Leading Rotarian

My son and I are building an 85 RX-7. The steering seems to have a bit too much play. Most domestic recirculating ball steering boxes have a way of tightening steering play. Is this true of the RX-7 box?

1badFB

iTrader: (1)

It most certainly is true of the RX-7 steering box. If you do a quick search Im sure youll find the writeup prety quick.

But..

First thing I would do is check the idler arm bushings, balljoints, tie rod ends, controll arm and tension bar bushings.
Once you know those are all good to go, there should be much less play in the wheel and you might not even have to tighten up the box. I was convinced mine needed tweaking, but as soon as I was done all my front end work the steering was a very pleasant and tight surprise.
If everything else checks out then go ahead and try to tweak the steering box, but Id only reccomend it if everything else is positively in good condition.

Kentetsu

After you check everything listed above and confirm that all is good, then read this thread:

https://www.rx7club.com/showthread.p...steering+grind

Leading Rotarian

All look good, but one can never tell until one takes things apart. Who makes the best front-end rebuild kit. Also, it appears as though my rear springs are sagging a bit. Where can I get factory springs? The car is being prepped for SCCA CS autocross so I cannot use aftermarket springs.

Kentetsu

http://www.mrcmfg.com/respeed/catalog/index.php

These guys will have almost everything your heart desires.

trochoid

iTrader: (6)

I don't believe ReSpeed carries stock springs, Racing Beat will probably be your best choice. Replace all 4, replacing only the rears will most likely make the handling worse.

How stock do you have to stay in this class?

Rx-7Doctor

iTrader: (13)

Bump

1badFB

iTrader: (1)

Racingbeat doesnt carry stock springs....
I assume you meant mazdatrix????

85 FB

There is a guy who lives here in my area who collects a ton, and I mean A TON, of stock 1st Gen RX-7 parts. I've seen the stuff he offers. If you need stock rear springs, give this guy a buzz. He just might have them and ship them out to you. He also has an eBay store, too.

Jim Hull
Rotary Restorations
Specializing in Mazda RX-7's
jameshull777@hotmail.com

Leading Rotarian

I have to stay very stock. I cannot change the rear swawy bar (front is unlimted). I cAn use any shick.strut that uses the exact stock mounting points I.E. no camber kits, no coilovers. Whels must be of stock diameter and width. Exhaust must be stock from the engine to the cat. The engine must be stock. Stock ports, carb and even aircleaner. R tires are legal. In autocross, over steer is desirable. antything I can do to stiffen the rear and/or sodten the front is good.

Rx-7Doctor

iTrader: (13)

I'd put the 1.25 inch bar on the front and remove the rear bar. Then I would run the Se stock springs on the rear.

84stock

iTrader: (5)

I have a pair of perfect rear SE springs that I took out oand installed RB springs as a replacement. No sag at all!

84stock

iTrader: (5)

Replace the entire idler arm with a Moog idler arm rather than doing the bushings

Kentetsu

You can get the Moog ilder arm cheap at www.rockauto.com

I also highly recommend the Racing Beat swaybar, it made a hell of a difference on my car. No lean at all anymore. The difference was drastic even though I already had the new struts and springs on the car (see sig). Without the option of camber plates, you might have a hard time getting any oversteer, but you might be able to run a little toe out to get there...

84stock

iTrader: (5)

did you just do the front swaybar? Right now I run stock on front and none on rear on my SE

Kentetsu

After all of the upgrades listed in my sig, the swaybar was the last to be added. I cannot begin to describe the difference that it made... It did seem to increase understeer slightly, but it improved the car in so many other ways that my times still improved quite a bit. I plan on putting the rear bar back on over the winter, along with all new rear end bushings to keep things moving smoothly and reduce binding/snap oversteer.

Leading Rotarian

Why remove the rear bar. The rear bar stiffens the rear end and makes it slide. I need to be able to kick the rear and out around very tight turns. Basically, I want to induce a bit MORE ovesteer than the car came with from the factory. I wnat to increase grip at both ends of the car, but more so at the front. The alingment specs should reflect that as well. I would want as much negative camber at the front than at the rear, but both more than the factory specs.

Kentetsu

Well, the effects of removing the rear bar are still debatable. Most feel that the biggest handling problem that the 7 has is "snap oversteer". This is when you are hard in a turn, and the rear suspension suddenly binds and whips the rear end around on you. The main cause of this is due to poor design of the rear suspension, which leads to the binding issue.

Removing the rear bar will sometimes help with this issue, but the main benefit I found is that the inside rear wheel spins less coming out of hard cornering (autocross) without the bar in place. Since I have upgraded the front bar, this has mostly been corrected, which is why I am now contemplating replacing the rear bar.

Replacing all of the original bushings in the rear end will help with all of these issues. The stock rubber bushings will stick to the metal parts, which keeps them from moving properly and adds to the binding issues mentioned above. Once they have been replaced, and are moving freely, then the snap oversteer issue should be mostly corrected.

Adding stiffer springs to the rear, and upgrading the rear shocks, will also help with this by limiting the range of motion in the rear end. The more range of motion you have, the more likely that you will experience binding and therefore enter into the zone of snap oversteer....

The only way that you will achieve the camber you desire at the front end will be with camber plates. However, if you can't do that right now then a touch more toe out may help you to achieve the oversteer that you are looking for...

Leading Rotarian

Camber plates, stiffer springs and polyurethane bushings ae not allowed in SCCA stock classes. Neither are smaller crash bolts to get extra camber. However, any shock/strut is ok as long as it mounts in the exact stock location.

Rx-7Doctor

iTrader: (13)

The Se rear spring is stiffer than the others and wouldn't it still be considered a "Stock" component. And Kentetsu is correct on the removal of the rear bar. However with the correct matched bars front and rear the steering will be returned to a more neutral steer.

The pre 84 cars have most of the oversteer problem. According to the literature for 84-85 the oversteer problem was supposedly addressed.