Where are you measuring your EGT's? Where in the exhaust system is the probe mounted?

 

The probe is on the left side about one foot down from the manifold. It is a autometer unit.

 

I don't know what my EGT's are but i'm rarely in boost when i tow. It's pretty flat around here. And when i do pull up hills and bridges it might get up to 3-4 psi boost. but its not for very long. I think having the 4:10 rear make a difference on the load.

 

If your seeing higher EGT in vacuum then under boost, then I don't think you have much to worry about. There are a lot of things that come into play with EGTs on gas engine, fuel,timing and some other stuff. There not as cut and dry as diesels. Check out some of the turbo Buick boards, those guys tuned for a long time with EGTs and you can get a better idea on what affects fuel and timing have on EGTs. My truck get into boost all the time with my little motor and all the hills around here (5/6lbs on the at 75-80 on hills). I had an old pyrometer on it and finely took it off, cuz I didn't like what it said and my turbo is still running strong. I also do a bit of towing and don't worry about the EGTs as a lot of heat is dissipated between the temp probe and the turbo on rear mounts.

 

Yeah but that's what I was saying to begin with!!! He's not worried about the affects the gas temps have on the turbo!! He's saying that if temps are that high coming out of the block then he's affraid he'll end up melting a couple parts due to the fact they are alluminum!! The turbo isn't the issue at all... more so the heads and piston internally that are taking the direct heat. If Alluminum tends to warp somewhere b/n 1400+ then he's got a real problem on his hands, as do the rest of the stock engine people. I was thinking maybe larger exhaust system could help but who know's!! Maybe time to step up to some iron heads!!?? But then you sacrifice wieght. Not that it's that big of a deal but I know to some people it is. Then on top of that how do you keep the pistons alive if they too are alluminum. Luckily for me I have all t304, forged, & billet steel internals

 

Ya 01Blackerado hit it right on the head, who cares about the turbo lol.

 

Me too

NOt to hijack the thread but after reading this thread it seems the STS may be a better turbo kit to buy if you are going to tow? My 418 will be getting FI this summer after the head swap and I have been racking my brain on what to get.

 

I agree, and i have the CI heads so i'm not to worried. If it blows, oh well i'll have to put a 408 I've been towing over 9,000 lbs 5th wheel over a year with no problems.

 

Ya if I had the Cast Iron heads I'd worry less too, I think I'll try adding a lot more timing, keep the truck out of boost, and watch for KR.


O here is a pic of the Boat causing all my headaches.

She matches the truck well. Too bad it is almost December.

 

Ive seen egt probes measure 300 degrees different, same engine, same day, same location.

Hook up your boat, haul it down a flat stretch of road and watch your EGT. make a note of the temp. if it gets more than a few hundred degrees hotter than that when climbing, then you might have a problem. nice boat, btw