Prepping a high(ish) mileage 2004 for track duty
 

Not really a new member, given that I joined in 2008 when I bought my 2004 MT, but I'm a big-time lurker so here I am. I'm getting the itch to get the car on the track, and would like some feedback on how to make sure the car performs reliably.

My RX8 is bone stock and has has been reasonably well maintained. It had 20,000 miles when I bought it and it now has 114,000. Still on the original engine, trans, and clutch. I've recently done most of the recommended high mileage maintenance, including OMP line/injector cleaning, ESS cleaning and brake stomp, MAF, throttle body cleaning, etc. Plugs/wires/coils are new, as are oil, brake, trans, and diff fluids.

The main concern now is cooling. I've ordered a new radiator (CSF all aluminum). IIRC, I read on a thread here that the 2004 water pumps are especially poor performers. Mine is working fine, but is an upgrade needed for track use? And is the current Mazda Series I replacement pump acceptable (at ~$110), or do I need to plunk down the bigger bucks for the Re-medy? I will also go with the the 170F t-stat from Mazmart.

The only other upgrade I plan is to go with Hawk HP+ pads to avoid brake fade. Other than that I plan to stay stock. I just started pre-mixing for what that's worth, and I just switched from 5W-20 to 5W-30. I am in San Francisco so temps are generally mild. If I do any hot summer track days I may look at going up a bit in viscosity.

I have never de-carboned the engine, and haven't had (and don't plan to get) a compression test. My thinking is to let sleeping dogs lie as far as de-carboning. And if the compression is low it's probably not going to change my plans, so why spend the money. Anyone beg to differ?

If there are any other recommended upgrades let me know, and thanks for any feedback.

Edited to add: I am running with the stock cat, replaced about 30,000 miles ago.

1. There are literally hundreds of threads describing what/ how people are set up for track duty. Read through the racing subforum and see what others have done.

2. Many people will say that driver lessons will be more beneficial than any other mods. If your staying stock, get as much seat time as possible from a qualified instructor.

3. Stay on top of your maintenance. I would make sure you have a method of monitoring water and oil temps/ pressures.

4. Pass the decarb if you don't get a compression test.

5. Only you can recommend mods. Learn what your strengths and weaknesses of driving are and make decisions on your experience.

This definitely proves I really am a noob- I never scrolled down to find the Racing forum...

And just to clarify, the only upgrades or mods I'm interested in are for the health and reliability of the car. Other than that the only thing I plan to adjust is the nut behind the wheel.

Good choice for a track day car. I think you waited a bit too long, but what the heck.


Your current plans are pretty good. Soldier's point to racking is a good one. Several of the threads will talk about taking care of you as well. Pay attention to those tool (water, shade, food).


Get a good quality tire gauge. Spend at least $30 on it. Joe's racing at Amazon is one I like. Get one that goes to 60 psi. You tire pressure is the one thing you can adjust and control. The threads will tell you what to do, but a bad gauge will just lead you into peril.


Look at your tires. 300 treadwear is likely the least useful for the track. They have enough traction to do fairly well, but cannot handle the heat of doing fairly well. Harder slide and do not get hot, lower can handle the heat. That is just data. If you have 300s, and they start to feel squishy and squirrely (you will know), come in and check pressures. If pressures are fine, let them cool down, or you will be replacing them. I chunked 4 tires in one weekend. Twas expensive.


Get an ultra-gauge. $60 at their web site. Will let you track water temps and set alarms.


Regarding a water pump. The stock pump will cavitate above 7,000 RPM. There are a few threads on this. I have a Remedy to stop this issue. The tracks here have sustained running at that RPM, and I was getting hotter than I wanted. Remedy fixed that. You can also underdrive the water pump with a pulley set. About the same price for each.


Enjoy it. I suggest looking at in car video of a similar car, a lot, before you go. And, like he said, do not pass up any and all instruction.

Agreed. I raced Formula Vee for a long time in SCCA (cumulatively around 250 track days), and stopped doing it a few years before I bought the RX8. Vowed my pause in racing would only be temporary, but here it is a dozen years later. Life happens...

Appreciate the other suggestions as well. I'm dredging up a lot of my old racing stuff that's been stored away. I do have a nice liquid-filled Longacre pressure gauge. As a joke my daughter asked me to put on my race suit. It was, ahem, a bit snug. That was depressing.

I checked this out and like the idea of a dedicated solution that is hardwired with its own display. I found your DIY bracket fab as well. Does that hold it well enough that it's acceptable for track use (and passes tech)?

A good brake fluid flush is advised on a car with that mileage. It is unlikely to have been done for routine maintenance and it absorbs a lot of water over that many years. Same for transmission and diff fluids. Personally I would run a higher viscosity oil as well, especially if it is hot. I like 5-40 :) You would be advised to pre-mix as well

You likely will be good with stockish brakes if you are running street tires...but you will find that the pads melt off quickly when you start getting faster

For a semi-dedicated track car you are better getting a track pad and swapping back the street pads when you are done...otherwise you will be limited by your pads fairly quickly as most of the "combo" pads aren't much good at either

Regarding the bracket, it is in the new car. Was tough enough to not move when the old one was totaled. If that, or Sebring, did not shake loose, nothing will.

