Very high egts towing..

[Turbine Doc]

Kenny IC dropped my IAT when with my GM-8 so that IAT was never more than 30F over ambient for GM-X towing I think WMI or IC is a must have accessory when boosting over 10 psi.

When with my 1st Heath re-flashes or even with the GM F stock program fooled to allow for more boost, & with the GM turbo I never got close to melt, I saw 1200F EGT a time or 2, but I self limited to 12-14 boost

 

[Acesneights1]

I can hit 1300 in 2 seconds if I am not careful Maybe more. This is towing uphill. Even my Tahoe never did that. Unless Matt's carcode is off we set it at -1.50 . Truck runs starts and pulls great. Just gets really hot, really fast.

 

[iamdave0887]

That's nuts Kenny. I couldn't hit 1100*F towing uphill with a 7K load in 3rd TC locked going 55 mph. I was running ~ 12-13 psi boost, but the truck was smoking a good bit so it could've used a little bump on the T/M me thinks. This was with my GM-5 as well, and we all know the 5 isn't as efficient as the 8 your truck has from the factory. I ran 15 psi on my GM-5 for a long time(spiked 17 psi several times on accident) and my truck's never gotten that hot.

My timing is at ~ -0.90. I wonder if it's your -1.50 timing causing it.

 

[buddy]

I think its just a more sensitive pyro

 

[Acesneights1]

Yep. Autometer Pro series. All I use. worth the xtra $$.

 

[Acesneights1]

well, I finally got to talk to Bill today. I think he gave it more fuel than I thought. He said he would reprogram it if I want to less fuel or I could just drive it by the Pyro. I'll see how the Pyro thing goes. I like the way it runs empty. Very High SOP.
I saw an interesting truck over the weekend which put a few stupid ideas in my head. It was a mid to late 80s CCDRW K3500 OBS. It was lifted with a Cummins conversion. Had a standalone transfer case with a Road-ranger trans bolted to that Cummins bad boy. Talk about drool... Anyway as I was spying on how all this was shoehorned in they had taken the radiator and extened th mounts towards the motor basically moving the rad about 3-4 inches closer to the fan and then freeing up lots of room for a nice big Cummins IC. Now I realize this is a different body style truck but the idea holds water. IIRC the rad in NBS trucks is pretty frickin far from the fan and could easily be brought closer to free up room for an IC mounted where it should be not hanging under the truck lookin like I ran over an old pizzon with an organ grinder and got it stuck under my bumper. Whatcha all think ? Got's me a welder....
A nice big properly mounted IC could help although I still seem to have issue seeing how that will help egts. IAT's yes but Bill swears to me more boost lowers egts. I'm havin a hard time with that considering ex back pressure is built up by high boost via the wastegate.

 

[great white]

Hmm, moving the rad back is a very intriguing idea for a proper CAC. Bears a bit of investigation methinks....

I think the relationship of higher boost, egt's and "backpressure" is dependent on the particular turbo unit as much as anything else. We all know of the generally accepted limits with the GMx series turbos....IIRC it's not that they stop building boost, it that they start causing more of a restriction than they provide air mass to the engine. The compressor will also reach a point where they are no longer efficient, but I haven't been able to sourse a proper map for the GMx series turbo's, just the newer IHI models (rc6 IIRC).

TD can probably provide a bit more insight on that one....

 

[buddy]

I doubt he gave more fuel than you can handle, I run about as much as it can and dont have that problem. Although I run more boost than 15psi on the GM4, get it to 20psi pretty easy. I'll have to get a new EGT gauge someday to compare, since mine is like 15 years old Banks.

 

[1999gmc]

Before I had Heaths Reflash I had a boost fooler from Kennedy. Stock I would get about 11-12 psi max. When I put the boost fooler on it and set it to 15 max it lowered my EGT's 100-200 degrees. At 15 max, my CAC, and the stock programming I couldn't get above 1000 degrees on a 6% 5 mile pull with a 9000lb toyhauler behind me. I have HO injectors, Heath GLE reflash, CAC, and on that same pull now I will have to back out on the last 2 miles to keep it under 1150.

 

[great white]

Before I had Heaths Reflash I had a boost fooler from Kennedy. Stock I would get about 11-12 psi max. When I put the boost fooler on it and set it to 15 max it lowered my EGT's 100-200 degrees. At 15 max, my CAC, and the stock programming I couldn't get above 1000 degrees on a 6% 5 mile pull with a 9000lb toyhauler behind me. I have HO injectors, Heath GLE reflash, CAC, and on that same pull now I will have to back out on the last 2 miles to keep it under 1150.

Hmmm, now that's very interesting.

Your intital setup sounds kind of like what like a plan I've got in the back of my mind......

 

[Matt Bachand]

I doubt he gave more fuel than you can handle, I run about as much as it can and dont have that problem. Although I run more boost than 15psi on the GM4, get it to 20psi pretty easy. I'll have to get a new EGT gauge someday to compare, since mine is like 15 years old Banks.

Think an ATT would solve his issues Buddy? Do they offer money back guarantee if he's not happy?

 

[buddy]

I know that these trucks run very strong at high advance timing, and I have seen timing curves on aftermarket towing tunes that would make me worry about grenading the engine under high load. Running empty it works great, but if you tow or sled pull or race a bunch its bad. Because as IATs rise with boost, the ignition time of diesel decreases, so the lag between injection and ignition and complete combustion is less.

Anything to lower IATs will allow you to run more advance though, so ATT, intercooler, cold air intake helps in more way than one