EGT issue

Discussions concerning the M7790 cpu

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Adrian
 

Posts: 57
Joined: Tue Mar 13, 2012 1:57 pm

Re: EGT issue

Post by Adrian »

Hi
I made the same experience with SR20det. I saw already 980deg exhaust temps (measured before turbo) on stock S14, if you push them really hard on the racetrack or on the German Autobahn.
We spend days to bring the exhaust temp down because we reached over 1000deg with a GT2871 Turbo and AFR's below 11.0 ! Different compression ratios, intake manifolds, cam timing, removed squish area etc.
The only thing that has helped a bit was cam timing and the removed squish area, which alowed to run about 6-7 deg more timing on 98octane fuel.

Because of the very high exhaust temps still in stock condition, you will reach very easy the termal limit of the engine on pump fuel.
NO matter what we tried, we can't run above 1.3bar of boost. Otherwise EGT's will go about 1000deg, wich will end every time in blown gaskets, cracked manfold etc. Anything on exhaut side will get damaged sooner or later.

Because of the temal issues we made the decission to switch the fuel to E85. It's a great fuel for turbocharged engines. Made a 600HP+ Time attack Evo a month ago. EGT's are always below 900deg also on harsh Time Attack use and oil temps are about 15deg lower on track than on pump fuel.
Except of that, we benefit from much higher knock resistance and more safety with E85.
I really recommendend to map every high boosted, high powered or also hard pushed light modified engines on E85!
JM
 

Posts: 21
Joined: Fri Nov 27, 2009 6:43 am

Re: EGT issue

Post by JM »

i had the same problem with stock internals sr20de + gtir turbo. Everyone around is saying that sr20de+gtir turbo under 10psi is save, but i dont think so. I tried everything on my two engines to make them reliable. One finished with blown headgasket(by high egt) and other one melted spark plug when egt was at 800celsius(i added some timing to make the egt lower which helped with numbers on the egt gauge, but if you do it, the heat will move from exhaust area to cylinder head which is even more destructive)
thats my experience

edit: i was always using 100 octane shell V power on 11-12 afr
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