[jdoss2001]

I recently purchased a 2008 with 20k miles which was modified to include an eforce supercharger, competition cam, 3200 stall converter, dewitts radiator and dual fan setup, 160 tstat, fuel pump, injectors... etc

At highway speeds the car runs great 190-205, in stop and go traffic with the AC on the car quickly overheats 250-260+. The dealership I purchased from has been helpful but has not been able to correct the issue. I dont want to get rid of the car, simply fix it. If I leave it in park it doesnt seem to overheat (but its not much fun in park) its only when their seems to be a load on the transmission and the car is in slow stop and go traffic. Today outside temp was 68, transmission temp was 234, oil temp 240, coolant 245 and climbing quickly. Tstat is working. PLEASE HELP

[fishslayer143@yahoo.com]

its that big stall converter causing the heat...at low speed it can t lock and slips like hell, putting all that heat into your radiator [ look at your trans temp on a 68* day, thats 60* higher than it should be ]].at hiway speeds it locks, no heat.. ..solution, add a big *** auxillary trans cooler or go to a lower stall converter... IMO

[jdoss2001]

Thanks for the tip, I had suspected but was not certain... Realy appreciate the help!

[fishslayer143@yahoo.com]

welcome to Smokin Vette , by the way... we ve got a great bunch of members here..and that sounds like a pretty nice car, put up a pic or two when you can

[c6vette]

Welcome! Pics??

[Ragtop 99]

A dewitts should handle your set-up easy. 68* and no A/C running? It's easy to suggest more cooling such as an external cooler for the transmission would offload some of the heat or a separate engine oil cooler.

If your highway temps come down after a WOT blast from 60 - 100 mph, then you have adequate cooling capacity. I think you have an install problem. First I would verify the fans are wired correctly. Make sure the fans are both running at full speed; you could have a blown fuse, relay, melted wire, or other issue and only be running one fan. Next verify that air from both is flowing the proper way. Go out with a sheet of paper and slide it next to the radiator while the fans are running and see how the air pushes/pulls the paper. If one is out of phase, or both are reversed, you won't get any real cooling. This is easy to miss because the fans look like they are working, but in reality are fighting each other. Finally check for any blockage or anything restricting airflow.

[fishslayer143@yahoo.com]

I would think that since he says he can sit ,running in park,w/AC , not moving and not overheat , his fans are operating....raising the stall to 3200 rpm also raises the fluid temp..theres a lot of slip and heat at low speed where his overheating occurs..if you can t shed that extra heat, you ll fry the fluid and then the trans and if it goes thru radiator and raises engine coolant to 260*+ as he says his does,, it will soon cook head gaskets as well... once the converter locks at higher speed he says it doesn t overheat..sounds like a high stall/heat issue to me..based solely on the info he has provided.... I do agree an inspection of the car could show another reason

[jdoss2001]

Thanks for the reply, I've had some trouble logging in. 1st I will post some pics soon.
2nd. Fans are wired correctly. I'm also running 411 gears, what kind of performance decrease do you think I will see if I go back to a stock stall? The car can't really hook up anyway with the run flats.

[fishslayer143@yahoo.com]

I thought as much...the 411 gears aren t the problem..with the horsepower you have with the FI, not much loss... I m sure you cannot launch full power now and keep it on the road..3200 stall is a lot for a daily driver, they simply produce too much heat... but you can cool it down with an big auxillary cooler,shed all that heat.. coolers are not expensive compared to new Converter and labor to install..,if you like the stall, I would give that a try first.. whatever you decide, do it soon, neither the trans or the engine can take those temps for long....

[Ragtop 99]

It is easy to blame it on the higher stall, but there are blower cars out there with a 3000 stall and no problems. I do agree they all have external coolers. No doubt it contributes but IIRC the A6 uses lock up starting in 3rd gear. The extra rear gear actually reduces the amount of slip required on launch too. Did your tuner change any of the lock-up settings? If they are MPH trigger, with your gearing you may not be locking up as much as you should under light throttle conditions.

Just curious, have you measured your stall speed with the blower? A converter rated for 3200 behind an NA motor should stall much higher with the big bump in torque from your blower. Stock stall doesn't hurt as much on an eforce since it is PD and makes a lot of torque down low. The launch won't be as easy to modulate as with the 3200, but you will still be fast off the line with your gearing and torque.

You are the only one I've heard run 4.10s with an A6. That's a lot of gear.