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chrome@home
13th October 2003, 19:38
Would someone please mind explaining to me about the reasons for having an EGT guage in the car, and what is does, how important the readings are, and roughly what is considered to be a safe, and unsafe reading.


thanks in advance for bearing with me. http://bbs.22b.com/ubb/smile.gif

David_Wallis
13th October 2003, 20:16
AFAIK high egts can come from timing and mixture..

basically Im happy with anything upto 1150 / 1250 deg iirc..

or my turbo is at least http://bbs.22b.com/ubb/biggrin.gif

harvey
13th October 2003, 20:35
I hope these readings are in degrees `F`.

The EGT will vary depending on whether it is measured before or after the turbo. The EGT, especially before the turbo will help to identify weak (or rich) AFR. The difference in EGT`s before and after the turbo can also give an indication as to the efficiency of the set up.

At a high level of tune the EGT readout can be another safety feature to protect the engine, providing you are keeping an eye on it or have the tell tale set at a pre determined level eg. 940C in the collector.

David_Wallis
13th October 2003, 21:27
no, just checked... 1150 deg c

or as previously said you can use 713C Inconel turbine wheels..

see http://www.turboneticsinc.com/new_product.html

or http://www.mhi.co.jp/tech/pdf/e391/R1-391-Last-P-Subset.pdf

more interesting if your wanting to run jet turbine style antilag etc..

David

harvey
14th October 2003, 02:52
David: Where are you measuring these temperatures? I am not an expert but if these are EGTs in the up pipe or headers then IMHO they are way too high. At what temp does cast aluminium melt?
Could we be at cross purposes?
Sounds scarey.

David_Wallis
14th October 2003, 09:13
Im not seeing these temps, just quoting what I have read when choosing a turbo..

I thought alloys melted at around 600-700deg.. but its been a while since school http://bbs.22b.com/ubb/smile.gif

I know the heads are cast too..

Im not saying that I would be happy with those temps..

David

David_Wallis
14th October 2003, 09:40
Anybody thought about 4 egt's 1 per collector and logging using microcontroller and laptop or LCD display?

Could display average egt.. and then if the difference between cylinders was excessive then sound an alarm?

David

harvey
14th October 2003, 18:18
"basically Im happy with anything upto 1150 / 1250 deg iirc.."
Just to clarify: If your temperature at the collector exceeds 950 deg C or there abouts it is time to lift off and check AFRs. Run for any length of time signifigantly beyond 950 C and it is time to order a new engine.

David_Wallis
14th October 2003, 19:06
Which collector?

I have four..

One has the egt probe in.. this is just pre turbo.. the other two are below the right hand head..

Ok maybe I should have phrased my reply a little differently.

David

harvey
14th October 2003, 20:57
Hi David: When I refer to the collector I mean where the four branches join into one so you are measuring the temp of all four cylinder exhausts together after they have joined.

David_Wallis
15th October 2003, 09:28
figured as much, just being pedantic http://bbs.22b.com/ubb/biggrin.gif http://bbs.22b.com/ubb/smile.gif