The Ted Race Team: Because Racecar

[FormerHangie]

Sorry to hear that your evening was cut short, but that sounded like a reasonably successful first session with an old race car.

Doing my post-track check. I was certain I’d checked the idler arm, but obviously I didn’t. New bushings on the way. This should help the straight line stability…

https://youtube.com/shorts/-iNSM-hMc9Q?feature=share

Yowza! Are there any other old rubber parts about to turn into dust?

<SNIP> For its purpose, I don't think there's such a thing as too much oil cooling.

Some more thinking to do, but overall, not a bad list.

There absolutely is such a thing as too much oil cooling. There are coolant and oil temperatures that will make the most power, and they tend to be at the upper ranges of allowable. Back when I was racing we'd try for 230 degrees, and that was on mineral oil, the current lubricants are much better.

On that hose bursting, can you use the AN sized hoses that most racing supply houses sell? We always had good results with those.

 

[Ted]

Sorry to hear that your evening was cut short, but that sounded like a reasonably successful first session with an old race car.

That's what I thought too.

Yowza! Are there any other old rubber parts about to turn into dust?

As far as I can tell, no, probably not. I replaced all the hoses, bushings, etc., except for these. And when I checked the first time, they weren't entirely destroyed. So, I'll get it fixed.

There absolutely is such a thing as too much oil cooling. There are coolant and oil temperatures that will make the most power, and they tend to be at the upper ranges of allowable. Back when I was racing we'd try for 230 degrees, and that was on mineral oil, the current lubricants are much better.

I probably should've phrased that differently. You're right, of course, there are temperatures for optimal power. But I also don't want to blow this thing up, especially if I do end up running Lemons with it. When it comes to lasting, heat is the enemy. I did shrink the oil cooler vs stock (at the compromise of increasing the radiator, which is working great). I need to do some more reading up on how rotaries treat oil, but I think I probably undersized the oil cooler. I also don't have an oil temp gauge, which I could add.

More research to do.

On that hose bursting, can you use the AN sized hoses that most racing supply houses sell? We always had good results with those.

Yes, they probably will sell me an AN sized hose of some sort. I've bought a lot of hoses from this shop and none of them have failed. So dumb me for not just going to them in the first place.

 

[Spring Ford]

how rotaries treat oil

If I recall correctly, and the thing I read years ago was correct too, Wankel engines reject a greater proportion of heat into the oil than piston engines.

 

[Ted]

If I recall correctly, and the thing I read years ago was correct too, Wankel engines reject a greater proportion of heat into the oil than piston engines.

A high school friend who was big into RX-7s (ironically has never owned one) told me similar, and said oil cooler upgrades were common. Given that I shrunk the oil cooler, I decided to grow it again. New one is coming, I'll mount that and then I think everything should be fine.

 

[Half Fast]

Good idea. The stock cooling is adequate for street use, but on the track you’ll spend a lot of time WFO and will need better cooling. Another reason we ran straight water with Redline “Water Wetter” in our radiators.

I always used Castrol GTX. I was told dinosaur oil cooled better than the synthetics, but I didn’t confirm it. I think it’s better for the combustion chamber anyway, and the Wankels mix oil into the gas.

BTW - did you premix oil into the gas tank?

 

[Ted]

Good idea. The stock cooling is adequate for street use, but on the track you’ll spend a lot of time WFO and will need better cooling. Another reason we ran straight water with Redline “Water Wetter” in our radiators.

I can say that the engine cooling now is fantastic from what I'm seeing. It gets to temp and just doesn't budge. I've now become educated on the Wankel and oil heat rejection, so that should get fixed soon.

I always used Castrol GTX. I was told dinosaur oil cooled better than the synthetics, but I didn’t confirm it. I think it’s better for the combustion chamber anyway, and the Wankels mix oil into the gas.

BTW - did you premix oil into the gas tank?

I use Castrol GTX as well, 20W-50. Good dino oil. Yes, I've put the premix in the gas as well.

 

[Ted]

Apparently Tire Rack paid for (or at least took credit for) a photographer to get a photo of every car at Track Night the other day.

