S550 Brake Cooling - New Discovery

[Ewheels]

I, as many of you, have ducted brakes. A simple hose going from the high pressure zone of the front bumper feeding to the back of the brake rotor. This has been common place for racers for decades and has never been really questioned. It just works.

Now this is a great solution for race cars but it has its complications for double-duty street cars that see track time. The hoses get beat up over time and need to be replaced and especially for the S550 chassis, there simply isn't sufficient room for routing the ducts. (There is almost no room between the tire at full lock and the forward-most control arm.) It seems to be the general consensus that 3" ducting works a lot better than 4" ducting that Vorshlag uses on their S550 test car. Routing the duct in front of the control arm gets crushed by the wheel.

This crushed hose would also likely restrict air flow. Many people, including myself, have routed the hose between the control arms and the tie rod (see below) to prevent the hose from getting crushed.

This works better and keeps the hose in tact.

Well I have recently found on Vorshlag's development thread that they found the "scoop and flap" method actually produces cooler temps! I'm skeptical and even Mr. Fair himself said he was skeptical but he was kind enough to do the testing for us.
https://www.vorshlag.com/forums/for...2018-mustang-gt-s550-development-thread/page4
Scroll down a bit to see his full break down of his testing and results.

He tested his car with the regular 4" ducting to the back of the rotor on the left side and the "scoop and flap" method on the right side. Ran a few hot laps and pulled in to measure the rotor temps and consistently the scoop and flap side had 100°F cooler temps! (He states at one point that that corrugated hoses do not get the best air flow.)

To those of you on here who also use brake ducts (hoses), does this seem like a likely switch for you? It is much simpler, cheaper, and apparently works better. I may be pulling my backing plates off and switching to this method myself.

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[BmacIL]

There's a reason those pieces are on the PP cars.

 

[strengthrehab]

I overheated R16 pads using brake cooling ducting/hoses. Badly (based on pads and rotor wear). I have since removed the ducting and have re-installed my deflectors. From what I know from talking to the original designer/engineer, the stock PP deflectors/undertray were just as efficient or more efficient than 3" ducting he was using as a benchmark.

I'm a believer.

 

[Ewheels]

I overheated R16 pads using brake cooling ducting/hoses. Badly (based on pads and rotor wear). I have since removed the ducting and have re-installed my deflectors. From what I know from talking to the original designer/engineer, the stock PP deflectors/undertray were just as efficient or more efficient than 3" ducting he was using as a benchmark.

I'm a believer.

This is good to hear! Since I already cut holes in my lower grille for the duct inlets, I may leave the forward portion of the duct to get more air flow into the wheel wells and then use these deflectors. I personally think the hoses are a bit of a hassle on a street car

 

[strengthrehab]

This is good to hear! Since I already cut holes in my lower grille for the duct inlets, I may leave the forward portion of the duct to get more air flow into the wheel wells and then use these deflectors. I personally think the hoses are a bit of a hassle on a street car

The "street" routing has too many bends in it and the other routing results in beat up hoses. I've also talked to an instructor at the Ford Performance school and they run Pagid pads, SRF fluid and the deflectors and have had no brake fade at all. No problems with the stock deflectors.

 

[Ewheels]

I just did the old "hold a leaf blower up to the inlets and feel the air from the rotors" trick and I could barely feel any airflow if any at all.
I'm going to put the deflectors back on while I have the car on stands already.

Thanks for the reassuring comments!

 

[fatbillybob]

https://www.vorshlag.com/forums/for...2018-mustang-gt-s550-development-thread/page4
Scroll down a bit to see his full break down of his testing and results.


He tested his car with the regular 4" ducting to the back of the rotor on the left side and the "scoop and flap" method on the right side. Ran a few hot laps and pulled in to measure the rotor temps and consistently the scoop and flap side had 100°F cooler temps!

To those of you on here who also use brake ducts (hoses), does this seem like a likely switch for you? It is much simpler, cheaper, and apparently works better. I may be pulling my backing plates off and switching to this method myself.

