Ridetech Triple Shock Tuning [Archive]

tgrace85

05-24-2015, 10:18 AM

Hey guys,

A year or so ago, I decided to build a 1970 Camaro for autocross and road racing. Having little to no experience in the sport, my goals were to build a capable car that I would enjoy driving, and have the performance and tuning abilities I could appropriately use as I gained more experience and became a better driver. The car is fully spec'd with the Ridetech level 3 coil over suspension package, wearing 275/35R18 and 335/30R18 BFG Rivals, also adding a Hotchkis rear swaybar. The car puts down 400hp/tq at the wheels from an LS2 and runs a Wavetrac diff.

I participated in my first autocross last weekend at the Nashville Goodguys event and my first road course track day yesterday. I got a lot of good advice in Nashville (with special thanks to Rod Prouty) had a lot of fun, and put down a time I was proud of.

The help I'm looking for today deals with road course driving. Although overall the car and I did well, I feel like I left a lot on the table. The two main issues were: 1) lots of under steer in hard cornering, and 2) the rear tire on the inside of a long fast turn would lose traction and spin like crazy.

So, what can I do to try to counteract these problems? I would expect I could "tune out" a lot of this with proper shock adjustment, but I admit I don't really have the know-how to use these nice shocks to my advantage. Any help would be very much appreciated!

Oh, and I'm aware that it's possible I'm just not driving the car correctly. Feel free to offer any advice on that subject, too. I promise you won't hurt my feelings.

Rod

05-24-2015, 01:04 PM

2nd gens are nose heavy keep the full tank full to keep the car better balance...fuel is the biggest help in keeping the car balanced...perfect example is my car is built 51/49 balance with driver and full tank...with the tank empty in Nashville the car was loosing traction on the inside rear as you stated, once I filled it full and came back to the track the car was 1.2 seconds faster, and then I swapped the front roll bar for a softer front bar and the car ran 51's on Sunday just hundredths away from a 50 second run which would have won it Saturday....i was rusty I haven't raced since sema last year..7 months...

you didn't look at my website to tune your car did you??...........ok here is some basics that will help and there's more on my site.....Autocross101 shock tune (http://www.auto-cross101.com/Shock_Basics.html) you can look at the site...the info has been on the my site for about 2+ years now...

Compression

The compression control side of what the shock does resists:
1.The bump movement of a corner of the car when we hit bumps (rises in the track).
2 The movement due to the transfer of load to the front end during braking/deceleration.
3.The movement due to the transfer of load to the rear upon acceleration.
4. And the speed at which the springs compress when the lateral forces are applied as we deviate from a straight line and turn.

Rebound

The rebound control side of the shock dynamics resists the following:
1.Rear chassis rebound vertical movement on deceleration.
2.Front chassis rebound movement on acceleration.
3.And side rebound (in some cases, but not all) vertical movement caused by load transfer as we negotiate the turns.

to much?

Here's is a current script of the Fox/Ridetech triple adjust units that I use now........

Rebound Adjustment

The rebound adjuster effects low speed chassis movement on corner entry (rear shocks) and exit (front shocks) and also the wheels ability to track the ground over high frequency ‘cobble stone’ or rippled type of surface undulation.

As a rule of thumb it is advisable to only use just enough rebound to get the job done.
Excessive (too slow) rebound adjustment compromises traction due to not allowing the wheel to follow the undulations in the ground.

I would suggest tuning this adjuster first, staring 18 – 20 clicks out (from full clockwise) and adjusting in 3 clicks at a time until the driver is happy with the stability of the axle the shocks are fitted to and traction is not too compromised.

Compression Adjustment

The compression adjuster housing is split into two distinct circuits: high speed compression and low speed compression

High Speed

High speed control As we experience the greater velocities of shaft movement, we go into what is called high speed control with shaft velocities of from 5 to 10-plus inches of movement per second. Types of suspension movement that cause the higher shaft speeds in our shocks are:
1.Bumps or holes in the racing surface (creating very high shaft speeds).
2.The driver stabbing the brakes on entry and hard on the throttle on exit.
3.Or a sudden change in banking angle, such as transitioning from banking onto the apron of the racetrack.

The main high speed circuit is adjusted with knobs or a 17mm or socket/wrench.
This adjuster controls the high speed flow of oil into the reservoir.

Its function is twofold, primarily it is used to stop bottom out on rough tracks and should be increased as track conditions deteriorate - secondly it has some effect on traction, mainly in high speed/high grip, dry conditions when the vehicles corner exit speed is high and/or the corners are quite rough.
Increasing the high speed adjuster will increase grip in some high shaft speed situations, if this is detrimental, the low speed adjuster can be softened to reset the overall balance.

I would suggest starting with this adjusted to 12 clicks out from full stiff and adjust from there.

Low Speed

Low Speed Control, Low-speed shock movement is defined as shaft speeds that are between one to five inches of movement per second. These lower speeds are mostly associated with suspension movement caused by chassis roll and chassis dive at turn entry where the loss of speed is moderate. The low speed control dictates much of the handling side of the shock design and racetrack performance gains related solely to chassis balance and load redistribution.

Its function is primarily to control tire load at low shaft speeds (normally start line and corner exit).
This adjuster is the primary control for traction as track conditions change; in dry high grip conditions, it should be screwed in for more traction and in wet weather and low grip, screwed out.