New member in the Southeast

[FreeSC]

An engineer by profession and longtime car enthusiast. I have, since being very young, had an interest in kit cars in general especially the Mirage.
I am interested in seeing what project cars are available and what updates work and are desireable. I am interested in putting together a state of the art car.

[Blueovalz]

Boy, that last sentence can elicit a huge number of responses. I've tried to put together a SotA car, with a strong emphasis on the suspension configuration of the '60s sports racers. Take a gander if you have time by clicking on the signature. This included upgraded corners, EFI, Porsche transaxle, and a bunch of other things to make it a very well-mannered car on the street and confident on the track.

[FreeSC]

I'm going to go thru the pics in detail. Looks very impressive!
I would very much want to get rid of the VW/Corvair suspension bits and use double A arms front/rear; use a modern all aluminum FI engine (probably an LT3), and a modern Porsche 6 speed transaxle. Very moderate F/R spring rates (about 125 # / 150#) so it actually rides good.

[Blueovalz]

Even with a 100% motion ratio, a 125-150 lb spring will be at the very lower end of a usable spring. IMHO, dampers are more important than spring rate in determining a "good" ride. My motion ratios vary between high 70% to mid 80% range, which I think is more realistic. I started with 250 in front, and eventually rested at 350 lb springs on the front, using the QA1 double adjustable dampers on a 5 (out of 16) setting, with even heavier springs at the rear.

[FreeSC]

Probably very true. It all depends on how/where/what angle the spring is attached to the suspension.
I was basing my statement on the fact that this is in the range of the Fiat X1/9, a car that is slightly heavier than the Manta and is also midengined. However, since the struts/springs on the X1/9 attach directly to the hub, which probably would not be the case on the Manta, I can certainly see the Manta having higher spring rates; maybe considerably so.

[Blueovalz]

When I built my rear uprights, my intent was to have as high a motion ratio as possible. Thus the coil-overs are mounted directly to the upright, and barely fit between the upper arm bars (as vertical as was possible). It has the higher ratio compared to the front, and I believe I'm running 450 at the rear. Static compression is only about 1.5" (maybe) on the dampers, which seems pretty small for any street driving, but the set-up is not harsh, or unduly restrictive. I was very surprised at how well it works on the street.

[FreeSC]

Great information. Thanks!

[Blueovalz]

One other note. I spent some additional effort to stiffen the frame so that the stiffer springs were more effective. IMHO, when work is done on the Mirage frame, this goal will improve the handling and allow stiff springs without harshness.

[FreeSC]

I think that is an excellent idea. I had decided to do exactly the same thing if I get a Manta project. The original car was clearly designed to be relatively inexpensive, not to handle massive horsepower and the cornering and braking forces possible with modern performance tires.