The Ted Race Team: Because Racecar

[Ted]

Did get those front calipers (with pads) on the car today. I haven’t yet got new brake hoses coming (that’ll probably be a tomorrow order) but if I still haven’t found rebuilt rear calipers by then, I may bleed the fronts and then just use hydraulic pressure from the brake system to force the rear pistons out, assuming other methods don’t work.

 

[Half Fast]

What pads did you get? I always ran Hawk Blue in the front and Hawk Black in the rear as that seemed to give reasonable brake bias without needing an adjuster.

 

[Ted]

What pads did you get? I always ran Hawk Blue in the front and Hawk Black in the rear as that seemed to give reasonable brake bias without needing an adjuster.

I got Hawk Blues front and rear. When I searched, I couldn't find the Hawk Black rears. I looked for that first since it's what you'd suggested as a proven good combination. But, I guess these cars are getting harder to find parts for all around...

 

[Half Fast]

Yeah, probably true. You need to connect up with some RX7 racers, do a little networking, and learn how people are keeping them on the track these days. My knowledge is badly outdated.

 

[Ted]

Also got the hoses on the way, so I'll at least have that.

I should join an RX7 forum and start poking around there some...

 

[Half Fast]

Be sure to sign up with Mada Motorsports. Those folks are VERY helpful and they know most of the Mazda racers in the country. They were a terrific resource for me when I was racing.

 

[Ted]

It’s been a rough past couple of weeks here. There wasn’t much on the calendar this afternoon and my wife had the kids out, so I took the afternoon to be in my shop and have some zen time. Most of this was focused on the RX-7.

I had the front calipers on that arrived, but I also ordered new brake hoses all around. Put those on the front calipers as well as replaced the one going to the rear axle. After that I took care of replacing the fuel hoses around the rear of the car from the tank, to the pump, and up forward as well as replacing the filter. The old ones were bad enough that they started leaking when I touched them. There are still a couple at the tank that I have to drop it to replace, I’ll get them. But that can wait until after first drive.

Then there was the oil cooler hoses. This ended up being really simple. I cut the crimping ends off the existing hoses and the fittings are just fine. So new hoses are coming and I’ll use hose clamps. That’ll be sufficient for the pressure. Once the hoses are on I can try starting it with the rebuilt carb.

So now, it’s really just two things before I drive it:

1) Mounting/wiring the battery box in the interior
2) Rebuilding the rear calipers.

 

[Half Fast]

It’s been a rough past couple of weeks here. There wasn’t much on the calendar this afternoon and my wife had the kids out, so I took the afternoon to be in my shop and have some zen time. Most of this was focused on the RX-7.

I had the front calipers on that arrived, but I also ordered new brake hoses all around. Put those on the front calipers as well as replaced the one going to the rear axle. After that I took care of replacing the fuel hoses around the rear of the car from the tank, to the pump, and up forward as well as replacing the filter. The old ones were bad enough that they started leaking when I touched them. There are still a couple at the tank that I have to drop it to replace, I’ll get them. But that can wait until after first drive.

Then there was the oil cooler hoses. This ended up being really simple. I cut the crimping ends off the existing hoses and the fittings are just fine. So new hoses are coming and I’ll use hose clamps. That’ll be sufficient for the pressure. Once the hoses are on I can try starting it with the rebuilt carb.

So now, it’s really just two things before I drive it:

1) Mounting/wiring the battery box in the interior
2) Rebuilding the rear calipers.

Be sure moving the battery to the interior is allowed by your sanctioning body. We weren’t allowed to do that.

 

[Ted]

Be sure moving the battery to the interior is allowed by your sanctioning body. We weren’t allowed to do that.

It is, that’s why I’m doing it

Well that and because it makes it easier for me to hook up the oil cooler hoses with where the new one is.

 

[Ted]

Oil cooler hoses are on, which means it could run without making an enormous mess. The JIRA tickets are getting checked off…

I haven’t run the car since rebuilding the carb, so that will be a whole other question of whether I screwed that up. I don’t think I did though, but it is a complicated thing. Once I get the battery box in I’ll probably start it in case there are other things I need to order or repair.

 

[Half Fast]

Have you replaced the trans and diff fluids? IIRC, I was using Redline for both. Once you get it moving, see how well the LSD is working and whether it needs rebuilding. It has non-stock 4.88 gearing.

