Messages

BC,
This is going to be pretty rough but I took some measurements from the picture and it looks like the motion ratio squared is approx 1.8 so if you have 350 lb springs then the wheel rate is 350 divided by 1.8= 195 lbs/inch. This is probably pretty close that would mean that the suspension would compress, assuming that your wheel weight is 1/2 of the 1334 # front end weight (667#), approx 3.4 inches. You can check this by raising a front wheel off the ground, take the tire off and then set the front end back down on something like a wooden block that is either under the lower arm outer pivot of the spindle its self.

Looking at the picture it certainly looks like the spring is to long to allow you to lower the spring collar and add spacers. You may want to go to a shorter 350# spring. The other thought is going with either a 400 or 450 # spring. Going with the 400 # would put your wheel rate at 400 divided by 1.8= 222 lbs/inch which would then make the amount of wheel travel to be 3 inches which would raise your car about .4 inches with out preloading the spring. Going with a 450# spring would make the wheel rate 250 lbs/inch and the travel to compression would be 2.7 inches which would raise your car about .7 inches. Of course going to heavier springs does make the ride more firm but it does eliminate the preload which makes the ride very harsh until the preload is over come.

Rex
Rex

34,
If you jack the front end up and let the axle hang by the coil overs is the spring lose on the shock? Or have you had to "pre-load' the spring to get the ride height that you want? If you have pre-load i.e. you have the spring compressed by screwing the lower spring collar up and compressing the spring, then this pre-load has to be over come by the suspension travel before the spring starts to compress. Makes for a pretty rough ride an could be causing the bushing problem. The wheel rate related to the the spring is dependent on the motion ratio of the wheel movement to the spring compression squared. So if the the wheel moves 2 inches and the spring moves 1 inch the ratio is 2 to 1 and the wheel rate is therefore the spring rate divided by the motion ration (2 in this case times its self (squared) equals 4) So the wheel rate would be the spring rate divided by 4. So using your car as an example with approx 675 lbs on each wheel and if the motion ration was 2 to 1 and with your spring rate of 350 lbs/inch the wheel rate would be 350 divided by 4 = 87.5 lbs/inch. Using this number and the corner weight of 675 lbs the wheel, once the spring is seated would travel 650 divided by 87.5=7.4 inches before the spring held the weight and the spring would compress 3.7 inches. If your case is somewhat like this, i.e. your car ride height was to low and you screwed the lower spring collar up until you got the right ride height you preloaded the spring and this makes for a harsh ride and possible bushing problems. The cure is a heavier spring or a longer 350 lb spring. Measure the length of your lower control arm and then measure the distance from the arm bushings to the spring mounting bolt. Divide the arm length by the distance from the spring mount to the arms bushings and this is your motion ratio. From there you should be able to come up with a wheel rate that you want and also the spring required to give you that rate.  If the coil over is slanted at less than 30 degrees you don't need to consider the angle.

You mention that there is approx 5/16 inch between the coils when the car is on the ground, and I would guess that the spring probably has between 8 to 10 coils, this would certainly mean that the spring is not in coil bind, what you probably need to do is to add some spacers below the coil to do the inital ride height set up (get it close) and then fine tune it by turning the spring collar.  If you are preloading the spring to get the desired ride height you need to measure the length of the spring when you have the weight off of it  and then subtract that from the spring free length and that is the amount of spacers you would need.

Rex

Rex

More pictures, I hope!

Rex

The engine is a 2000 Ford Zetec, 2 liter, 4 valve DOHC, mine if from an Escort but they also used it in the Focus. It is stock except for the headers and the Hilborn electronic fuel injection, the ECU is from Pantera Inc and there is lots of tuning left to do although for a "flange head" like me I am catching on to tuning with a laptop! The body is all steel 28 pickup skins from Brookfield and the frame is 32 rails that I have pretty much butchered until they looked like I thought they should. The tranny is a T5 from a Turbo Thunderbird and the rear end is a mag Hildebrand quickie. The change gears that came with the rear end are 29/31s and even with a 4.11 ring and pinion it is only around a 4.4:1 and it is way to high! I am going to something that will end up around a 5.0. The wheels are 4.5 x 15 fronts and 8 x 18 rears from Wheel Smith, great people. The tires are Coker Firestone dirt tires. Still need to do some details to get it finished and still need to convince the DMV that it should have a tag, so still have plenty of challenges left.

Sum, she rids rough and steers hard but come hell or high water I am driving her to B'ville this year.

Rex

I haven't posted in a while, but I finally got my roadster on the ground and actually drove it around the section. Still have some tuning to do on the injection but it does run and is lower than a snakes belly! I hope that I can get a couple of pictures to post.

Rex

Big weekend to get something done on the roadster! Fabridated an air cleaner, got the injection throttle linkage done, make fairing for injectors and got the hydraulic clutch to function (still work to do on it though)

Couple of picks of the progress.

Rex

The engine is a two liter Zetec out of a 2000 Ford Escort.

Rex

Very subtle and VERY NICE!!!
Great job!! I can see why it took 3 years.


Rex

Just got all the detail parts so that I could get the Hilborn injectors mounted on my little banger also am getting close on finishing the aluminum gas tank.

Rex

Don't use it, you will have a soft pedal and it is WAY over priced. You will think that you always need to bleed the brakes. Use good grade brake fluid, keep your reservoirs full and covered and don't worry about water. The silicone is not worth the problems and cost.

Rex

Completed tranny cover and most of floor, pics attached, also built breather tank for engine, started wiring also had hood side panels louvered at Vern Tardels. Getting closer!

Rex

* nice trucks!!! Love that panel, great stance, nothing looks better really low than the early Chevy pickups and of course your panel.


Rex

Drop me a PS and I'll give you my phone no. When I did my track roadster I started with some Speedway 32 fram rails and the first thing I did was cut the front and rear frame horns off! So I have a set laying around in my shop. As far as I am concerned they are free but I won't pay the frieght.

Rex

Doug,
I don't know Steve but he can't be married, a 6000 sq foot shop with an attached living quarter. My and I am sure a lot of other guy's dream shop!

Keep us informed.

Rex

That big front splitter really made some down force plus they have a completely flat bottom with a slight difuser at the rear so they make lots of aero downforce. They knocked the splitter off on some salt ruts and I think that the car got better after that. As you said they did run 235 on a 250+ record so they still have a ways to go. Great guys though and a pretty neat car.

My roadster is coming along, still think that I will get it on the road before summer,(I HOPE!!) and then drive it to B'ville with my son in Aug. As I always say, its only time and money that keep me from finishing.


Rex