LocostUSA.com

Just for anyone that is thinking of using these, the Celica caliper brackets do not fit the van spindles and neither do the dust sheilds.

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+442 - Miata

Slightly off topic to measurements but I was considering grinding on the spindles to both lighten them and also make them "prettier" what is everyones feeling on this?

I wouldn't. For the weight you'll save, you'll be removing the material that adds strength and stiffness to the uprights.

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-Andrew
Build Log
Youtube

Plus it would be a PITA.

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+442 - Miata

I took off almost 2 lbs on each HiAce spindle. The Wt was mostly removed by just cutting off the non-functional bosses and grinding the parting lines. Really would not effect the strenght, not that you would every see high enough loads when the vehicle is only 25% of the original design wt. As stated it is a PITA and took about an hour for each spindle. But since they are right out front and exposed the ground surface looks much better then a rough surface.

Then next you start can remove 3/4 lbs by removing the steering stop and clean up the steering arms, Dave W

I'm going to grind off casting flash and unused bosses from my Miata uprights. Not only does it make them look better but also keeps me from bleeding on them. Some of the casting flash is very sharp! Strength is not removed as long as it's non-load-bearing "nubbies" sticking out on the sides.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

The other advantage to cleaning up the castings is that you will remove stress risers, Most (all?) cracks are going to start at a sharp edge. By removing these you reduce the probability of the part failing. In some stock car racing classes the connecting rods need to have the parting lines left on, removing them by grinding makes the engine illegal because they can stand more stress (higher RPM, higher cylinder pressure).

I guess it depends what you're grinding. My initial thought when I read the question was thinning the upper and lower legs of the uprights...flashing and unused lugs are a different story.

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-Andrew
Build Log
Youtube

I did grind off the sharp parts. No more cutting of the hands.

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+442 - Miata

Chevette spindle extended interchange/brakes/trivia

First, I love your web site/forums. I own 6 Lotus
(Elan’s/Europa’s/Esprit). I’ve been looking for a spindle to use
on my Elan’s/Europa’s to get away from trunnions. I also want to
convert to 4X100 bolt circles. I thought Miata was the answer, then I
saw your posted Chevette spindle dimensions and had two thoughts, first
it does look to be the right size for our Lotus uses and wait, it looks
just like my Esprit!!!. 1976 to 1980 Esprit’s used Opel Manta/1900
front suspension. The Chevette being a “world car” borrowed much from
existing European GM design. I bought some Chevette spindles to compare
to the Esprit/Manta/1900. All critical dimensions are the same. Minor
detail differences are a bolt-on verses cast-in steering arm and the
ball joint tapers are slightly larger on the Opel. The Opel spindle
uses a separate hub/rotor design making swaps to big brakes easier (more
on that). I decided that I wanted to make a post on this forum
reporting the Lotus/Chevette connection, so I did more research and made
an additional discovery. Chevettes were marketed around the world using
several different model names (there was even a Chevette based pickup
truck). In Japan, Chevettes were marketed as Isuzu I-Marks. An I-Mark
is a Chevette? I looked at exploded suspension diagrams and Isuzu
I-Marks use the same suspension design as a Chevette. As they say in
infomercials; But wait there’s more! All rear wheel drive Isuzu sedans
use the Chevette spindle. So here is a list of years/models that I
believe use the Chevette spindle design:

1971 to 1975 Opel Manta and 1900 (great autocross cars in their day)
1976 to 1980 Lotus Esprit
1976 to 1979 Buick Opel (which is an Isuzu I-Mark)
1976 to 1987 Chevrolet Chevette (Vette for short)
1981 to 1985 Isuzu I-Mark
1983 to 1989 Isuzu Impulse
1976 to 1987 Pontiac Acadian (for those from the great white north)
1984 to 1987 Pontiac Fiero
1981 to 1987 Pontiac T1000

All of the above use the same Set 1/Set 4 wheel bearings. The Isuzu
Impulse, intrigues me because it has a separate rotor/hub design similar
to the Manta/1900. I need to find one and compare it to the Opel hub.

Now for brakes. The Opel owners group has worked out an inexpensive big
brake option for 13 inch wheels. They use 1977 BMW 320i vented rotors
(only year in U.S. with vented) which bolt directly onto the Opel hub
(which fit Chevette spindles). For calipers, they use either the BMW
(rare) or early 80’s Volvo. Caliper to hub clearance is tight, but they
fit inside 13 inch wheels! I considered this for my Esprit, but I have
upgraded to 17X8 on the front and wanted something more visually
substantial. I’m now using Volkswagen Corrado 4 bolt rotors (11 inch
vented) re-drilled to bolt-on Opel style. For calipers, I’m using Mazda
RX7 4-piston aluminum. Rotors can be bought for as little as $22 each
(not drilled or slotted, hubbearing.com) and junk-yard calipers for $15
each. The aluminum caliper adapter is easy, all 4 holes are in a
straight line (AN washers to shim the spacing). My mock-up was a
Chevette spindle, Manta hub, Corrado rotor and RX7 caliper. On the car
I retained the Manta spindles. I haven’t tried smaller wheels yet, but
15 inch may clear this combination. There are bigger 4-bolt rotors.
Lotus Exige is 11.3 inch. A 2005 Mini Cooper JCW is 11.57 inch. Both in
4X100 bolt circle, easily modified to fit the back side of an Opel hub,
and maybe a direct fit from the front of an Impulse hub.

But wait, even more! Because Fiero’s are popular kit car platforms,
bigger brakes and drop spindles are offered. Streetdreamsbyross.com has
2-inch drop 84-87 Fiero spindles with aluminum hubs drilled in any bolt
pattern (you want Lambo wheels on your replica, they drill to fit). For
Locost builders who can mount suspension pickups wherever they want, a
drop doesn’t matter, but for my Vintage Race Europa it does. Vintage
rules require original suspension mcontrol arms are free. By having the option of standard and drop
spindles and using AFCO standard and extended ball joints, I’ll have 8
different combinations of roll centers and swing arm lengths. It’s worth
the cost of the drop spindles to get those options. By the way, drop
spindles are not offered for Miata.

Vic

Nice post Vic...welcome aboard

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I'll keep an eye out for you!

To err is human...
I am more human than most.

Holy awesome first post Vic! Great info. So that's why the old Isuzu Impulses had the "Handling by Lotus" badge???

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He is a wise man who does not grieve for the things which he has not, but rejoices for those which he has.

Vic I loved the info but a question on the rapid subject change from Chevette info to Fiero? Did I miss something and there's a connection from Chevette to Fiero or was were you just changing subjects and giving us another option?

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

The Fiero/Chevette connection is that 1984 to 1987 Fiero’s used a complete Chevette suspension. Hollander and other interchange books acknowledge this as has previous posts on this forum (that’s how I learned about it). The good part for us is the Fiero kit car market offering lots of aftermarket support. The Fireo/Chevette spindle is one pound lighter than my Esprit/Opel spindle by virtue of having a cast-in steering arm. I will be fitting Chevette spindles to my Esprit by fitting Fireo/Chevette upper and lower Moog ball joints (a little research to make sure this works).

The Handling by Lotus badge was created when Lotus (owned by GM at the time) assisted Isuzu (owned by GM) with springs/shocks/sway bars. Lotus also used Isuzu engines in the front wheel drive M100 Elans. I grab the badges when I find them, but paid little attention to the car. I need to look further, it may have been front wheel drive cars.

Vic

Fieros used a Chevette based front suspension. The factory uprights are basically interchangable.




And a GM "X" (Citation) car based front suspension in the rear.