Cosworth coolant temperature

[weederr33]

Originally Posted by sly

Done. I went ahead and ordered one from RSD. If the one from Cosworth ever shows up, I guess I'll just list it on eBay.

Good idea or you could post it on the for sale section here since it may be more... applicable haha

[sly]

Yaaay! Rally Sport Direct gave me a tracking number. My thermostat should be here by Thursday. Maybe I can finally pull this car off the ramps and drive it again.

At least in the down time I did get an OEM oil cooler installed. I figured that since I had the cooling system drained anyway for the thermostat, it would be easy to install the oil cooler, and it was. So in the time that I've been waiting on the Cosworth thermostat, I ordered an oil cooler with all the hoses and fittings and completed the installation.

[sly]

Got my replacement from RSD today. It showed up early. First thing I did was put it in hot water to verify when it opens. This one started opening at 165F instead of 120F. Much better. This one also had no markings on it. Anyway, I got it in and now the engine heats up properly. Mileage has gone up from 32 to 37.5mpg. Techstream indicates that the car is running around 175F.

[Matt@Cosworth]

thats exactly where its supposed to run
hopefully it will all be bit more plain sailing from here on in

[mav1178]

Running an aftermarket performance thermostat on a street car really doesn't do much, especially on newer cars.

I used to change out thermostats in Nissans, but that was because the cars were 10-15 years old and parts needed to be changed.

-alex

[sly]

Originally Posted by mav1178

Running an aftermarket performance thermostat on a street car really doesn't do much, especially on newer cars.
-alex

Normally I would agree on a stock fuel injected vehicle. But according to Cosworth, the coolant temperature was not selected from the factory for performance reasons but for emissions. I've already flashed the car over to their stage 1.0 tune and with the spark advance mapping they recommend a cooler thermostat to help prevent engine knock. I've also seen some charts that show that the coolant temperature spikes just before the thermostat opens. By opening sooner, you lessen the temperature spike and maintain a more even temperature.


Either way the car is now running in closed loop mode. All the race rom features seem to be working reliably. I know my bank account will regret it but I'm already itching for the 1.1 and 1.2 exhaust and tune. This time around, though, I won't take apart my car while waiting on parts.

[mav1178]

Originally Posted by sly

Normally I would agree on a stock fuel injected vehicle. But according to Cosworth, the coolant temperature was not selected from the factory for performance reasons but for emissions. I've already flashed the car over to their stage 1.0 tune and with the spark advance mapping they recommend a cooler thermostat to help prevent engine knock. I've also seen some charts that show that the coolant temperature spikes just before the thermostat opens. By opening sooner, you lessen the temperature spike and maintain a more even temperature.

... wait, what?

Let's say at the track you are running the car hard. Your coolant temps are around 100C.

What does a cooler thermostat (in reality, all it does is open sooner) have anything to do with temperature spikes or engine knock? 100C is full open, stock or aftermarket thermostats.

Edit: I understand what you are trying to describe is hunting, however this has nothing to do with opening sooner. It is an improvement in flow control. Aftermarket companies can easily make a stock-type thermostat w/ superior flow control vs stock, yet because this would have the same range as stock there is no marketing benefit to it.

-alex

[sly]

Originally Posted by mav1178

... wait, what?

Let's say at the track you are running the car hard. Your coolant temps are around 100C.

What does a cooler thermostat (in reality, all it does is open sooner) have anything to do with temperature spikes or engine knock? 100C is full open, stock or aftermarket thermostats.

Edit: I understand what you are trying to describe is hunting, however this has nothing to do with opening sooner. It is an improvement in flow control. Aftermarket companies can easily make a stock-type thermostat w/ superior flow control vs stock, yet because this would have the same range as stock there is no marketing benefit to it.

-alex

Yes, once you heat soak your system, opening sooner will make no difference. If your radiator is heat saturated then it can not remove any additional heat. In a track setting this might not make much difference except for providing a little buffer by opening sooner. However I don't plan on tracking this car. It's primarily driven as a DD. On light cruising to and from work I've definitely seen a drop in engine temperature when compared to OEM. It seems that the stock radiator is more than enough for daily driving but on a track, it may heat soak and make the thermostat irrelevant.

