When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Wanted to both update my on going situation and ask a question. I finally had a chance post undertray, reroute, water w/ water wetter, aluminum rad, 2x spal fans, removed bumper support, 2 hood vents drivers front and one directly behind it and sealed (though not perfectly) radiator ducting. I maxed out at 216F on coolant and about 250F on oil temps (have a low mount FM oil cooler), on a 90F 100% humidity day in FL. I'd like to keep it cooler so I'm going to add 2 of the passenger side hood vents (it's the 7 piece kit from DCN) as well to see if there's a noticeable benefit. I also got to see first hand what turbo heat can do (more than a few melty plastic things were found post sessions).
On to my question which is hopefully cooling enough related for this thread. I did 2 or 3 easy sessions just testing the car and coming off track after 3 or 4 laps. On my first hard session I did 25 minutes ish of mostly push laps and again peaked at 216F coolant and 250F oil (assuming my gauges are correct). When I came off, I had obviously blew out the power steering fluid from the reservoir. Any suggestions on keeping this from happening other than the obvious of removing power steering which isn't an option for me? Although there was still some in the reservoir, the next hard session I had, which was the last of the day, didn't seem to cause the same issues.
Thanks to everyone in this thread for all the help. I'm not sure I ever would have figured all of this out without the help here!
I ran a barrel cooler on the racecar tucked under the bonnet lock position, but the secret is to not over-fill the reservoir. Check the rubber(?) sealing gasket is on the filler/dipstick and sealing properly. IIRC I also ran an under-drive pulley so as to not overspeed the accessories, that would also have helped.
I had this issue with my MSM and it went away once I replaced the P/S fluid with a quality synthetic. Eventually I depowered my rack but it was because I kept throwing belts off on the track (which, half the time, took out the crank angle sensor, stranding the car completely).
I can only guess that there is no line of sight between any exhaust or Turbo component and your power steering pump and lines. I can only assume that you have layers of heat shielding completely isolating the two sets of components already. Please do provide pictures that we may see what you are dealing with.
Even police cars and pickup trucks have power steering coolers, so you may look there once complete shielding is in place.
Put an oil cooler on the low pressure return side of the power steering hose. If I remember correctly (I removed PS ages ago) , there should already be a loop of aluminum tube that goes in front of the radiator to act as a very small heat exchanger. Replace it with something that has some real heat rejection capacity. Same rules apply as a regular oil cooler - multiple plate style will be more effective than the tube and fin style, but you may not need the most bestest cooler out there. I'd make sure whatever you get has pretty low restriction to flow.
Power steering coolers are common in modern high performance cars and trucks/SUVs with tow packages. If you're more of a junkyard than new kind of guy, check there. I'm not very trusting of junkyard oil coolers though.
So to update, PS reservoir is in the stock location. The cool side of the turbo is separated from it by a k&n filter I have otherwise there's nothing hot other than the radiator. I'll try the redline synthetic fluid, I'm sure the existing fluid was old AF. I didn't know power steering coolers were a thing, though I'm not sure where the **** I would put it at this point with everything else i have jammed in there. Actually, i supposed there's space in front of the radiator somewhere in the bumper area, so I take it back. I'll also wrap some of the aluminum corrugated heat shielding around it where I can. Thanks everyone!
I don't know enough about the maturity of Miata electronic power steering products, but it might actually be easier to just go with a tried-and-true EPS solution rather than fiddling around with more heat shielding and aftermarket coolers. Unfortunately I've become very skeptical of "v1" products so I'd want to make sure that the product has had all the kinks worked out, not just some statement that "it (the hand-built prototype that looks only a little bit like the production part) has been working fine on our cars for years".
Of course, I suggest you do the easy stuff first like checking the level, replacing the seal, and using high quality fluid. Also, burp the hell out of the system if you're replacing fluid.
What Emilio says about flammability is very true. You do not want a large volume of vaporized ATF near any sort of ignition source.
I see that I missed out on participating in your fire extinguisher discussion. I had a block ventilation event that resulted in some fire (details in my thread). It was pretty much over by the time I got out and got the hood open, but it absolutely sold me on the utility of the Element fire sticks. 15 seconds of fire-smothering discharge is very nice and they're easy to mount.
