Road Racers gurus. prep recomendations?
 

For all the 3gen road racers , recomendations on preparing a car for road racing, on cooling, suspension, shocks, power, weightness, aligments, tires and wheels, electronics, etc.

Going against 911 porshes turbos and non, supercharge rabbits, mitsubishi eclipse turbo, nissan 300 twinturbos, etc.

Something like a Gt3-GT2 class.

Pedro.

I've been road racing for 4 years now with my FD. Here's what i've done. You might want to check what is allowed in your class, unless you are in open class, which means you are better off to buy a tube frame car.

must do's
K&n filter
gut or change thermostat
install ford griffin rad with custom silicone hoses.
lower temp plugs
gut or change pre cat
go non sequential and open wastegate to 1.24(you will have probs)
racing pads
open exhaust with dynomax muffler
929 master cylinder
pulleys

I run gab super r's with 650 eibach's frony, 450 rear.
I run mazda motorsport fr.swaybar, stock rear bar
fiberglass hood, t78 turbo, F40 brembo front brakes,2.85 :1 pedal ratio(rock hard brakes) modified stock, intercooler, K&N filter, full cage ,lengthened adapter for momo wheel, rear battery, lexan rear window, glass doors, trunk, 3.5 exhaust, additional injectors, power FC, 94 supra rear discs, corvette single calipers, bosch 911 turbo external fuel pump, 26 gallon cell, close ratio tranny with straight cut gears, speedline 17 inch wheels 8.5 &9.5 should be bigger, M2 rear suspension, ACt clutch, M2 flywheel. All these mods and a newer porsche 911 turbo is still a bit faster. They have more torque off the corners . I will dyno tune this year
and hopefully be quicker.I've spent $30,000 on the car. when it was stock it won the 98 western canadian championship (No porsches) but as an unlimited car its hard to beat a purpose built Tube frame car.

I think the one in your attachment will work just fine

how long did you wait for your momb adapter with spacer to come? I''m still waiting after 3 months for mine :(

Thanks for all the recomendations !!!!

Thanks for all the recomendations !!!!

Hi Racedriver,

Did you change out your rear brakes? Could you please elaborate on your 94 supra rear discs and corvette single calipers. Thanks -- Tommy

Thanks for all the recomendations !!!!

For the rear brakes I use a 94 front supra turbo rotor, 1.1 thick, about 12.6 dia.

bring it to any brake shop and enlarge the center hole to that of the rx7. Then machine .1 off the thickest side of the rotor. The caliper is off the back of a 99 corvette. it is a single piston and made for a 1 inch diameter rotor. I found a rebuilt one for $60 . You need to fabricate a mount.

This mod is usefull for a racecar to balance out a front big brake kit. The bigger diameter rotor gives more leverage and better cooling. In my experience big 4 piston rear calipers are too much rear brake and require a limiting valve. They also displace more fluid which gives a soft pedal. Also with a limiting valve and more fluid displacement the ABS doesn't work properly as it is designed to a certain volume of fluid . I drilled a hole near the top of the pedal arm and connected it to the master cylinder with a chunk of about 1 inch aluminum. this with a 929 master cylinder will give you a rock hard race car pedal.I use the F40 front caliper, 38/44mm.

wouter Bouman

All the japanese tuners (FEED, PANSPEED, RE AMEMIYA) all choose generally the same approach. first get coilovers, then get race tires, and get racing bushings all around for your car. For cooling and power, go single turbo, take out the non essentials like power steering, AC, and the airpump and relocate the battery to the rear cabin bin. you want as much space freed up under the hood as possible so that there is more room for the hot air to escape under the car. Get dual oil coolers, in japan they custom fabricate the FC middle oil cooler for an FD in road racing. get a radiator upgrade, and also brake and engine upgrades. Get a full rollcage to increase chassis stiffness and handling and safety. Get a steering wheel, racing seat, and 5 point harness. Tear out the interior and get a vented hood, a nice functional wing, and all the other power essentials. For road race you probably need only about 340-350 rwhp and you will be sufficient. If you really want to be competitive your most primary concern is to get your car to run 2 to 4 hours of hard driving, not high horsepower or handling. Of course in the end, the determining factor for winning races is still driving skill....

Tranny
 

Hi racedriver.

Where did you get , the close ratio tranny with straight cut gears?

Thanks

Pedro

Tranny
 

Hi racedriver.

Where did you get , the close ratio tranny with straight cut gears?

Thanks

Pedro

a friend i know had a 3 rotor fc and had the tranny built by houseman autosport. They weld syncos on jerico gears and make their own shafts. They do this for several types of cars. He then bought an imsa rx7 which came with a saenz race tranny. He paid about $4000 for the conversion. When i bought it i simply put the bell housing and tailshaft of the fd on the fc casing, which is basically the same as the fd. the gearing is close ratio and it should have no problem handling 600 hp.

wouter

Well, I now know what my FD wants to be when it grows up "racedriver".

Where did you get the lexan rear window? I have been looking for one. Is your slotted for air to pass through?

1FooknTiteFD
Where do you get race bushings for an FD?

I had a window taken out of a trunk lid to make a mould of the trunk in fiberglass. I took some thin card board and laid it out on the rear window and cut it to size. Then i took that to a plastics shop and had them cut a piece of lexan to that size. Make sure you get them to cut it as it is very hard to do. Then i used rivets all the way around to keep it in shape and in place.

Mazda motorsports makes and sells harder rubber bushings but they are extremely expensive. M2 sells them too i think. For a purpose built race car i'd probably use solid rod/ heim's ends.

Do you have a FMIC.......If so, I was told to spray the IC down before you race with some cold water, it helps reduce the heat......

i have a trust smic . I haven't sprayed it because the races are too long. In road racing they are between 30 min to 1 hour.

Hi race driver and 1fookntiteFD.

What is the best shocks for the money for road racing? with a single adjustable and rebuildable?

What are your'e car weight ?

The best value in my opinion is the gab super r's, available at m2.
Bilstein is also one of the best, but not adjustable. Buy direct and they will match them to your springs.
M2 sells Advance Design for about $2000. Very adjustable

Tri-point sells Penske's aluminum bodied shocks at a whopping 4000.

I would go with Bilsteins or Gabs.

With windows and stock panels, and full cage, my r1 weighs 2700 lbs. Now that it has a fiberglass hood, door skins , trunk, & lexan rear window I estimate it weighs 2500 lbs.
Wouter

Hi racedriver.

Yes, I have seen many roadracers using gab's, taking advantage of price, ajustability and that can be used with hi spring rate a requirment for road racing.

You have save some good pounds, as weight saving is a very important issue you turn faster, acelerate quicker, and brake in shorter distance.

Thanks
Pedro

Hi racedriver.

Yes, I have seen many roadracers using gab's, taking advantage of price, ajustability and that can be used with hi spring rate a requirment for road racing.

You have save some good pounds, as weight saving is a very important issue you turn faster, acelerate quicker, and brake in shorter distance.

Thanks
Pedro

I have a fiberglass drivers door available that needs some sanding, and two fiberglass front fenders, L&R . $100 US for door, $150 for fenders.

Are you planning to build a race only car or a race/ street car.
A guy in the Florida rx7 club has done a 93 up quite a bit, strictly a track car.He's got pics & info on their site about his race in Daytona.

wouter

Check your PM racedriver

hi race driver.
Are the fender price 150 each or both? do you make those ?
Some photos for the door and fenders?

Yes, the proyect is to make only race car.
May you give me the web site of the daytona racer?

Thanks
Pedro.