FYI, RX7 transmissions had notoriously bad synchros, especially 3rd gear. At race speeds, plan on heel-&-toe double clutch shifting.

 

[Spring Ford]

plan on heel-&-toe double clutch shifting.

Who would consider anything else?

 

[Half Fast]

Who would consider anything else?

Showroom stock racers.

 

[Ted]

Have you replaced the trans and diff fluids? IIRC, I was using Redline for both. Once you get it moving, see how well the LSD is working and whether it needs rebuilding. It has non-stock 4.88 gearing.

I changed the trans and diff fluids over this winter. I went with Mobil 1, but may put something different in after a race or two. The first goal was just to get rid of the old stuff in there. At this point all the fluids are new, all rubber is new (tires, hoses, master and slave cylinders, bushings...). With it in the air, the LSD seems like it's working well. We'll see what it does when driving it.

But you really hit on my plan there. Get it driving, register and drive it, see what needs adjustment and tweak accordingly. Try to get to the first track/race day prepared with a car that I think will survive, learn and adjust as appropriate. We were looking at the Lemons schedule over dinner and it looks like starting in August onwards there are several events we might be able to make, and I'll be looking at closer events as well.

One thing with Lemons is that they apparently like weird and goofy ideas to get more power. Being a fan of Engine Masters, this therefore has me thinking about adding a salad bowl:



Yes, it's a real thing, it makes horsepower (on the dyno). No, I won't do it on the RX-7, it's not practical at all and I'd have to mangle the hood, which I don't want to do. But you are allowed to make interesting modifications so long as you don't exceed your budget for purchase/mods. Porting would be allowed, so that may be something I look at at some point in the future. Not now, of course - but things to consider for the future.

FYI, RX7 transmissions had notoriously bad synchros, especially 3rd gear. At race speeds, plan on heel-&-toe double clutch shifting.

Thanks for that tip. I have a lot of mechanical sympathy, and definitely follow the motto of "In order to finish first, you must first finish." I double clutch the truck quite a bit.

 

[Half Fast]

Does Lemons require a competition license? Do you have to attend a racing school?

 

[Ted]

Does Lemons require a competition license? Do you have to attend a racing school?

You have to have a Lemons competition membership, but that's it.

 

[Ted]

I wired up the battery in the cabin and, well, I couldn’t resist starting it.

https://youtube.com/shorts/W0j_T1N1Cow?feature=share

I was surprised at how well it idled before any adjustments. I adjusted the idle to around 1000 RPM since it should be a bit higher with the underdrive pulley. When I got it running the first time it went up to around 5000 RPM and it wouldn’t come down no matter what I did. The carb was also pretty rough after sitting (no surprise).

So now I better get moving and get those rear calipers rebuilt - I want to drive this thing!

 

[Half Fast]

Yep, still sounds like a race car!

 

[Ted]

Yep, still sounds like a race car!

Because racecar!

 

[Half Fast]

You have to have a Lemons competition membership, but that's it.

If you have never raced before, I highly recommend you attend a school. Skip Barber or equivalent would be a good investment.

 

[Ted]

If you have never raced before, I highly recommend you attend a school. Skip Barber or equivalent would be a good investment.

That would also be a really fun date weekend, like when did the BMW motorcycle course. I like this idea…

 

[Ted]

Rear calipers apart and cleaned, ready to go back together. Unfortunately one of the o-rings is incorrect for it with the Raybestos kits I ordered, so now I’ve ordered the genuine Mazda kits. Shouldn’t take long to get back together once I have that figured. The caliper design is an interesting one, as well as the hand brake mechanism.

Get those back together and on, bleed the rear brakes, and we’ve got a driver! Also need to do the battery hold down in there but that’s not needed to drive it. I’ll try to get it done anyway.

 

[3393RP]

Did get those front calipers (with pads) on the car today. I haven’t yet got new brake hoses coming (that’ll probably be a tomorrow order) but if I still haven’t found rebuilt rear calipers by then, I may bleed the fronts and then just use hydraulic pressure from the brake system to force the rear pistons out, assuming other methods don’t work.

Did I make an earlier mention about a guy I know that specializes in refurbished calipers? He does quantity jobs as well as onesies. They'll come back with properly applied plating, new bleeders, puck replacement, seals, etc. He does a lot of work in vintage Porsche stuff, racing, and exotics.

