AzDave47

On the Dewits, an alternative is you can get integrated oil cooling and use the Z51 oil cooler hoses. I understand that deals with both engine and oil cooling needs well.

Going with a factory upgraded radiator should keep your warranty. I do know that at least one forum member running a Dewitts and aftermarket air/oil cooler (his was an '08Z) had his engine let go (exhaust valve) and the engine was replaced under warranty. That's no assurance your dealer would do the same.

X25

I just ordered the Z07 radiator w/performance package; looking forward to seeing how it will fare! My baseline is that with the base radiator, I frequently hit 270 degrees. I hope for settling at 20+ degrees lower.

I'm also hoping that installing this radiator is a simple bolt-on replacement. If any one of you know about what is needed to get it installed, please let us know.

skxf430

X25,

Are you going with a dedicated oil cooler?

I was still thinking about the dedicated oil cooler and upgraded radiator to a DeWitts or Finspeed.

I was hoping for a nice plug and play setup but I don't think that really exists for my base Z06.

X25

I don't want to have any question marks whatsoever about warranty, so I will just replace the base-Z06 radiator with the Z07 model's. If ZR1s can keep temps in check with this set-up, it should work even better for the Z06. It is not a small investment ($1040 shipped), but if it drops the oil temps to 230 degrees range as people claim, it would be a vast improvement! Considering the radiator also handles the transmission cooling(?), and I know that the transmission starts resisting to fast 2-3 shifts when it gets too hot, this might also be a good investment on cooling the transmission, too.

Dedicated oil cooler works great at the track, but compromises the street use. If you can make the Z07/ZR1 work in terms of acceptable temperatures, it would be excellent for street use, too, since it quickly warms up the oil. I will definitely report back on the impact of this rad. It will have to wait since I'll be on vacation until 28th June, though :P

Werks

As an fyi my car came stock with the Z07 radiator, I upgraded to the DeWitts and now I see 230 degree oil temps on the track even in the 90's. IMHO save your money and skip the Z07 radiator and keep it stock. If you decide to spend money to upgrade get a DeWitt's or our touch base with the Daniel at Finspeed, they are good people to work with

skxf430

Hey Ron,

I won't upgrade to a Z07 radiator and was only thinking of going with a DeWitt/Finspeed radiator and a dedicated Setrab oil cooler. I wasn't even pushing that hard at Buttonwillow and saw oil temps at 300 degrees, and the ambient temperature that day was only 85 degrees. Since my oil cooler is the newer oil to water cooler, there really doesn't seem like there is a plug and play kit out there.

Randy at DRM might have a kit but I am still waiting to get more feedback from him.

Werks

Ya if you are seeing 300 degree oil temps I'd be looking at alternatives too! I'm not sure what Katech did with my car but I believe that the DeWitt's radiator that I have in an integrated oil/water one also so you might want to look into that (or shoot Jason at Katech a PM and ask him what he put on my car) because whatever it is I can hammer on the car all day in 90+ weather and the most that I have ever seen was 238 degree's on the oil temp. Only drawback with the system is that I have to let the car idle for about 10-15 minutes first thing in the morning to warm up the oil to 100f before I drive it.

AzDave47

It is better to drive it easy and keep it under 2K rpm than to warm it under idle.

Werks

A little hard to do that at the track First think in the morning I idle the car for a while in the pits to warm up the oil (I run 15w50) to at least 100 deg. First lap out I take it a little easy and by lap two it's good to go

AzDave47

If it is a dedicated track car then that's all you can do. If not, do a little drive around.

For my last race car, I had to plug in the 115 AC dry sump tank heater, take off the dry sump drive belt and turn the oil pump over with a 90* air ratchet to get 80# of warm oil in the engine before I could start it!

jedblanks

If anyone in here has the oil to water cooler and wanted the oil to air cooler, it should be difficult to find a local member with 06-09 willing to swap.

Oil to air (06-09) is better for the track, cooler temps.
Oil to water is better for the street, oil warms to operating temp faster.

z51vett

Don't know if this is a cause for higher temps but 2012 and 2013's have 2 more cats could this cause back pressure and more heat. The oil water cooler is very close to the cats at the manifold. I see my street temps warmer than I like 2012 Z06.
z51vett
Doug

Katech_Zach

Yes, just take it out on the road and drive normally until it's warmed up. It doesn't need to sit and idle.

skxf430

Jason,

Do you think Werks' combo radiator/cooler setup is adequate? Or, do you prefer the separate radiator and oil cooler route? My car is primarily weekend and track duty only.

Katech_Zach

The Dewitts oil cooler an radiator has been good for our light/medium duty HPDE cars. It's only the really heavy duty track cars that have needed more and we've done the Pratt & Miller C6.R stand-alone oil to water cooler. That takes a lot of fabrication though which includes tipping the radiator forward.

Werks

Ok skxf430, got some more real world results for you. I just got back from 2 days at Thunderhill. Thursday was 97f and yesterday was flames of Hades blazing hot, basically it hit 108F. It was so hot out there that people were leaving at lunch time because they could not handle the heat lol. I stuck it out all day and ran hard and after hard 25 minute sessions the highest oil temp that I saw the whole day was 258f. So in a nutshell I'm pretty confident that the DeWitts radiator that Jason put in my car (combined with the vented Halltech GT2 hood that I have on my car) will pretty much handle anything that you can throw at it as far as HPDE days are concerned. If your running hour long session or endurance racing and stuff like that, then you might need more but for what we are doing can hammer on the car at will and not have to worry about anything.

skxf430

Werks,

You are the true iron man in that type of heat!!!

My car is going in for a dedicated oil cooler and radiator in the next couple of weeks. I hope to get up to Thunderhill in July to give it a work out. I hope to see you up there.

Werks

It was pretty intense yesterday. The day started off with something like 120-140 cars. By the end of the day there were probably only 50-60 people left lol! Mike was down there for part of the day shaking down his new Honda race car that he picked up and mentioned that some of the guys from down south might be coming up in July. Unfortunately my car is going back to Katech the end of the month for another round of mods so I'm going to be out of action for July and August. Decided to ship the car down during the hotter months as we can pretty much run year round here. If you are coming down in July it's going to be 95+ every day at T-hill so be prepared! Having said that though if you are going with separate oil cooler and radiator your car should be able to handle the heat without any issues!

skxf430

Werks,

That is a lot of cars to start with. I hope we don't have that many cars next month, as that sounds like 405 freeway in bumper to bumper traffic.

Mikymu has waaaaaay too many toys and he needs to share some with the rest of us.

The Katech event sounds like blast. Too bad we can't have something like that here on the west coast.

My car should be sorted out before TH and overheating shouldn't be an issue. It is a long haul for me so many other things could likely go wrong. Lol

Werks

It's really not too bad when you consider that was split between 5 run groups including the drivers school. So you only end up with about 20 cars in each run group when all is said and done.

Regarding Katech's Track Attack, it is a blast! The closest thing that I think there is here on the west cost is the HOD event that is done with the National Corvette Museum at Thunderhill in I believe it is September which you might want to check out also. As far as your car is concerned I think that you are going to be fine once you upgrade your cooling, which you are already working on. For the rest it's just typical little issues that you have to deal with any time that you are working with a new car!