Front Suspension Frankensteins?

[TOOF]

I decided that in 2017 I will cut and weld more steel than I did in 2016. I am going to do a conversion that will probably mean I won't make it to my 24 Hrs of Lemons race in May but who knows.

I want to take the from end (subframe and shock towers) of a Mazda Miata and force it into the front of my 1970 baja-bug-restoration-racecar-moneypit project.

I was wondering if anyone has done this, or if anyone has tried anything similar?

[5.0 Chero]

what are you looking gain by this?

[TOOF]

Good question: disc brakes, quality braking components options (discs and pads), wheel options that don't suck, performance, reduced bump steer, steering rack (opposed to box).

I had a miata in the past that was a track car. Good parts for those cars are cheap. I can get 15x7 wheel that weight 12.9lbs for $89.

I may do the rear and fab a conversion CV for type 1 trans to miata stub axel if I find a good donor car.

[TOOF]

Also, this should be cheaper than buying a disc brake conversion kit and having the rotors drilled for 100x4. I have priced these around and a complete subframe with brakes, steering, suspension will cost about $300. Shops around me wanted ~$90 to drill 8 holes on rotors (not complaining).

Not including my time and the equipment to make it happen (which I already have).

[ChadH]

Looking at pictures of a Miata front and rear sub frames on the 'net. The front subframe sure looks awfully heavy and complicated to incorporate into a beetle. Not that it couldn't be done with some creativity and a lot of hacking, but it would be a lot of work.

Just bantering around with ideas, would it be better to build up a custom tubular subframe that incorporates the Miata suspension pick-up points? Check this out - Project Binky. These guys are grafting an AWD Toyota Supra suspension and drive train into a 1st Gen Mini Cooper. For the suspension, they fabricated a reverse jig off of the Supra to locate critical points, transferred it to the Mini, then built the frame to the Jig. These guys are absolute artists. I'd really suggest watching at least the first few episodes to get a feel for the scale of such a project.

https://www.youtube.com/watch?v=9VKegYsSRG0&t=803s

[Piledriver]

I spent a couple hours awhile back watching those... Celica GT AWD setup, awesome fabrication.

Another ...simpler option is to use one of the tubular Mustang2/Pinto front clips available cheap.
Can also be set up with struts if you are so inclined.
You can get really good brakes, cheap for that setup, although std bolt pattern is IIRC 4x112 or such.
This was discussed previously as an alternative to the currently available a-arm setup for T1s etc.
It was mostly suggested for the European guys for whom fabricated spindles are a showstopper.

[Ol'fogasaurus]

Its been a while since I played with the MII/Pinto suspension but as I remember the Pinto is bit better; if I remember correctly the difference is in the steering box. The bad part of the 2 vehicles is that Ford copied GM's style of the long trailing leaf on the rear springs for a softer ride but that caused handling to weaken. Shorten them up to the same length of the front part of the parallel springs and Wha-la a very different vehicle. I doubt that off-road travel would benefit much from the swap!

I wonder if the additional weight of what is shown in the picture posted would balance out the front to rear weight bias for handling.

After market front brakes are so available to the MII/Pinto spindles you can shoot for the moon there.

Lee

[Marc]

...as I remember the Pinto is bit better; if I remember correctly the difference is in the steering box...

The Mustang rack mounts on two big rubber bushings while the Pinto is more rigidly mounted - I'm unaware of any internal differences. Picked up a second-hand racecar that was set up for the Mustang II rack and replaced it with the same style from Flaming River, just replaced the rubber with metal sleeves and it worked fine. That car is lying in pieces in my backyard right now (only ran it a couple of races before cutting it up) and the near-new rack is available ...would have to dig out the paperwork to confirm but IIRC it's this one: http://www.flamingriver.com/index.php/p ... 002/FR1502

[ChadH]

Similarly - there's Miata tubular subframes available, if TOOF wanted to stick with Miata bits. This one is pretty pricey, but looking at it, it wouldn't be impossible to fabricate something similar (certainly beyond my skills though.)