 

[Ted]

Did I make an earlier mention about a guy I know that specializes in refurbished calipers? He does quantity jobs as well as onesies. They'll come back with properly applied plating, new bleeders, puck replacement, seals, etc. He does a lot of work in vintage Porsche stuff, racing, and exotics.

You may have and I may have forgotten. At this point I've got rebuilt fronts and also have the rears apart and ready to go back together, so if these don't work out, I'll ping you for his contact info.

Yesterday the genuine Mazda rebuild kits for the calipers showed up, and I got the O-rings on, lubed up, and started putting one together. I didn't finish it (had some other things distract) but hopefully later this week I'll get them both done, on, and bled. With any luck, next week I can actually drive it.

 

[Half Fast]

What brake fluid are you using?

BTW, it might make sense to rebuild the master while you’re at it.

 

[Ted]

What brake fluid are you using?

BTW, it might make sense to rebuild the master while you’re at it.

Motul DOT 5.1.

I replaced the master, clutch master, clutch slave, and all associated hoses already.

 

[Spring Ford]

I replaced the master

i tried that but the divorce didn't work out very well.

 

[Ted]

Ladies and gentlemen, we have a driver:



I managed to get the brake calipers rebuilt, rear brakes bled, and got it out of the shop for an initial short drive. An oil hose popped off (oops), I'll need to look at alignment more, and the brakes need bled more. But that's the list. Got a few more parts on the way. But so far, nothing much to complain about. I'll need to drive it more to get more impressions.

 

[Racerx]

Ted, you got me hitting up racingjunk again. If I had a spouse she'd probably be upset. But it's just the dog...but the dog could tell I was contemplating taking time off her hunting season. So no dice...for now.

 

[Ted]

I had a little bit of time to work on the RX-7, tidying up some details. After the oil hose popped off on the first drive, I got better hose clamps. I knew the ones I had were just barely the right size, and when I pulled the old ones off, it looks like I may have forgotten to tighten them in the first place on the engine. So this will hopefully fix the problem.

I also adjusted the alignment. In doing so, I realized that I hadn't tightened the radius arms, and so the caster wasn't fixed. Oops. I also had a LOT of toe out, which was just how the tie rods went together. So I set it to more of a 0 toe, and tightened the radius arms down for minimum caster, which theoretically should make the car pretty responsive handling wise. I need to drive it some to see.

The windows were also very oxidized after sitting outside for 10 years or so. Cleaning them didn't seem to do much, but my contractor suggested I try some very fine steel wool with glass cleaner to get it off. Sure enough, worked like a charm. I wouldn't call the windows "like new" and it'll probably require some more work, but I can now absolutely see out of them well, something I couldn't before. A major improvement.

@Half Fast is a good bit shorter than I am, and so his seat was... very far forward. I hadn't looked closely before (or I did but forgot - that seems likely too) but the seat back was connected to the rollbar, with pins going through. I removed the pins and was able to slide the seat back further, in a much better spot for my height. Now I can sit in there quite comfortably. I'm still going to plan to replace the seat anyway, but for now, this helps.

Hopefully over the weekend I can drive it some more, and maybe even take it to get legal/registered next week. Not that registration is the goal of the car, but it is an important part of being able to drive it around and try things out with it. And it's nice getting some of these little details worked out on it.

 

[Half Fast]

but the seat back was connected to the rollbar, with pins going through. I removed the pins and was able to slide the seat back further,

Be sure to drill new holes for the pins with the seat back. That connection (and the bend in the bracing plate) is needed for safety. The seat requires the extra support, but it also needs a little “give” which the bend provides.

SCCA required that brace. I don’t know whether Lemons does, but you want it there regardless.

 

[Ted]

Be sure to drill new holes for the pins with the seat back. That connection (and the bend in the bracing plate) is needed for safety. The seat requires the extra support, but it also needs a little “give” which the bend provides.

SCCA required that brace. I don’t know whether Lemons does, but you want it there regardless.

That was my intent, yes. For now, this just lets me drive around on the street more comfortably.

 

[Half Fast]

That was my intent, yes. For now, this just lets me drive around on the street more comfortably.

BTW, I did the connection with holes and pins because it made it easy to reposition the seat for a co-driver during a pit stop in an enduro.

 

[Ted]

BTW, I did the connection with holes and pins because it made it easy to reposition the seat for a co-driver during a pit stop in an enduro.