@Half Fast it's been a while since you've seen your car on the track, but here she is.



Unfortunately you can't see my ponytail flopping in the breeze, so it's hard to tell for sure that it's me. So y'all will just have to believe me.

 

[Half Fast]

Outstanding!!

 

[Half Fast]

Apparently Tire Rack paid for (or at least took credit for) a photographer to get a photo of every car at Track Night the other day.

@Half Fast it's been a while since you've seen your car on the track, but here she is.

View attachment 109863

Unfortunately you can't see my ponytail flopping in the breeze, so it's hard to tell for sure that it's me. So y'all will just have to believe me.

BTW, Ted - I see my name is still over the window!

 

[Ted]

BTW, Ted - I see my name is still over the window!

I haven’t removed any decals… yet

 

[Half Fast]

It’s okay to leave my name, just make me proud!

 

[Ted]

It’s okay to leave my name, just make me proud!

Well, I think passing 3 or 4 cars that are faster than me the first time out before blowing a hose isn't a bad start to that. Now if I can make it actually survive a track night!

I do have some thoughts on cosmetics, but haven't decided what I want to do there yet. For now I'm going with focusing on mechanical items. As you know, the paint is showing its age from the Florida sun, there are a few rust holes around the rear hatch glass (common design issue with those cars from what I can tell). If I race the car in Lemons, then there's not much of a point of doing anything cosmetic. Depending on the longer term goal and path for the car, that may be different.

I'm just going to keep on driving it for the moment and go from there.

 

[Half Fast]

Spending big money on cosmetics for a race car is silly unless you’re courting a sponsor. The cars just get banged up too regularly. My paint job was literally done in my garage with 12 spray cans of bright red Rustoleum, which also made repairs and touch ups simple.

But I never did get the right rear corner correct after slamming the pit wall at Roebling Road, despite lots of trying with a Porta-Power, pry bars, Bondo, etc. I couldn’t bring myself to fork over money to a real body shop, knowing how it would continue to get pounded.

Besides, a snazzy look might make you to reluctant to swap paint with a competitor.

 

[Ted]

If I do body work, it would really be for the purposes of practicing body work before the Cobra more than anything.

 

[Half Fast]

With the Cobra, you can remove the body to paint it, right?

 

[SoonerAviator]

Harbor Freight $25 paint gun will work wonders. Painted the hood of my F-150 with primer, urethane black, and clear coat. Came out fantastic.

 

[SoonerAviator]

With the Cobra, you can remove the body to paint it, right?

Whole thing comes off for paint on the FF Cobra. Hood separate, but still. It's getting it back on without scratching or ruining new paint that's the challenge!

 

[Ted]

With the Cobra, you can remove the body to paint it, right?

Whole thing comes off for paint on the FF Cobra. Hood separate, but still. It's getting it back on without scratching or ruining new paint that's the challenge!

It can be done either way, but most people agree that off the car is the best way to do it. The fitment is done on the car, then it's taken off to paint, then reinstalled. I've never done bodywork before, certainly not a whole car paint. While plenty seem to do it just fine, it wouldn't be bad to have some practice.

 

[Ted]

The new oil cooler arrived today - much better. Now I’ll figure out mounting and hoses.

New wheel studs arrived too, and so I replaced the rear studs. A little detail that was good to do, albeit not 100% necessary.

I want to get the exhaust hung a bit more securely - it was moving around some. I also cleaned the K&N air filter, something I just hadn’t gotten around to.

 

[Half Fast]

With the wheel studs, my method was to clean the male and female threads with brake cleaner, thread in the studs using LocTite (red), then immediately mount and torque a wheel so that the LocTite would cure with the studs under tension. Doing it this way I never had a problem.

If you don’t do the cure with the studs under load, the first time you torque the lugnuts you can break the LocTite loose. You really really don’t want those studs to back out.

 

[Ted]

Yesterday managed to get some time to clean up a few details. The exhaust had been flopping around and I got things tightened up on that system. Wheels are back on and torqued. Got the old oil cooler off and ready to put the new one on, and from there it'll just be a matter of getting new hoses made up (higher quality this time) and putting them on.

