BRealistic

Ok, I think my car may need new springs- since they are original and seem weak. BUT, after looking at 'spring uprgrades', I have found that they are all LOWERING SPRINGS. Now, I drive on many roads that are bumpy, and suspension travel is important, so I don't like the idea of loosing 1" just to get 'better' springs. And I know that lowering the car helps handling, but it only helps til you hit the first bump. Anybody have any experience with this? Are there any performance springs available that don't lower the car?

O 16581 72452 5

Well if you think about it those stock springs have done alot of sagging so lowering springs would probably not change your ride height at all, it would maybe lower the back but in the front it probably wouldn't lower it at all, if anything might raise it.

Aico

You can get costum springs@Mazdatrix, GFeng en I believe RB also

peejay

Lowering doesn't really help the handling on 1st-gens unless you do a bit of work to the suspension.

In stock form, the rear roll center is too high and the rear suspension geometry binds at extreme lean angles.

When lowered, the front roll center gets lower relative to the center of gravity, meaning the body has more leverage over the suspension and the front wants to lean more. The rear roll center gets higher relative to the center of gravity (to be precise the CG comes down closer to the roll center since the roll center is a fixed point on the axle housing) meaning the body has less leverage over the rear suspension.

The end result of this is that the car oversteers even more than stock.

Worse is that when lowered the lean angle at which the rear suspension binds gets to be less. When the rear suspension binds up, roll stiffness goes near infinite just like if you bottomed the suspension. This causes sudden, unexpected oversteer.

The front roll center can be fixed with spacers that space the ball joint further down. The rear roll center can be fixed with a Panhard rod, and the binding can be fixed by converting to a 3 link suspension.

Band-aid fixes include not lowering it so much or at all, front spring rates much higher than the rears (stock is 110-ish front and rear, most lowering springs are MUCH stiffer front and the same or LESS in the back), and removing the rear sway bar.

BRealistic

So I either lower it, or have special ($$) springs made?

And peejay, some interestinmg info- but not sure how that adresses my question. I have always thought lowering springs were more for looks that actual handling anyways. Based on what you described. a stock 1st gen with lowering sprimgs actually has a looser rear end. - BUT didn't the 84/85 have a revised rear end geometry, to help reduce drop throttle oversteer?

peejay

The rear suspension geometry was revised to alter roll steer. By lowering the lower links' front pickup points, when the car rolls, the rear axle tries to steer the rearend more to the inside of the corner, pointing the nose away from the corner. This is known as roll understeer. I dunno how much roll steer the '79-83 models had (ALL solid axle cars have it to some extent) but the '84-85 was tuned for more roll understeer.

This is at the expense of anti-squat... this is why when you goose the throttle on an '84-85, the rear end squats down, because the torque reaction of the rear axle is trying to pick the rear tires up off of the ground. (Not what you want for drag racing)

Most lowering springs have greatly stiffer front springs and same/weaker rate rear springs, compared to stock. Also as mentioned before, these cars all all 20-25 years old or so and the stock springs are way sagged, so lowering springs usually raise ride height back UP a bit. My '85 is practically on the bumpstops with stock springs, and this weekend I discovered just how much the car likes to oversteer with the geometry all screwed up and with stock rate springs. (I yanked my rear bar off this afternoon)

Directfreak

iTrader: (2)

My original suspension was too low, and and riding on on the bump-stops constantly.

I installed Eibach-Progressive lowering springs all around with Tokico Illumina struts. I also replaced the front sway bar with a Racing Beat one. I also relaced every worn bushing with fresh Urethane springs.

The car, even though "lowered", actually sits higher than it did before on the original stock (and worn) suspension components.

With the new suspension, the car does not squat (unless I set the Tokico's to do that), and barely leans. It is not nearly as tailhappy as before either.

Conclusion:
A new "lowering" suspension will actually raise the car just a little. It will look good, and feel good.

Go for it.

BRealistic

Well, the Illumina Tokico shocks are pricey: 500$ for them all around. How much better than just normal shocks are these? I don't plan on any serious racing- maybe an aout-x or two if I ever find one somewhat locally. And the Tokico springs are 80$ cheaper than the Eibach, are the Eibachs worth 80 more bux? Or is it name recognition?

Directfreak

iTrader: (2)

Check around the forum (search)

The Tokico springs have had some fitment issues on some cars.

BRealistic

Yeah Yeah yeah, the search feature. The search feature on this forum blows BTW. Absolutely no control over the search- you can't specify just the topics, or the entire thread. I have done many searches, only to get tired of looking through the haystack to find the pin. A search feature that allowed more controls over the search would very much help us RX7 nubees. I am sure nobody likes answering the same questions over and over, but try a search ans see how many threads you have to sift through to find any information. The more words, the more threads you get, even if the words are not even in the same post.

peejay

Body lean =/ bad

BRealistic

FOr the record, the previous onwer of my seven replaced all the suspension bushing with urethane (well, except the rear sway bar). The car handles flat and sticks like glue, until you hit a bump.
But it does hit the rear stops sometime- I suspect because the rear spings are weak.- oh, and the front is way floaty over high speed bumps. If only the world was flat.