i would know which radiator is correct for a 7 second car ... my engine is 572 nitrous .. if start the pass at 140 degree al is ok finish line at 210 ... if start at 170 ... finish line at 230 .. need new aluminium bigger radiator ? no air from the grille ....

I'd try a bigger fan first since the front is closed off.

That much temp gain in that short time says your radiator is WAY TOO SMALL and your water pump doesn't flow enough. You have enough airflow moving down the track that the fan isn't a factor.

By the time it gets hot your going to shut it off 😛

That much gain that quick is not the radiators fault. Are you running the thing lean? Timing slow? You can usually see the difference in the temperature gauge by moving the jetting a few numbers one way or the other.

You're effectively pulling air through about 1/2 of the core.
Something that moves the fan back and incorporates a shroud like the HHR fans will make a difference.
Just circulating coolant through it and not transferring some of the heat to passing air doesn't help much.

why are you starting so high ?
my car I try to roll through the water at 90-100
stage at 110-120
return road usually 145

If you look at a lot of heads up racers, they have small rads to save weight. If using a small rad and it doesn't have the capacity, just start lower.
As long as it comes up on the trans brake, your good

This would be my first question....My car goes in as cold as possible, they make more power this way too(cold water, warm oil). You could use a shroud as that will make sure you have airflow across the entire radiator. I use a small sirocco style radiator with a shroud and my car only sees over 140 when my opponent takes forever to stage ie turbo guy. My car runs low 7's N/A

yep
..this was my idea... two fans ..but im undecided if try also bigger radiator

yep ! but the problem is when pass is close ! no time for make cold !

no Lean... and very Fast ... a little bit rich ... best ET is 7.82@175

you right ... but is from a pass and another pass is 15 minute .. no time for make cold ... i started minimum at 120 .. i can start at 90 ? but some time for wait before burnout go fast from 100 to 140 ...

https://youtu.be/WWxrBGgS1kI


you can see the water gauge on lower .. the second from right side

DEMON 572

C & R Racing 317-293-4100 Radiators https://www.crracing.com/

Ron Davis Radiators 623-877-5000 http://www.rondavisradiators.com/

Either of these would be good

Take a note from Stock/Super stock guys. Take you upper hose off rad, dump 5 gals in there and let it come out the top of the rad. If you want rig up a hose that you can slip on the rad, and let the water flow into a bucket. OR get real creative and use two buckets with a pump, fill one 5 gal and use a pump to pump it through the engine and into another empty 5 gal bucket. Cheap mans chiller
You can get a cheap digital gauge from Jegs or Summit that goes down real low. Mine was 50* this past weekend. Now you can make sure you are 90* in the lanes.
Don't know if you are, but towing up helps a lot.
YOu have paired exh on your engine, that's a hot spot you don't need for nitrous use, run it cool even if just for that reason

Maybe consider putting a small duct for air from the grill. At you speeds you won't need much. One 3 inch hole in the grill could feed a lot of air to the radiator.

Mine is completely closed off as well with no issues. My Cuda was closed up as well with a tow row sirocco radiator an even hot lapping it NEVER saw 190. Fwiw my Cuda went 7.94 171 NA at 29752

1 question comes to mind..... Do you have or are you using a flow restrictor in the thermostat housing?
Also, Double check and make sure you have good flow and the Pump is flow well.
I think I would also check the inlet and outlet flow of the radiator. Some of these radiators are really slow flowing from very small tubes.
Keep chipping at it Raffa.... Looking good

Hola Hog ! i don't have any restrictor in the pump !