And, ++ ^^

All fluids, especially brakes. I ran stock rotors and HPS with no issues. HPS (Hawk) are fine for the street too. I run Roebling Road and Sebring. Both have 100+ to 40 corners as well as 130 to 80 corners. Never saw an issue. I am looking at a little extra cooling up front, not from fade, but for pad life. Beware the HPS when below freezing though. Takes a bit to warm up the first time.

Given your experience, you will likely progress quickly. Your next steps will be harnesses, to stay behind the wheel (Schroth Rally 4), stiffer springs (go straight to coil overs) and a set of light 17" wheels (think Conti Take Offs, 225/45 17, $50 each). Then tell the guys in the vettes they got passed by a 1.3L 4 door sedan....

Good luck. Sounds like your have found most of the threads, and your experience will tell you how to take care of yourself. The trick is to never slow down. Car loves to trail brake. Throttle steer works fine. It will move around on the suspension until you tighten it up though. Look at the lower the seat mod if you need the room.

Post Pictures.

Lots of great advice and suggestions in here. I will be going to the track with my car for the first time. Sorry don't mean to hijack the thread; just got a few questions related to track use
Therefore, I felt there is no need to create another thread :-)

Remedy T-Stat is on the way should I also get the Remedy Water pump at the same time or would stock Pump suffice?

I have been debating on replacing all radiator/heater hoses with Autobahn kit to be on safe side. Though my hosses are only about 2-3 years old and the car has only put on about 20-30k in 3 years.


Gauges have arrived, will be installed soon so the critical info can be monitored.

Just needed some suggestion with tranny / diff fluid, Normally I like to flush them every 50k and refill with redline fluids. But since I will be tracking this car, should I mix redline fluid with lucas tranny treatment to add extra lubrication? I kind of have a slight grind in 4th, when shifting above 6k rpm.

Thanks a bunch!

Just wanted to follow up on this. I did 2 days at Sears Point last weekend with NASA HPDE and had a great time. The car ran flawlessly. My basic prep steps were:

1. Change all fluids, including tranny and diff (I used the usual Redline tranny/diff stuff that is recommended)
2. New dual-pass CSF radiator, Remedy pump and t-stat
3. Fan relay kit to turn both fans on 100% at 185 F
4. Hawk HP Plus pads

Everything else was bone stock. Car has 117,000 miles and original engine.

It felt great to be back on a track after a 12 year absence. And unlike racing, I wasn't dealing with the logistical nightmares of getting the RV, trailer, race car, plus practice, qualifying, and race tires and everything else needed for a race weekend. It was really nice just jumping in the DD and heading to the track.

I've already signed up for another weekend next month. Of course, I'm now thinking about the things I will do to make it more track-worthy. I'll try not to make it too much of a slippery slope. Right now I'm considering track-specific wheels/tires (Enkei RPF1 17x9 or 17x9.5 with Nitto NT01 255/40/17), and a suspension upgrade to Ohlins DFV coilovers or similar.

Khurram, it sounds like you are doing the right things. The only thing I've heard is that the Series II pump is better than the Series I and probably is ok. I just made the jump to the Remedy for high RPM happiness. I've heard the Remedy does not have as good flow at low RPM, so for those conditions I figure the fan relay kit will help.

That all sounds good to me. The main points are cooling and lubrication, and you have those well-covered.

The fan kit set at 185 seems low. I think 200 would be more appropriate. I did the fans on low mod instead and just turn mine on at the start of my cool-down lap. By the time I leave the track, my coolant temp will have dropped from 210 to 180. Like you, I upgraded to an all-aluminum, high capacity radiator that is much more efficient than stock, so my temps don't ever go much above 210 on the track.

I like Redline MT-90 in the trans and Redline 75W90 in the diff. I use Mobil 1 0W40 in the engine most of the time. I also premix with Lucas Semi Synthetic 2 Cycle oil.

You are also on the right track for your mods for increased grip, and I use those exact items. I went with Enkei 17x9" rims to save a bit of weight. The 255/40/17 tires fit them nicely and protect them a bit from curb rash. I don't see any evidence of tire roll or squirm, so I don't think going to 9.5" is necessary at the 255 section width.

Ohlins coilovers are pretty damn awesome. The honeymoon just doesn't seem to end with them.

You might find you need a slightly stiffer front bar, depending on how you like your car to balance. I like to start a session with slight understeer that becomes neutral after a few hard laps, then tends toward oversteer near the end as things get greasy. I am running a Progress Miata NC bar set on the middle position in the front (the stiff position does not work). Of course, don't forget the performance alignment. I am running -2.4 camber in the front and -2.0 in the rear.

Finally, you may find you need to upgrade your brake pads when you go to the Nittos. I like Carbotech XP10 in the front and XP8 in the rear. They seem to have the perfect amount of bite for those tires, with excellent midrange modulation. The milder compound in the rear keeps the car straight when I accidentally send the front into ABS.

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Thanks for the advice. What do you think are the pluses/minuses in going to a wider tire, like a 255 or 265? I keep defaulting to 'wider is better', but I know that can be a simplistic view.