I also replaced the idler arm bushings, which had disintegrated. Once I get the hoses made up I'll test drive it and see how the steering is now, probably have to make some alignment changes.

I'm already signed up for the next track day on 9/20. Can't wait!

 

[Ted]

Last week I went to my friend's farm to make up some new hoses. He's got a hydraulic hose crimper for all of his farm equipment and offered to make me new hoses for the RX-7. So now I've got full on hydraulic hose, rated at 4,000 PSI working pressure and burst rating of 16,000 PSI. Major overkill.

This week or weekend I hope to get the new oil cooler on and hoses on. At that point, assuming test drive goes well, the car should be ready for the next track night on the 20th.

 

[Ted]

Got the new oil hoses and oil cooler installed yesterday. Now to test drive it, and be ready for the next track day in a week!

 

[2-Bit Speed]

I just want to thank you for the work you're doing on that car. Might sound weird, but that car was a part of my childhood and it's nice to see it rolling again.

 

[Ted]

I just want to thank you for the work you're doing on that car. Might sound weird, but that car was a part of my childhood and it's nice to see it rolling again.

It's been my pleasure.

These things are more than just the sum of their parts, aren't they?

 

[Half Fast]

I just want to thank you for the work you're doing on that car. Might sound weird, but that car was a part of my childhood and it's nice to see it rolling again.

Someday the red truck may be yours.

Your mom and I plan to spend everything else.

 

[Ted]

The test drive of the RX-7 today went well. The steering is noticeably improved between the tightened steering box and the new idler arm bushings. The latter probably did more than the former. I think there's some more room for improvement, but nothing that can't wait until after the next track night.

The brake pedal was a hair spongy, so I bled the brakes (again - that power bleeder is proving useful) and sure enough, the front brakes both had some noticeable air in them. Rears less so but I did all four anyway. Adjusted the alignment a hair more, made sure the oil was topped off, confirmed no leaks, and everything looks good to go.

 

[Half Fast]

Be cautious of over-tightening the steering box. Too much will make it wear out quickly and it might be a challenge to replace.

Hope you have a great track night!

 

[Ted]

Be cautious of over-tightening the steering box. Too much will make it wear out quickly and it might be a challenge to replace.

Hope you have a great track night!

Definitely being cautious of that concern. I’ve tightened my share and it this one has a good feel with what I did. I also only tightened it a
small amount, something around 1/4 turn.

Before I could note the play of 1-1.5” in the steering wheel before there was any movement out of the box. Spec is 0.5” on the stock wheel (which is less on this small diameter wheel) and that’s roughly what I’m seeing now.

 

[Ted]

Loaded up and ready for track night!

 

[Half Fast]

So how went the second track excursion?

 

[Ted]

So how went the second track excursion?

It's tomorrow, so I'll let you know tomorrow night or Wednesday morning.

I just had some time yesterday to get it loaded up and it wasn't supposed to rain between then and track night, so figured I might as well.

Forecast is highs of 100F... I will be testing the cooling system for sure. But my test drives have had no issues with the new hoses.

Last night I did go through my JIRA tickets for my shop, and I closed out some that existed on the RX-7. The driveshaft U-joints look original and, while they feel fine, I'm going to plan to replace them. The next track night (in October) is the last for the calendar year. Depending on how tomorrow goes, I'll figure out what I want to make adjustments on, but I think that my hope will be to make it through the next two track nights with just maintenance and notes, and then I can figure out what my plans are over the winter and for next year's track time.

 

[Half Fast]

I’m pretty sure the U-joints are original. I never had need to replace them, and it’s unlikely they would have been replaced while it was a street car.

 

[Zeldman]

Loaded up and ready for track night!

View attachment 110635

Wow.... off the pavement and into the grass already.!!

 

[Ted]

I’m pretty sure the U-joints are original. I never had need to replace them, and it’s unlikely they would have been replaced while it was a street car.

They certainly look it, and agreed you wouldn't expect a need for them. There is no play or indication of problems, so it's more of a preventative item that I will probably do at some point since it is at this point a 40 year old car that's being raced.

