Assuming the stock turbo (50mm inducer) is similar in size to a 3076R (51mm compressor flange), 450whp @ 22 psi is around 70% efficiency. If incoming air is 25C/77F this means the compressor outlet comes out at 152C/305F. Finding a larger turbo that operates closer to 80% efficiency would drop compressor outlet to 136C/276C. This is less heat that's shed into the manifold, therefore Hx dumps less into the radiator.
Since this topic stated from seeing oil temps from my track video... Here is actual data from the track, 11 laps in at Lime Rock park. Charge air gets wayyyy more toasty than theory would have you think.
Okay embarrassing question time. How the hell do you actually read a compressor map?Assuming the stock turbo (50mm inducer) is similar in size to a 3076R (51mm compressor flange), 450whp @ 22 psi is around 70% efficiency. If incoming air is 25C/77F this means the compressor outlet comes out at 152C/305F. Finding a larger turbo that operates closer to 80% efficiency would drop compressor outlet to 136C/276C. This is less heat that's shed into the manifold, therefore Hx dumps less into the radiator.
If you want the layman's version:
For the record the "500 with 91" is a joke/reference to a different thread, a real knee-slapper if I do say so myself.
My setup:Since this topic stated from seeing oil temps from my track video... Here is actual data from the track, 11 laps in at Lime Rock park. Charge air gets wayyyy more toasty than theory would have you think.
Pure800, 27-28psi peak out the top.
Wagner manifold (shedding 249F of charge temp at this point in the log!)
Do88 aux radiators
Speed Engineering intake duct
MAD intake
Soo in short bigger turbo at lower boost ? Or i understand this wrong?Assuming the stock turbo (50mm inducer) is similar in size to a 3076R (51mm compressor flange), 450whp @ 22 psi is around 70% efficiency. If incoming air is 25C/77F this means the compressor outlet comes out at 152C/305F. Finding a larger turbo that operates closer to 80% efficiency would drop compressor outlet to 136C/276C. This is less heat that's shed into the manifold, therefore Hx dumps less into the radiator.
Yes. The charge air temps will be lower when you have a larger turbocharger as it will not have to work as hard to make the same boost pressure.
There's a bit of math that would go into the sizing, but the simple version is what you said. The larger hotside of a larger turbo means less restriction. Boost is simply a measurement of restriction for forcing air through. Then you also get a turbo that's working in a more efficient area which also adds power. The obvious downside is the larger the turbo, the more energy is required to bring it's wheel speed up.
General rule of thumb is larger turbo at the same boost will create less heat than a smaller turbo.
Cylinder temps do make some difference to oil/coolant since it's in the block but not a TON.Well then why @razorlab having bigger turbo but also visbily more boost still have lower temps? its 1.5 vs 1.9bar so pretty visible difference. Only due to running Etanol?
Eh mechanical stuff... i can only drive fast
I’d imagine having that massive hood vent does help evacuate a significant amount of heat. I’m also always surprised how you managed to get good oil temps and pressure.