What are you running for toe front and rear?

I mis-typed my tire size above. I am actually running 255s. I don't feel the need to go any wider. If you do go to 265s, you probably should go 9.5" on the rims.

At some point, on a chassis like this, adding more grip just adds rolling resistance, but does not help you corner any faster without adding chassis stiffness, increasing spring rates, upgrading brakes, etc. to allow you to take advantage of it. Doing all that makes it a different car.

I am running 0.1 toe-in in the rear and 0.1 toe-out in the front per side. Next time I have it aligned, I will have the front set to 0 toe. The front toe-out is giving me quicker turn-in, but less stable corner exit. And, it is causing accelerated tire wear. I don't find it to be worth it.

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Makes sense. BTW, your thread is what turned me on to the Ohlins suspension, thanks for that.

Thanks for taking time to share your prep! What radiator are you using? I'm replacing my 11 year old stocker. Will be upgrading foam as well.

I am using the Koyo HH 48mm radiator referenced in this thread. I am seeing slightly lower average coolant temps, lower peak temps, and faster recovery times with it. It is technically a S2 radiator, but it should fit S1 cars with the exception of 1 mounting bolt (IIRC). One of its best benefits, of course, is that it is all-aluminum and should never fail. I did it as a reliability mod more than anything, but the extra cooling capacity is welcome.

I'll go back and update that thread RE the use of foam. I found that stuffing rigid foam all around the radiator was overkill and resulted in high engine compartment temps. There is a reason Mazda used rigid foam on the bottom and light foam on the other 3 sides. Some air is supposed to make it past the foam to cool the engine bay. And, the radiator has a max flow rate. Holding more air in front of it than it can flow does no good. That air is better used to carry heat out of the engine bay. So, what I ended up doing, is removing the foam completely on the passenger's side. That allows direct air flow to cool the exhaust manifold, and the negative pressure that creates pulls air in from other openings to create flow around the engine. That approach works very well.

On a side, err... bottom note, the way I ended up holding the foam in place on the bottom is, I drilled a hole next to an existing hole on each side of the undertray near each of the radiator mounting bolts and used zip ties to hold up the undertray and keep it from sagging. The foam fits tightly in the space just in front of the radiator when the undertray is cinched up with the zip ties. I'll take a picture tonight if I remember.

Your findings sound intuitive, but were the temperatures subjective or did you have a way of measuring underhood temperature? I'm very tempted to leave a "bypass" to reduce underhood temps as you suggested, but I'm curious as to how the passenger side bypass affected your coolant temperature as well.


(As full disclosure, per other's recommendations [Eric Meyer XOWii Racing World Challenge] I have sealed up the sides of my radiator as tightly as possible and even sealed the holes in my factory undertray to try to force as much air / create as high a pressure area in front of the radiator as possible...)

I'm going to try that!

My water temps on track hovered around 209 F which I think is acceptable, but returning some airflow to the engine bay can't hurt.

I first noticed the higher ECTs very soon after installing the new radiator and sealing everything tightly with foam, as my fans would stay on after shutting the car down all the time, where they only came on very occasionally before under the same conditions. My coolant temps were a little lower, so the reason had to be the ECTs as described in the service manual. The other clue was the blast of melt-my-face-off hot air I would get when popping the hood.

I have a pyrometer and had measured the temps of various surfaces under the hood in the past. Temps were typically 190 to 210F before. I took new measurements, and found surface temps to be 240 to 270F. After removing the foam on the passenger side, surface temps under the hood dropped back down to normal.

Removing the passenger side foam had no effect on coolant temps. My peak coolant temp on the track in 90F heat is still about 210F, and the average temp is still about 198F.

You only need enough positive pressure in front of the radiator to max out its flow rate. Once you pass the threshold of having enough, anything above that does you no good. In my limited experience, sealing 3 sides of the radiator creates enough positive pressure. Of course, YMMV.

I took a couple of photos tonight as mentioned above. Upon taking one of them, I realized I could extend the bottom foam past the OEM length by about 3". I am changing the oil tomorrow, so I will take the opportunity to do that.

https://cimg6.ibsrv.net/gimg/www.rx8...db96d03aa2.jpg

https://cimg7.ibsrv.net/gimg/www.rx8...587142b73d.jpg

Don't you have to remove the bumper cover to access that area? I only ask because you mentioned you'll get in there since you're changing the oil, but I don't think access to the drain plug and oil filter would give me access to the radiator.

I'd like to remove a bit of foam for more air to the engine bay.

To access the area directly under the radiator, I remove 2 screws and 2 clips at the rear of the undertray and pull it down slightly. It is tight and uncomfortable, but you can gain access that way.

This thread is awesome, keep it going!

Since I'm a masochist and a data guy, here is a chart of my coolant temps during a 30 minute track session in 100F heat with the Koyo HH radiator and 3-sided foam treatment described above.

https://cimg8.ibsrv.net/gimg/www.rx8...d38f8f8b0a.png

Data dispels all myths.

Data is excellent insight into the radiator's performance. On your S2, where's the coolant temperature probe location?