Dirk Miller

I track my ’08 C6 that still has the original magnetic shocks. 3 years ago I put on Pfadt’s sway bars and really experienced a positive difference in cornering. Now I am considering coil-overs. In addition, I run A6 18” Hoosiers all around. One friend of mine who coaches at our local tracks here in the Bay Area has the same liquid metal shocks on his '07 and loves them. Today’s current Z06 models all have these same electronic shocks,so is it worth it to remove the leafs and go with the Feather Lights? I realize that removing the leafs will lighten the car and that is a good thing. Just wondering if anyone else out there who has done this could chime in and describe the differences.

Dirk Miller

Since I have been a big supporter of Phadt products, I will first consider theirs. However, if anyone has had this experience going from magnetic shocks to any coil over, please chime in a let me know what the outcome has been for you.

Pfadt Racing

Hey Dirk! We do have plenty of folks who have moved from their Mag Ride shocks to our Coilovers. TMeyers is the best example I can think of on CorvetteForum who has made the switch. You can see his impressions here: TMeyers moves from F55 Mag Ride Package to Pfadt FeatherLights

The car will become a little more aggressive over bumps, but overall the control you have over rough road surfaces and the predictability while on track make this a very worth while upgrade! The F55 Mag Ride setup is really neat, but for track use you're going to see an increase in performance not only because of the way the shocks are valved, but the overall increase in spring rate as well. You could probably PM Terry and see what his thoughts are as well.

froggy47

Do a pair of coils & hardware weight less than a composite leaf? I don't know & am just asking so facts can be made clear. Those leaf's are pretty darn light weight.

Just askin.

Got numbers?

Since the leaf is bolted to the sub frame it's not counted towards the unsprung weight on each corner right?

What are the coils, the same or do they add a certain % to unsprung weight.

Just learning.



I know coils are super easy for ride height adj & easier to change than leaf.

Must be some benefit to leaf?

jd86L98

Good questions

geerookie

First thing you have to remember when comparing weights with coil-overs........It's not just the weight of the composite springs which are lite.
You have to consider the shocks and the mounting hardware which do partially count towards unsprung weight.

I don't have actual numbers for the featherweights but it is about a wash give or take less then a pound per corner.

My rule of thumb is to count 50% - 60% of the coil-over weight as unsprung.

froggy47

Thanks for the post geerookie.

Shocks count of course and all the other stuff. I always figured shocks as a wash whether in a CO setup or leaf setup, gotta have them and they attach the same & count 50% to unsprung. So the rule of thumb is.

It seems theres a bit more hardware to to CO setup. Ole Mr. spring just sits on the LCA and attaches to the sub frame, not a lot of hardware there.

I've never installed CO so I don't have intimate detail to how they go in.

It just occurred to me that so far as weight I don't think CO wins that unless the coils are CF or some other exotic.

Just like to have discussions using facts as there is so much hyperbole on all the forums regarding performance upgrades.

I would love to see one of the companies who sells them list a side by side comparison plusses & minuses of the two systems.

redtopz

I have coilovers on my ST2 car and leafs on my T1 car. I would say they are both great setups. If you are going to the trouble to change to stiffer springs and new shocks, then I would recommend getting a coilover package from one of our supporting vendors. The benefits include the ability to cheaply and easily change spring rates if you want to down the road. And it makes working under the car easier without the leaf springs in the way. I don't think the weight difference (if any) is going to be significant enough to make any difference in performance.

froggy47

One thought occurs to me, that , if you go CO I think you are buying into that vendors shock pkg, unless you go to some amount of trouble to modify another vendors shocks to attach into the coils.

OTOH with springs you go with any shock vendor and it's easy to change to a diff shock pkg.

Unless I'm wrong and ALL CO systems have exactly the same shock attach points.

redtopz

They do. They use the stock attachment points. Most of them also use the same coil spring sizes. If you change shocks with a coilover system, you might as well sell your old coilovers to someone else and start over.

Pfadt Racing

Hey guys, before we head out for the 4th let me make a quick post on this:

Lighter, Stronger, Faster. If you're looking at one specific feature, like weight savings, it's tough to quantify faster lap times or better engineering through one specific feature. The cumulative effect and how the entire product works together is where your significant gains will be found.

Generally coilover packages mount at the top and bottom in the same locations, but our BOA upper mounts work very differently from other clevis or pin top style upper mounts. The BOA upper mount allows us to effectively package the upper mount, while still allowing for a really wide articulation range, and design more shock stroke in at the same time.

