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View Full Version : Putting a car on a diet. Smaller radiator?



joedoozer
10-14-2011, 11:07 AM
What size radiator do you run? And how small is too small?

My car is really nose heavy and I might put it on a diet in the off season. Reworking the front bumper will be done. And I had thought about radiator size. The car cools extremely well now, so I don't have any fears of downsizing. But the standard has always been run the biggest radiator that will fit in the car. But at what point is big overkill? Can a small radiator be run and still be efficient?

TPR30
10-14-2011, 11:35 AM
I know a guy that went to one of the new thin fluidyne radiators this year. Took around 30 lbs (both were filled with water) off the front with it. Still runs as cool as the big one.

MasterSbilt_Racer
10-14-2011, 11:36 AM
I have had a lot of success using the single core radiator that AFCO used to sell as an "alky" engine radiator. I don't know if they still sell it or not?

joedoozer
10-14-2011, 11:45 AM
I know a guy that went to one of the new thin fluidyne radiators this year. Took around 30 lbs (both were filled with water) off the front with it. Still runs as cool as the big one.

That is kind of what I was thinking. My car can weigh 2300, but to get my percentages right I need to weigh 2400. All my lead and battery is on the rear of the car. And at 2400 I am still only 53% rear. The bumper I have was built for 1/4 mile bullrings, and entirely to beefy for the tracks I run. So that will save me a few pounds. A few pounds waaaay out front too. So I figured a slightly smaller radiator, a little less water capacity. Even if I save 3 pounds on the bumper and 12 on the radiator that's 1.5% savings.

A handful of guys we run against have 604's that can weigh 2200. And my iron heads is 50 pounds on the wrong end of the car.

rubbinsracin
10-18-2011, 03:42 PM
im in the same situation. we run a steel head against the 604. we all have to weight 2400 which seems fair, however, as you said our steel heads put a ton of weight on the wrong end of the car. in order to get our percentages right, we have been in the 2500ish range when the percentages are corrent and the guy we park next to has a 604 that he has to fill up gas before the feature just to make weight after the feature.

ALF401
10-19-2011, 08:04 AM
Has anyone tried to move the rad to another location?? Any luck with that???

joedoozer
10-19-2011, 08:46 AM
Has anyone tried to move the rad to another location?? Any luck with that???

Rules state it must be close to stock location and in front of the motor.

Speedway has a lightweight radiator that only weighs 11 lbs. Its a single 1.25" row that is roughly the same dimensions as my old radiator. I have had my radiator out numerous times, but have never weighed it. I do know its a 2 hand lift, so it is much more than 11 lbs. Are these single row radiators strong enough to handle the vibrations of a dirt track car?

hpmaster
10-19-2011, 09:26 AM
I moved the radiator back about 6" and up about 4", did away with the shroud as the fan is now 1" away from the radiator and went to a slightly smaller double pass radiator as it now sits between the inside mounted upper A frames. Then I went to a 19" fan. I also lightened every thing I could in front of the frt axle line and removed the old shrouding or ducting. Ran car all last year on gas, 14+ to 1 compression ratio 720hp gas motor, never went above 215 on days over 90 degrees. I had my new chassis built to do this again this year. Saved weight and moved as much as possible closer to center of car. As for inspectors that was one thing they didn't question!

Almost forgot, I left my Dominator nose intact, no air holes, just figured it would do what it was designed to do better with no holes and motor was still cool.

joedoozer
10-19-2011, 09:35 AM
I moved the radiator back about 6" and up about 4", did away with the shroud as the fan is now 1" away from the radiator and went to a slightly smaller double pass radiator as it now sits between the inside mounted upper A frames. Then I went to a 19" fan. I also lightened every thing I could in front of the frt axle line and removed the old shrouding or ducting. Ran car all last year on gas, 14+ to 1 compression ratio 720hp gas motor, never went above 215 on days over 90 degrees. I had my new chassis built to do this again this year. Saved weight and moved as much as possible closer to center of car. As for inspectors that was one thing they didn't question!

I don't see anything wrong with it. In fact it makes more sense then running the radiator further away and spacing the fan out. I like it.....and I am going to steal your idea haha.

hpmaster
10-19-2011, 09:56 AM
I don't see anything wrong with it. In fact it makes more sense then running the radiator further away and spacing the fan out. I like it.....and I am going to steal your idea haha.

Steal what you want, hell when I leave this world if I leave behind one improvement to what I loved doing all my life it will be more than what some others will.

ALF401
10-19-2011, 11:59 AM
So again has anyone moved the radiator to another location and had any luck with that??

ALF401
10-19-2011, 12:01 PM
So again has anyone moved the radiator to another location and had any luck with that??

JCSullivan00
10-19-2011, 12:23 PM
I used to see some cars back in the early and mid 90s with the radiator in the back. They would angle the deck to feed air to it, but it seems like pumping water there would be a massive headache. None of them were ever front runners.

hpmaster
10-19-2011, 05:33 PM
In thirty years I have done or seen almost everything you can imagine done. It takes horse power to cool a roundy round motor. Hell re route your right header, run a fan off your bellhousing accessory belt put the radiator where your right side header was and vent it under the body. Now if after that if you gain anything that you wouldn't of gained by lubing all your heims, understanding how brake bias works with handling or grinding and preppin your tires correctly I would be real surprised. The % of weight saved or relocated is almost negligable. I think a better plan would be to have the driver lose 30 or 40 lbs but you go first I am going to eat another piece of pie.