crap? do you own a FC or have driven one?

 

Read up on suspension engineering. There's all sorts of things wrong with the execution of the FCs rear suspension, even beyond the basic fact that trailing arm suspensions aren't that great.

The live axle setup on the FB also has its own geometry issues, but they've been solved by various people, quite successfully. I've always figured better the devil you know...

Now, the FCs front suspension has some nice refinements; I'm working on swapping that over as well. The rear... well, I just might have to get a Mustang rear end and adapt the G-Force enhancements over to that.

Oh yeah, it *is* possible to get rear toe (not that you'd really want to) and camber with a live axle rear. Caster... well, I'd like to see how you'd get caster changes with a trailing link suspension.

 

I just dont understand why anyone would want a solid axle over independent. Solid axle is truck suspension!!! Yes, trailing arm isnt the greatest, but the FC's suspension has many refinements that a standard trailing arm does not have. It's also free. Before this FC idea, I wanted miata suspension, which is 10 times the suspension of the FC's (BASICALLY downsized 3rd gen suspension), but that would cost some money. If i did miata suspension, i would just design and fab my own, because i have the capability to. There are doctors in Mechanical Engineering with emphasis on chassis and suspension who are totally willing to review my designs if i wanted. But being a freshman, and not having taken the chassis and suspension courses yet, I'm sure i would have a myriad of problems in my designs. Then i would have to fab it, which is a tedious and painful job. I'm not sure i am up for that yet, being that i am in school and all.

 

They had a team of engineers designing and refining the suspension, they had mechanics install it.

 

Yes, yes, and crap.

I'm not the only one who thinks so... Dave Lemon does not have nice things to say about the FC rear suspension, either.

 

I've taken the classes that are in your future. Including vehicle dynamics. I can tell you that the FC suspension isn't the one you want. I'd agree that a Miata suspension will be superior to the solid axle in most respects, but not the trailing arm.

 

If there was a Mazda IRs to use, the Miata would be it.

As long as you don't mind poor suspension travel.

 

Me and SHM21284 have been thinking about a FC rear and front suspesion swap. I'm also having a hard time understanding the downfalls to the FC suspension. After driving my widebody FB, with very good tires and braces and ect, and 390 horsepower, I can say the Solid axle is pretty damn good, excpet for one huge thing. When you accelerate, the engines force transmits to the rear end, so under acceleration, the soild axle wants to push down hard on the drivers tire, and lift up on the passenger tire, causing uneven loading. And handling changes from a right turn and left. I didnt notice the strange feeling until this year with more horsepower, since it is exagerated greatly. Unless there is a remedy for this that I dont know about ( someone may be able to clue me in here) A IRS will not transmit this uneven torque, since the differental is bolted to the chassis. True? And REamemyia has a killer FC, that is still using stock rear suspension componets.

 

But with a swingarm suspension, *both* tires get picked up off of the ground, leading to traction loss (in a big way)

Plus you'll have to do some major hackery to the body rails in order to fit the subframe in there. If you're a good fabricator/chassis engineer you can gain back the lost strength, but we're still talking about a lot of work.

 

It's not that much work, i have pictures of mazda's fc suspension in the first gen and it aint too bad. Weld a few brackets in and throw a couple tube braces in for the hell of it. I will probably buy a completey trashed FB (thats not wrecked), flip it over, and first put the suspension on that so i know what to do on my car and GTORx7's car when the time comes. It would be a pain to try to do that the first time while lying on my back.
Ask GTO how his 2nd gen handles. He will tell you how close it was to his third gen.
By the way, probably the most important factor is the unsprung weight of the suspension. 2nd gen suspension has much less than the solid axle's first gen. I see an advantage there.

 

oh yeah, i believe it was the 2nd gen that won the GTO or GTU championship? correct me if i am wrong.

 

PM me for a good deal on some FC suspension

 

NO! Email me. Some how I was logged in as jsmiley

 

They did win with the 2nd gen for a year or two, but the SA, and FB won the GTU every year it was produced, from 1979 on up.

 

1st gen owned in IMSA

 

i have a GS and i want to do a rear end change i do hav a spare 2nd GEN but how hard would a miata be i can get my hands on one and if so what year is the best

 

Oh, and just like solid axle suspensions, all IRS are not created equally. The semi-trailling link suspension was an engineering feat by mazda, in that it had a few interesting features. Unfortunatly though it also has some major flaws that made developing it a major PITA for mazda. It took them 3-4 years of engineering and reegineering to get it even somewhat decent.

The 1st gen's rear suspension has some serious flaws too, but at least they can be corrected. There are autocross racers extracting close to 1.3g's with the solid rear, so it can't be that bad.

 

It was both. Every single damned year from 1980 to 1989. Ten years in a row.

 

More like 1.5-1.6g.

The only trick to getting high lateral grip is tires. Suspension comes in for handling.

Hell *I* was pulling well over 1g with a bone stock '80 with some ancient DOT-R tires. Plow like pig due to insufficient front suspension travel, though.

 

I'd like to hear more on getting the front suspension in there with the 4-Pots

 

The only advantage to the four piston calipers is larger pad area and a somewhat stiffer caliper. The effective leverage (hydraulic pressure vs. clamping force) is the same.

 

one of its best features is that its flat and gives you a HUGE trunk space over say the fd. granted trunk space isnt high on the list for a race car

 

The four pot calipers aluminum, so they weigh less (less unsprung weight), aluminum dissipates more heat, which translates into less brake fade and cracking. The brakes will also wear more eavenly due to having 4 pots, a more even distribution of brake force.

Also, the center of gravity is effectively lower on the IRS. The roll center gets lower as the suspension travels, where on the solid axle it stays the same.