jvp

I'd almost guess that the doing the EOC first might produce more noticeable results immediately. Were I in this market, I'd do that, then the rad if I wasn't doing them both at once.

fleming23

I already have the Gen 2 from DeWitts waiting to go in. I will very likely order the EOC from them once released and I can see all the install details. The only other item left is whether I want to screw with the HX or leave it as is.

Once I am done, I will take my car (M7/Z07) to Road Atlanta and beat the crap out of it at some point this summer. Only real issue is I won't have any "before" data to compare to.

ZeeOh6Nut

I was going to schedule a trip to Bondurant with my 2 son-in-laws (my 3rd trip). They no longer have Vettes at all and have replaced them with Vipers. When I was there 11 months ago they had recently had their new fleet of standard C7's and were awaiting 2 Z06's to be delivered. It seems like they changed brands rather hastily.

thebishman

JVP,

I failed to mention that the only reason for planing on the cooling mods in two stages is for warranty considerations; meaning that I think that GM would have a very hard time denying a warranty claim on the motor caused by a more efficient radiator. BUT, they would have more of a claim in denying warranty coverage if the oil 'pathway' had been changed.

Again, I'm convinced that the EOC alone would be far and away the best solution, and would probably negate the need for the Gen 2 radiator; I just have to convince myself that the 'risk' is minimal.

Bish

jim2092

Excellent opportunity for you to report temperature improvements as each coolant fixture is installed.

johnglenntwo

I believe he said this cars owner has put it into limp mode.

The results will be from all three beefed up radiators, and they are all probably necessary in the A8! The luxury of this is it is a simple bolt-on versus moving the intercooler out and all of that.

rsilver

Bish, I agree about doing the radiator first. I don't want warranty issues with GM. As for shiny aluminum parts, I was just commenting on the workmanship

0Tom@Dewitt

I feel you are being a little hard on us here. The Gen1 radiator was actually a success and we had mostly good reviews. The only two reviews posted on the website were both five stars. We do not limit the number of reviews people can post.

http://www.dewitts.com/collections/c...ducts/1139114m

The main reason we went to an improved design is because a few hard core racers still had issues. But another reason is because we can. Any other radiator supplier buys their cores from someone. In most cases they do not have options and will take whatever the supplier offers in the x by y size they need. We build and braze our cores in house. We can make anything we want or need for a given application.

I understand the need for validation and testing. We have spent thousands of dollars in wind tunnels and labs over the years. While the test data was interesting, it was the feedback from owners that was the most valuable. We have been solving cooling issues for twenty years, on six Corvette generations, and we're about to add one more. Yes, we do need some 90 degree days to completely remove all doubt but I do not control that or the fact aluminum is shiny. It won't be long until we have dozens of customers using both the radiator and the EOC and summer will return.

Operations

Tom
Really like the oil cooler,
Question, will this added section of the oil circuit the pressure or return?
I wondering will this new section need to be filled before oil is supplied to bearings etc. and will it empty between startups?
Lastly about how much additional oil will take to fill the lines and cooler?

Thanks for working on this

Painrace

Oil pump is variable displacement pump which should supply the needed oil. I am sure Tom will tell us.

Jim

NemesisC5

I agree Bish. Factory design for packaging is marginal at best and a setup similar to Tom's should have been part of a ZO7 package for those that are more serious about HPDE.

In a lengthy discussion with an engineer at Evans cooling I was told with their coolant you would not experience cavitation as much preventing air bubbles and lower combustion chamber temps. He explained that on hot days you likely will see slight increase in coolant temps but larger drop in oil temps due to reduced cavitation enhancing heat removal from combustion chamber area. I was told GM water pumps are driven ~24% faster than crank rpm and factory pumps with 50/50 mix of water/glycol cavitation can begin ~5500 rpm or lower. Air bubbles in engine coolant does not remove heat as efficiently and this seems to somewhat validate that short shifting has helped members that track their cars run cooler, especially those with A8's.

In the discussion I took away several good points:

1.) A separate air/liquid EOC is most effective for track events.
2.) You will still need a larger more effective radiator like Tom's in addition to separate air/liquid EOC for track events.
3.) Removing heat from the combustion area is adversely affected with cavitation (bubbles in coolant). Heat in the combustion chamber causes knock = knock retard = reduced power
4.) Cavitation reduces main radiators efficiency as well
5.) Closing off the bypass on water pump forcing all coolant through main radiator and running without a thermostat is recommended for racing. (LG stated they don't run thermostats on their race cars)
6.) Double pass radiators generally hurt more than help because of increased pressure drop slowing coolant flow. Race cars that utilize double pass radiators have pumps/systems designed with higher flow rates.
7.) Evans coolant in a system reduces cavitation, steam and "pressure cause by steam". Pressure on the cap of your overflow tank can be an indicator of this.