 

[Ted]

Last night was fun!

This marked the second track night for the RX-7 under my care. I'm happy to report that there were no issues with the car. Aside from the 3 20-minute track sessions, the Novice group also has paced laps first thing, and then there are also "parade laps" in the middle of the event. The parade laps are slow, no helmets required (I wore mine anyway) and anyone is allowed to come on track including passengers, but I wanted to get some more laps on the track and the slower paced ones gave me more time to think about markers for turn-in points, brake points, etc. So, it survived a total of 5 20-minute sessions on track, 3 of which were "hot laps".

The car really performs and handles well, and this time around I was getting to learn the track better and paint the picture in my head of what it looked like, know what corners were coming up after the corner or straight I was in, things like that. It was 100 degrees out yesterday (or at least very close to it). The cooling system worked great. I don't have oil temp, but oil pressure stayed consistent the whole time, and coolant temp never got even up to half way. I'm running a 160 degree thermostat in it which probably helps a bit. But the real takeaway there is the cooling on the car is adequate, at least for the moment. No brake issues at all. Had zero fade, and the brakes were working great. I'll probably do a bleed/flush anyway just for good measure as part of my post-track inspection.

I did come away with a few notes. The front right fender needs some more massaging as I was getting a bit of tire rub in hard left corners. The car overall turns better to the left than the right it seems, probably due some to the L/R weight distribution (i.e. me in the driver's seat). I played around a bit with tire pressures and need to do this a bit more. 1st gen RX-7s are known for 50/50 weight distribution, but with all of the interior removed, I'm not sure if this is still at that point or if it's moved a little more of the weight bias forward. The car feels like it needs more rear weight distribution as-is. One thing I observed was that it seemed I was able to take corners faster/harder when I was going through them at full throttle, in other words having more force over the rear tires seemed needed. Maybe I have the rear tires at too high of a pressure, but this seemed to be an area of improvement.

@Half Fast had pointed out that the rear sway bar on the car was intentionally removed, and this is common on road race RX-7s to bias the car less towards oversteer. This makes sense figuring the above observation of needing some more force over the rear wheels. I also did end up spinning on the last lap of the last session coming around the last corner onto the straight. Obviously that was my fault and not the car's (I'd been creeping up on the limits further and, obviously, found it), but ties in with the above.

Something I won't change but is interesting of note, the car has 4.88 gears in it right now. I'm rarely getting into 5th gear on this track with them, and so something in the 5s would get me more acceleration. It's not worth doing anything with, but it's a note for this particular track.

Overall, I'm really happy with how things went. I was getting more comfortable with the car and the track, learning both of them and their limits. This is a track night not a race, but I ended up big in the mirrors of some cars that should've all been significantly faster (at least as big as a 1st gen RX-7 can be) and passed them. Both a C4 and C5 Corvette, newer Boxster S, newer Camaro (that apparently had a 427 in it if the custom license plate was truthful), plus a "newer" MR2 (not the 80s first gen) and Subaru BR-Z. Maybe there was something else in there, but those are what I remember. I passed more cars than passed me, which in a ~120 HP 40 year old car (definitely the oldest and lowest horsepower car there yesterday) and only the second time I've been on a track at all and with it, isn't bad. I was definitely feeling like I wasn't so adrenaline focused and even the faster laps "felt" slower and controlled, having more mental bandwidth and situational awareness. Not unlike instrument flying, but I can see better out of the RX-7.

I'll get the car off the trailer and plan to inspect it some over the next week and make notes for what I want to work on before the final track night of the year in October, and from there, I can think some more about what I want next year to look like for the car and work to do on it over the winter.

I'll post some pictures in a bit...

 

[Ted]

Spent some time over lunch doing the post-track evaluation on the car. Really, everything looks good this time. No new play in the steering or the wheel bearings. Brakes all look good. I bled/flushed the fluid anyway (this power bleeder is really useful) and there was a good amount of dark fluid coming out before it got good and clear. Not surprising - it was hot yesterday!

