Track Time Limited due to High CHT

[TeeLew]

Fine, I guess. But it feels like enthusiasts are left to chase their tales because the gauges are not dependable, literal values we can trust. The scene seems ripe for a vendor to produce a gauge and sensor package so we have a fair chance to understand the true operating parameters and the effect of any mods we make.

https://www.aim-sportline.com/us/products/mxm/technical-specifications.htm

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[TeeLew]

For the record, I'm not upset. I am a little incredulous at people comfortable running engine temps that seem seriously out of control to me. Maybe I am completely out to lunch, but I'm just trying to share a little bit of my personal experience.

 

[67Fast_V]

hey, thanks for the explanation, it really helps understand what exactly you are referring to. just my opinion - no need to get upset, we are all trying to figure out a collective solution, I don't feel that anyone is trying to ignore you, but that's just my view.

I'll wait for others comment on your numbers, as I only know that calculated coolant temp is usually 5-7 degrees Celcius below measured CHT, so it translates to around 24F delta at 200F CHT. However, I doubt that this calculation is for cool side of coolant and how much we could rely on it. I don't have an aftermarket coolant temp sensor.

Porsche knows how to do a lot of good things and cooling is one of them. But as they say, it cost money and you get what you pay for.

When I traded down to buy this GT, I knew I was getting a passenger car. But it still can be a little frustrating to correct things that the OEM could have addressed. For me, I look at as a challenge and an opportunity to learn.

I almost feel like it would be better for all of us and others reading along to get on a conference call have a discussion and show & tell. Massive Google meet or Teams meeting. But oh well, let me try to share my thoughts in a sentence or two.

To cool these engines, you need two things (1) airflow through the radiator and (2) radiator surface area. That's it. Just two bits. Simple. This assumes that there is adequate coolant flow in the system which in our case there is.

Now how you get (1) and (2) is the challenge and the amount of (1) and (2) needed depends immensely on the operating conditions and engine power/packaging. There are near infinite combinations/ways to achieve success. And a lot of guys have already put a stake in the ground with good sucess.

Hopefully in the coming 1 or 2 months, I will be able to 100% define that for my application. I just need 2 more track days or maybe 3. I have outlined this solution in this thread, but I can't be 100% confident until I prove it.

On the delta between the OEM's calculated ECT and CHT, it's 13-14 deg F at heavy thermal load. Cruising, the delta is 0F. I have logged a lot data from the OBD2 port through HPT tuners device, and those are the results. Now is the OEM calc accurate? Not sure. Needs to be measured. It's on my list but looks like NeverSat hopefully will beat us to it.

 

[67Fast_V]

I’m gonna be lazy on this one. I have a hard time understanding the value in Ford’s strategy of using lots of calculated values. Speculating that it gives them a cost savings and some latitude in reporting values that help manage people’s reactions on both the high and low end of the scale.

Fine, I guess. But it feels like enthusiasts are left to chase their tales because the gauges are not dependable, literal values we can trust. The scene seems ripe for a vendor to produce a gauge and sensor package so we have a fair chance to understand the true operating parameters and the effect of any mods we make.

What makes this worse, is the thermostat is located on the exit of the radiator and not at the exit of the engine. I was floored when I found that out. So with a 180 t-stat, that means the coolant temp at the engine exit is 195-205F, of course depending on operating conditions.

I digested this one using the premise that most engines have a 192-196F t-stat located at the engine exit. So okay, Ford, if you want to do it that way, fine. Same with using a head metal temp (CHT) vs. measuring directly the coolant temp. Many ways to control an engine. Coyotes are different. But I like the 7500 rpm redline vs. 6700 for the LS engines. DOHC's are not bad either. So pluses and minuses.

And I agree w/ you, it's shocking to me that Steeda and/or other vendors have not put together a simple instrumentation package. It's not hard. Just a little development is needed. But that's what they do and do reasonably well. I almost want to do it myself and sell it but just too many other things to chase out. All valid points, though.

 

[67Fast_V]

be great to see your artwork with the fan shroud. I started thinking along the same lines of just gut the crap out of the OEM shroud and keep the two fans.

Sure thing. See attached modified Fan Shroud. Dug them up. 1st pic is stock of course.

If you look closely, you will see the aluminum angle pieces that are bolted-in to isolate the fan and give the assembly more structural stiffness. This is the finish product. Unfortunately, I didn't take any pics before I painted everything, so you can't see the aluminum.

As mentioned and as expected, this hurt temps driving around town. But still acceptable. I hit 198F CHT today after some shut downs and stopped in traffic. And after moving for 3/4 of a mile later, 180-182F CHT. It was 92-94 deg F ambient.

This was the 3rd cooling mod I made from stock.
1) 170 t-stat ... cus oem failed
2) 1st attempted at sealing the radiator (maybe 50%)
3) Fan shroud mod

Track event after 1), no improvement. Track event after 2)+3), most definitely helped but a mile away from acceptable temps. Cheers.

 

[NeverSatisfied]

Sure thing. See attached modified Fan Shroud. Dug them up. 1st pic is stock of course.