*** Again this is what I was told and it made sense to me so thought I would pass this on. I don't claim to be an expert or anything close, just making the best from common sense and what I have experienced, seen or heard.

Rookieracer

No Evans for me, since a friend of mine burnt up very badly at Bonneville in a stream liner when Evans coolant sprayed onto a hot header.

0Tom@Dewitt

The cooler will be pressurized, directly off the pump.
It will self fill instantly and most likely hold a little oil when shut down.
The lines and the cooler might hold an additional pint, we'll find out when we refill.

Snorman

Tom...I have a brand new in box Gen 1 radiator. Is there any way that I can get some trade credit to Dewitt's for a Gen 2 radiator? I want to install the radiator first, and would have this installed to run at Daytona-Rolex event April 14-15th (I ran same event last year bone stock).
Otherwise, I'll sell it in the classifieds.
Thanks.
S.

descartesfool

What would be best is if your firm tested and validated your product, and not expect customers to buy your product and then let you know if it works or not.

In the engineering world one is expected design, test and then to validate products before releasing them for sale. It never ceases to amaze me how in the automotive aftermarket industry how little actual proper engineering goes on. Just because a guy can weld a header does not mean it makes a lot more power, and same goes for cooling expected just because one can make up a radiator. If you want to know how much more power a header makes for example, you test it on a dyno and compare it under similar test conditions to the OEM or other competing part. You check the torque vs RPM, the AFR, EGT's, resistance to cracking, fit and finish, etc. I've been running on track for almost 20 years now, and have put on countless aftermarket parts that to be polite I would say they were less than fully developed, so I am always hoping that the industry will get better.

I know for example that the GMPP secondary radiator was thoroughly tested on track for hours in Nevada by Ron Fellows because I spoke to him about it at the SEMA show, and he told me he ran the modified Z51 with the T1 suspension and slicks for multiple, long, back to back sessions and was never able to overheat it. I also spoke to an engineer from GMPP at their booth and he told me he and others drove it as well and they had validated its cooling effectiveness (all on the Z51). One has to use fast drivers for long steady sessions without slow laps during the session to see if cooling products are adequate to control thermal run-away. I can overheat my Z51 in 86 degree weather in about 30 minutes, or perhaps in the second 30 minute session, both engine coolant and manual transmission.

0Tom@Dewitt

S. I would have to ebay too, so no. If it was mine, I would put it in. You would still be going from 35mm thick to 57mm thick and a major upgrade. The Gen1 was a great radiator and 90% of the customers were satisfied. If you have any cooling issues with it at all you could add this air/oil EOC and that would take a load off the radiator.

Snorman

Thanks Tom, appreciate the reply. I think I'll stick it in the classifieds here and order a Gen 2 from you.
Honestly, if I'm going to upgrade the radiator I'd rather have your best.
S.

jvp

If I'm not mistaken, you're no longer a Corvette owner and if to be believed: will never be again. So why concern yourself over what Tom's doing and how he's carrying out his business? You haven't been elected as the voice of the track-going C7 consumer base, so why not move along to your AMG user forums?

descartesfool

JVP, I think many people would benefit from manufacturer tested solutions. I will be installing a secondary radiator on my track buddy's Z06 shortly as soon as it arrives, since his car runs too hot on track, and he was happy when I reported all the info I got from the GMPP booth at SEMA and posted all those pictures. So while I will be selling my Corvette this spring because GM cannot find a solution to my AFM actuator failures, I am currently helping more than one C7 owner with their cooling issues on track.

5thGear

Jvp, although Claude might sound harsh, his points are valid and very logical. All Z06 owners would be statisfied with stock radiator for normal driving conditions and even slower pace at the track. The idea is to buy something that would work for advance level driving on the track. Some owners posted that GEN 1 didn't provide any better cooling gain on the track than stock unit. The anwser was to get rid of it and buy GEN 2. Neither unit were tested properly (track condition) and no data to support any gain. The marketing pitch for Dewitt's was that it is cheaper than other radiators. Well it's not so cheap if you are going to keep swapping between generations. They won't even swap radiator for Sean who can really provide some valuable feedback on the GEN 2 radiator. That's a very cheap investment given the feedback that would come out of it.