Best radiator option?
Thread Starter
Instructor
Joined: Mar 2018
Posts: 121
Likes: 29
From: Madison Mississippi
Best radiator option?
Thinking about increasing the engine (oil and water) cooling in my 2003 Z06. What is the best option? (1) Larger radiator (ie Dewitts) with built in oil cooler or (2) Larger radiator plus separate oil cooler. All thoughts and options appreciated.
Tech Contributor
Joined: Oct 1999
Posts: 41,057
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
I used the DRM Ron Davis Racing Radiator with built-in oil cooler plus a remote oil filter setup on my two C5s. The radiator was a cooling monster. On my 03Z oil temps went from 319 degrees on a hot August day at Watkins Glen to 230 degrees. Coolant temps were maintained at 200 degrees and all with the stock thermostat. The biggest issue was in cold weather driving I had to block off sections of the radiator so the engine oil temperature would go above 140 degrees. If I was at the track when ambient temps were in the 40s I had to let the engine idle in the garage until the oil got up to temperature. That way when I hit pit lane for the first track session the oil temp was high enough that I could push the engine enough to keep it high.
With the radiator and the remote oil filter (which used an older version oil filter with a 1-quart capacity), I had 9 quarts of oil in the engine after I added the extra quart to make sure the bearings didn't go south when making long high G left-hand turns.
Bill
With the radiator and the remote oil filter (which used an older version oil filter with a 1-quart capacity), I had 9 quarts of oil in the engine after I added the extra quart to make sure the bearings didn't go south when making long high G left-hand turns.
Bill
Advanced
Joined: May 2021
Posts: 86
Likes: 17
If you go with Dewitts make sure you get the updated radiator. No one likes to talk about it on this forum but they screwed up their radiators and made an update without telling their customers. The post about it a few months ago mysteriously disappeared.
Last edited by Brewssard; May 27, 2021 at 07:27 PM.
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Joined: Apr 2013
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From: Oregon
St. Jude Donor '14-'15-'16-'17-'18-'19-'20-'21-'22-'23
Le Mans Master
Joined: Jan 2000
Posts: 6,299
Likes: 416
From: Michigan
I looked at the 2001 model they brought in to do the research and I really didn't think any change was warranted. The hose touching the brake lines would not have been an issue if it was my car but they decided to make a change and angle the upper tube. I think it was 8 ° or something like that. They also found out that the replacement Gates hose was missing a slight kink that was on the stock hose. That's it, no great conspiracy. The thread did not mysteriously disappear, it's still available, just closed by the moderator. THREAD LINK
Last edited by Tom DeWitt; May 28, 2021 at 12:37 AM.
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Drifting
Joined: Sep 2009
Posts: 1,862
Likes: 594
From: Prescott, Arizona
I agree with all the above. I have a DeWitts with transmission and engine oil coolers that I installed in May 2013 before track day 7. I could not be more pleased after track day 22 last month. I do have an Improved Racing engine oil thermostat in the oil cooling system as well as an auxiliary transmission fluid cooler.
Keep in mind that I am apparently an odd duck, I have tracked my A4 since early 2011. See post 9 below-
https://www.corvetteforum.com/forums...track-car.html
Keep in mind that I am apparently an odd duck, I have tracked my A4 since early 2011. See post 9 below-
https://www.corvetteforum.com/forums...track-car.html
Race Director
Joined: Oct 2004
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Last edited by grinder11; May 28, 2021 at 09:25 AM.
Burning Brakes
Joined: Nov 1999
Posts: 901
Likes: 83
From: Los Angeles
I run a Dewitt’s with the integrated oil cooler. It had a faulty oil temp sensor that AHP identified during install. Dewitt’s jumped all over it and sent another right away.
I am unaware of any belt clearance issue.
I am unaware of any belt clearance issue.
Advanced
Joined: May 2021
Posts: 86
Likes: 17
I remember the post, and, IMHO, it was total BS. I've had a DeWitts since 2005, and what little interference there may be is insignificant. I see you're a new member. You sound like Chogan835 reincarnated. If not, I apologize. But the fact is you'll find NOBODY on this forum who has experienced damage due to a DeWitts radiator. THAT is the reason nobody "wants to talk about it on this forum", because there's nothing to talk about.......
While you may think it’s “total bs” the manufacturer of the radiator made a design change so they disagree with your assessment. Last edited by Brewssard; May 28, 2021 at 02:32 PM.
Drifting
Joined: Mar 2000
Posts: 1,956
Likes: 135
From: Maryland
I'm also running the DRM / Ron Davis but added an Improved Racing thermostat on a cam'd HPDE car. Oil temps while on the track have plummeted. Ran the car on the track as hard as I could all last summer and never had any oil or water temp issues. Thermostat lets the oil come up to temp in cold ambient temps.
Last edited by Rx7Rob; May 29, 2021 at 08:16 AM.
Drifting
Joined: Nov 2019
Posts: 1,266
Likes: 381
From: SC
Your statement isnt true though. As you’ve already been told they didn’t “screw up” their radiators. It appears none have caused any problems with the brake line. And they didn’t change it without telling anyone either. They acknowledged the “issue” in a previous thread and expressed their intent to redesign the part.
Advanced
Joined: May 2021
Posts: 86
Likes: 17
Your statement isnt true though. As you’ve already been told they didn’t “screw up” their radiators. It appears none have caused any problems with the brake line. And they didn’t change it without telling anyone either. They acknowledged the “issue” in a previous thread and expressed their intent to redesign the part.
2. Dewitts acknowledged the mistake and redesigned the radiator for late models.
3. The “acknowledgment” in the previous thread didn’t reach all prior buyers.
4. A manufacturer doesn’t redesign a product without a concern of future issues. If there was no concern of damage, why was it redesigned?