There is very little distance between number one exhaust port and the power steering pump. There should be no line of sight opening between the two. Radiant heat travels in line of sight from the hot spot to the target. If you can see the exhaust manifold the exhaust manifold can give you heat.
PS flushes are a thing, it needs to be changed about as often as oil in our enduro cars, aka every ~15-20 hours. Otherwise it starts to puke out the reservoir cap vent.
The loop of hard line in front of your bumper beam is the factory "cooler", but get a 3/8" (5/16"?) barbed cooler from B&M/mishimoto or similar. It adds a small amount of capacity, helps a bit with cooling with the fins, and at the same time you're doing a flush.
I had heat related power steering issues when I ran a SVT Focus as my track car. (Still my current daily driver.)
It would blow out the front seal on the pump when overheated. The car was new and blew the seal on it's 8th day on track.
Many people had the same issue, but they believed it was due to the PS running near the header, downpipe/ Cat, etc.
Everyone was using some form of synthetic performance PS fluid, but still had the problem. Lots of internet theories but no actual testing.
I had access to good quality temperature probes at work and checked what the temperatures were at various locations.
After logging PS temperatures in daily driving for a few weeks, the temps were 100* to 110* and nothing pointed to the lines gaining heat from the exhaust components.
As an FYI, I had added reflective heat shield tubing on all of the exposed lines after getting the new pump and before installing the temperature probes.
Similar to https://www.summitracing.com/parts/the-17101
My track test was at an event at Thunderhill in July. It was probably 95* ambient.
After about two hot laps the PS temp in the reservoir would rise to ~240* to 250,* if I remember correctly. The other probes affixed to the PS lines near the header, Cat and downpipe were elevated but not nearly as high as the reservoir.
On the cool down lap the temp would drop quickly, so that by the time I reached the paddock the temp was ~100* to 120*.
The Ford shop manual said to bump the starter to flush the system and add more fluid after each bump. My friend would bump the starter as I watched the fluid drain.
Each bump completely drained the reservoir and the line to the PS pump. The reservoir was really just a place to fill the PS system.
I learned later, that removing the belt and hand turning the PS pulley was the best way to flush the system.
The issue was there was not enough fluid capacity and cooling capacity with the factory bent tube "cooler", given the rpm on track.
I found an inexpensive Derale transmission cooler on Summit Racing and installed it in front of the factory bent tube cooler with zip ties.
It was similar to this one, no need to go with a fancy or large cooler. https://www.summitracing.com/parts/der-12902
The next event was again at Thunderhill on a 90+* day. With the extra fluid capacity the cooler offered, as well as it being a finned cooler, the PS temps were now ~120* to 140*.
On the street they were a few degrees cooler than without the cooler.
I used barbed hose fittings on the lines with a couple of short hoses, so I didn't even have to cut the stock return hose.
There is very little distance between number one exhaust port and the power steering pump. There should be no line of sight opening between the two. Radiant heat travels in line of sight from the hot spot to the target. If you can see the exhaust manifold the exhaust manifold can give you heat.
I took a bit last night and saw what you are talking about. It looks like, what I think is the low pressure return, is routed towards the exhaust manifold instead of just straight to the reservoir. Which is weird b/c it has to do a literal u-turn to get there. Any idea if the output pipe from the pump is rotatable? I did mock up a heat shield to wrap around it but would prefer to just rotate that thing and go direct to the reservoir.
Originally Posted by shlbygt
I had heat related power steering issues when I ran a SVT Focus as my track car. (Still my current daily driver.)
It would blow out the front seal on the pump when overheated. The car was new and blew the seal on it's 8th day on track.
Many people had the same issue, but they believed it was due to the PS running near the header, downpipe/ Cat, etc.
Everyone was using some form of synthetic performance PS fluid, but still had the problem. Lots of internet theories but no actual testing.
I had access to good quality temperature probes at work and checked what the temperatures were at various locations.
After logging PS temperatures in daily driving for a few weeks, the temps were 100* to 110* and nothing pointed to the lines gaining heat from the exhaust components.
As an FYI, I had added reflective heat shield tubing on all of the exposed lines after getting the new pump and before installing the temperature probes.
