Spring Rate Suggestions for '68 Camaro

[Mkelcy]

Originally Posted by Sieg

How many miles on the suspension? There is a break in period for springs, shock seals, and bushings. Subtle but still a factor. Another factor is personal perception, what are you used to driving or what are you comparing it too?

Fair questions. Perhaps 200 miles on the suspension.

I'm comparing it to '68 Camaro with 550lb./in. front springs and 200 lb./in. composite rear leaf springs

[Sieg]

Originally Posted by Mkelcy

Fair questions. Perhaps 200 miles on the suspension.

I'm comparing it to '68 Camaro with 550lb./in. front springs and 200 lb./in. composite rear leaf springs

Lighter motor in this one?

Brake packages similar?

Overall car weights?

[Matt@BOS]

I would guess that it is more shock than spring related. If you start to drop rates you might end up with a car that wallows a bit and bottoms out over dips in the highway. I've upped rates 100-150 lbs all around on my DSE suspension, and upgraded shocks. It rides better than with softer springs and the original non adjustable Koni/Afco shocks.

My first suggestion would be to gas up the rear shocks in case the rear is getting rattled around over bumps, without much shock control.

If that doesn't fix things, you may want to swap shocks. Trust me, in the long run you will have less headaches. My Afcos always leaked down and the verishocks seem to blow seals, and, in my opinion, they don't ride amazingly well, either. Please don't take this as an agressive sales pitch, or attempt, (I have a small fortune worth of JRi shocks and work with JJ all the time) but the fastest way to get your car driving down the road with the ride you are looking for would be to call RideTech up and get a set of their shocks. Their Ride Quality and Handling Quality series of shocks (hope I got those names right) flat out work the way they should. The cars I've driven with them ride so well I don't even think about the suspension. The ride is smooth, solid and pretty composed without clunking over bumps.

Bret/Rod please don't ever let that end up as a testimonial on your website, accompanied by that picture of my car under the Fox awning at Laguna Seca. I will get in trouble.

Matt

[Sieg]

^^^Agree. The spring rates don't seem aggressive at all, the unknown is the shock valving and without dynoing them it is blackmagic. That said, Ride Tech's shock offerings are one of the best reasonably priced pro-touring oriented shocks on the market.

[Rod P]

Originally Posted by Matt.A

the fastest way to get your car driving down the road with the ride you are looking for would be to call RideTech up and get a set of their shocks. Their Ride Quality and Handling Quality series of shocks (hope I got those names right) flat out work the way they should. The cars I've driven with them ride so well I don't even think about the suspension. The ride is smooth, solid and pretty composed without clunking over bumps.

Bret/Rod please don't ever let that end up as a testimonial on your website, accompanied by that picture of my car under the Fox awning at Laguna Seca. I will get in trouble.

Matt

Oh no...I would never do that........ ....but its gonna cost ya!

[David Pozzi]

I entered the measurements from my Morrison sub into the Ride Tech calculator. The Morrison sub is nearly the same as the 21'st century using the same lower control arm and nearly the same shock angle.

Ride Tech Calculator:
Cruiser/daily = 375
Perf driving = 425
Racing =450

Mary has been running the 350 rate since last fall.
James has 425 on OLC and it's doing very well. With the Ride Tech shocks set at mid-range, the car rides great on the street.

We had some indication of hitting the bump stops on Mary's car when she tried lower shock settings. So we will be trying some stiffer front coils. I think if you have a more streetable ride height, the 350's will work fine, but I'd turn the shocks up for an autocross.
FYI, Morrison runs/ recommends a 450 front coil on their 69 Camaro.

[Mkelcy]

Originally Posted by David Pozzi

I entered the measurements from my Morrison sub into the Ride Tech calculator. The Morrison sub is nearly the same as the 21'st century using the same lower control arm and nearly the same shock angle.

Ride Tech Calculator:
Cruiser/daily = 375
Perf driving = 425
Racing =450

Mary has been running the 350 rate since last fall.
James has 425 on OLC and it's doing very well. With the Ride Tech shocks set at mid-range, the car rides great on the street.

We had some indication of hitting the bump stops on Mary's car when she tried lower shock settings. So we will be trying some stiffer front coils. I think if you have a more streetable ride height, the 350's will work fine, but I'd turn the shocks up for an autocross.
FYI, Morrison runs/ recommends a 450 front coil on their 69 Camaro.

Thanks David. I ran the Ride Tech tool (nice job there, by the way) and came out in the low to mid 300's depending on shock travel. My car's not down in the weeds (my LCA's are essentially level with the ground), so I should be okay at those spring rates.

The 350 lb./in. springs came in today, as well as the nitrogen setup for the rear shocks. I'll get everything installed, drive it and see where I am. It's quite possible that a new set of front shocks are in the cards.

I have tell tales on the rear shocks, which are about 1" to 1.5" from bottoming out.

This car is primarily a long distance tourer that's supposed to be fun on curvy roads; it's not focused on auto-crossing or HPDE.

[bret]

Keep in mind that our spring rate calculator provides a starting point...rates can be tuned to satisfy a particular car, driver, tires, swaybar, shock set up.

We worked very closely with Hyperco to develop this tool. They've been building springs for awhile. We took their lengthy and complicated engineering algorithms and translated them into a tool that most of us can understand. We've found it works pretty darn well. If we get a car that is on the extreme fringe for weight or traction sometimes it can miss a little, but such cars are typically serious track units that are subjected to an appropriate amount of tuning anyway.

The other cool resource we've developed is the huge library of vehicle weights that we've gathered over the last few years. http://www.ridetech.com/tech/coiltech-2/

If you take a look at that library I'm sure you will find a combination that is darn close to yours. This will save you the trouble of finding a 4 corner scales for your own car. Then all you need is a tape measure and the discipline to use it!

[Mkelcy]

Thanks for the suggestions.

I've got a nitrogen fill setup on the way. When it gets here, I'll get a bottle from the welding gas store and gas up the rear shocks.

I also heard from David Pozzi who's tuned Bad Penny, which has the same front and rear suspensions I'm using, as well as the One Lap Camaro, which uses the same rear suspension.

David's suggesting I leave the rear spring rates alone for now and drop the front springs to 350 lb./in. He noted that 350 lb./in. springs in the 21st Century Street Machine subframe would be equivalent to a 600 lb./in. spring in a stock subframe, which suggests that the 450 lb./in. springs in there now are the equivalent of a 770 lb./in. spring in a stock subframe. In any event, I'll swap out the front springs, leave the rear alone (other than gassing up the shocks) and see where I am.

I'll consider shocks if I can't get it where I want it any other way, but springs are about $70 a set, and gas charged shocks (which I need because they're mounted upside down) are going to be $400-$1,000 plus a set.

[GregWeld]

FWIW -- I had QA1's on my Nomad --- and switched them out to Strange... which is what Art Morrison uses and sells on his chassis... it was like I built a completely different car... Until then - I had no idea a shock (really a damper) could make that much difference!


The Nomad ran coil overs all the way around.