We will be revisiting this thread when we get back on Thursday!

sperkins

I installed a new set of SA Featherlites last week on a customer's car and was absolutely amazed at the articulation that the BOA upper mounts provide.

Here's a crappy video taken with my phone, but you can clearly see the range of movement.
Click on the picture to play video.



http://s69.photobucket.com/albums/i5...t=d0820e97.mp4

Cobra4B

I need those... steal them from Khoi when he's not looking.

froggy47

I have something like that (from Pfadt) on my pin top Pfadt shocks.

meldog21

When I swapped my C5 leafs/shocks for Pfadt coil over shocks I got a 10lb savings in total weight including brackets/bolts. So my weighing the components appears to be within a pound of your weighing.

Savings a (very) few lbs might help slightly with acceleration and braking, but moving the weight you have out toward the wheels probably has an equally negative effect.

So although total weight is reduced 10lbs I considered the weight difference as zero benefit.

The ride and handling difference of changing the suspension from stock C5 Z06 suspension to the Pfadt coil overs was definitely beneficial.

Dog

97coupechuck

be prepared to lose your nice street ride as CO's are really stiff. When I changed over the car became track only for me.

Racingswh

Does anyone have any lap time comparisons with only the change to CO's?

I have never done anything as smart as change just one thing at a time to see how much actual difference it makes.

TMyers

Now that I am back from vacation I will chime in.

Going from the F55 system to coil overs takes a bit of work and you need a shop that knows what it is doing to defeat the system but it is not really hard. I don't know haw far you are from Abel Chevrolet but they have experience in doing this. I did the R&R myself, took about 4 hours and had a local shop remove the ESM, jump the LAN wires and remove the option from the computers.

What drove me in this direction was an HPDE I attended last year as well as I hit the limit in what the car would do in autocross. At Portland International Raceway the front straight is around 140mph slowing down to a 35mph chicane. The first time I went through there it felt like I was picking the rear wheels right off the ground. The nose dive was down right scary. The other problem in autocross is the slalom, way to much nose dive, car lean and slow to react even with a bigger sway bar.

Anyway, the difference is night and day. Brake dive is virtually gone. The car reacts almost instantly to my inputs making slaloms a blast. We have 4 or 5 guys I consider very good in our autocross group, corvettes only. Last race I took 3rd overall out of all groups. My car is stock except for suspension work and I am on R888's which are not really an autocross tire.

On the street the ride will be firmer and with good roads the car rides great. If you have rough roads though and drive the car daily I would suggest you find someone that has them and get an idea what you are getting into. You can adjust the dampening though and make it bearable.

All in all this is a big step up from the F55 package. Even on twisting mountain roads that are not perfect the car stays planted and does not exhibit any of the skittishness the base and Z51 suspensions do. If you want to get more out of your car and still keep some street manners this is the way to go.

Dirk Miller

Can I hear from more of you who can spell out the benefits coil overs have over magnetic shocks other than possibly saving a few pounds? I drive my car on the local road courses here in the Bay Area and want to know more about the handling benefits I would experience if I change out. Because we have so much power, I don't mind when a friend rides with me as a passenger and adds an additional 175 lbs. What specific track handling characteristics will be found if these are swapped out? Again, a new Z06 has magnetic shocks and why hasn't GM changed these over to coil overs? I know bean counters often get their way, but what really is up here?

TMyers

I will give it a try. Since you and I have the same car it should be an apples to apples comparison. Mods to my car prior to putting the coil overs on where poly bushing and Z51 sway bars running R888 tires.

With this setup the car was pretty neutral when driven at 80%. Trying to drive at anything higher and problems started to creep in. First and IMO the biggest problem was brake dive. It was so bad at times it would drag the front air dam. Second was turn in, slow to set and excessive body lean. Last was exit, pickup the throttle a little to early and it induces over steer and could be very snappy with to much throttle.

Jump forward to this year and the coil overs. First the car is lowered all the way around, approx .5 inches up front and 1 inch in the rear. This tends to shift weight towards the rear of the car getting closer to 50/50. Second brake dive is virtually gone. In fact no matter how hard I brake I can't hit the air dam. Body roll is much reduced and the car sets the corner very quick. If anything there is slight under steer on turn it if the corner is very tight. On exit the car is great, I can pickup the throttle and the car just goes.

Here is a video from the last autocross. I hope it works.