This is just the first one I found...
https://v8roadsters.com/shop/suspension ... ubframe-2/

[GS guy]

Some decision points?
Track width of the "new" suspension. From my notes (suspension analyze software) the MII is 55.6". That's C-C at the true center of the OEM wheel/tire (13 x 5.5, 10mm offset). This can be tweaked a little with different offset wheels, but the overall track must be kept in mind if you intend to keep something close to the original MII geometry, and very importantly the OEM steering rack dimensions. Also to consider the brake plumbing, likely some adaptation will be necessary to get from VW to domestic (or NPT if going aftermarket). MII bearings and the hardware in general are "overbuilt" for VW weight - better in my mind for HD/race car application. Also there are several variations on the MII spindle available if you want to grow your own IFS based on the spindle geometry, plus near unlimited brake options. Then there's the wheel bolt-pattern mis-match, for both MII and Miata vs. VW in the rear. Can you match the rear bolt pattern with whatever you plan to run up front?

Not sure about the above details for the Miata suspension, but points to consider/investigate before starting to buy parts. A ground-scraping Baja intended for road-course racing might be more flexible on track width (who cares if the tires stick out past the fenders a few inches??).

[Ol'fogasaurus]

...as I remember the Pinto is bit better; if I remember correctly the difference is in the steering box...

The Mustang rack mounts on two big rubber bushings while the Pinto is more rigidly mounted - I'm unaware of any internal differences. Picked up a second-hand racecar that was set up for the Mustang II rack and replaced it with the same style from Flaming River, just replaced the rubber with metal sleeves and it worked fine. That car is lying in pieces in my backyard right now (only ran it a couple of races before cutting it up) and the near-new rack is available ...would have to dig out the paperwork to confirm but IIRC it's this one: http://www.flamingriver.com/index.php/p ... 002/FR1502

(sigh) Too bad I am 1800 miles away from you right now . I'm still mentally working on the black buggy' steering design. Question: is the connection of the steering rack to steering shaft splined and if so might it be 36/38 splines?

I don't remember if it was the mounting that was the only difference between the two R&Ps or not.

[Marc]

The Mustang II and Pinto are both front-steer end-loaded racks, about as far as you can get from what you'd want to use on a VW torsion-bar front end. The input shaft is splined (9/16"-26), I had to buy a coupler from Flaming River too - they didn't have one to adapt from a VW column though.

http://www.flamingriver.com/download.ph ... lRackSpecs

[Ol'fogasaurus]

I have also been told that a GEO Metro or something of that nature is an easy fit.

What I have is a 7/8 X 36 spline universal, 7/8 steering shaft, 7/8 pillow block and a 7/8 sreering wheel disconnect.

[Ol'fogasaurus]

I do have a r&p that came out of the blue buggy I rebuilt the front end on but I have no idea what it is from. The AL K&L beam it was a bit too long for it so the steering was way off. I might have to take a better look at it when I get back home.

[Evil_Fiz]

I will be watching this thread as I too am toying with designing and building a bolt-on front and rear suspension based on the NA or NB Miata. I have a long way to go before I am capable of such a feat and would not begin until my Ghia restoration is complete. If the guys at Mendeola were able to design a bolt-on solution then the Miata solution is definitely possible. Here are the dimensions I have come across in my research. To me, the Miata numbers appear close enough to be replicated with minimal body work needed, even on a Ghia. This would leave the suspension geometry intact and any improvements that work on a Miata could be translated to the adapted suspension.

Dimension (mm)---2000 Miata.......1970 Ghia Conv.
Overall length-----------3940......4140
Overall Width-----------1680.......1630
Overall Height----------1230.......1320
Wheel Base-------------2270.......2400
Track - Front-----------1410.......1290
Track Rear-------------1428.......1350
Rocker - Grnd Clearance-0147.......152/160
Weight----------------2200.......2000