Twin turbo ls overheating issue
- Thread starter johnnunez29
- Start date
Are you running those fans with just through the radiator tie straps, and NOT mounted on/in a full core covering shroud? If that's the case, I would bet that's your problem with running hot sitting still at idle since your not pulling air over/through the entire surface area of the radiator core. A tightly sealed shroud behind the radiator is key to generating a negative pressure differential that will get air to draw in from the front of the radiator, and all four corners. You also want the fans to be about 5/8"-3/4" off the radiator core as well (about the thickness of the shroud) in order to get that pressure drop on the back side. If you're just relying on the 12" round area of each fan against the radiator core, you're likely only using about 60% of it's cooling capacity.
Also, you mentioned that you are feeling super hot air on the backside of the radiator off the electric fans. Are you shrouding/foam sealing the sides, top and bottom of the FRONT side of the radiator so it's not sucking/reverting back hot air from the engine compartment back through the radiator? If you have an intercooler in front of radiator, have you "walled off the space between it and the radiator so air can only come through the intercooler, and not from the under hood area? Again, think top/sides and bottom of the radiator support.
Just some additional things to think about...from what you're saying temp is fine when moving down the road you need to make sure you're getting maximum airflow through your radiator core when not moving and relying on the electric fans.
Brushless fans are definitely going to outperform the brushed counterparts, and typically can be fit into the tighter spaces. You have Terminator X, so you have the functionality built in to drive PWM OEM type fans.
Some great info here along with pics, and some measurements, etc if you decide to go that route. You'll see some of what I did with the Chevy Volt SPAL Brushless dual 12" fans and shroud on my Cutlass.
Brushless PWM Fans - Holley Performance Products Forums
As many of you know, I'm a proponent of using PWM fan control with any Holley ECU that supports it (everything except Sniper). Originally, on my LS swapped '67 Cougar, I used a C6 Corvette fan (400 watts) with an external controller (same as the Ford Fusion controller). This works great for fans...
forums.holley.com
Really nice setup you got going there, hope you figure it out and good luck!!
NM on shroud advice, went back to re-read entire thread but I think the reversion of hot air from engine bay making it's way back to front of radiator is something you want to consider, and mitigate if needed. 👍
Yea I need to figure out how to get heat out of the engine bay. I may look at the brushless fans. Unfortunately the charge pipe goes right down the center so mandatory dual fans. The fans I am currently running are the maradyne dual setup. They seal against the radiator with a gasket. So def pulling through. There’s def been a change with running the plus 400 cfm fans. But not enough. When I figure the rpm issue out that’s next on the list.
Could get a set of these in whatever size floats your boat.
But I still say it should keep its cool at an idle.
But I still say it should keep its cool at an idle.
See how much 'pull' the fans generate. The quik & EZ way is a piece of notebook or legal document in front of the vehicles grille when it's sitting still. The piece of paper should be sucked into the grille like a vacuum is pulling it. Test the full size of the grille/radiators surface opening area.
The rain is rain, basically it falls through and most would evaporate unless it's downpour....but if you can duct the underside somehow to direct where you want that's one thing.
On other cars, like on my C7 they duct the entire top half of the radiator so all that heated air goes right out through the center hood vents. Any water that enters drains right out the bottom near radiator. Granted it's all a packaging thing with what you can fab and fit in the space you have.
I'll tell you, that hood louver stuff works, I've driven with the top down on cool nights and rested my hand on the top center of the windshield and you can feel that hot air on your hand exiting and flowing up over roof. If I moved out to either side of center, the air was cold.
For my old Hardwood hood on my Monte, I made some aluminum hood vents because I was having an issue getting the heat out that the 565 Big Block created, they worked well but I didn't drive in the rain.
A friend of mine grabbed a cheap manometer off Amazon that plugs into Android phone with app. It's a little propeller you can use measure air flows.
While it's not gonna be like spal fans dead head cfm ratings testing, you might be able to find where you have drafts of air flow around your radiator stack. Also a smoke wand could help to see where air is being pulled while it's sitting idling with fans on/off.
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