I may not fully understand the thermodynamics to a full degree (but am learning all the time), but have noticed a definite improvement in engine efficiency. Drove home from work tonight and averaged 38.5mpg. I have never gotten this kind of efficiency. I ran the stage 1.0 tune for almost a month with the OEM thermostat and was getting around 36mpg. Maybe it's just the warmer weather we are getting now, I don't know.

[sly]

All apologies to Cosworth. It seems that they have done a bit of restructuring in regards to their authorized dealer network. I originally ordered the stage 1.0 system from Speedzone Performance and it was they who sent me the wrong thermostat. I contacted them to make it right and they just passed the buck off to Cosworth rather than attempt to fix the situation. Cosworth doesn't really seem to deal directly with the consumer but recommends dealing with the distributor instead. I think they were caught in the middle on this one. I still have never received a replacement thermostat from Cosworth (even though I did buy the correct one from RSD since then). So I saved $100 by buying from Speedzone Performance but ended up spending it in buying a replacement thermostat from RSD. So for me, I will not be dealing with Speedzone Performance any more. They were unwilling to remedy the situation and sold me the wrong part. As for RSD, I have had nothing but good experiences and will be sticking with them.

So Matt@Cosworth, what would you recommend in this situation? Is there any way I can get reimbursed for having to rebuy the thermostat from RSD? Speedzone Performance sent me the wrong part and doesn't seem to want to do anything about it.

[mav1178]

Originally Posted by sly

Drove home from work tonight and averaged 38.5mpg. I have never gotten this kind of efficiency.

If you are using the dash gauge as a measure of efficiency, that's the worst way to observe results considering that information is pulled from the ECU.

-alex

[Matt@Cosworth]

Originally Posted by sly

All apologies to Cosworth. It seems that they have done a bit of restructuring in regards to their authorized dealer network. I originally ordered the stage 1.0 system from Speedzone Performance and it was they who sent me the wrong thermostat. I contacted them to make it right and they just passed the buck off to Cosworth rather than attempt to fix the situation. Cosworth doesn't really seem to deal directly with the consumer but recommends dealing with the distributor instead. I think they were caught in the middle on this one. I still have never received a replacement thermostat from Cosworth (even though I did buy the correct one from RSD since then). So I saved $100 by buying from Speedzone Performance but ended up spending it in buying a replacement thermostat from RSD. So for me, I will not be dealing with Speedzone Performance any more. They were unwilling to remedy the situation and sold me the wrong part. As for RSD, I have had nothing but good experiences and will be sticking with them.

So Matt@Cosworth, what would you recommend in this situation? Is there any way I can get reimbursed for having to rebuy the thermostat from RSD? Speedzone Performance sent me the wrong part and doesn't seem to want to do anything about it.

I would say the simplest route is that as James ( Cosworth sales admin) has already sent you a thermostat, once that finally clears customs ( I'll try and sort you out a tracking number) send it back to RSD to get your cash back?

and our reasons for going to a low temp stat were all about performance
a cooler cylinder head increases volumetric efficiency and also reduces knock sensitivity
our dyno testing showed a small but measurable advantage by lowering the coolant by 10° so it was wrapped up into the kit

[ajc209]

Regarding coolant temps.

The coolant system is very good on the FA20 and does not reach full capacity even on the track.

Stock I used to see ~93C coolant temp on the track. OEM thermostat is fully open at 95C.

I fitted the cossy thermostat at the same time as fitting the Cosworth SC kit and even with ~250WHP, coolant temps are rock solid 83C. Its fully open at 90C so not at full capacity.

[churchx]

It's not the same for oil temps though. Even more so on track.

[FRSBRZGT86FAN]

Originally Posted by churchx

It's not the same for oil temps though. Even more so on track.

This is true but when the thermostat is coupled with the OEM water/oil cooler setup like OP it will make a difference because a slightly lower coolant temp will probably scale to the oil temp.