DMclean

i have searched for short body short stroke dampers that people have used on there fb's and can't find anything that the body is significantly shorter than the illuminas i have. i was thinking as long as its shorter and narrower in diameter i could use some sheet metal and make a shim that surrounds the damper.

Does anyone know of possibly any dampers that are similar but smaller?

Kentetsu

I've got some short Bilsteins on the rear, but it sounds like you're looking for a solution for the front end. Shoot Billy a PM, he knows a lot about what the circle track racers are using, which gives us a lot of options. His username is Bwaits_




.

j9fd3s

iTrader: (3)

i looked into this, the FB struts are already way shorter than even the short stroke hatchi/corolla struts.

if you wanted to go shorter than that, its either bilstein or koni had a shorter insert.

typical DIY strut housings are thickwall pipe, sheet metal is not strong enough.

DMclean

yeah i knew that the ae86's are longer, and as far as the sheet metal, i meant i would roll it around the damper to fill the gap if there was one between the existing housing walls.

j9fd3s

iTrader: (3)

perhaps it should be mentioned that the FB can only be lowered so much before the suspension geometry goes out the window, so the short stroke shock thing would need some major suspension changes in the rear.

DMclean

i know some people say that the rear binds when its lowered too much, is this true?

bshusted

iTrader: (1)

I'm using the front struts from a 99 Miata in the the rear of mine lowered about an inch.

j9fd3s

iTrader: (3)

yeah, the lower links are parallell, but the upper links are not. so when the body rollls, it tries to pull the upper links out of the car.

additionally, the range of motion on the bushings is small

and on top of that, mazda rubber gets HARDER as it ages, so it just makes it worse.

if you want proof, the hatchi guys like a 6kg spring in the rear, the FB only like 3kg, yet they are both 2300lbs, 4 link rear...

j9fd3s

iTrader: (3)

if anything you'd replace the strut tube to run a larger diameter strut too.

i don't know if its clear from the other post, but i found a shorter strut insert that is the stock diameter. i just don't remember if it was a koni or bilstein. they both have online catalogs

and BTW the stock FB strut diameter is the same as the hatchi/toyota's, so that's what got me started looking for something better than the BZ1086 illumina.

i bought the BZ1086's...

Keith13b

iTrader: (6)

The rear binds if you just think too hard! Yes - common problem.....

Get in touch with Billy @ ReSpeed. He can answer your questions with experience and knowledge. Great guy to talk to, and he won't steer you wrong.

Kentetsu

As already mentioned, the rear end will bind and induce the dreaded "snap oversteer" when the body rolls if the car is lowered. The key part of this is "when the body rolls".

My car is severely lowered, which is why I had to give up my beloved Illuminas in the back and use the great performing but harsh riding Bilsteins. But, I do not have any issues with snap oversteer/rear end binding, even under the harshest of driving. Even using urethane bushings in all four of the rear links (reportedly a huge no-no).

Here is my theory as to how this can be. Respeed front tubular swaybar + adjustable rear bar set to stiffest setting + "proper" ride height. Basically, if the car doesn't roll even at the most extreme of cornering forces, there is no movement in the rear end to potentially result in binding.

A great deal of the roll control comes from the swaybars that I use, a lot of it comes from the coilovers and dampers, but I think that most of it comes from the ride height that I run. The lower the car is, the less it will tend to roll in corners. My car handles unbelievably well.

However, if you tried to run my ride height while missing any one of the components that make this possible with my car, you will be driving backwards in a heartbeat (again, just my theory).

Billy advised me on my build, holding my hand every step of the way. It all started with me asking what I needed, and Billy asking me what I wanted the car to be able to do. I said I wanted "a car that can eat Miatas for breakfast in weekend autocrosses, but can still be driven to work every day". He delivered exactly what I had dreamed of.

Billy has years of racing experience, and even his Father was a gearhead (rotaries in rally racing). There is a pretty big thread in the Non-Tech section with lots of very cool photos from years past, along with some details of his (and his dad's) racing experience. Worth looking up if you have the time, just search for threads started by him and you should find it.

