Turbo heat management ideas
 

I was just wondering what some of you turbo guys are doing to keep heat down. I just towed a 5,000lb trailer about 25 miles, and saw my coolant temp hit 225 degrees. The IAT temps were 120-130. The road was mostly flat so I was not in boost very much. I had the cruise set at about 62mph, and the outside temp was 93-97 degrees. Is this normal temps, and I shouldn't worry, or is it too high to be considered safe?

I have a turbo blanket and the pipes are all wrapped. I pull a 5k boat almost every weekend and will see 210 if it is 95 outside. My truck is not in boost very often at all though unless I am climbing a steep hill.

I just wondered if stuffing 130 degree air back into the motor was driving temps up. I have a 72mm turbo on a 6.2 so it will make boost under 2000 rpms if the load is right.

Yea that turbo is pretty small for that engine. A more properly sized turbo would definitely lower IAT's.

I'm towing my car to LS Fest with this truck. So I'll log the temps real close and if I'm not happy with what I see, then I guess I'll take everyone's advice and move up to a larger turbo.

Either go to a larger turbo or buy a VERY good intercooler. I know the ones that come in the KB and Trick kits work good, but there are better options out there.

I have the large Trick Performance intercooler, but I had my methanol set to start spraying at 4lbs and hit max pressure around 7lbs. I might lower the turn on point when towing and see how that does. Still considering the larger turbo route.

Your coolant temp shouldn't be that high on such low boost IMO... Mine only ever got to 210ish on a longer 15+ psi pull... Those ambient temps really aren't all that high either in the big picture, and I wouldn't say those IAT's are a problem either Maggie's deal with 160-180 degree IAT's periodically and to my knowledge have no ill effects.... I'd be looking at a bigger turbo, more intake and engine cooling, or a bypass that keeps you out of boost so much just while towing. something just doesn't seem right...

Yea i agree..
There seems to be another problem with your cooling system, unless the Intercooler is blocking alot of your air. Assuming you have the intercooler right infront of the radiator.
I ran the poo out of my truck towing a z71 tahoe (~6000# + 1700# trailer) and never got past 195* along with my W/A intercooler is between my Efans and water pump, IATs never got over 120.

im running the 75mm and i can barely get boost under 1900rpms.. and from 2000 and up i can get the whole 5psi.

Id try a bigger Turbo and either a better intercooler or just use your Methanol. Mine comes on 10% at 2psi and ramps up to 100% by 10psi. with a 10 and a 5 nozzle, she will drink thru thru some Windsheild washer fluid.

i run a borgwarner s300 60mm on my 5.3, i run 12psi all day, tow 7500lb enclosed trailer 250 miles to a race one way, pull 6-8 degree inclines, my water temp will climb on a 6% grade that is 7-8 miles long to about 225*, intake temps sit at 110 with a 31x11x3 ebay intercooler and two trans coolers stacked infront of it. i also run the stock thermostat. no methonal. rolling on 23" rims too

maybe look at the turbo. people tell me that my 60mm is too small all the time, but you can compare a cheap masterpower junk turbo to a garett or borgwarner. the better 60mm will outperform the cheap 76mm's all day.

Also, the only way if found to over heat my truck was either in some icky mud or a ton of playing in the pasture where im not moving alot but turning high rpms and my fans hadnt kicked on yet.. it got up to 235 and trans hit 210.. fans kicked on and i popped the hood and it took a few min to cool down..

whats the exhaust housing/wheel dia on it?

EXD Wheel 67.0
IND Wheel 74.2

what AR housing?

.96 a/r

ok just checking...

let us know what happens when you do the tow to LS Fest..

That S300 is a pretty bad little unit :D

I sure will. I'll be heading out Thursday night.

is a 1.10 a/r, not sure the diameter, Reed @ works turbochargers picked it for the application.

bringin this back from the dead!

I've had my build finished for almost a year with no problems (save a 4l80e tailshaft housing) and it never got hotter than 210*F except when running A/C. I recently took my turbo RCSB down to tail of the dragon (bike and stuff in back) and she got real toasty in the mountains on the drive home up to about 230-235*F on some of the real long uphill straights. This was converter locked up cruising at about 70 the whole way, manifold pressure around 8inhg vacuum

Some specs on the setup are;
bone stock 5.3L oil pan to valve covers
on3 7875
4l80e with 2800 circle d stall
flex fuel conversion
stock 28" radiator (i know i know not good)
ls1 efans
tru cool 40k trans cooler
huge ebay 4" core intercooler
fully heat wrapped hot side and turbo blanket

I'm thinking I need to just bite the bullet and get a 34" rad and the big truck efans. The truck has about 150k on it, so I was planning on doing a water pump and a 180*F thermostat as well when I put in my LS6 cam. Just wondering if anyone else if running into problems like this, maybe when towing or in real hot climates

180f thermostat
34 rad
70-30 mix

Im in the same boat. What big truck fans are you talking about, id be interested. As of right now, im planning to do a 160 Tstat, ill report back with my results. If the t-stat doesnt remediate the issues, i might be swapping over to a bigger rad as well.

A thermostat isn't going to change jack in the temperature range everyone is talking about. You need to get the heat out of the engine and that requires heat exchangers or to better utilize the ones you have. You can increase the effectiveness by increasing coolant flow, by increasing airflow over them, improving the working fluids' heat capacity, or by increasing the heat transfer coefficients (think water wetter). A thermostat that is full open by 100 F vs one full open at 200 F won't make a bit of difference at 210 F.

Most people don't consider how much heat their coolant has to reject to the atmosphere when you start increasing the power. Most get away with it because they don't use it for more than a few seconds at a time, but even a simple timing advance adds more power but also increases the amount of heat going into the coolant due to the change in the in cylinder residence time. (it moves the energy from exhaust heat rejection to coolant). With a turbo, now the energy that used to go out the exhaust becomes turbine power and is used for compressing air.

This is a little longwinded, but imagine your truck's most powerful engine option 6.0 or 6.2 running full tilt on a 125 degree day up the longest grade in the country. You can bet that your stock cooling system will handle that without overheating, but any well engineered system won't allow for much more.

The 07-10 truck had "big" electrical fans that push much more air than my tiny LS1 efans. I considered a 160 stat but I drive this thing thru michigan winters so I'm hesitant to put too low of a thermostat in and never get the oil hot enough to burn off all the fuel/shit in it. I figure 180 is a good balance


Yeah I understand the concepts of cooling systems, I'm an engineer in the automotive sector. What you're referring to is a system in equilibrium, where I'm taking about a system that starts in equilibrium (at the bottom of a hill) and sees a large change in heat rejection demand. It can't handle that demand so temperature starts increasing until equilibrium is reached (right now for me that's probably around 235*F) A cooler thermostat gives your a larger thermal mass to heat up, therefore more time until that equilibrium is reached. Because I don't have an issue other than these big hills, I think a thermostat will *help* but not solve the issue.

How do you like that stall on it? I have On3 7875 and 4L80E too but it's really sluggish on take off with the 3.42 gears in the back. A 3200 stall fixed some of it but I didn't like to have to Rev it up that high to get any kind of performance around town; stock went back in. Thinking of going with 4.11 gears.

It's the perfect combo for me, I don't drive it too crazy just a fun daily driver that I can haul stuff with and scare people on the highway. It is a little sluggish in first, but I just spin 1 tire anyways so until I get the the tru-trac installed it doesn't really bother me. I think the 4.11's would be a good solution for you though, but would definitely be better with a stall