darguy

Hey Gang,

Finally got some time to work on the '99 FRC yesterday and got the control arms removed (for Delrin bushing installation). The plan all along was to install SKF hubs and do a brake upgrade while everything was apart. But, now that I'm that far into it there are more obvious things to be done...

1. Ball joints: car has 130,000 mostly street miles & is a dedicated track car now. I'm thinking that while the spindles are out, now's the time. Who do we like for replacement ball joints?

2. Sway bar bushings & links: I've got the Z-51 suspension and am leaning towards keeping the bars for now & getting good links & Delrin bushings. Suggestions for end links, or am I wasting my time with the stock bars?

3. Spring mounts & adjuster ends: Is there any point to changing out the rubber mounts that hold the transverse leaf to the frame (and is the spring under tension by these mounts - that is, will I kill myself if I undo them without any special tools?). I see Hardbar has an end kit, not sure if this is for the front or rear - and if there is a manufacturer for the other.

4. Rear toe adjustment rod (what's it called?): again, 130,000 miles - should I do this while it's apart & is this a service part, or is there a more track friendly alternative out there?

5. Shocks: I'm pretty sure these are stock. In my class, I can't use coil overs or anything with remote reservoirs. I'm thinking of a set of Penske 7500/T1 non-adjustable shocks, but I haven't done tons of research on this - they'll need to work well with the Z-51 springs. Thoughts?

Thoughts & comments always welcome!

CHJ In Virginia

Please give us a little more info to go on. What is your intended use for the car, what group do you run with, and what class are you running in ? Many of the choices depend on what rules and regs you will be operating under. In general, fix it all and make all the mods while you have it torn apart - budget allowing of course.

travisnd

1. Ball joints: car has 130,000 mostly street miles & is a dedicated track car now. I'm thinking that while the spindles are out, now's the time. Who do we like for replacement ball joints?
I bought my car in 2010 with 119k street miles on it and prepped it into a dedicated racecar. Still running on the original balljoints. They have no play in them at all. If yours won't move laterally in the socket then they're not worn out. In the five C5s I've owned I've never had one go bad. Pfadt makes a trick replacement lower balljoint, but they're expensive. I think moog makes an OEM quality replacement for uppers and lowers available on Rockauto.com.

2. Sway bar bushings & links: I've got the Z-51 suspension and am leaning towards keeping the bars for now & getting good links & Delrin bushings. Suggestions for end links, or am I wasting my time with the stock bars?
I like Powergrid enlinks. I use them with my T1 bars. They're an OEM-style sealed end so they don't clink and clank like a heim-joint. Also, I found that my original T1 endlinks didn't have adequate range of motion and the bearing races were getting beaten and bent. They clinked and clanked a buch. The Powergrids are silent and since they're reverse threaded on one end, you can adjust the link's length w/o disconnecting one end. Since I run T1 bars I use the poly bushings that come with them, don't know who makes delrin ones for stock bars, but lots of options for poly including Pfadt and VB&P.

Powergrids...


3. Spring mounts & adjuster ends: Is there any point to changing out the rubber mounts that hold the transverse leaf to the frame (and is the spring under tension by these mounts - that is, will I kill myself if I undo them without any special tools?). I see Hardbar has an end kit, not sure if this is for the front or rear - and if there is a manufacturer for the other.
Never heard of anyone swapping the OEM monoleaf mounts. www.ls1howto.com has a good tutorial for swapping springs. You need to undo the upper control arm and the shock to let the tension off the spring before unbolting.

For spring adjusters you can get more accurate alignment and corner weighting results using delrin adjusters. Hardbar makes a nice set for the front. Forum member Drivinhard makes a nice set front and well as well. I have the fronts, but never seen any need to do the rears.

4. Rear toe adjustment rod (what's it called?): again, 130,000 miles - should I do this while it's apart & is this a service part, or is there a more track friendly alternative out there?
Again... 119k on my car, 122,xxx now, 3k all track/race miles and no issues with the rear toe-rods. No issues with the front tie-rods as well. I do keep the ends wrapped in DEI cool-tape to keep heat off the joints


5. Shocks: I'm pretty sure these are stock. In my class, I can't use coil overs or anything with remote reservoirs. I'm thinking of a set of Penske 7500/T1 non-adjustable shocks, but I haven't done tons of research on this - they'll need to work well with the Z-51 springs. Thoughts?
Sky's the limit with shocks. Penske 7500 > most anything else. Many of us run OEM 2004 Z06 shocks due to the class we run in. They're the best C5 OEM shock by far. That said, there are obviously better options out there.

Good luck

PushinTheLimit

Darguy, I have some Koni 3013 adjustable shocks that I took off my car and have for sale. I used them with my T1 springs and T1 swaybars and they worked well with them. If you are interested, send me a PM and I'll give you some more info on them.

Bill Dearborn

I wasn't as lucky with my tie rods. In 6 years with my C5Z I changed both front tie rods once and both rear tie rods twice. I changed all 4 tie rods on my 97 once in 6 years.

