Track Ready '87 Turbo Hardtop

[Van]

My intention is to take the stock '87 turbo hardtop and lighten it up, upgrade the suspension and brakes to improve handling and safety on a road course. At the same time, I don't want to make this car require the use of a kidney belt to drive it on the street. I also don't intend to change the stock wheels, but the rubber going on them will be as sticky as I can afford. The stock brakes will also remain, but they will get improved stopping power w/upgraded pads and calipers coated w/ceramic heat dispersant. Also, changing the brake fluid from stock to one that can handle 600 degree dry temp, is planned. I've already upgraded the pads to Porterfield R4-1, for track use. In addition the rotors are getting cooled w/air delivered to the center through a 3inch, neoprene, flex tubing leading to the front air dam. I'll remove the fog lamps and install ducting there and connect the tubing.
Handeling is currently good IMO, but not up to racing on the track, so an upgrade is planned.
With that in mind I'm changing from the TRD progressive springs and stock anti-sway bars, to an RS*R linear race spring, and Tanabe Sustec chromoly anti-sway bar set-up, as the front of the car rolls and dives more than I'd like, now that I am able to drive quicker around the PIR road course.
I installed the linear, 8 kg/mm, RS*R race springs on the back and they are .5 inch lower than the TRD springs. I also noted the TRD springs were noticably softer than the RS*R springs. The 12 kg/mm, RS*R race springs for the front, are sched to be installed later today.
The 22 y/o stock anti-sway bars are being replaced today, w/Tanabe Sustec chromoly anti-sway bars. I'll be setting up the car today and will take the car to get an four wheel alignment. Then a test drive on the track to see if I'll need to have the set-up tuned further. Van

 

[cjsupra90]

Your idea's sound pretty good but there are a few areas that I would address.

1st. spend some money on better wheels... The stock wheel are way to heavy. This is unsprung weight which is not benificial to handling... Reducing unsprung weight is would of the best things you can do for handling.. It allows the suspension to do what its supposed to do.. Another added benifit with lighter wheels is better acceleration due to less rotational mass..

2nd thing is atleast get some cryo'ed rotors especially if your staying with the stock rotor size... The stock rotors are way to thin for how heavy the car is... Even with good cooling as your planning they will still distort from the heat especially if any tracks that you'll be running on have a lot of heavy braking zones. I F'ed up stock untreaded rotors in about 15 to 20 laps on sebring, granted, I am hard on brakes and late brake like crazy (comes from my days of running an RX-7 in SCCA E-Production) .. With Cryo'ed units, I could get a couple of weekends of track time on one set (probably around 100 laps or so)

 

[Van]

Great feed back.
I was at the Cascade Sports Car Club meeting last Saturday, and asked five Club members and one of last years point leaders, all of whom compete in the various SCCA classes, about cryo rotors and although they don't know anything about my car, they have used cryo'd rotors, but found them too expensive and have gone to some really inexpensive $20 - $60 rotors. They reported getting 3-4 race weekends out of them, then throw them away and purchase more replacements through local parts stores. Go figure!
I'll see how I do this year on the stockers. Van

 

[cjsupra90]

Yeah, Cryo'ed rotors aren't always benificial. It really depends on a number of factors including car weight, brake design, the cost of replacements track conditions and so on.....

Like exaple here, we run stock O.E. off the shelf rotors on RX-7's In IT. But for example when I had my E-Prod. RX-7, I had to run cryo'ed rotor or they would be shot to hell before the end of a 1.5hr induro. this obviouly because the car was a lot faster then an IT car and thus harder on the brakes for each turn. The track also makes a big differance too as does the driver him or her self.

Your plan to try stockers and see how you do is a good idea, but I have a feeling that you will be destroying them pretty fast but you wont know unless you try....

Good luck..... and play with setup adjustment as much as you can... Geometry setup is probably the most important part...

 

[tekdeus]

The stock brakes are just terrible. I cooked the heck out of mine even with performance pads and drilled/slotted rotors just doing a few street tuning pulls. I would at least see if you can pick up a set of the Doward goup buy brake kit, and put the 13" Mustang Cobra brakes on the front. I have my set here, and they are HUGE and very thick.

 

[cjsupra90]

Brad, you most likely destroyed them in short order cause they were drilled. A rotor that was not desigen to be drilled should not be drilled. Slots are ok, but drilling a OEM rotor (which is all that 99% of the companies that offer them do) is one of the worse things that you can do. You are taking away substantial mass from the rotor and mass is what absorbs and disappates heat that is generated. Drilling also flat out weakens the structure of the rotor... Rotors that are intended to be drilled are specifically designed and engineered with drilling in mind....

Drilling is said to increase surface area and an increase in surface area allows for better heat dissapation, but the loose of mass makes the rotor unable to absorb the heat and the surface area does not increase enough to take away the heat faster enough. Basically its a ratio of mass to surface area and the ratio is worse if a rotor is drilled that was not engineered to be drilled.

Having said that, yes for our car, the stock rotors are junk. I will not agrue that fact at all. One thing people have to remember though is that production model car was never designed for track use and to add to this, braking ability as designed for typical daily use and typical highway speed of that era which for the U.S. was only 55 to 65 MPH. For typical intended use, the factory brakes are fine but as soon as you start to push the envolope, they quickly show that they are a weak link.

 

[tekdeus]

Brad, you most likely destroyed them in short order cause they were drilled. A rotor that was not desigen to be drilled should not be drilled. Slots are ok, but drilling a OEM rotor (which is all that 99% of the companies that offer them do) is one of the worse things that you can do. You are taking away substantial mass from the rotor and mass is what absorbs and disappates heat that is generated. Drilling also flat out weakens the structure of the rotor... Rotors that are intended to be drilled are specifically designed and engineered with drilling in mind....

Drilling is said to increase surface area and an increase in surface area allows for better heat dissapation, but the loose of mass makes the rotor unable to absorb the heat and the surface area does not increase enough to take away the heat faster enough. Basically its a ratio of mass to surface area and the ratio is worse if a rotor is drilled that was not engineered to be drilled.

Having said that, yes for our car, the stock rotors are junk. I will not agrue that fact at all. One thing people have to remember though is that production model car was never designed for track use and to add to this, braking ability as designed for typical daily use and typical highway speed of that era which for the U.S. was only 55 to 65 MPH. For typical intended use, the factory brakes are fine but as soon as you start to push the envolope, they quickly show that they are a weak link.

Well said. The car had the drilled rotors when I bought it. My new BBK rotors are slotted. :thumbup: