Hey guys... well I'm joining the forced induction ranks... Procharger came in yesterday, so I've got a long winter project ahead of me.

If you would care to share brands/sources/prices for aftermarket radiators. Part of doing this right is going to be increasing the cooling capacity to compensate for the intercooler hanging out in front of the radiator.

Thanks!

 

I bought a dewitts for $500.00 I think.......happy with it....besides the bigger rad, a high flow thermistat made the biggest differrance......high flow water pump didn't do anything.........

 

Another DeWitts here. Very happy with the unit.

Ron

 

I believe mine is a griffin. I can commute to work in traffic going 5 mph on a 100* day and it doesn't over heat. I'm content with it.

 

mines stock. if the cooling system works properly you dont need a larger aftermarket rad. you think your getting more cooling your wrong a single row rad will cool better then a double row. i have never had a cooling problem. i run gregs complete system +the 8 rib set-up and run 13 psi and run 176 hyway and in town no higher then 195 and thats on days in the 90 s. have better things to do with the money. 383 being built as i type and still going to run single row rad. if you need a double your cooling systems not working right. more flow dont dont mean run cooler, air across the rad cools. get the air flow right and you will see what i mean. alot of guys are going to not agree with this but get the air across the rad right and then see if you need a new rad.

 

I will have to disagree with you for the most part. The only part I do agree with is that an infinitely large single core radiator is most efficient, but unfortunately, the C4 is limited on frontal real estate.

HP generated equals heat generated; which is carried away from the cylinder heads by the cooling system, and expelled by the radiator. If you have increased the HP by an appreciable amount, the radiator will need to be upgraded. I find that 500-550 RWHP tends to be the limit for the factory radiators in the C4. The front mount IC serves to exacerbate the problem.

I currently run a Dewitts HD manual only radiator in my street car. I am happy with the choice.

Aaron

 

Hmmmm.... well, at least a few viewpoints. I am going to have to make my own plumbing & mounts for my IC as the 89 kit just doesn't fit under the '90. Radiator shroud & placement is quite diff. I may just leave my rad. be for now & see if I have issues. I'm running a high flow therm at 180 but my current fan setting is also 180 so it runs most of the time. And I current have zero heating issues.

Thanks for the input & if I decide to upgrade I'll be back w/ a request for sourcing. I have to agree that $500 is a good chunck of change I can use elsewhere.

 

martin
now your using your head, wait to see if you have any problem. then decide what your going to do.

 

Back in 1990 I did some extensive testing on a 1988 Vette with a "406" and my Vortech S/C kit. First thing I found out was that the air flow thru the radiator was critical and much depended on how the vehicle was used. These observations are much the same for the LT1/LT4 which we later tested in much the same way.

Take a totally stock L98 Vette. Equip it with a 180 degree high flow thermostat and reprogram the cooling fan to come on at 190. Change the auxiliary fan thermostat to 200 degree (the auxiliary fan was part of the H.D. optional cooling package - it's a pusher fan in front of the radiator). With the car in Park on a warm 90 degree F day and the A/C on the cooling system will settle out at 220 degrees. No wonder GM set the first stage cooling fan at 228 and the booster at 238! The problem with a 'sitting' Vette is the airflow. Since the radiator cooling air is drawn from down underneath and then pushed out back under the chassis much of the air is 'short-circuited': simply recyled from back to front. Without the vehicle moving there's not much you can do short of changing where the air comes from. The '406' was even worse. The extra heat from the extra cubes at idle raised the temp another 10 degrees. Putting in a bigger aluminum radiator did nothing at idle.

Now let's talk cruisin' speed on the highway - say a steady 60 or 70 MPH. If the radiator had "off-set" fins (highly restrictive air flow) it did not perform as well as a stock radiator. If you go with a bigger radiator with say 2 core you need make sure the fins are not off-set. Also remember that when idling or cruisin' (with or without a blower) you are rejecting the same amount of BTU's (more or less unless you've increased the cubes) as a stocker engine.

Now the real question is will the bigger radiator help under acceleration with an engine say making double the horsepower. If the burst of power is short, say 10 seconds or less (which on the street brings you to a 100 MPH or so) a stock radiator will do fine. The bigger radiator holding more coolant may buy you a little more time. If you are able to keep your foot into it eventually the bigger radiator will help, particularly if the fins are not offset as the speed of the vehicle assists the air flow. The negative pressure under the chassis helps pull the air thru the radiator at a greater rate. Just remember no matter how big the radiator is, if the corresponding air flow is not there, no extra heat rejection can take place. So, first there must be air flow, then we go from there. I found that mounting a pair of pusher fans to the front of the radiator (and pulling out the GM pusher fan) did the most to help cool the coolant. This becomes particulary true when you place an I/C in front of the radiator.

Regarding coolant - water rejects more BTU's/pound than glycol. A 50/50 mix of water & glycol reduces your coolant capacity by 15% versus staright water. I always go with 70% distilled water and 30% glycol where winter temperatures permit.

Finally to dispel another old wife's tale. The amount of heat the coolant can transfer to the radiator from the engine is very dependent on 'turbulent' flow. The more 'turbulent' the flow the better off you are, particularly with a supercharged engine. 'Turbulent' flow around the heads is absolutely crucial to preventing detonation. That's why a high flow thermostat and pump are good ideas. Even if you don't notice a drop in overall coolant temperature the turbulent flow is helping keep head temperatures even and is promoting maximum heat transfer inside the radiator. This is why an underdrive pulley system on a supercharged engine is a bad idea !!!

To come full circle - if you place an I/C in front of the radiator - thereby reducing air flow and introducing more heat, be sure whatever radiator you use promotes maximum airflow.

Anyhow, that's my two cents worth. Regards, Greg

 

i just did a "Griffin" in mine, it is a dual 1.25 core and it seems to work ok. the cooling system was marginal at best with the intercooler (aftercooler) in front of the stock radaitor. i think i will take Greg's advice about the pump and high flow thermastat, anything to increase the detonation margins will be a positive thing.

 

I find the Robertshaw thermostat with three ~0.125" holes drilled around the perimeter to work the best. However, I had to ditch the Robertshaw with the MRII, as there was not enough space for the taller thermostat. I currently run a "washer with 1.125 hole" in place of the thermostat. It seems to work well, even idling in S. TX weather.

Aaron

 

Arron, I sent you a e-mail let me know if you do not get it. It is about your Dana 44. Thanks Greg Nettles

 

Is this statement based on actual testing?

If so, I wonder why I have hundreds of customers that tell me the double row lowered the temps?

Why did GM contract us to make a double row for the 2006 prototype?

If the single row works better, how do we explain the 20 degree drop GM recorded with our prototype?

Why did their tunnel test show a higher btu rating?

Weird....

 

Im using tunnel heat exchangers from a sKi-doo as supplemental heat sinks. they are giant finned aluminum heat sinks less than an inch thick.
Combined with a small fan cooled cenventional rad up front. Just big enough for idle/stop/go traffic.
As a side note I have begun to swear by that Evans NPG+. You just need a really high flow water pump to take full advantage of the reduced Dynes rating/faster heat transfer.

 

i want a fluidyne.

http://www.fluidyne.com/pl_hpexotics.html

 

What features do you like about them? I'm curious because we make the exact same thing for less money and I believe they fit better.

 

really??!! Do you have a link? I may have to buy one of yours instead.

I just like fluidyne becuase i had one in my mustang and it worked pretty good.

 

DeWitts Direct Fit Radiators

 

Hey Tom, what does forum member pricing look like? :-)