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-   -   EGTs, not just for breakfast anymore (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/egts-not-just-breakfast-anymore-788548/)

thewird 06-19-09 09:24 PM

^ what about WOT?

thewird

arghx 06-19-09 10:19 PM

I've got 380 miles on the motor, I haven't dropped the hammer yet. I'm just feeling it out slowly.

Dudemaaanownsanrx7 06-19-09 10:42 PM


Originally Posted by arghx (Post 9302228)
Ok so I've been working on my base tune. At about 2/3 throttle I'm hitting 1650 degrees rear rotor and about 1500 front rotor. This is with a series 5 LIM (no flow imbalance). Boost is about 13.5 psi, leading advance 15 degrees with 15 split, 8.5:1 rotors.

So how hot is "too hot" on straight 93 pump fuel?

Have you tried adding fuel to the rear rotor via lag settings to see if it changes at all? Maybe the exhaust manifold causes differences in flow?

Or maybe because the coolant runs from the radiator to the water pump, then to the front rotor, then through the centerplate and finally to the rear housing, maybe the water cannot remove as much heat since it's already been heated by the first housing. Thoughts?

Arghx are you running or plan to run any aux injection? Glad to see your project has been coming along, you seem to document your results quite thoroughly. I've seen people report much higher EGT's then that, but the general idea has been to keep them under 1700 if possible. I don't even have any idea what mine are, maybe ignorance is bliss lol... that is unless mine are low then I wouldn't mind knowing.

fritts 06-28-09 02:04 PM

Before you make changes in the fuel balance swap rotor EGT probes. I would also check temp at ambient and after driving (engine not running) to so if you see the same imbalance. It may not be an imbalance in the manifold but an imbalance in the EGT probes and amplifier. It doesn't take much difference in resistance to cause large changes in temperature reads.

arghx 06-28-09 04:17 PM


Have you tried adding fuel to the rear rotor via lag settings to see if it changes at all? Maybe the exhaust manifold causes differences in flow?
has this ever worked for anyone? Because it's never worked for me, at least from adding up to .15 additional lag on the rear secondary injector. The exhaust manifold doesn't have perfectly equal length runners I don't think. But both probes are located 1" before the flange. If the exhaust weren't so damn hot I would put widebands in the exhaust manifold preturbo, but it would never survive for any length of time so there's little point given my current budget.


Before you make changes in the fuel balance swap rotor EGT probes. I would also check temp at ambient and after driving (engine not running) to so if you see the same imbalance. It may not be an imbalance in the manifold but an imbalance in the EGT probes and amplifier. It doesn't take much difference in resistance to cause large changes in temperature reads.
At ambient temperature the two probes (which are brand new) read within 4 degrees F of each other.


Or maybe because the coolant runs from the radiator to the water pump, then to the front rotor, then through the centerplate and finally to the rear housing, maybe the water cannot remove as much heat since it's already been heated by the first housing. Thoughts?
this is honestly the best hypothesis I've heard up to this point. It's certainly not an LIM issue--I have a series 5 LIM which doesn't have the imbalance of the series 6. I wonder how much of an effect factory EGR systems have on EGT.


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