Bobby B

I live in the desert near Palm Springs and in the summer my 2001 Coupe runs hot hot. Looking for info from those who have replaced their stock radiators with custom ones. Good, bad, no diference?

stingraymyway

Unless you're doing any performance driving, a custom radiator is just a nice but expensive option. I'd try a twin fan setup with a manual switch on your current radiator.
Good luck.

Pumba

Bobby,

The very simple and correct answer is YES.

Here is what you need:

1) Either a DeWitts or Ron Davis Racing 2 inch heavy-duty radiator.

2) A Vinci Hi-Performance 170 degree thermostat.

3) Have you fans reprogrammed so that they the first fan comes on HIGH at 195 degrees. The second fan comes on at HIGH at 196 degrees. Both fans turn off at 189 degrees.

You MUST do all three items to gain the benefit!

The end result will be that your Vette will cruise down the highway at 185 to 187 degrees coolant temperature. Corvette Racing Engineers recommend that the LS series engine be run with its coolant at between 185 and 189 degrees.

Generally you will find it difficult to get the coolant temperatures above 200 degrees even in heavy traffic with the air conditioning on.

Oldvetter

You never say what "hot" is? Your C5 is designed to turn on the high fans at 239 F, so this is NOT HIGH.

What temperatures are you running?

WKMCD

For a stock car I think the first thing I would try is putting in a 160-170 thermostat and having your fans reprogrammed. Secondly, I would add a bottle or two of Water Wetter. Make sure there is no debris on the AC condensor and in between that and the radiator. Total cost about $40. If that doesn't bring the temps down then you might want to think about changing the radiator which will run $600+.

You might want to talk with other owners in your area to see what they do.

Just my $.02

Bill Dearborn

You could just re-progam the fans to come on at 200 degrees. The stock thermo starts to open at 186 F and is fully open by 195 F. The stock cooling system will keep your temps down to 200 if air is moving through it.

If temp readings are within the stock tolerances they will not hurt your car no matter how many people try to tell you you should drop the temp. These cars were not designed in the 1960s and do not have to run the same temps as those cars did.

Bill

Twospeed

I wasn’t going to comment on this, because some one might consider it negative, but in the interest of saving someone else an expensive trip down “I learned my lesson the hard way lane" I will.
I had a C-4 that was running hot. So I replaced the thermostat with a 160. No real help. Then I added an additive to the water that was supposed to drop the temps. After 50.00 worth of additive no difference!
Next I had the fans come on earlier, automatically and with a switch) Very big help!! So I decided to go one better. I purchased a Be-Cool double core radiator. That is supposed to (Guaranteed) drop temps 20+ degrees. After $750 + shipping the drop in radiator, wasn't, and I had to modify the shroud. Be-Cool said "gee," that isn't supposed to happen.
So I finally finished the install. After a week of waiting for something to happen, I contacted Be-Cool and told them that my car did not experience any temp drops that were supposed to be guaranteed with the use of their product. They informed me that I now needed to use their special high performance” Fan” system. So I asked them for a vendors discount on the price since they couldn’t guaranty that the use of their fan system would solve the problem. They told me absolutely not! They wanted me to take the chance on buying their product and going through the install totally on my own. Forget about their supposed Guaranty! I told them what I thought of their customer service, and they told me that they couldn’t care less.
In the end, I had the worlds most beautiful radiator ( It really is very well made with beautiful welds) covered by a shroud that no body could see, when the fan modification was the only thing that really worked. Oh yea, that radiator worked great in the winter time by causing the car to take 3 to 4 times longer for it to warm up to normal operating temps. Even with a computer change that would run twice the clock speed of the original computer the temps really screwed with the tune during cold weather driving, I live in Florida, and yes it does get cold here, for a little while.
I would hope that the other brands that were mentioned worked better and had better customer service. Just my 2 cents.

Wicked C5

Not worth it on a stock car. I used to cruise out in your area and it was 118 out by Coachella. My car with a t-stat and CAI ran under 200 and didn't overhear in city driving.

MattB

I'd try the re-programming the fans first, if its really needed. What temps are you seeing? Usually the low speed fans don't come on until like 224 and the high speed at around 235, if you lower than that then your OK.

A bigger radiator is usually not needed unless you road race. 160 deg thermostat is only needed with highly modified engines that get knock.

If the heat you are concerned with is the temp in the cabin a ceramic coated tunnel plate will help out a lot more. It keeps some of the heat from the exhaust out of the cabin.

Bill Dearborn

Even then it really isn't needed. If you are running a stock cooling system there is only so much cooling capacity available. The thermostat does not increase that capacity. Under hard useage coolant temps will approach 230 at speed whether or not you have a 160 or stock thermostat. The fact that it might get to 230 a little slower with a 160 is basically moot because you are talking less than 2 minutes run time.

