Coil over adjustments

[chasefrehley]

Is there a website or a book that a person can get to learn what 1 turn down on the RF actually does to the chassis and what effects it will have on drive?

Taking 1 turn off will soften the effects of the RF spring but by how much? And what other aspects will happen?

Not just the RF but what will adjusting the other springs do? I know the car works on angles but how does a person learn this if testing is not an option and trial and error has run out?

[Kromulous]

Your talking effects on the track, 1 turn in / off the RF or wherever, and then go drive it?

Yes, leaning that stuff is an up hill battle, you get very little track time and thats the determing factor of whether the car is set up correctly or not.

Essentially you could be a couple turns here and there from winning, and never know.

I have said it before, and will again but renting a track and testing for a couple hours is well worth the money. Even for a low budget guys.

[chasefrehley]

I have the chance to go test but work comes first.. Racing is my hobby but with that being said I want to learn all that I can so I can perform at my best.

Yes, My question is what are the effects of adjusting the coilovers say 1 turn in here and 1 turn out and then go out and run a heat or hot lap session.

My car would not get over on the RF at all so mid corner on throttle it pushed up the track, I had a friend who works for a wOo driver tell me to take 1 turn off the RF because I did not have a softer RF spring.

[Kromulous]

Well just thinking out loud, but one turn (.100 per turn, usually, depends on the shock) you would take 30lbs of load off the spring, if it were a 300lb spring. Now, thats just a rough hack at it, is it actual? no idea.

So depending on your spring, just take 10% of the number.

So that should give you some idea what you adjusted, but to think about it on the track is another. In my mind i think about this, say the load on the spring at ride hgt is 450lbs, RF, so in order to compress that spring at all it has to see 450lbs min. In order to travel 3" you start with the 450, and add 3" of travel of a 300lb spring, so thats 300lbs per inch of travel thats 900lbs. So in total thats 1350lbs of force will have to be generated by the chassis and the CG on that spring / coilover assy to realize that 3 inches.

This is the use case of a spring smasher. You can determine the per track lbs number you need to be at in order to see the X amount of travel. Plus it will change as the night goes on, slick track the number obvously goes down because the traction level of the tire decreases.

Now keep in mind, all these numbers are generalizations, very broad.

Anyone, see an error in that logic? Don't want to give false advice.

[billetbirdcage]

To be honest with ya, 1 turn out of the RF is probably more of a placebo pill for the driver more then anything...

Most people couldn't tell you did anything to the car, if they was being honest or wasn't imagining things, IMO.

[Matt49]

I agree with billet. That being said, adding or removing a quarter inch packer from the bump stop could make a huge difference.

[CCHIEF]

I like clanking some wrenches against the frame and interior tub from underneath, and telling the driver it's going to be so good. Drive it down deep to the center of the corner. Without changing a thing, I've got him to drive it the way it should be. Then your hear" Man whatever you did really put this thing on a rail"......big grin!

[7uptruckracer]

Best tuning tool ever! Deception is worth tenths!!!


I like clanking some wrenches against the frame and interior tub from underneath, and telling the driver it's going to be so good. Drive it down deep to the center of the corner. Without changing a thing, I've got him to drive it the way it should be. Then your hear" Man whatever you did really put this thing on a rail"......big grin!

[MasterSbilt_Racer]

I agree with billet. That being said, adding or removing a quarter inch packer from the bump stop could make a huge difference.

I once had a guy tell me to "really wedge up the bumpstop and make it push". I added a .25" shim. After he went from a perfect car to pushing, he didn't believe that was all I put in. Lol

[hucktyson]

MB considering that the next 1/16” of travel can increase the load a 1000 plus pounds as a certain point in the travel a 1/4” shim is enormous .... I’m
Not an “ engineer “ though so my eyes while watching a coil loader might be lying to me ...

[hucktyson]

1 turn off the RF isn’t going to be noticeable unless you were 1/16” off where the bump stop goes solid and that turn made you hit that point

[hipower17]

at this point of the post mr.kennedy should come in with his comments, waiting.

[chasefrehley]

So instead of taking turns off the RF every weekend, I changed my spring to a 300 from a 350. My intentions are to get over on the RF harder, and stop the throttle push mid corner. I run the med tree type bump stop, it's yellow with the red stripe.

[MasterSbilt_Racer]

I don't like to be operating at that point on the curve, Huck, but yes it can.

[7uptruckracer]

That's about how I have this Penske Red Stop 4" pin to pin is like 250 an extra 4.25 is like 400 total, 4.5 is 550ish roughly but from 4.5 to 4.75 it going to 1,00 to stop travel normal operation will have it around 2700 ish max out would be around 3100 I accidently forgot to remove two 1/8 dividing washers and wasn't watching the smasher load numbers just my pin to pin and looked down and when it was reading 3700 and grunting really bad i about fell over lol


I don't like to be operating at that point on the curve, Huck, but yes it can.

[Matt49]

So instead of taking turns off the RF every weekend, I changed my spring to a 300 from a 350. My intentions are to get over on the RF harder, and stop the throttle push mid corner. I run the med tree type bump stop, it's yellow with the red stripe.

Without knowing how far you were traveling with the 350 and what the dynamic number was, you're completely guessing with that spring change. Trust me, I learned the hard way...without a spring smasher, you're doing a TON of guess work trying to run bump stops or any variable rate system for that matter.
Directionally, you are very likely doing the right thing by softening the spring but whether or not you should be going to 300, 325, 275, etc.
It could be that all you need is less compression in the RF shock to get what you need or just to take packers out. Plenty of ways to do it.

[Kromulous]

I think he needs some more basic help. Sounds like he is just starting out.

Anyway, softening the right side springs is a basic adjustment. Also moving the J Bar, down on the pinion side. Then maybe bar changes, LR upper, move up. Compression out of the right side shocks, and you can add some rebound to the RR, and take some out of the RF.

I say try the 300, when the track is cleaned off, and maybe take a little compression out of the RF shock.

What shocks are you running?

[chasefrehley]

Shocks are non adjustable Genesis gas bulb shocks. I have an Afco silver series double adjustable on the RF so I can get some adjustments.
I am new to the late models, this is my 5th race in this car. I was in a modified before and did not need to know this due to the rules package.
Now I'm trying to be like a sponge so I can make myself more competitive, not set the world on fire...
I have tried the basic bar angle adjustments which do help but I'm trying to learn what the "advanced" adjustments do to my car. I have an 06 Rocket Black Front. New RF 300 LF 550 LR 225 RR 250 My thoughts are to go softer on the rear 225rr 175-200 lr

[CCHIEF]

I doubt the AFCO silver series is even in the ball park with rebound dampening for a bump stop setup. I'd steer clear of bump stop deal for a novice to late models...without a load rater...and what to do with it.

[Kromulous]

A lot of Mod guys i notice they want to get a car "Set up" and call it good, and that works to a degree but with a SLM as your finding out is a constant chase or a constant tune to stay on it or with it.

I hated the Black front Rockets, you have to drive them very hard to get any speed out of them.

Anyway, yep softer as the night goes slick. Work with your J bar and get used to how that feels. Lower on pinion side etc.

Envy can tune them AFCOs for a bump stop, we run the blue ones with Penske valves, there fine when set up right or get an Integra mega RF, that will keep the nose down for sure.