Front suspension sag
 

I have a low mile FD 93 R1 that is in excellent OEM condition.
My front suspension has started to sag over the years.
Otherwise I'm happy with the OEM suspension and can't upgrade for autocross stock class purposes.

Replace the front struts?
Replace which bushings? If so, which ones exactly?
Thanks!

the front bumpstop is usually the culprit, FD15-34-110B

Let’s see auto crossing, 25 year old rubber in the suspension, you have more problems than sagging. It’s time to replace all the rubber in the suspension system if you want to maintain top handling performance for auto crossing. That includes the shockadsorber rubber. In my low mileage 7 I replaced everything front and rear with Mazda Comp bushings and stock rubber pieces to keep it “stock class” :) (I compete in the BMW Club’s Autocross and they don’t care). OEM regular bushings will still transform the handling over your current 25 year old rubber bits. I was amazed at the handling differences, the old suspension deteriorated at so slow a rate over the years that I just didn’t notice it and unknowingly modified my driving style to compensate. If you compete, Mazda comp is hands down the best place to get OEM and competition suspension parts at a ridiculously low price.

I'm going to agree with both of the above. The most common causes are the strut mount and the rubber insulator the bottom of the spring sits on.

Vince

Upper shock mount and the rubber insulator that the spring sits on.

Ray Crowe can get you the OEM parts at a discounted price. His contact info is in the FAQ

A stock... up against modern LS V8 corvettes with 30 y/o turbo rotary tech. Gotta love SCCA classing!

I am getting rid of my stock suspension soon which includes like new (less than 2k miles, maybe even less) upper rubber isolators. I just replaced them last year. PM if you're interested in buying the isolators. Will be available when the Ohlins DFV setup gets installed in the next month or two.

Ordered the parts recommended in this thread from Ray.
Will update with pics for others.
Thanks!

The rubber shock mounts are a common problem, they sag over time and the driver's side sags more since it's typically one person in the car.

The rear mounts can sag but they aren't as bad/noticeable as the fronts.

Dale

https://cimg7.ibsrv.net/gimg/www.rx7...1f69de8862.jpg
Pre repair
https://cimg4.ibsrv.net/gimg/www.rx7...3ff3b8802b.jpg
Post repair
Well, after replacing the aforementioned rubber mounts / bushings on my low mileage FD (39k miles) there was a slight 10mm change. Not overwhelming. Oh well. For anyone else with this issue, consider replacing the shock and spring as well.

So what exactly are your current right height measurements?

Stock OEM FD R1 suspension.
225/40/18 tires
65.5cm front ride height after suspension rubber bushing replacement

I just went thru the same thing a little while back. Little to no improvement in height/rake replacing front mounts.
Two things that might help from my experience...

1. My garage floor was nowhere near level.
2. The drivers front fender lip is lower and closer to the tire than the passenger front. I heard from other owners/experts that this is common on the FD for some reason.

I wouldn't expect a change much different that that. The spring isolators at the bottom of the spring are only ~2 mm uncompressed. The upper shock mounts are under 1" thick iirc and the springs recess into it ~1/4 - 1/2" (longer over time)

Were you trying to raise the front higher?

Shock will make no difference to static ride height, short of being restricted internally or all the rubber components are shot, the spring supports the weight of the car.

No idea on the rules over there, but the FD came with a shedload of spring options over the years, if not restricted to 1993. Hard part would be figuring out what springs are which. Older cars, used to be shimmed under the spring seats to even out discrepancies - if that's not against the rules - which might be another way, if you're trying to fix a corner weight problem....what fun!

Your after shot looks about right. A little hard to compare with the aftermarket wheels. FDs are naturally higher in the rear. That's probably part of how they got away with so much travel and squat in the rear.

edit: Mazda tried, to make the care liveable on the street. The front is a lot stiffer than the back. If you switch to performance oriented suspension, the car almost immediately becomes a skateboard. And you spin out, cause the rear end breaks loose instead of squishing and wiggling. And then you get to complain about sway bars and spring rates and staggered tires.