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Hot truck, why, high boost, bad IAT, cooling issue???

The GM4 does push 14-15psi easy enough, but its not efficient at all, my fuel economy goes way down when I do it even empty, and yes Turbine Docs testing on the GM8 showed ridiculous backpressure of like 40psi when running around 15psi. I just got another boost guage to tap into my exhaust manifold.
 
ITA, Buddy... should only be an issue if it's sustained, though. When I'm pulling hard on hills, that 'sweet spot' I talk about changes... if you watch your EGT and Boost gauges, you can find a place where boost stabilizes, EGTs drop or stabilize, and she just pulls.

Combination of Load, RPM, speed... find the right gearing and it's fine - if you try to push past that, you can watch the EGTs climb with the ECTs right behind. The Maxetork will help to prevent defueling, but sooner or later, it backs off, too.

I agree completely with you that the GM4 is a crappy turbo, that the -8 is better, and that the ATT is best. But ... pulling hard with a -4 can be done, and if Kenny is having issues with that, there is another problem - that's all I'm saying here.

I eliminated the other problems, and my truck pulls - it would be much better if I would get off my butt and install my intercooler - or sell it and buy me an ATT - but it does pull.

Kenny's should pull, too.
 
Not disputing what youre saying JiFaire, you are saying exactly what I originally explained. He doesnt need 14psi sustained boost, and he is getting it because of the TM, so he needs to adjust it down.

Or if you want the greater power and boost then get a better turbo that wont transfer so much EGT to IAT and create an ECT issue.
 
Matt if system is healthy you should not need the TTC lock IMO, none on mine, and I'm hauling up to 18K with no cooling issues,

I'm with Jim something is out of whack with Ken's truck we haven't nailed it down yet, and most times even with a with hogged down GM-8 I was steady rolling that load with just 7-10 boost flat cruising, only got to 12-14 on hills, could have pushed it more than 14 but I chose to just drive a litte slower 60-65 vs 75 up grade.

Buddy I don't think it the 14 psi+ (that is a contributor to hotter running) but the why 14 is needed that concerns me with just 7K of load on flat grade. Unless I'm reading data wrong.
 
Wait, let me clarify if I didn't TD, That snapshot IIRC was taken pulling a hill. Bill Heath said the same thing. iddn't think 14psi was too much. He said more boost it should run cooler of course that is on the boost side...but what I think you are saying Buddy is that to get that 14 psi the turbo is workin it's a$$ off and creating high egts by the backpressure which is why maybe the ATT is the way to go. Sucks too cause Slim won't have any ready till June and I had the chance to grab one last month. Story of my life. Dollar short...Day late. The fact is this, I did all the mods except TM and 4" exhaust and the truck was ALOT better. it could still briefly hit maybe 215 on a real hard pull but came back down quick enough. After 4 inch ex(which I can't see how that would hurt) and TM The high temps came back with a vengence. I mean the snap shot pretty much say it right ? IAT @ 260. I did want to measure the rad but this problem existed before the rad change and was almost solved after it. Have to look at..well what changed ?? The addition of a TM..
 
higher boost doesnt mean cooler. And Yes, to create 14.4psi of boost sustained your turbomaster is set to put more of the exhaust through the turbine creating more backpressure and the engine has to work harder (to compress the exhaust stroke to like 40psi), on top of having higher IATs. The vacuum setup would have dumped some boost, but the TM cant, you just have to adjust the TM to lower the boost.

You were only going 50MPH, imagine if you were going 70MPH when you hit the hill, at 2500RPM, and your boost went to 17psi and then dropped to sustain 14psi.
 
Higher boost means cooler up to a point... more boost = lower EGTs in general, but the inefficiency of the -4 can raise IATs which have a limited effect on EGTs. (read: not as much as not getting enough air into cylinder)... it's a balancing act... too much, you raise IATs because the GM4 is crappy. too little, you raise EGTs because there isn't enough combustion air. But 1* increase in IAT doesn't = 1* increase in EGT or in ECT.

Kenny, I went back and re-read your snapshot... that isn't the one from this recent run, is it? From it, I can see that you're lugging the thing on the hill... pick up your rpms a bit (drop to 3 locked at that speed) and you'll be fine... mine pulls nice and cool on hills at 2150 in 3lock... 4lock overheats me.
 
Yeah that snapshot was last summer. I sold that camper giving up all hope of towing(that and 5$ gallon diesel which now looks like it will return).
 
Not that bad, pal... that just means it costs me $50 to get 140 miles away from work with my 5er and a cooler of beer....

