Has anyone heard or seen of anyone modifying a first gen with rack & pinion steering?

Does anyone think that it's possible?

 

I think its one of the first things to cross many a 1st gen owners mind

try searching I think people have had lengthy discussions about this already

Mike

 

Contemplating it.... Won't be easy though!

I need to find a rear-steer car with 22" between the inner tie rod pivots. That will get us the rack. Then need a way of attaching it to a 1st-gen steering column (this pretty much requires hunting down a '84-85 power steering car's column). Then, to properly mount the rack to minimize bump steer, a custom oil pan needs to be made, and the engine needs to be raised a bit (about 1/2-1 inch is as far up as we can go before hood clearance is a big issue) so the rack clears the bottom of the engine.

Basically it sucks Some people have swapped FC crossmembers in 1st-gens - this allows use of the FC front-steer setup and requires the use of FC struts and knuckles (allowing use of the bigger FC brakes) but so far I've seen no details on what they do for engine mounts, and the ones I have seen have used the FC steering column (yuck).

 

the millen rally cars use rack and pinion in the 80's, but now that i think about it they used the whole 626 front suspension too.

mike

 

we should petition Racing beat or Mazdatrix to build a conversion kit. If either one made a kit I would buy it.

 

it would cost so much nobody would buy it!

 

what are miata's? i figured with that tight engine bay and their size that they would be a good source.

 

Miatas are front-steer.

 

Virtually every production car is front-steer. I think the question was are Miatas rack & pinion, to which the answer is yes.

 

Actually, for rack and pinion cars, most FWDs are rear-steer (with exception of Subarus) and most RWDs are front-steer.

I was thinking of using a Saturn SC/SC2 rack, which is 12:1 ratio (RX-7 manual steering is 18:1, power is 16:1), excellent feel, no lash (play) at all, and it mounts solidly to the frame with no bushings (Saturns have excellent steering!). But they are 29" center to center, meaning bumpsteer would be a problem. Ah well.

 

Heres a Idea, what if you got a Jspec right hand drive miata R&P steering system. If you fliped it upside down, you would have a left hand drive rear steer system.

what about that, then you would just need to modify the streering shaft with a CV joint

 

What's the inner tie rod pivot center to center distance on a miata rack? That's the issue. Any rack we try would have to be 22" c-c.

 

well, we'll just have to scour the scrap yards with a tape measure.

Where do I measure exactly.

 

Pivot point to pivot point.

I'm FAIRLY sure the necessary distance is 22"... to be sure measure the center to center distance on an RX-7 center link. When I measured it, I was crawling around in the grass and it might not have been too precise

 

Did the BMW Isetta have rack and pinion steering? Maybe you could use that.

 

what do you mean by pivot point.

 

Where the inner tie rod end pivots... crucial to get the correct length and precisely mount the rack (mounting the rack is the hardest part of fabbing a chassis) in order to get zero bumpsteer.

 

peejay, an Isuzu Imark is rear-steer

 

with the stock recirculating ball loosey goosey steering I get a ton of bump steer as it is.

 

define bumpp steer for me.

 

The toe angle changes as a function of suspension travel.

Bump steer is generally a Bad Thing(tm). However it's somewhat beneficial to have a SLIGHT amount of toe out on jounce (suspension compression), especially on a rear-steer car where bushing compression makes outside wheel toe in in a corner. (That's why front-steer is better)

 

Im going to go to the yard soon, anyonw know the exact size is it 22"?

 

Looking at it more carefully, I don't think we could realistically put a R&P on our cars. You'd have to make a new oil pan, you'd have to raise the engine, just to make room for the rack. Might have to raise the hood. And then you have to figure out how to mount the rack to the car... have to make a new subframe because you can't attach it to the current subframe - the oil pan is in the way. (If you hacked out THAT part of the oil pan, you'd lose all oil capacity)

Looks like the easiest way is to do the FC front crossmember swap.

I'm sure it could be done with the FB crossmember, but there would be so many compromises that it really wouldn't be worth the effort compared to properly adjusting the existing steering box.