I'm leaning towards an S5 to be a track/autocross/weekend car(preferably GTUs). I'm very new to RX7's and have done quite a bit of reading in the FAQ(second generation) and Aaron Cake's page/s about how the RX7 isn't much different than a 'normal' FR car... Other than it consumes a bit of oil in the combustion process, COOLANT is more important than the driver, and the 13B likes to rev.

I've been known to push my cars, pretty hard, and was wondering what modifications I should look towards in order to enable the car to survive my abusive driving? (I guess it could be compared to light to moderate track driving) In the FAQ I saw a link to Mazdatrix for a conversion to use the TII transmission with the NA rear end. Something to look more into?

Thanks

 

getting a new radiator is a nice modification.

 

New OEM radiator, or a larger one?


I'm pretty sure there's more I should do in order to make the car last...

 

Depends how hard you push it and for how long.

The engine holds up to high revving pretty well. In fact, high revving keeps it clean.

I have a stock radiator and even when I push the car hard the temp doesn't rise... even during a certain highly abusive test after removing a bad thermostat. Which reminds me, you MUST use an OEM thermostat or you'll run into trouble. The S5 temp gauge isn't very good... it always reads 1/2 until you overheat, then it's too late. You may want to get your own to warn you if you're running hot. If you upgrade your power or if the stock system gets hot on the track you should get a performance radiator, not a replacement stock one. People have had a lot of cooling system complaints on these forums but I have yet to hear about a bad stock radiator. If your car runs hot on the street, fix your cooling system first.

The drivetrain and fuel system is good to about 250HP. Its life gets short between 250HP and 300HP, at ~300 it blows. From what I learned in my engineering classes about steel and fatigue, the drive train should have an infinite fatigue life below 165HP (55% of 300HP)... which is flooring it at redline in a stock S5. Gear wear during shifting could increase, though. And somebody please correct me if I'm wrong about the limits of the stock drivetrain (is it 300HP?).

 

Well I use my S5 NA for daily driving, autocross and track schools and it's been perfectly reliable. The first time I had it on track it was stock except for a Racing Beat Exhaust and a cone filter and it was great. I've now had it on track at 3 different schools for a total of 6 days, 4 of which it was doing double duty (2 drivers) and it took it all in stride, never once giving me any trouble. It's got a stock cooling system and even in a late July school in Spokane with 2 drivers it didn't overheat.

Now that I'm getting better and more serious I'm going to upgrade to an alumium race rad and get some oil and water temp gauges to be safe, as I'm pushing it a lot harder now. I must say, it's a PERFECT learner's car for track driving, it's not so fast that you'll get in way over your head, but it's fast enough to be fun and keep up with a lot of other cars. For track work I must say, an NA is more than enough, a turbo will be more likely to break parts, and while power is nice, driving an NA will be easier and it won't mask bad driving with acceleration. An NA car also has the potential to become a race car in a competetive class, where the TII will only be able to run in open classes (In the SCCA), which is much more expensive if you want to win. The FC's got some of the most benign handling characteristics you can ask for, give it hell and it won't bite, but it still handles very nicely. The brakes are good, all you need is good pads and fluid and you'll be fine. It's not the best autocross car (too big and heavy, Miatas are better for that), but it's still fun, and in the end that's what matters. The stock drivetrain is fine untill you get boost basically.

It does have a rebuilt motor in it though, so that helps, but it's only twice failed to get me home, once was when the alternator died (got me to the end of the driveway and died), and once it blew a heater hose, but both are standard old car issues.

Here's what I'd suggest for mods over the long run (no particular order)
Reliability mods: temp gauges (oil and water), race rad
Performance mods: Intake, exhaust, ecu, bushings, coilovers, swaybars, remove all unecessary weight, LSD, wheels, tires, brake pads and fluid, remove PS and AC
Safety mods: Race seats, roll bar, harnesses

But before modding it, make sure it gets a full tune up replace all the fluids, filters, spark plugs and wires, old belts and hoses, etc.

 

Thank you guys for the input!

Okay, so water gauge, oil gauge(precautions), and a racing radiator.

Probably going to leave the engine pretty much stock(insurance, mother, city, etc.), so since that's around 160hp, the drivetrain should hold up. Cool!

Going to search this, but wondering what coilover setups are out there for the S5, and what susupension setups are the best bang for the buck?

Thanks again!

 

Bang for the buck is probably Koni Yellows and Ground Control coilovers, 400lb/in front and 275lb/in rear springs with a stock front bar and no rear bar. That'll get you started, you can add camber plates, bushings, braces and all that other stuff later on if you want. Just don't go too low without being able to change camber (can't change it on a stock car), or you'll have problems with tire wear from too much camber.

 

Thanks again for the info.



I searched for exhaust sizes and it seems that a lot of people are using the Racing Beat exhaust. Does anyone know the size of the piping used on that system? And if I were to go with a custom bent single exhaust, what size piping should I look into?

 

Racing Beat Y-pipe and two 2-inch (OD) 304-stainless steel Power Pulse muffler canisters. The replacement Y-pipe is manufactured using 2.5-inch (OD) tubing, splitting off into a pair of 2-inch (OD) tubes feeding the muffler canisters.

here is a nice single set up run a google on the makers to find out the price and size piping it is i think its 2.5"

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/my-new-exhaust-pics-inside-589263/

one more thing look for in a car are 5 lug wheels they have disc brakes all the way around and extra beefy 4 piston front calipars

i dont like the stock clutch its too easy to glaze up if i drive it hard for more then 2 or 3 min it starts to give