To the OP. If I was looking at rear tie rods for my C5 now I would be considering ones like the tie rods that come on the C6Z51, C6Z, GS and ZR1. They have grease fittings and the owner's manual for the cars recommends greasing them after each track day. Must be a reason for that.

Bill

travisnd

^ Curious what the symptoms of failure were? How did you verify? I've never had one go bad. Always heard best way to test was to grab wheel/tire at 9 and 3 and shake quickly and check for play. On the front it can be harder since the steering rack/shaft will move when you move the wheel/tire combo.

darguy

Thanks for the feedback guys! I'm running in CACC IP class, which is kinda like SCCA IT, except I can do full brake upgrades providing my friction surfaces are cast & the original caliper mounting points are used. I can upgrade springs, shocks & sway bars as long as I don't change the type (no coil overs), and bushings are allowed. I've got some mega brakes on the way, so that's sorted.

My understanding has been, that springs/shocks/bars are usually done as a complimentary upgrade. I guess what I'm curious about is, is it worth me upgrading to better leaf springs (Z06, T1,?), and pick shocks & bars to go with those. Or, if the Z51 springs are plenty good, then work around that - would T1 bars still be the way to go, for example.

Is there significant handling to be gained with a T1 (or alternate) setup, and is it another quantum leap to go with coil-overs (and move up to GT), or is that more about fine tuning to different tracks?

I'll likely replace all the joints while it's apart - a few of the boots took some damage coming apart, and the peace of mind knowing everything is new will help on the high speed corners.

darguy

Well, it's all back together & track tested.

I'd like to start by thanking the CF community & supporting vendors for all the info, advice, PM's, emails, phone calls, and parts that it took to complete this upgrade. There were a lot of little details along the way, and it would have probably been impossible to do without your help.

I did all the wrenching myself, on jack-stands, in an ill-lit small garage without air tools. I ate some ibuprofen with my beer in the process, or at least after working on the car. With the exception of the alignment, which I ball-parked in the garage and then had dialled in nicely by a local race veteran.

Here's what it looked like in there, and coming apart:









Here's what got done in the process...

1. Delrin control arm bushings from Phoenix Pfm (new lower ball joints & tie rod ends in the process - everything cool taped), and Phadt camber/caster kit.





2. T1 springs and sway bars (by way of 2 CF members), and T1 shocks new from GM. Also, PowerGrid adjustable end links.

3. SKF hubs with ARP studs.





4. Performance Friction ZR31 callipers & 2 piece rotors F&R - which have 4-pads per calliper, very cool (by way of CF member).







5. Used scrubbed set of Toyo R888 305/35/18s (dry) (CF member) and a new set of Yoko A048 285/30/18s (inters), all on C5Z rears. Some Hoosier R6's are on my wish list, but they can't be had locally.



6. Setrab 'race' stand alone oil cooler kit from DRM.



One major snag: I couldn't get the rear axle nuts loose by hand (broke my 18" flex-bar in the process of trying), so I haven't installed the rear SKF/ARP hubs yet. Subsequently, I couldn't run the rear Performance Friction brakes (they require a 1/8" spacer for the C5Z rears to clear, and the stock studs aren't long enough - I found that out after hanging rotors & callipers). So, for the first race weekend I went with my existing rear setup, stock callipers & rotors, SS lines, and Carbotech XP10s).

One minor snag: When running the lines for the oil cooler, I figured the long one went to back of the adaptor & then ran out of length. That was after attaching them both at the filter and routing them by the block & over the spring (under the car in a half-situp position with a flashlight in my mouth - that would have been a good time for some alternate lighting). So, I had to re-route them (long line to front of adaptor & far side of cooler - FYI for the next guy installing this well put together kit).

Shakedown: After some post assembly fine tuning, I was ready for the 2nd to last race of the season. The car performed flawlessly – fade free braking, predictable handling, grippy, and temps within the normal track range. I, on the other hand, will require some more seat time to get used to the new setup. I'll do a full race report separately, but the short version is that I knocked 2 seconds off my previous fastest lap time within 20 minutes on the track. There is a bunch of time still to be gained, but now it's largely up to me & not the car. I'll try to get the rear brakes installed before the last race, and then give it another run!

0Louis @ LG Motorsports

I use safety wire Zipties will melt

Supercharged111

What exactly did you use to shield the joints?

waddisme

Sounds like a big project with awesome results. I also did the oil cooler install with car on jack stands, laying on my back, contorting, bending, bleeding. Hardest thing I ever attempted on my car. But, oil temps at VIR in July with ambient at 105*+, oil temps were 259* at end of session. Enjoy the fruits of your labor.

darguy

Cool Tape, from Design Engineering -> Link. That was the tip I got.

darguy

Yeah, that oil cooler install was a real workout. I swore a couple times, if memory serves. Works like a charm, though.

So, I got some time in a buddy's shop and got the rear SKF/ARP hubs installed and hung the rear Performance Friction brakes before the last race weekend. Much easier with air tools & a hoist.



For the record, here's the alignment results before I hit the track:



The brake balance was better than with the PF fronts & stock rears, it was much easier to control front lockup when going deep into the corners. Full write up on the last two race weekends to come, but I'm getting much more comfortable in the car, and in traffic.