Similar to https://www.summitracing.com/parts/the-17101
My track test was at an event at Thunderhill in July. It was probably 95* ambient.
After about two hot laps the PS temp in the reservoir would rise to ~240* to 250,* if I remember correctly. The other probes affixed to the PS lines near the header, Cat and downpipe were elevated but not nearly as high as the reservoir.
On the cool down lap the temp would drop quickly, so that by the time I reached the paddock the temp was ~100* to 120*.
The Ford shop manual said to bump the starter to flush the system and add more fluid after each bump. My friend would bump the starter as I watched the fluid drain.
Each bump completely drained the reservoir and the line to the PS pump. The reservoir was really just a place to fill the PS system.
I learned later, that removing the belt and hand turning the PS pulley was the best way to flush the system.
The issue was there was not enough fluid capacity and cooling capacity with the factory bent tube "cooler", given the rpm on track.
I found an inexpensive Derale transmission cooler on Summit Racing and installed it in front of the factory bent tube cooler with zip ties.
It was similar to this one, no need to go with a fancy or large cooler. https://www.summitracing.com/parts/der-12902
The next event was again at Thunderhill on a 90+* day. With the extra fluid capacity the cooler offered, as well as it being a finned cooler, the PS temps were now ~120* to 140*.
On the street they were a few degrees cooler than without the cooler.
I used barbed hose fittings on the lines with a couple of short hoses, so I didn't even have to cut the stock return hose.
Great info. I guess I need to figure out how to do this. With the Miata already never seeming to have enough space, it seems like I'm always shoving more **** in there!
I also run a finned aftermarket cooler in the low pressure return line and 3ft of high quality hose. You don't need anything fancy, just something more efficient than the stock hard line. Job done
I use a Hayden 15" PS cooler. Mounted in same place as stock tube cooler with Home Depot brackets. I found it crucial to fill the reservoir to the low line. I use Walmart Supertech Dexron 6 ATF, nothing fancy. I did swap to an NB reservoir dipstick, which fits but is longer, because it has a gasket on the top, unlike the NA, as a just in case. Currently surviving SoCal 100+ degrees summer track days, although I'm natty aspirated. Tip: I wrap the reservoir fill tube with a paper towel, zip tie it, and press it against the cap to capture spewing fluid.
The way I see it, you need to address: 1) fluid temperature 2) fluid agitation 3) reservoir pressure
Easy, add as big a cooler as you can. Most of the plumbing is there due to the stock tube cooler.
Underdrive the pump or use thicker fluid. Redline PS fluid is a thicker weight oil than Dexron 6 ATF. Redline D4 ATF is even thicker and could be the last ditch effort. Thicker oil will decrease steering assist.
Underfilling gives more volume for the aerated oil. Or, modify the reservoir to hook it up to a separate VTA catch can to act like a breather. Or, customize/retrofit a larger reservoir.
Here's my update. I used the recommended cooler posted. At 40 bucks it was immediately ordered. I was able to use only parts from the kit except I needed one extra hose clamp and a double sided barbed fitting. I think it was 5/16". I tapped into the same low pressure supply that went to the OEM cooler and then back up to the reservoir. Since I had already made a mess, I went ahead and refilled the reservoir until the pump stopped making noises (had the car running) with Redline Power Steering Fluid. It took almost an entire quart.
Edit: Haven't had it track tested but on the road it doesn't leak. I think I'm going to add some heat shielding around the reservoir with the corrugated aluminum stuff. I'm not sure its needed for heat shielding, but I'm hoping if it still boils over it'll keep any spray away from all the hot **** that'll catch it on fire.
Depower the rack and reduce the caster settings to lower required steering effort. About 4 to 4.2 caster is quite tolerable and gives great steering feel compared to powered.
Depower the rack and reduce the caster settings to lower required steering effort. About 4 to 4.2 caster is quite tolerable and gives great steering feel compared to powered.
Heard, but my wife still drives the car from time to time on the weekends so that's not gonna be possible for me. I'm hopeful based on the responses above heat shielding plus this trans cooler will do the trick.
08-25-2024, 02:50 PM
Power steering overheating on track
0
