Camaro XV

[frojoe]

Originally Posted by mikels

In this case, there is 3 sources of heat - engine, supercharger and AC. Breaking that down further, engine heat in form of coolant and oil, supercharger heat in form of air and AC in form of refrigerant.

Engine heat in coolant and oil comes from the inefficiencies of an IC engine - only about 1/3 the energy released from combustion actually makes power, another 1/3 goes into cooling system (coolant & oil) and 1/3 goes out exhaust.

Since this is a SC engine, also have to take into account mechanical energy used to drive supercharger - in Red Devil and Mayhem, this worked out to ~120-140HP. So Mayhem generating an output of 878 HP is actually generating over 1000 HP already - and that also nearly equals the amount of energy we need to release from cooling system.

Complicating this further, we have the heat from the intake air charge to reduce as well - and use air-to-water heat exchanger with a stand-alone cooling system to then convert this with a water-to-air heat exchanger in front of car. Since delta-T is critical for heat exchanger effectiveness, we package the intercooler radiator in front of the cooling stack (all the heat exchangers in front of car) to get greatest delta-T for charge air cooling. This adversely effects radiator efficiency as air temp reaching front face of it is already heated above ambient. And we have 1000+ HP worth of heat to dissipate from it.

Packaged between the CAC (charge air cooler radiator) and the coolant radiator is the AC condenser. At least Mark hasn't become too much of a wimp is his old age to want to race with AC on, so while this doesn't add heat to air flowing through, it does add pressure drop of airflow through entire cooling stack.

We also have engine oil to contend with - and can either use oil-to-air heat exchanger, or oil-to-water. If oil-to-water, this is more KW to release through radiator. If oil-to-air packaging, airflow restriction and preheated cooling air have to be considered.

All this is converted to heat transfer equations and calculated to optimize the entire cooling system of heat rejection balance.

Drag racing is easy - you can get away with a whole lot if only running in <10 second bursts of WOT. Road racing makes this much more difficult as entire system reaches equilibrium.

And haven't even talked about trans and diff oil cooling yet....

Dave

Spoken like a true engineer. Very well worded.

[Track Junky]

Thanks Dave, that was an interesting read.

Amazes me how you guys continue to raise the bar with each build.

[clill]

Don't give em a reason for even fatter heads.

[glassman]

Can fatter heads process more data?


Cause this s#\+s awesome

[Vince@Meanstreets]

Originally Posted by clill

Don't give em a reason for even fatter heads.

you can only pull so much foam out of a helmet.

[Radlark]

Originally Posted by Vince@MSperfab

you can only pull so much foam out of a helmet.

LMBO!!!!

[WSSix]

Dave and Mark too, would locating the different fluid to air exchangers in separate spots be better? Or do you run into other obstacles such as air flow and packaging that cause it to be too cumbersome or add too much weight? I'd also imagine aero considerations have to be factored in there too. Instead of having one central area to concentrate on having proper air flow through, you'd have multiple.

[Stielow]

Originally Posted by WSSix

Dave and Mark too, would locating the different fluid to air exchangers in separate spots be better? Or do you run into other obstacles such as air flow and packaging that cause it to be too cumbersome or add too much weight? I'd also imagine aero considerations have to be factored in there too. Instead of having one central area to concentrate on having proper air flow through, you'd have multiple.

On Red Devil we ran the diff, tran, engine oil good and power steer was all sent to the front of the car to be cooled. On Mayhem we move the trans and diff cooler to the back to reduce the thermal load on the front. Mayhems engine coolant temp as very on track but we are still chasing an engine oil cooling issue. On Camaro XV I'm adding an even bigger rad and oil heat exchanger.

But as we attempt to rebalance the thermal load Thomson is upping the power..
I think we can keep it cool and make more power.

Mark

[coolwelder62]

Originally Posted by Stielow

On Red Devil we ran the diff, tran, engine oil good and power steer was all sent to the front of the car to be cooled. On Mayhem we move the trans and diff cooler to the back to reduce the thermal load on the front. Mayhems engine coolant temp as very on track but we are still chasing an engine oil cooling issue. On Camaro XV I'm adding an even bigger rad and oil heat exchanger.

But as we attempt to rebalance the thermal load Thomson is upping the power..
I think we can keep it cool and make more power.

Mark

[Track Junky]

Originally Posted by Stielow

On Red Devil we ran the diff, tran, engine oil good and power steer was all sent to the front of the car to be cooled. On Mayhem we move the trans and diff cooler to the back to reduce the thermal load on the front. Mayhems engine coolant temp as very on track but we are still chasing an engine oil cooling issue. On Camaro XV I'm adding an even bigger rad and oil heat exchanger.

But as we attempt to rebalance the thermal load Thomson is upping the power..
I think we can keep it cool and make more power.

Mark

I'm probably going to step out on a real thin limb here but I dont see the purpose of running coolers for rear diff, power steering, and trans when you may run 25 minutes a session at most?