Ritch

As I understand the way of things Mazda created an oversteering monster in '79 with the SAs. Over the years they worked on correcting this "problem" (only in the minds of some) achiving a more balanced car. Is this true? How neutral did it become before the FCs came about?

My 7 tends to push on corner entry with the back end only a bit of throttle steer away being fairly easy to put into a four wheel drift or all out butt side-ways. I'm going to investigate this further later and think it has something to do with my tires first off. I'll mic my sway bars later too and see if there wasn't a change made that I didn't know about. As far as I know it is stock with the exception of the coilovers and Eibacks listed below. Ft. springs are 350 lb/sq. in, R. are 175 lb/sq. in.

This set up may not be too far from balanced but I'd like to get rid of the initial understeer I'm getting. I guess I'd like to know how my '85 SE behaived from the factory as a starting point. Everyone else here seems to think their cars oversteer terribly.

Ultralights

almost all cars, sports cars Included, are designed to Understeer a little into corners from the factory!! , as 90% of drivers cannot handle Oversteer or control it!

its a designed in safety thing.

Rx7carl

Your understeer is probably from the extra weight of the 351.

jimmdog

My car drives the same way now I like it. before with the stock rims tires springs and shocks it was scary at high speed cornering. maybe go with an adjustable rear swaybar and dial out the under steer until you like it Good Luck

Zeta-Gouki

76.87% of all statistics/percentages are made up on the spot.

peejay

RX-7s are a bit like 911's.

They plow like pig if you take a too-early apex (get on the throttle too early). Accelerating unloads the front tires and they just sorta slide.

But brake deep into a corner and you get to see where you just came from.

This is why many people remove the rear sway bar. IMO that's only needed on cars that are lower than stock ride height, I thought my '80 was perfect. Lower the ride height and you have plow, plow, plow, SNAP OVERSTEER. So you remove the rear bar so you only get plow, plow, plow, plow....

31rx7

From the description, it sounds like you are having understeer on turn in. Are we talking on an autocross course (low speed) or open track (high speed)? A couple thoughts:

How smooth are you when you turn the wheel? With relatively high spring rates in front, a quick jerk of the wheel to turn in will cause the front tires to break loose, and hence understeer.

Similarly, those spring rates will quickly overload the tires if you don't have high performance tires.

Another thought: check ALL your bushings and pivot points in the front suspension. I would not be surprised to find a bad bushing in a control arm or tension rod that causes issues on turn in.

Finally, how is your alignment set? Toe? Camber? Caster?

Rich

851stgen12a

I have to agree with the earlier comment. I would put my money on the weight of the 351.
The Rx-7 was origionally weighted 50/50 distrubution.
Throw a whole crap load of weight up front and its going to over weight the front tires, creating understeer on entry.

Ultralights

this one is Not made up!

how many road tests have you read? almost all talk about the oversteer in most cars! even jeremy clarkson!

peejay

I doubt it weighs significantly more than a GSL-SE setup.

My '80 had stock ride height, stock suspension, stock everything, and it would ploooooow if you drove conservatively. (brake early and power through the corner). The '85 was worse, only because it sits much lower the suspension geometry is all thrown out of whack so it plooows then snaps at a certain point. The limited slip diff isn't helping things any either. The car made me understand why people yank the rear bar off... when I raise the suspension back up the bar can probably go back on.

851stgen12a

I dunno, maybe its just me, but my car handels so incredibley neutral, its awsome. If I lift off the throttle at any point through the corner it understeers a little.
Mash the gas and the rear end goes wherever I want it to go. It is absolutly fantastic!
If only I had a little more power.

Ritch

A couple of you really need to slow down when you read. I have a nearly stock 7. My '69 Cougar has the 351. The 7 has the Eibach springs and Hawk pads. That's all I changed so far.

31RX7 - Your tire suggestion is at the top of my list of possible problems. My tires are front 185s and the rears are 195s. Someone put skinny little buggers on before I bought it. I haven't put new rubber on because I haven't made up my mind on what wheel size I should use. That decision is held up by what body kit if any I might add. I think a matched set of rubber on all fours will help get more traction up front.
BTW I did change all the front end bushings with Ground Control Poly bushings.

MosesX605

My '79 oversteered quite predictably to the limit with stock suspension and rear bar installed. When I went to the '81 GSL rear end and removed my rear bar, the car had more usable grip before transitioning to full on oversteer. The LSD also made corner exit more of a science, it's definately great for putting power down when coming out of a corner, but it will make the car understeer more under power because the rear wheels are spinning closer to the same rates. Once I got used to it and adjusted my corner entry and exit, I got quite a bit faster because I could put the power down earlier.

Next season I am going to experiment with the smaller '81 bar and the larger '79 bar to see if I can net some faster times with one or the other, or if neither is the best bet. I do think that having the bar on for the street is probably best, as it makes light and medium cornering easier.

31rx7

The tires will make a big difference. With higher rate springs, force is transferred to the tire more rapidly overloading them.

If you are looking for an interim solution while you sort out what you want to do long term, check with some SCCA racers in your area that have some old 13" race rubber they will part with cheap, and throw them on an extra set of rims. It will make a world of difference.

peejay

Race tires with stock springs will cause the front suspension to ride on the bump stop on the outside. This is why my SA plowed like pig on the road course despite me retaining the 18mm rear bar.

31rx7

Peejay,

You are correct. However he has 350 / 175 F/R springs, so he should be fine.

peejay

Yoicks, didn't see that. Nebbermind then!

Columbus, eh? Longshot, but did you happen to sell a set of tires/wheels to some longhaired kid with a rusty '80 in Upper Arlington, about three-four years ago?

Ritch

31 RX7 - Thanks for the advice on the used racers. Never thought of that. Great way to try out different sizes and manufacturers without the big price tag. I'll give that a go.

31rx7

Peejay,

That's me.

Ritch,

I would offer to sell you a set but shipping would make it not a good deal. High performance race rubber in 13" is getting harder to come by. Try a person that runs a 1st Gen in ITA, Spec 7, or NASA Pro7, or a person that has a Spec Racer Ford. 205/60-13's work pretty well on the stock rims.

If you find a 1st gen racer, offer to crew for him or her in exchange for some tires. You'll find out a lot about racing, get setup ideas, and have some fun.

You might be able to pick up some freebies, should easily find a set for $100 - $150, and certainly should pay no more than $200 for a set that maybe has only a couple of heat cycles on it.