U D C

Drive pressure is a function of flow and resistance, as EGT's decrease the CFM's decrease so it's not a good indication.

Really the best way is to know your timing and run EGT's accordingly. It's not so much the actual degree when injected, but how much is before and after TDC. Each truck will be slightly different, and usage will determine the max safe EGT's.

More timing and high EGT's means high cylinder temps, less timing and high EGT's means lower cylinder temps.
 
dvst8r said:
I disagree, I have had piston's melt with under 1500 degree's seen on egt's and others last for dozens of passes at 2000+. There is more that goes on with cylinder heat then what is read by the egt gauge.
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AH64ID said:
Precisely, timing plays a huge factor. It's why the 04.5-07 stock motors can live all day at 1450° towing, but if I were to try that with the timing I have in UDC it would melt something.

EGT is just the easiest thing we can measure, but it's not always a direct reflection of cylinder temp.
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Thank You!!
I've been telling folks this for years. Esp on CF, but most think an EGT gauge is the end all be all.
 
Big Swole said:
Thank You!!
I've been telling folks this for years. Esp on CF, but most think an EGT gauge is the end all be all.
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Somebody put it best a while back.. the EGT gauge replaced with a clock would be more useful for that spot on the pillar. (or something to that extent)
 
AH64ID said:
Drive pressure is a function of flow and resistance, as EGT's decrease the CFM's decrease so it's not a good indication.

Really the best way is to know your timing and run EGT's accordingly. It's not so much the actual degree when injected, but how much is before and after TDC. Each truck will be slightly different, and usage will determine the max safe EGT's.

More timing and high EGT's means high cylinder temps, less timing and high EGT's means lower cylinder temps.
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It wouldn't help for drag racers and street trucks, but for those of us that tow heavy, watching your oil temp would probably be a better indication?
 
bgreen776 said:
It wouldn't help for drag racers and street trucks, but for those of us that tow heavy, watching your oil temp would probably be a better indication?
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Yes if oil temp is rising faster than coolant temp you are probably putting a bit of heat into the pistons.

I can watch my oil pressure drop on long grades, even thou the coolant stays steady.


I was just thinking about drive pressure. It self isn't an indication of cylinder temps, but it does lead to higher cylinder temps from more exhaust staying in the cylinder, and thus less boost and cool air entering. The more DP gets above boost, the less clean air enters the cylinder on the intake stroke.
 
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All things that can be measured with gaugess are important. Being blind is stupid.

Knowing the whole truth and understanding what is going on between the relationship of all is what matters period.

Keeping drive close to boost...egts under 1500....rail pressure under 27000...and coolant and oil pressure up there is the ticket.
 
cquestad said:
All things that can be measured with gaugess are important. Being blind is stupid.

Knowing the whole truth and understanding what is going on between the relationship of all is what matters period.

Keeping drive close to boost...egts under 1500....rail pressure under 27000...and coolant and oil pressure up there is the ticket.
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Well put.
 
still haven't gotten an answer if you guys are running udc or ssr, this thread seems to have gone off track if ssr is getting discussed.
 
I kinda figured, but why the hell are they talking about it in the UDC thread? I wish the guys that are running UDC would put UDC beta in their sig so we can keep this straight, I'm all for chatting up what works in for SSR, but in its own damn thread. Leave this one for UDC happenings.
 
Finally I got her to spin over 5000rpm last night. Gonna hit the dirt drags Sat. and see how it all works out.
 
That's the problem there is nothing happening in the UDC thread. If we didn't say something anything on this thread it would have fell off the page already! Just trying to keep it alive right now!
 
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