What's the flowrate on the CSR ?

The Mez HD flows 55 gpm, I have one on my vette and I've been on road trips of over 1000 miles in a day without overheating (sustained 75-80+ mph driving)


Mike

 

Sustained 75-80mph driving is nothing compared to going all out on a road course. If the OP switched back to a mechanical pump that should solve his problems.

 

How is the front end of the RX7 setup? I ask this because if you used the same engine setup in another car and it worked fine I would guess maybe there is an air flow problem across your radiator. Maybe the bottom feeding 4th gen got better flow over the radiator compared to the RX7?

 

That is a very good point that I did not even think about!

Just look at the affect of taking the front air damn off of an fbody...they start to overheat on the highway.

 

The Hawk was at 9.2 DCR also with a 11.3 SCR. The only thing a dyno tune would do would be to get my timing correct. My AFR is dead on because I know how to tune for it and at WOT, I am at 12.2 AFR intentionally to keep the charge a slight bit cooler.

I just took my WOT timing tables and moved them over to my RX7. I cannot say if this is optimal but there have been no issues. No doubt I could back off the timing a few degrees. I noticed in my dyo tuning that 3 degrees timing before or past optimal made less than 10 HP difference.

 

That is something to note. 4 gens have the radiators angled down so the air being discharged is not hitting the engine and slowing the flow. My RX7 has the radiator pushed up closer to the engine and is perpendicular. However, I would think the huge flow of the Taurus fan could compensate for this difference.

 

Not sure how your computer is tuned and how your fans are wired, but with factory fans and tune the cooling fans turn off at cruising speeds - I forget the exact mph though. At that speed though it relys on the air pushed through the rad from the front air damn to cool the rad.

If your aftermarket fan is wired the same, it is not doing any good at speed since it is not running...you probably have it wired in with a manual switch, but just figured that would be worth mentioning just in case

 

Fans always on. When ignition goes on, so does EWP and fans.

Thanks for thinking of it.

 

There seems to be some perception that the "steam line" only flows air bubbles and steam. In fact, it constantly flows coolant. It just provides an escape route for air and steam bubbles that may collect/form in the back corner of the head. I've got a temp sensor in the steam line, and it pretty much mirrors the temp in the water pump, running a few degrees hotter under cruise conditions. Since the LT1 cooling system feeds the heads first, then the block, the coolant that flows through the steam line is not used to cool the block. Probably don't want too much flow, or you might limit cooling at the block. Too little flow, and you will see overheating on #7 and #8. Hard to say what the ideal flow would be.

The LT1 cooling system constantly flows water to the heater core, so eliminating that flow might help engine cooling.

 

Yeppers, I am in AZ so that has been done.

You have confirmed what I suspected on the vents and so I will try that solution...not making the flow too extreme where limited flow goes to the block.