redstreak

Hey guys,

I haven't been on here in a long time - I switched to racing BMW's for the last few years. Next year however I am considering helping my brother modify his '90 RX-7 for local competition. He removed the cat so we won't be able to run in CS, we'll be running in CSS (Canadian Rules).

My question is what are the most common and best improvements for the FC's for autocross? And what brands/products do you guys recommend? I'd like to run on some V710's what are some good competition 15" rims? Are the stock sway bars good enough - or do we need to replace the front? What's the best linear rate spring that's not too harsh for the street?

redstreak

ok, I've done a little looking.

Looks like the Kosei K1 16" rim is a good choice for the rim. What the best size V710 for a 16" rim on an FC?

Also, are the RS*R Race springs a good choice? Are they too stiff for the street? One of the vendors here seems to have a good price on a set.

Anyone know where I can get some Tokico Illumina's in Canada? Or a good supplier? Are they externally adjustable?

Sorry for all the questions - I'm not too familiar with the Jap/RX-7 market anymore.

Ni5mo180SX

I 8kgF and 6kgR springs with JIC dampers and it seems to handle very flat. I've seen higher used on JRZ dampers with excellent results as well. Also am using stock ASBs and the car is easy to enough to rotate. What are the spring rates of the RSR Springs? Id go with something like an 16x8F 16x9R and 235s on all four corners or wider if you're willing.

redstreak

Oops, looks like those springs are for the FD's.

What springs do you recommend? And where can I get some?

Alex-7

The illuminas are externaly adjustable. I just bought a set from www.shox.com for a decent price.

The springs most comonly used seem to be: Suspension technique, Eibach, and Racing beat.
Search the forum for reviews on each. Racing beat makes a suspension package for the FC which includes Springs and sway bars. Might look into that.

Search the forum for DSS eliminator bushings as these are also a common mod for FC's

Good luck

Ni5mo180SX

Id recommend Eibach or Hypercoil.

redstreak

Won't be going Eibach - their springs are progressive. I put a set of those on my Bimmer thinking I wasn't going to autocross it, now I wish I had a linear rate spring.

Are Suspenson Techniques or Racing Beat springs linear?

Snrub

iTrader: (1)

Both ST and Racing Beat springs are linear.

Black91n/a

For wheels and tires you should get the smallest diameter possible. You can get Kosei K1's in 15x8 from the tire rack in a 35mm offsset I beleive, but they are custom, so you have to call them, then they machine them for the bolt pattern and hub too maybe. With coilovers they should fit just right. They are light, cheap and strong, perfect race wheels. For a size of tire 225/45/15's would be good to get a wide tire with a small diameter. I don't know if 710's come in that size, but Hoosiers do. Another size to consider would be 225/50/15.

Get good coilovers. They are probably the next most important thing for car prep. On the cheap you can get ground controls with some adjustable shocks, but beware of lowering too much as the camber will increase very quickly, especially in the rear, and to get it back to reasonable levels, expensive parts are needed. A 1" drop is generally regarded as veing as far as one should reasonably go.

When getting swaybars try to get adjustable ones so that you can tune the car's balance to your liking.

Get as much weight stripped from the car as possible, this helps everything. Do it to the limits of the rules. Weight up high is the most important. Move the battery to the passenger side storage bin and replace it with a smaller, lighter one.

Don't worry about upgrading the brakes, just get good pads and make sure that you have good clean fluid.

Good. lightweight, well boulstered seats help the driver, but there's no good way to do harnesses without a rollbar. If you only use the harnesses on the autocross course, then I wouldn't worry too much about having harnesses and no rollbar.

It's a good idea to get the DTSS bushings and poly bushings all around. Competition motor, tranny and diff mounts can help.

Get a limited slip diff, the miata 1.8 torsen will fit in the NA housing with S4 half shafts.

Some suspension bracing may help. I made my own lower arm brace (search my username) and my own master cylinder brace. The front and rear upper braces help a bit too, there's lots of choice.

A cold air intake, true duals and a fuel computer will help raise power levels.

Get a shorter geared rear end. The 4.3 is available from Mazda and you can get shorter ones from race vendors/shops. This will really help acceleration.

Get a 15:1 power steering rack and de-power it (my writeup is in the archive), remove the ps pump.

Get the car aligned.

MOST IMPORTANTLY. Get lots of seat time, the drivr is the most important part.

There's more, I'm sure, but these are some of the big things. READ THE RULES! This will be your guide to what you can and can't do. It's not as much fun to be hopelessly outclassed and loose all the time (ask me how I know, I'm in CSP, we race using SCCA classing). Don't be crushed if you don't win, it's a learning process and you're there to have fun, as long as my times improve and I get the most out of my car, then I'm happy.

joeberentsen

this is a really good thread.