Cheap.:D

Seriously, try Buddy's suggestion, turn your TM down a bit. If it's a genuine Heath, open it so that the spring length is 2.25"... that'll drop you to stock levels.

Mine is set at 1.8", and it's fine there. Also try the TCC - I don't care what anyone says, it made a world of difference with me, with Rob317, with a pile of other guys.

Cooling these things is a matter of doing lots of little things right... if there was one big thing that works, somebody would have built it by now.

Other than the ATT - that works. But cooling in general, without ATT, means you gotta do all the little stuff.
 
Thanks Ken, 14 on a hill is reasonable, I was reading into it 14 all time, all stuff Jim said. ATT may still need some cooling, I haven't towed big non ICd with it yet, but I'll be adding WMI soon anyway, in addition to Jim's advise,

for under $150 the Derale aux cooler will help a lot, less trans heat for the radiator to be taking on, and with the electric fan operating independedntly/remotely you aren't in need of lots of air flow thru the rad or across the grille mounted cooler.
 
Turbine Doc said:
Thanks Ken, 14 on a hill is reasonable, I was reading into it 14 all time, all stuff Jim said. ATT may still need some cooling, I haven't towed big non ICd with it yet, but I'll be adding WMI soon anyway, in addition to Jim's advise,

for under $150 the Derale aux cooler will help a lot, less trans heat for the radiator to be taking on, and with the electric fan operating independedntly/remotely you aren't in need of lots of air flow thru the rad or across the grille mounted cooler.
Click to expand...

TD, your theory on the Derale aux cooler seems to contradict your theory on the TCC mod. With the TCC locked up, the tranny isn't developing unecessary heat via torque converter, which is passes along to the radiator. Yet, you seem to think this mod wont help him? Just curious. Not doubting the doc by any means. :)
 
No contradiction, probably both will be best, my direction that the TCC lock wouldn't help is that I don't think TCC slippage is cause of his issue, based on me not having TCC and ability to pull 18k in OD without TCC going goofy on me., and no overheat issues,

I've yet to see over 200F in the pan since adding the Derale cooler, since this engine design is so heat rejection challenged, any drop in temp anywhere you can grab it go for it IMO.

Jim says the TCC lock helped him and I believe it, so if any of my responses read as if I did not agree, not the case at all, with Ken's rig I'm thinking there is more to the story and TCC for him would not net as much as a extra cooler would do for him.
 
You guys gotta remember that Tim has a 98 (OBDII)and can't use the TCC lock mod... also, his truck has better cooling (2 x t-stat, high-flo pump) than ours to start with.

I have a HC Deraile pan also with cooling tubes, but never got it put on, after I got things to run cool the impetus just disappeared, along with my ambition.

I should sell all my leftover stuff someday, huh? Either that or put it on the truck... :D
 
Link to the cooling pan you guys are talking about ? PM me if can't be posted.
Thanks
Packratt is loaning me his GM8 in the interim to see if that makes any difference. It's an easy swap so worth a shot.

So no one likes my hood scoop/topmount I/C ??
:)
 
Acesneights1 said:
Link to the cooling pan you guys are talking about ? PM me if can't be posted.
Thanks
Packratt is loaning me his GM8 in the interim to see if that makes any difference. It's an easy swap so worth a shot.

So no one likes my hood scoop/topmount I/C ??
:)
Click to expand...

Here's a pic:
14107-large.jpg

Bill Heath, Kyle, Chad all have high-cap pans, but they're the case aluminum ones, and are more expensive than this one. Still, you might give them a try... all our vendors have also been very good about finding and ordering stuff in for us, if they don't carry it to start with.
 
Scrufdog built a really cool Top-Mount IC... I thought it was about as fine as froggy-fur, but I sure wouldn't want to dismantle it all every time I changed fuel filters, OPS, Glow relays, CDR, etc. Besides, I have had the furry little buggers try to set up shop under my Turbo-Power Cover with Pine cones and nest material... I wouldn't want them living under an IC.

Unless you are off-roading, a hanging IC works just fine... anything that hits it is gonna hit the cross-member, too. JMHO.
 
Actually, No, Tim... like I said, I bought the damn pan and then when my TCC Lock provided the last little thing I needed for cooling, I sort of lost the urge, and I never got around to installing it. I kept telling myself "next time I change fluid, it's going on"...

...guess who hasn't changed fluid lately?

I am such a bad man. I haven't hauled through the mountains for 2 years, so really didn't need the extra cooling - lots of that kind of stuff has been waiting for me to get my butt in gear, and now I'm probably selling the truck/trailer this spring, so I might not get around to it, anyway.

Gonna be one heck of a garage sale.
 
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