Bill

0Tom@Dewitt

I agree with you on the thermostat issue but I've noticed from many of your comments on bigger radiators your not a big fan. Here you support our findings that the stock radiator capacity is exceeded at times and runs much hotter. Doubling this capacity (which is what our radiator does) you will not see that rise in temps.
The facts are the engines are designed to handle 230 without any problems. The other fact is the stock radiator is marginal. Some people simply do not feel comfortable running that hot and want a robust system. Now the OP's question here is, are they worth it?
Aside from the extra cooling capacity you are also eliminating the plastic tanks that do crack and the gaskets that do blow out. So if those features are a value to you, then they might be worth the price

vsocks1

Worth it to me!

MattB

I'm with ya on the 160, by themselves they do next to nothing.

Got to say though, the DeWitts radiator is great. Very easy install and works very well. Makes the thermostat work more LOL

Bill Dearborn

Tom,
I support using a larger radiator when required. I don't believe a larger radiator is required for street useage anywhere in the world unless the car has been equipped with a huge heat producing modification. Engine mods for street or strip driving don't fall into that category since their excess heat production is only seen as spikes of a few seconds to a few minutes. However, continous WOT driving for a long period such as in a road race or HPDE may require a larger radiator or some additional cooling such as an external engine oil cooler.

I personally have a Ron Davis Racing Radiator with an internal EOC in my 03Z. I purchased that radiator 9 years ago and had it installed in my 97 at the time. With both the 97 and the Z I saw significant temperature drops from stock when running at Watkins Glen. However, I also had problems related to excessive cooling when driving on the street. In the fall and winter it is very hard to get the oil temp above 100 degrees unless you have some sort of thermostatic bypass of the cooler. Even with the stock thermostat which is what I have always run the coolant in the return tank of the radiator is cold enough to cool the oil excessively.

As for the plastic parts of the stock radiator I realize there are some people who have had problems with them but the vast majority of cars on the road have these radiators and most do not have problems. There are quite a few people on this forum who have C5s with well over 100K miles on their cars and they don't report having radiator problems.

I also realize there are people who are uncomfortable with the temperatures they see with the stock cooling system. However, it probably would be interesting to see if they have that problem with their other vehicles (daily drivers) as well. I sort of doubt it due to the lack of temp gauges that actually indicate the temperature Vs the ones that just show a green strip when the vehicle is running at designed temps. Many of those cars go for 100s of thousands of miles and do not have problems due to the high temps. As for reduced HP at higher temps if it is there it is negligible. Certainly it can't be seen on dyno runs as the accuracy of the various dynos is around 1% which means on a car with 350 HP at the rear wheels the dyno can read anywhere from 346 to 353 HP from one run to another with no changes to the car.

I do believe your product is an excellent radiator and well worth installing in a car under the right conditions and I recommend it to people who may be looking to solve a true excessive temp problem.

Bill

hotwheels57

If the plastic tanks are replaceable (are they?), why doesn't someone come up with replacement aluminum tank(s)...maybe slightly larger in capacity?

Is that feasible or even worthwhile?

vsocks1

Don't think they are replaceable or would it be worthwhile IMO.

DevilMan02

Based on what was said in the general c5 section, i will NEVER buy a DeWitt radiator. They have terrible customer service and really screwed one guy an a defective unit. Then took their sweet time to resolve the situation.

0Tom@Dewitt

If one negitive report changes your opinion of us when we have several hundred people that would say otherwise, you're easily duped. Let's face it, Corvette people are very fussy and I'm one of them. We all demand excellence and when that doesn't happen news travels fast. We have been in the Corvette parts business since 1986 and I've been building radiators for the past 15 years and if you were truely interested enough to search out the name Dewitts, you would find endless happy customers that rave about our customer service. That just doesn't happen in this business unless you build good stuff and back it up with excellent customer service.

The simple fact of that customers case was they badly damaged the radiator when installing/removing it and wanted a full credit. We have numerous people buy a radiator and then change their minds and want to return it and that is never a problem. I just have to be able to resell it to another person and that was not possible.

Hey, even Bill Dearborn said we made good stuff! That should be good enough for anyone

black98c5

It's pretty sad when people bad mouth a vendor they probably never had first hand experience with . I on the other hand heard nothing but great things about Dewitt's radiators along with countless others.


Tom, I'll be purchasing one of your radiators in the near future!

tiojames

I live in Az. and had a H/C pkg., headers, UD pulley, etc. and my vert never ran hot after Andy reprogrammed the fans when he did the H/C pkg. and put in the 170 stat. I did have to go to a bigger radiator when we put the Vortech on however. I think the fan reprogram and the 170 stat would be all you will need.