Looking at the car, it's always looked like the right front was a bit lower than the other corners, although I never checked the measurements on it. So I checked and sure enough, it was about 3/4" lower than the others, and looking at the adjustable coil-over it was adjusted about 5 turns lower than the driver's side. I got them up to match and they're about the same now. That ought to resolve the wheel rub issues.

Otherwise, that's really about it. I might do some looking into the carb and consider changing the jets around some, but I think that sounds like a better winter project since it might take multiple attempts to get it "right".

I may do some more looking to see if there's something I can do to try to help the oversteer some, but I think running with a full tank is the main thing to get some more rear weight bias and then I can go from there, especially as I consider what next year's racing should look like. Plus doing full fluid changes.

 

[Half Fast]

EXCELLENT!! Delighted you and the car are doing so well! It's really a blast, isn't it? Just wait until you're actually racing and get into a dice with a close competitor.

I think somewhere in the paperwork I gave you are probably some w&b sheets. I know I had the car weighed several times at the track and got weights on each wheel with myself in the driver's seat. Back then I think I weighed around 140, so your values may be different. I usually ran with a little extra fuel to be sure I met minimum weight after a race and I don't recall the rear as being too light; that could be why.

You could try adding a rear sway bar, but if you do you'll need a heavier (preferably adjustable) one in front, so I suggest you work on optimizing everything else first before making a more drastic change. Doing so would mean starting all over with other settings.

One thing I observed was that it seemed I was able to take corners faster/harder when I was going through them at full throttle, in other words having more force over the rear tires seemed needed.

YES!!! That's exactly how you should be driving the car and I had it set up to be driven that way. The sooner you can get to full throttle in a turn, the faster your exit speed and the faster you'll get down the following straight. You'll need to heel-&-toe the brake and throttle. Brake as late as possible for the turn, do a heel-&-toe double clutch downshift if needed, trail brake through the entry to assist the turn-in, then smoothly roll from brake to full throttle as you ease off the steering input and head for a late apex through the turn. You should be WOT well before the apex and let the car track out of the turn on its own.

Set up properly, the car will oversteer a bit at turn entry while carrying a little braking and having weight transferred forward, which gives a nice crisp turn-in. As you transition to full throttle, the weight will transfer to the rear and kill the oversteer. It should then be neutral in a fast open turn. In a tight, slow turn it will push a little bit, so you want the apex as late as possible so the entry is tight and the exit is open, thus minimizing the understeer.

I bled/flushed the fluid anyway (this power bleeder is really useful) and there was a good amount of dark fluid coming out before it got good and clear.

I put in fresh brake fluid before every race weekend, and sometimes bled the brakes at the track if they got spongy. The brakes are a bit undersized for the car when driven at race speeds and when you're going fast you'll get them very hot.

SUGGESTION - after a track session, be sure to stay off the brakes during the cool-down lap, then back in the paddock it's a good idea to keep rocking the car back and forth once in a while so the pads don't trap heat over the same part of the rotor. If you come in hot and let the car sit still, the rotors can warp. Warping and cracking rotors was a common problem with these cars (but the Z cars were much worse).

Something I won't change but is interesting of note, the car has 4.88 gears in it right now. I'm rarely getting into 5th gear on this track with them, and so something in the 5s would get me more acceleration. It's not worth doing anything with, but it's a note for this particular track.

Some folks would run a 5.12 rear on tracks without long straightaways and that can work well if you'll be running the right tracks. It will certainly get you a better jump off the turns (beware of it on a slick track, though, like a rain race). Most of the places I ran had long straights (like the back stretch at Sebring or the front straight at Roebling Road) where you'd run out of revs with a 5.12. I knew some racers who had both rear ends and would swap them out for different tracks.

FWIW, the car was ~120hp stock, but it should be producing something over 150hp now. Doesn't sound like much difference, but it matters and it's how stock clutches and transmissions get overstressed. The whole drivetrain - clutch, trans, and diff - were rebuilt and race prepped.

 

[Ted]

As promised, pictures.

 

[Half Fast]

VERY NICE!!!