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axl911 axl911 is offline
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Join Date: Sep 2002
Location: texas
Posts: 863
Originally Posted by TurboKraft View Post
The 1994-94 Turbo straight 11-blade fan does not just drop into the 964/993 fan housing!
You can purchase the ~$600 fan housing, too, and then find out it doesn't fit the 964 or 993 plastic fan shroud. The fan housing that does is the 993TT -- and new you're over $1,000 new, plus the fan strap, plus...

Ruf's RCT's didn't run hot, and neither do our 964/993 Turbo conversions. Better to determine why it's getting too hot in the first place under these long, light loads. Confirm fuel and timing. What is your oil temp -- do you have enough oil cooling?
This is a NA 993 running a supercharger. Timing is somewhat pulled back by the piggy back computer under load. Mixture at part throttle is in closed loop and controlled by 02 sensor, although there is a 7th injector. I'll try to check timing in these situation, but Durametric software is not good/fast enough for me to see & log timing.

Mixture I see in closed loop is around 14.7 which drops upon throttle tip ins. Oil temperature is actually under 200F when I activate the cooler fans. IAT is only 15F above ambient. These numbers are very good.

The main reason I brought this up is that I was seeing cht climbing up to 400 on the hottest cylinder during a long hill climb. Normal highway cht is about 370F at 95F ambient temperature.

Anyone know what CHT the ruf or factory turbo run at part throttle? WOT? The only data I find is from the VW and air cooled airplane engines which recommend keeping cht <400.

Last edited by axl911; 08-22-2011 at 01:27 PM..
Old 08-22-2011, 01:23 PM
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