul

 

A 10 degree increase in ambient should give a 10 degree increase in charge temperature.

 

Taken it to the dealers...

Happend just as I said...we took 3 snapshots using the select
monitor all of which are being uploaded to Prodrive and Subaru
now (gets to .5bar at about 2500 revs and holds it all the way).

Should hear back this afternoon...

Thanks for the advice John.

 

Find out the knock correction and the igntion advance multiplier figures for interest.

 

I'll back your warning alright Floyd. I was enjoying myself on a country road and although usually mine will only just manage one green light on the KL, I got a rapid four lights up to the second amber when I wound it up in third. Must have been the high ambient temps yesterday.

Les

 

Ive now took my Dawes off, and im hitting 9 PSI max instead of the standard 14.5 PSI (UK MY00)

 

A little heavy handed, welcome to the world of Audi 1.8T motoring

 

PMSL

Feels like im back in the old golf gti turbo (saying old it was newer than my scoob)

I think the reason is that Im missing the restrictor in the turbo pipe now

so back on with the Dawes