If you look closely, you will see the aluminum angle pieces that are bolted-in to isolate the fan and give the assembly more structural stiffness. This is the finish product. Unfortunately, I didn't take any pics before I painted everything, so you can't see the aluminum.

As mentioned and as expected, this hurt temps driving around town. But still acceptable. I hit 198F CHT today after some shut downs and stopped in traffic. And after moving for 3/4 of a mile later, 180-182F CHT. It was 92-94 deg F ambient.

This was the 3rd cooling mod I made from stock.
1) 170 t-stat ... cus oem failed
2) 1st attempted at sealing the radiator (maybe 50%)
3) Fan shroud mod

Track event after 1), no improvement. Track event after 2)+3), most definitely helped but a mile away from acceptable temps. Cheers.

Atta boy. Nice work

 

[Scootsmcgreggor]

Sure thing. See attached modified Fan Shroud. Dug them up. 1st pic is stock of course.

If you look closely, you will see the aluminum angle pieces that are bolted-in to isolate the fan and give the assembly more structural stiffness. This is the finish product. Unfortunately, I didn't take any pics before I painted everything, so you can't see the aluminum.

As mentioned and as expected, this hurt temps driving around town. But still acceptable. I hit 198F CHT today after some shut downs and stopped in traffic. And after moving for 3/4 of a mile later, 180-182F CHT. It was 92-94 deg F ambient.

This was the 3rd cooling mod I made from stock.
1) 170 t-stat ... cus oem failed
2) 1st attempted at sealing the radiator (maybe 50%)
3) Fan shroud mod

Track event after 1), no improvement. Track event after 2)+3), most definitely helped but a mile away from acceptable temps. Cheers.

Holy crap nice work I need to do this.

 

[Flyhalf]

Great job mate

 

[67Fast_V]

Atta boy. Nice work

Thanks fellas. Appreciate the kind words. Wish it would have done the trick but as usual, it's more complicate than I originally thought. But I'm not done trying ... getting closer with each mod. Sure would be nice to have a recipe .

 

[NeverSatisfied]

Whelp… got my gauges in… still at drawing board…

Ran pittrace. ~80f and sunny. Running 305mm heat cycled RS4s and short shifting at 6500. Things would stabilize after about 10 minutes…

Cht 225
Ect 210
Oil 250

Pushing any harder would take temps even higher. That last 500rpm REALLY generates some heat.

Guess I’ll box in the radiator seven more than I have, customize the fan shroud, and start looking at even bigger oil coolers!

Another interesting data point is CHT to ect delta would range from 5-25F.

 

[nbjeeptj]

Worked on the track temp issues this weekend also. I went with the Watson racing radiator closeout duct work and race louvers in the hood. The Watson piece is real nice and should work great, only complaint I would have is they are really no instructions other than several cad images of it assembled. It was difficult to figure out the best order of operations. I ended up fully assembling it out of the car and installed it in one piece attached to the radiator, to do this means taking a lot of the front end apart. Bumper cover, headlights, upper support that hood bumper and top of radiator, and the radiator with fan shroud. I looked at just building the piece in the car and I believe it could have been done with just pulling the bumper cover, but I could not convince myself that I was not going to have some unforeseen issue.

It will be a few weeks till I can test this on track, but I am hopeful that it will do the trick

 

[nbjeeptj]

One more thing to note about the Watson kit. It requires that you remove the AC condenser coil. Since I removed it I went ahead and pulled the compressor also. I only use this as a track car so for me it was not a big deal, but if you want to keep the AC this kit will not work.

 

[NeverSatisfied]

Worked on the track temp issues this weekend also. I went with the Watson racing radiator closeout duct work and race louvers in the hood. The Watson piece is real nice and should work great, only complaint I would have is they are really no instructions other than several cad images of it assembled. It was difficult to figure out the best order of operations. I ended up fully assembling it out of the car and installed it in one piece attached to the radiator, to do this means taking a lot of the front end apart. Bumper cover, headlights, upper support that hood bumper and top of radiator, and the radiator with fan shroud. I looked at just building the piece in the car and I believe it could have been done with just pulling the bumper cover, but I could not convince myself that I was not going to have some unforeseen issue.

It will be a few weeks till I can test this on track, but I am hopeful that it will do the trick

Interested to see what you think about the kit. I did an art project today as well to see if it helps

 

[Ewheels]

Whelp… got my gauges in… still at drawing board…

Ran pittrace. ~80f and sunny. Running 305mm heat cycled RS4s and short shifting at 6500. Things would stabilize after about 10 minutes…

Cht 225
Ect 210
Oil 250

Pushing any harder would take temps even higher. That last 500rpm REALLY generates some heat.

Guess I’ll box in the radiator seven more than I have, customize the fan shroud, and start looking at even bigger oil coolers!

Another interesting data point is CHT to ect delta would range from 5-25F.

Which Setrab oil cooler do you have on the car currently?

 

[NeverSatisfied]

Which Setrab oil cooler do you have on the car currently?

I have a 6 series 25 row. And I have it 1/8” spaced off the condenser. I used it because I had it leftover from a turbo Miata.

Looking at Pegasus's site, the chart recommends a 40 row 6 series for the 450-550hp range. Guess I'm undersized currently.

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