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Author Topic:   spring cups
Whitelightning
Member
posted January 01, 2003 08:14 AM
How Much do you cut of a afco spring cup that goes on the front of a metric monte carlo with the 9 1/2 inch springs? I finally got them just want to install them right. I heard that the lf needs to be about an inch shorter but dont no where to start. Thanks for all the help yall are great.


Eljojo
Member
posted January 01, 2003 09:11 AM
Where to start? IF..you know anyone who will loan you a set of scales, start by borrowing them. If not, at least take the car and get it weighed, so that you know that you are at at least the minimum your track allows. Fill up the fuel cell..
Then..put the car on jackstands and remove the existing springs. Get out your jig saw and make yourself about a dozen temporary shims out of some scrap plywood (use 1/2" and 3/4") These will look like a doughnut about 7" on the outside and 5" on the inside.
I'd start by setting 1 1/2' inches of shim on top of the front springs and 2" on top of the rear springs.(using the 11" rear spring)
Leave the shocks off, it will save you a lot of un nessecary work. Set the car back on it's wheels and air the tires you plan to run up to racing pressures. Put enough ballast in the seat to simulate your drivers weight. (3 chevy cranks and an old battery=ME)
First things first- you'll want to set the ride height. I like to set the front right an inch higher than the left and the rears an inch higher than the fronts. This gives the car an inch of "rake" right to left and an inch front to rear.
Place a small piece of angle iron (about 6" long) with the V up on the jack pad of your floor jack and slide it under the differential housing. That will let the rear end tip from side to side as the car is raised. Slowly jack the rear wheels off the floor and note the relationship of the RIGHT tire at the point when the LEFT is slightly raised to clear the floor. This measurement is called "wedge" or "bite".
You're going to have to make a judgement call at this point. "What kind of track am I going to run?" Lower banked tracks or ones that get really slick will require less wedge than high-banked or very tacky tracks will. I wouldn't start off with less than 3 1/2" of bite. I run a VERY high banked clay oval and wouldn't run less than 6" of bite. You can run more bite if you drive waaaaaaaaay on in, don't use a lot of brakes, and let the car take it's own "set". If you feel like you need to drive the car around the corner or can't drive in deep your car will push with too much bite.
Why don't you start with about 41/2 inches? You may have to change the shims on all four corners of the car before you reach the desired wedge. Go a little at a time, a half inch here and a half inch there cris-crossing the chassis either removing or replacing shims. You don't want to change the ride heights too much so just take a 3/4" shim out and put in two 1/2"ers.. get the picture?
When you've got the wedge and ride heights BOTH where you want them, take your new spring spacers out of the box and get a new blade for your hacksaw. Measure each of the temporary shim stacks and cut the shim to duplicate them.
If your car is LOOSE on corner exit, take it back to the shop, get out your temporary dough nuts and repeat the process, putting a little wedge back in. If your car doesn't want to turn under acelleration, take a little wedge out.
Wedge in-more bite--right rear higher off the floor before the left raises off--tightens the car
Wedge out- left off less before the right leaves the floor-frees the car up
You weren't looking for someone to say "cut an inch off the right and an inch and a quarter off the left were you? Give yourself time to do the job right, you'll be much happier with the results!


dean_7585
Member
posted January 01, 2003 09:35 AM
I usually start by cutting off about a 1/4 inch of coil off and then put it in and hook everything back up and check your ride height. keep doing this untill your happy.takes awhile, but safer than just hacking up your new spring. Don't tourch it!! Use a saws-all or grinder.
Good Luck


Whitelightning
Member
posted January 01, 2003 09:42 AM
will the afco stock shocks work wit the 9 1/2 inch springs and spacers


justin
Member
posted January 01, 2003 04:30 PM
I did have some trouble w/ my camaro when I used the 9 1/2 spring, the spring cup, and an AFCO 1022 shock on the right front. The shock did rub the cup a little but it was easy to fix w/ a sawzall.

Justin

Whitelightning
Member
posted January 01, 2003 04:33 PM
where was it rubbing and could you tell before racing it


awkwardjeff
Member
posted January 01, 2003 04:39 PM
the simple answer.......1 1/2 above the flat that the spring sits on.....that's where I cut the cup for the left front. For the right front I use 2 inch, above the flat for the spring.......

I tack weld these into the bottom of those little fingers that are left in there from stock.

The will build wedge into the car......If you are updating a existing race car that didn't have cups in the past.......you should make a few measurements before you take the car apart..........THE CHASSIS MAY HAVE BEEN BUILT WITH A TWIST.....to create wedge......only you can answer that.....

if the chassis was built with a twist to add wedge the spring cups will need to be cut off equal to keep for adding too much wedge.

I hope this makes sense

[This message has been edited by awkwardjeff (edited January 02, 2003).]

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