No. I'm skeptical. 1st I'm not impressed with PP1 at all. So just because this is the cheapest way for ford to produce the car does not make me feel warm and fuzzy. 2nd the "100F cooler temps" is too vague. Where exactly is the measure and is that significant? If a rated race pad is 1500F and those pads and rotors see that temp which they probably do as evidenced by all the night glowing rotor pictures, 100F is 7%. Is that significant? Also we know that our lowly tire temps must be read in the hot pits and that just the cooling off of tires driving to the paddock makes the results useless. That is only ambient temp to around 250F. What is the significance of the measurement cool down time like does the wheel have to come off? How much time does that take? And is measure at the surface or the core? Is the obstruction on the rotor by the duct and the cooling duct plate holding the duct to the rotor also act as a 100F blanket when measuring? Is that the delta? Rotors are cooled not by air flooding the wheel well. Rotors are cooled by the vane shape pumping air from the center out to the edges. That is why rotors have a left and right. I suspect that more cubic feet of air are pumped through the center of a rotor via a duct than splashing air all over the place filling a wheel well even if directed.

The deflector concept still has merit. I think the design study should be max temps using templaq paint on caliper and rotor at various places. If all that was done (and I don't know this) is guy shoots an IR temp gun at the rotor that is no data at all just like an IR temp gun is useless for tire temps.

 

[BmacIL]

No. I'm skeptical. 1st I'm not impressed with PP1 at all. So just because this is the cheapest way for ford to produce the car does not make me feel warm and fuzzy. 2nd the "100F cooler temps" is too vague. Where exactly is the measure and is that significant? If a rated race pad is 1500F and those pads and rotors see that temp which they probably do as evidenced by all the night glowing rotor pictures, 100F is 7%. Is that significant? Also we know that our lowly tire temps must be read in the hot pits and that just the cooling off of tires driving to the paddock makes the results useless. That is only ambient temp to around 250F. What is the significance of the measurement cool down time like does the wheel have to come off? How much time does that take? And is measure at the surface or the core? Is the obstruction on the rotor by the duct and the cooling duct plate holding the duct to the rotor also act as a 100F blanket when measuring? Is that the delta? Rotors are cooled not by air flooding the wheel well. Rotors are cooled by the vane shape pumping air from the center out to the edges. That is why rotors have a left and right. I suspect that more cubic feet of air are pumped through the center of a rotor via a duct than splashing air all over the place filling a wheel well even if directed.

The deflector concept still has merit. I think the design study should be max temps using templaq paint on caliper and rotor at various places. If all that was done (and I don't know this) is guy shoots an IR temp gun at the rotor that is no data at all just like an IR temp gun is useless for tire temps.

Uh....what?
Based on your other thread, you don't know how to drive these cars (or any car with significant power and mass) properly, so your feedback on the car's brakes and dynamics is taken with a truckload of salt. And to your last point, you also don't seem to have any understanding of why you need to use a pyrometer for tires vs an IR temp gun. For how it was being measured for this testing, it's perfectly valid. 100 F when you're in the 700-800 F range is also quite significant. It was repeatable, too.

Rotors are cooled much better by the air being pushed through the vanes from the center....that's what the deflectors do, where as most ducting setups force air onto the inside of the friction face and that's it. It's very, very difficult to get a duct setup on this platform that will outperform the tunnels and deflectors because of where you can route hose. The restriction created by forcing high pressure air from the front bumper area into a tube means you're not getting the flow you think you are.

I'm going to be a snarky and an ass because you're being a beer-belly armchair quarterback. Learn to drive the car.

 

[fatbillybob]

Uh....what?
Based on your other thread, you don't know how to drive these cars (or any car with significant power and mass) properly, so your feedback on the car's brakes and dynamics is taken with a truckload of salt. And to your last point, you also don't seem to have any understanding of why you need to use a pyrometer for tires vs an IR temp gun. For how it was being measured for this testing, it's perfectly valid. 100 F when you're in the 700-800 F range is also quite significant. It was repeatable, too.