That's what I figured, and that makes a lot of sense, especially given that I'm expecting this to be a team with people at different heights.

 

[Ted]

Yesterday I took the RX-7 for another drive. Overall, it really drives well. I found a few little nits to take care of, and the alignment (not surprisingly) needed some more tweaking. I still haven't taken it to an alignment shop, so that's going to be off. But the steering and handling is good. The ride isn't actually as bad as I would've expected, but Kansas roads aren't bad. It is LOUD between the Supertrapp muffler (I may need to do something with that before it'll be allowed on the track - Lemons does talk about decibel limits).

I had to bleed the brakes a third time, but that seemed to get everything working well. However the left rear brake got really hot, moreso than any of the other brakes. That makes me think it was dragging and so I need to investigate further to see what's going on there. It wouldn't surprise me if the caliper is still sticking a bit after the rebuild and needs another rebuild. The other calipers seem fine, though.

All the gears work, the engine runs strong (well, as strong as a ~110 HP engine runs). I cleaned up a few things on the left rear brake and need to run it some more. Hopefully I can make an upcoming track night.

 

[Half Fast]

We had dB limits, too. With the SuperTrap, you can add or remove plates as necessary.

With the carb, intake manifold, header, and straight pipes, plus no more emissions controls, that little 110hp motor should be making somewhere between 140 and 150 now but I never dyno’d it. The increased power cooked the stock clutch which is why it has an ISC race clutch installed.

Do you still have the electric radiator fan? Be sure to switch it on in hot weather when you’re driving around slowly. I used it even on pace laps, switching it off just before the start. The stock radiator is only sized for the original low hp and it’s easy to overheat the motor if you’re not careful.

 

[Ted]

We had dB limits, too. With the SuperTrap, you can add or remove plates as necessary.

Yeah, and I saw the extra plates.

Maybe I'll play with that some today.

With the carb, intake manifold, header, and straight pipes, plus no more emissions controls, that little 110hp motor should be making somewhere between 140 and 150 now but I never dyno’d it. The increased power cooked the stock clutch which is why it has an ISC race clutch installed.

That makes sense. I'm also used to some pretty powerful cars, and so even with only ~2k lbs and 4.88 gearing, the power to weight ratio isn't amazing. It gets up and goes nicely still.

Do you still have the electric radiator fan? Be sure to switch it on in hot weather when you’re driving around slowly. I used it even on pace laps, switching it off just before the start. The stock radiator is only sized for the original low hp and it’s easy to overheat the motor if you’re not careful.

As part of the work I did, I replaced the radiator, oil cooler, and I had a bigger electric fan off of a Ford of some sort so I threw that on. The cheapest radiator I could find was actually bigger than the stock radiator. Yesterday was HOT, mid 90s, and I spent as much time at full throttle as I could, and the temperature seemed very happy. The oil pressure also was happy. I don't have oil temp, but the fact that the oil temp stayed happy makes me figure the oil cooler I put in is fine, too.

 

[Half Fast]

It’s a “momentum” car. If you blow a turn you’ll pay all the way down the following straight as there just isn’t enough acceleration to make up for mistakes. The car really rewards the correct line and carrying speed through a corner. That makes suspension setup and especially driver skill very important.

That’s great about the radiator. We weren’t allowed to run anything but a stock Mazda one.

 

[Ted]

It’s a “momentum” car. If you blow a turn you’ll pay all the way down the following straight as there just isn’t enough acceleration to make up for mistakes. The car really rewards the correct line and carrying speed through a corner. That makes suspension setup and especially driver skill very important.

Driving a slow car fast.

For sure, it's obvious that if you don't keep the speed in, you won't have the power to get the speed back.

That’s great about the radiator. We weren’t allowed to run anything but a stock Mazda one.

One thing that's nice with Lemons is you can do whatever you want, you just may get penalized for it in terms of laps taken off your total time depending on cost. In this case, I'm arguing this was the cheapest radiator I could find (which it was). I suppose we'll see how they respond to that, but I feel like I'm meeting the spirit and intent.

 

[Half Fast]

https://www.amazon.com/Driving-Competition-Alan-Johnson/dp/0393600114

This is dated, and there are plenty of other sources available on the Internet now, but this book originated the idea of type 1, 2, and 3 corners and has a good discussion of racing lines.

Road racing is a game of chess played at 140mph with lots of details and tactics and strategies. When the cars are closely matched, every little detail matters.