I don't claim that this will always be the case, all I claim is that Peter's coolant temp gauge never moved on that 100 degree day, and you saw the videos in his car and in mine! And my gauge moved! (I'll be able to tell you exactly what temp in a few days as I'm installing a 3 gauge pillar with a coolant gauge in a matter of hours, and road racing at TWS again this weekend.)Originally posted by Grant:
<STRONG>If you run high boost I think it might... I remember someone blew one up on the list a looong time ago, think it was Tozer with 28 psi + NOS, can't remember.
I've (Accedentally) pressure tested mine to 1.7 bar with no problems.
Andi now claims that a Supra with a big FMIC and an oil-cooled turbo will not overheat even on a roadcourse, with the stock radiator! I find this a little hard to believe myself.
[ August 22, 2001: Message edited by: Grant ]</STRONG>
I haven't done any testing to confirm this, but I doubt the lack of water cooling is what made that single equipped car run cooler at the racetrack than a comparable BPU car. My guess would be that the reduced restriction on the exhaust side is what helps. Somebody on the mkiv list (Lance I think) said that the stock turbos have a terrible pressure ratio, with pressure in the exhaust manifold being 3 times that of the intake manifold. With a single, and much better exhaust flow from a header and bigger exhaust housing, less heat gets retained in the head area, and there is less load on the cooling system. I'm pretty sure the heat removed from the turbo by water cooling isn't very significant compared to the load on the cooling system as a whole since the amount of coolant that flows through the turbo just isn't that much(look at the size of the hoses and pipes).Originally posted by Grant:
<STRONG>
Andi now claims that a Supra with a big FMIC and an oil-cooled turbo will not overheat even on a roadcourse, with the stock radiator! I find this a little hard to believe myself.
[ August 22, 2001: Message edited by: Grant ]</STRONG>
Thats a good point, I've heard people mention the huge amount of backpressure is what blows our wastegate open at BPU, preventing us from getting 30+ psi of boost like Chris B. was with his wired shut wastegate. I know for sure that the extra heat and pressure causes detonation.Originally posted by Eric:
<STRONG>I haven't done any testing to confirm this, but I doubt the lack of water cooling is what made that single equipped car run cooler at the racetrack than a comparable BPU car. My guess would be that the reduced restriction on the exhaust side is what helps. Somebody on the mkiv list (Lance I think) said that the stock turbos have a terrible pressure ratio, with pressure in the exhaust manifold being 3 times that of the intake manifold. With a single, and much better exhaust flow from a header and bigger exhaust housing, less heat gets retained in the head area, and there is less load on the cooling system. I'm pretty sure the heat removed from the turbo by water cooling isn't very significant compared to the load on the cooling system as a whole since the amount of coolant that flows through the turbo just isn't that much(look at the size of the hoses and pipes).</STRONG>
