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guyd_15
10-29-2006, 08:54 PM
Sneaking up on our new tune up. Installed the EGT gauge to complement the Dawes Device.
I believe I read once that a rich condition can cause elevated EGT readings. And I just wanted to ask you guys what you thought.

Took the car for a short ride at WOT the Dawes reads blue (rich) while at the same time EGT readings reached about 1650 (ambient temperature about 60 F). Pulled the plugs they look good (a little black) the car does display the symptoms of being rich, spools a little slow and some break up under boost. Boost is at 12lbs on a 15lb cal. Fuel pressure is 55lbs static.

If you need to know the car set up
2.2/swirl
88 TBI cam
+40's
TU 3 Bar cal 15lb/29lb switchable
Super 70/.63 turbine housing
2 core intercooler
3" swingvalve
3" downpipe
3" cut out

Thanks,
Guy

Frank
10-29-2006, 08:56 PM
Rich means EGT's will go down. However based on what you just said, high EGT but obvious rich condition, you arent running enough timing.


Frank

guyd_15
10-29-2006, 09:34 PM
Thanks, Frank. Are you talking about ignition or cam timing?
I forgot to mention the head had the deck cleaned up, when I was at E-Town DBL TRBL checked the timing with me and it was aboth a 1/2 tooth retarded, combined with the round tooth cam switched to square pulley I bet I'm close to 3/4 of a tooth off.
Guy

Frank
10-29-2006, 09:38 PM
I was talking about ignition timing. I dont know about the cam timing if it would cause that.

guyd_15
10-29-2006, 09:47 PM
Thanks, I'll bump it up a couple degrees and see what happens.
Guy

Frank
10-29-2006, 09:59 PM
I dont know if that will do it. Base timing wont have enough of an effect for that... its the timing in boost. With the EGT's you are running, do not back down fuel. ;) So what is the scanner reporting for knock on this? It should be pretty dang low. Sounds like you may need a cal update.


Frank

guyd_15
10-30-2006, 05:29 AM
I'll hook up the OTC 4000 tonight and see what it says before I change the ignition timing.
Guy

Bubba
10-30-2006, 04:30 PM
I have a similar issue due to running too high compression on a 2.5 with a swirl head. Head was shaved too much.

Frank
10-30-2006, 06:14 PM
I forgot one thing guy... You could also have to big of a gap on your spark plugs... make them around 24.


Frank

shadow88
10-30-2006, 07:34 PM
Do you think it's possible this is running so rich, that the fuel continues to burn after it leaves the combustion chamber?
Just a thought, but I agree with ignition timing.

contraption22
10-31-2006, 01:17 AM
Do you think it's possible this is running so rich, that the fuel continues to burn after it leaves the combustion chamber?


The same could be true for retarded ignition timing.

guyd_15
10-31-2006, 08:40 AM
Didn't get the scanner hooked up last night, probably have to wait for Wednesday night at the track.
Thanks for the replys guys. My kid wants to get it right before Cecil.
Guy

BARRON
11-02-2006, 08:10 AM
I think Shadow88 is on to something.. It my understanding that if the probe is in the manifold runner,rich will lower the EGT's. If the probe is in the down pipe(After the turbo) That EGT's from bein rich will be hotter.

I'll get that link after a bit...

guyd_15
11-02-2006, 08:37 AM
No more Wednesday night at Cecil, guess I have to wait until tommorow night.
Guy

Rattlesnake
11-02-2006, 09:02 AM
Do you think it's possible this is running so rich, that the fuel continues to burn after it leaves the combustion chamber?
Just a thought, but I agree with ignition timing.
If that was the case, the turbo would spool fast due to the energy release of the expanding heat build up by the gas explotions after the cumbustion chamber and before the turbo. Try closing the gap on the plugs like frank said and recheck your ign. timming.