Rotors are cooled much better by the air being pushed through the vanes from the center....that's what the deflectors do, where as most ducting setups force air onto the inside of the friction face and that's it. It's very, very difficult to get a duct setup on this platform that will outperform the tunnels and deflectors because of where you can route hose. The restriction created by forcing high pressure air from the front bumper area into a tube means you're not getting the flow you think you are.

I'm going to be a snarky and an ass because you're being a beer-belly armchair quarterback. Learn to drive the car.

and what be your driving and automotive credentials doctor snarky?? Let’s hear it.

 

[fatbillybob]

Actually forget it. It’s not worth my time. But just for the record I’m a full competition licensed SCCA club racer. I hold two additional race licenses and race a corvette c5z06 at 3525lbs min weight at impound and 75lbs of fuel. That’s a 100-200lb delta to the s550. And heavy or light it dies not matter. Chassis dynamics is physics. All the laws of physics apply. Good bye.

 

[PoppinJ]

Thanks for the post. I just read through their entire build blog for the 2018. I really enjoyed it. This guy even runs at my home track MSR C. How freaking cool. Those ducting plates are for sale on their site now. 129. I may grab some. I'm running the Steeda bearing control arms instead of the stock ones so the arm kinda articulates around on the bearing. It causes the ducting plate to sit at an angle depending on how the bearing is swivled at the time, although it seems to default fully locked out in the inward position.

Also. Where the hell is that diff cooler prototype at vorshlag? The very last post of it has a pic and he talked about updating with the results of the prototype but never did. That was in Aug and it looks like they're selling the car now. Their design looks to use the stock diff cover which would save time and money on install and parts vs the FTB kit. TAKE MY MONEY! I'm going to reach out to them so see if it's something they are still working on.

 

[strengthrehab]

They are building another S550 so maybe it will be developed further.

 

[Ewheels]

I'm sure they're still working on it. I'm waiting to see it on their site too. I have heard nothing but good reviews for the FTB diff cooler and it is relatively cheap compared to the Ford one but market competition is always good for the consumers
If I remember correctly from their build blog, their's is a passive cooler (no fan). That's an interesting take. Less components to go wrong.

I personally haven't had any overheating issues yet so I figured I'd address cooling as needed

 

[PoppinJ]

I'm sure they're still working on it. I'm waiting to see it on their site too. I have heard nothing but good reviews for the FTB diff cooler and it is relatively cheap compared to the Ford one but market competition is always good for the consumers
If I remember correctly from their build blog, their's is a passive cooler (no fan). That's an interesting take. Less components to go wrong.

I personally haven't had any overheating issues yet so I figured I'd address cooling as needed

I hope so. It's addressed at the very bottom of page 4 on the build log. "I will also cover the development and install of the diff cooler we installed before the SCCA @ COTA TT event." but that was in aug. There is a picture that shows the prototype. Im stoked because it looks like it uses the stock cover. This would make the kit significantly cheaper than the FTB kit, plus like you said it doesn't have a fan, fewer moving parts and cheaper but prob not as effective. Looks like they are trying it out with and without the fan to see whats needed.

"Looking back on it, this probably wasn't the best event to try to get lap time test data from. We did test both the new diff cooler and brake cooling flaps. The brakes worked great, but with the narrow range 0-250°F Diff Temp gauge (the one on the far right above), it was still getting pegged in the later laps of the second hot session. We have to put a wider range gauge (0-300F) there, then test it again without the pump on + with the pump/cooler on + with the pump & fan turned on (I will show that stuff next time)."

Having the diff temp pegged at 250 (so its actually much higher) isnt really promising. If they can get airflow through that area (not an easy feat in that area) then I bet it would do without a fan. The gt350 uses areo on the rear bumper to funnel air across the radiator. Ive reached out to them so lets see what they say.

 

[Grintch]

I thought the plates/deflectors Vorslag tested were prototype larger ones rather than the standard PP parts?

They specificly mentioned they were working on new ones "that should be availible soon" (months ago).

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