Built 416 LS3 Overheating

[LS3_VE]

Hi all
In need of some help, have done a LS3 conversion which from day one has always pumped out drastically more heat the original L98 especially the trans, which I get given the mods and in general it runs like a dream except here is the issue I’m having(I mostly drive in sports auto it is my daily but I don’t thrash it)
Trans often produces a lot of heat, as in if keys are in centre console they can become to hot to hold, AC has had ongoing issues and rarely works unless ambient temp is cool enough that it’s not actually needed, dash temp will read half way mark as a constant and gets there quick, if the ambient temp is 28c or above will only be a short time before “engine high temp” warning comes on, and if use the air con on a day above 28c it will happen even quicker, I’ve been more than vigilant with maintenance and upkeep since the build which was completed in October since then I have had the 1000km service + a full service on first week of every month since and on this months one had the diff and trans serviced and fluids changed(was told trans fluid was very dark)
any thoughts on what cause could be or a point in some sort of direction would definitely be appreciated

 

[_R_J_K_]

which I get given the mods

Would be helpful if you mentioned what mods. Everything, engine, exhaust etc...

Also, what kind of radiator are you running and do you have a trans cooler?

 

[LS3_VE]

Would be helpful if you mentioned what mods.

Also, what kind of radiator are you running and do you have a trans cooler?

apoligies first time using this kind of platform had entered mods in profile and thought that was visible to others. Currently is the OEM radiator As was told it would be more than suited for the task, I’m starting to think maybe that’s not the case and yes have the harrop trans cooler fitted, the main mods are listed below

2012 SSV VE Z SERIES 2
LS3 416ci Built forged motor
Harrop 2300 blower
Harrop OTR intake
Harrop H.02 cam
Tridon hi flo 86c thermostat
Callies compstar diamond dish pistons
Callies rods
Higgins heads
Manly inconel exhaust valves
LS7 lifters
Harrop 3” pro extreme exhaust
Harrop trans cooler
Harrop 8-pinion TRUTRAC diff
Shockwerks coil overs

 

[_R_J_K_]

Cammed, blown, and stroked, I'd be looking for a much bigger radiator, even after doing just one of those. I can't find Harrop's transmission cooler, do you have a link?

You get Harrop to build this for you?

 

[LS3_VE]

Cammed, blown, and stroked, I'd be looking for a much bigger radiator, even after doing just one of those. I can't find Harrop's transmission cooler, do you have a link?

You get Harrop to build this for you?

that’s what I would of thought and had questioned it but when was told it would be fine trusted that information given who it was coming from

sams performance built the motor
Harrop done all fitment and all servicing so far
I’ll just find the trans cooler on invoice and add to this

 

[Skylarking]

I’d drop by a dealer that has an HSV VF GTS LSA in stock, new or used doesn’t matter as you won’t be buying it. Then spend a little time looking at the cooling solution designed into the vehicle, paying particular attention to radiator size, fan size, radiator cowling, trans cooler size, etc as compared to your home grown beast. Then you’d get an idea of how it is correctly engineered.

I’d think there would be much more cooling capacity designed into the GTS LSA than a LS3. 130 odd kw extra power needs lots of fuel which creates lots of heat when burnt. And you need to be able to get rid of it some how

Once you understand the differences between the VF/GTS cooling solution, then have another discussion with Harrop. Ask them about the heat issue and whether they think it’s normal for your keys to get so hot when placed on the centre console and the car to flag an overheating issue...

Such heat problems are not normal in my view so Harrop stuffed up and they should fix it at their cost (it’s their liability).

 

[gtrboyy]

Workate has all the gear & more on his vf clubbie built by Sams...thing sits in traffic & behaves like a stocker.


Hot them up on FB or ring for advice.

 

[07GTS]

how is the intercooler situated in front of the radiator ? i had to change mine and play around with it as it didnt allow good airflow thru to the radiator and engine fans were still coming on even upto 80kph driving, overheating was never an issue but the fans shouldnt have to come on if ur over 60kph if airflow has proper flow even with stock radiator, make sure u are actually getting hot as the ect sensors can play up also make sure u are using the L98 ect as some later ls3 may be different, i have seen ls3 heat up pretty quick but all fine once at operating temps, if cats are beside the trans they will be heating it up in that area more and heating up the floor either more insulation or get the headers and cat pipes ceramic coated to help, also if u have trans cooler u then have trans, intercooler, a/c before the radiator so flow at that point can be reduced alot

 

[Daniel Souza]

You could get the actual figures via OBDII

Below follows some stock VF II ls3 temperature baseline from cold

 

[Daniel Souza]

Do you have a wideband installed?

I would definitely have one installed with all those mods.

If the engine is running to lean , it could cause the EGT to increase heating up everything.