Anyway, he has the knowledge and experience to give great advice and a personality that allows him to do so freely. He is a genuinely "nice guy". Last spring at DGRR I watched him spend an entire day swapping out a differential for a Canadian that had driven down for the event (dj55b). No charge, just helping out another enthusiast. Like I said, a nice guy. If you get in contact with him, he can tell you the best route to take. Or, if you want (and I can actually understand this view), you can reinvent the wheel for yourself and possibly come up with something nobody ever thought of before. Either way, best of luck.

Below are some photos to show my ride height, just keep in mind that the wheel gap looks larger than it should because of the low profile tires.

Also, here is a video from one of my favorite autocrosses. There were over 70 cars, and the only ones that came up with a better time were a supercharged Mustang, an unbelievably modified STI, and a supercharged Miata, all of which were on race rubber. I run $50.00 Sumitomo HTR 200s.


http://www.youtube.com/watch?v=rWpEYAKo0fU


.

81WideMariah

iTrader: (8)

^^^^ more Kentetsu cone ****...

jshiz

iTrader: (4)

I love looking at your car... I can't wait til you bring it back to life

Kentetsu

Thanks man. All of the drunk's damage has been repaired now, I just have to reinstall one of the headlight assemblies and she'll be complete. However, with winter right around the corner she'll be taking a rest until Spring gets here (why do I live in Michigan!?)

(sorry for getting off topic for a minute)

DriveFast7

iTrader: (1)

Revolution wheels rock.

DriveFast7

iTrader: (1)

What was the deal with those RZ struts in the Mazda Motorsports catalog?

"We also carry Tokico “RZ” series strut cartridges for racing use. The “RZ” strut cartridges
are designed for spring rates as high as 400 lbs., but are not adjustable.
“RZ” cartridges are larger diameter (43 mm) and shorter length (11.6") than stock
strut cartridge replacements. Please call for further information."

j9fd3s

iTrader: (3)

typo? the MR2 illumina we all run is a BZ, B=R?

hmm although the BZ1086 drops in like its made for us, its not shorter bodied, maybe shorter stroke?

Kentetsu

I think the only difference is in the valving. The BZs can be used with springs up to 450 Lbs, whereas the stock model is only good for (I believe) 300 Lbs or so.

But even the BZ is adjustable, where they are saying that the RZ is not adjustable.

DMclean

Hey Kentetsu,

i did talk to billy before buying all of the respeed suspension. my fb is very low as well. i'm just trying to take it a little further. here are a few pics of what it is now:

bwaits

iTrader: (12)

Yep, DMclean PMed me about this. I hope I helped in his search although I did not have part numbers for him.

The inserts we used to run were from bilstien and were for the Volkswagen cup cars back in the late eighties into the early nineties. No longer available. The lenght was shorter and the strut housing were cut down to hold them in place.

This allowed the rockers to be 3" off the ground (SCCA ITA rules limit) but still had bump travel. Stock length struts at the level gave you less than an inch of bump travel.

Of course the rest of the suspension needs to modified in order to run that low as well.

Now a days the only thing you will be able to do is research available "race" inserts from a few reputable suppliers to find something near what you need. OD will more than likely be larger than factory. This is not an issue since the strut tube would need to be modified shorter anyway.

Sounds like that is what Mazda Comp has done with the “RZ” inserts mentioned above.


-billy

Kentetsu

Ah, yes. Now I'm remembering some details on your car. Sorry for that lapse of memory.

One of my employees told me about a guy over by Detroit who is building custom shocks for some local racers. He said the guy will build whatever I want; size, valving, etc. I'm pretty happy with what I've got now, so I told him thanks but I'm all set. However, if you're interested I can try to get some contact info.

I'm trying to build some relationships with the local circle track guys. They've got all sorts of connections already figured out, like where to get Hoosiers at wholesale, who does great body work at cut throat prices, who can straighten a frame after meeting the wall, etc. The employee I mentioned is one of those racers, and he hooked me up with a guy with a frame shop in his garage so I could get the damage caused by "the drunk" repaired. Pulled the right front corner back out for me for a couple hundred bucks. Fantastic!

DMclean

yeah if you can get that contact info for me that would be great.

thanks

Kentetsu

He won't be back to work until tonight, but I'll see if I can get the info from him. Might take a few days though, because he probably won't have it with him when I ask.