Coilovers JRI /DSE , Ridetech etc How much spring preload are you guys using?

[CTSV]

Im throwing this out because i my car is sitting in the body shop ready for paint and the builder of my car just gave the front and rear about 1.5 of preload but my front nose is slammed to the ground as if the springs are too soft.

they told me it was getting very tight to get more spring preload and that the spanner wrench was hitting the control arm and the shock would need to come out. They also told me giving a coilover too much pre load is a bad idea.

my car honestly needs to come up almost 3 full inches.

the front DSE springs are 400lb and the shocks are JRI


id just like to hear some thoughts on this soon so i can relay this over to the shop.


my prior ridetech ta coilovers did mot have this issue at all but those spring rates were based on the original mustang geometry and were 750lbs. My new dse conversion is all GM C6 based and they are using 400lb springs.

[jerome]

What is the motion ratio and estimated front weight?

[dontlifttoshift]

Spindle centerline is plus or minus 1" from the top of the frame if I remember right. So a 26" tire equals 13" to the top of the frame plus or minus 1" at ride height.

Don't be afraid to preload the coilovers. The math is already done, you have the right parts, just turn up the adjuster until you reach a ride height that you are happy with within the parameter given above. You can double check those against the instructions.

[Ron Sutton]

Spindle centerline is plus or minus 1" from the top of the frame if I remember right. So a 26" tire equals 13" to the top of the frame plus or minus 1" at ride height.

Don't be afraid to preload the coilovers. The math is already done, you have the right parts, just turn up the adjuster until you reach a ride height that you are happy with within the parameter given above. You can double check those against the instructions.

I'm just adding to what Donny said.


You don't want to get into a coil bind situation, so check to see when you compress your front suspension fully ... what stops it ... shock travel or coil bind?

If it hits the bump rubber first, do you best to determine how much all the little spring gaps (between coils) add up to & post that info. (A photo would be helpful for everyone to see too.)

[CTSV]

Guys here is a photo of my front coilover loaded

The car is slammed down as if i had airbags and let the air out

There is only 1/2 inch travel between the bumpstop and lower control arm

You can see a little more than 3/8 space between each coil on the spring

You can see how much preload is on the springs via the collar


Do any of,you think i can get more preload from looking at the photo?

I can remove the unit and compress the assembly with my strut compressor to take the load off the adjustment collar but i never had to do this with coilovers


What can you guys suggest? It is driving me crazy

[IMPALA MAN]

Assuming we are talking front shocks, it looks like you have a few issues that need to be checked first.
1. I would begin with removing both front shocks from the front of the car.
2. Place a jack under the bumper or frame somewhere in the middle of the car from side to side.
3. Jack the car up until the car sits at the ride height you want it at.
4. Measure from shock mounting point to shock mounting point. (In your case lower control arm mounting point to frame mount).
5. Remove the spring from the shock. (You will only need to do this to one shock)
6. Take the shock and extend it all of the way and measure from mounting point to mounting point.
7. Compress the shock all of the way and do the same.
8. You will now have the extended and compressed lengths of the shock.
9. Compare this to the dimension you need at ride height (the one you measured in step 4)
10. Typically you want the dimension determined in step 4 to be close to the middle of the dimensions determined in step 8. Example: Extended 16" and Compressed 12". This would be a good shock for a 13.5" to 14.5" ride height vehicle.

Now to address the "Preload" you are referring to. There is only one way to "Preload" a shock. Let me explain.
Let's begin with a 500 lb. spring for example sake. A 500 lb. spring means if we put 500 lbs. on it, it will compress 1". every additional 500 lbs. we put on it, will compress it another inch.
If we set the 500 lb. spring on a jack, then place the jack under the car and begin jacking. Once the spring makes contact with the frame (as you are jacking) the spring begins to compress.
For example sake let's say the item we are supporting (the car frame where the shock is) with the spring weighs 1000 lbs. That means that once the spring compresses 2 inches, the item (car frame) will begin to raise up the exact same amount the jack goes up.
Now to "Preload". A 500 lb. spring compressed 2" with the weight of the frame (1000 lbs.) is not "Preload". "Preload" is created when you have the shock extended as far as it will go, then crank the adjuster nut and compress the spring without the weight of the car. In other words the spring has "Preload" setting on the work bench, without the weight of the car being involved. In some cases, springs are "Preloaded" for a given performance advantage. Unfortunately in your case, once the shock is all the way extended, you can crank the adjuster nut another 3" and the car will not raise up as the shock is as long as it's going to get. In order for your ride height to raise, the shock must extend more and it cannot as the shock is already extended. Just something to check.
If you have the shock all the way extended setting at ride height, you may want to get the manufacturers phone number handy for when the shock gets damaged, as it will after a few short miles.
Hope this helps.
Always remember this: Shocks and springs operate separate from one another an have two complete different functions.
Shocks DO NOT determine ride height. The simply control the movement of the weight of the car.
Springs determine ride height.
I would first begin with calling DSE and discussing it with them. They didn't earn the reputation they have by offering substandard products. They are a great company that makes and proves great products. I am sure they would get whatever the issue is, worked out.
Always remember that with shocks, an extreme change in ride height can make the manufactures recommendation need adjusting. I would get the ride height dimension you want, then call DSE. They will get you taken care of. OR PM me and I will be glad to help.
Shocks are one of things that seem simple and basic but leave many people scratching their heads. Just like brakes. Good luck and PM me if you need any additional help.

[67cougnut]

what was the outcome of this?