problems with new fx3 coil over - ZR-1 Net Registry Forums

rkreigh · 01-27-2009

to continue my saga. car rides like a buckboard milk truck even with the softer springs. I reused the 95 shocks off the car with 50K plus miles, and I suspect they may have at some time been revalved by larry with the moracca valving, or maybe one of them is bound up.
I went with the 400 front , 250 rear spring rates, which should provide a decent ride. I know the 19" GY F1 Supercar EMTs certainly don't help but the car rides WORSE that it did before with the stiffer coil overs so I'm suspecting a shock problem.
it's coming back apart. for now I'm going to put the softer springs on my older coil over setup, and send the shocks back to bilstein to be revalved. Randy at DRM advised the Marlin valving would work well. first time I've hear of that.
I also think the car might be bottoming out. I removed the stock "rubber biscuit's" at the top of the shocks and used the poly bushings from DRM, and also removed the stock rubber at the top of stock shock shaft (bottom out cushion) to provide more shock travel. maybe the shock is bottoming out internally?? the car is pretty low and looks great, so I'm going to raise it back up a bit to both provide more travel and lower the spring rates a bit.
so much for my expensive "upgrade" I'll need to eventually get the car realigned and corner balanced which isn't cheap.
sheesh, my c5 with coil overs rides like a cadillac compared to the ZR-1 but something is definitely wrong. ride is WAY stiff and jarring over bumps, not complaint.
I'm also checking to see if I didn't "over torque" some of the bolts causing the suspension to bind up. I replaced the stock dog bone control arm brackets with the drm camber brackets to hopefully get better traction and handling.
I'll keep you all posted with what I find.

GOLDCYLON · 01-27-2009

Id go back to the rubber bushings and Biscuits first before going any further on modifications to see if thats the problem. Start one at a time Ron as you changed out quite a bit there from the get go. From the new DRM brackets, To the new Coils rates, To the new Shocks, to the new bushings.

Id start with the easiest to change back and go from there. Dont forget the brackets are susposed to change the factory setpoints to remove some of the squat during a launch and reduce lateral roll as well. Just some ideas. BTW I have never heard of a Marlin valving option? Daryll

-=Jeff=- · 01-27-2009

could be the valving too.. i was going to revalve my shocks to the moracca valving, but after driving my car this last month on a couple crappy roads, I decided the OEM valving is fine.. caddy like ride in touring mode and sport and performance for when I want it..

jonszr1 · 01-27-2009

you might want to give corey a call and see what he thinks he has a pretty good grasp of the coilover set up .if nothing else to get another opinion.

WVZR-1 · 01-27-2009

Ron,

There's one shop in NOVA that comes to mind that has a "shock dyno" and I would think the diagnostics could be done "locally" and you could determine the issue and then move on the fix! The guys I have in mind do a good bit of the Porsche stuff in the area. If they've got fixtures the diagnostics I would think reasonable and maybe the valving you're looking for also!

It would certainly be worth a "conversation" I would think!!

I've considered them for some Carrera "diagnostics"!!

-Dave

01-27-2009

Ron, have you had the sway bar off?

01-27-2009	#1
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,080	problems with new fx3 coil over to continue my saga. car rides like a buckboard milk truck even with the softer springs. I reused the 95 shocks off the car with 50K plus miles, and I suspect they may have at some time been revalved by larry with the moracca valving, or maybe one of them is bound up. I went with the 400 front , 250 rear spring rates, which should provide a decent ride. I know the 19" GY F1 Supercar EMTs certainly don't help but the car rides WORSE that it did before with the stiffer coil overs so I'm suspecting a shock problem. it's coming back apart. for now I'm going to put the softer springs on my older coil over setup, and send the shocks back to bilstein to be revalved. Randy at DRM advised the Marlin valving would work well. first time I've hear of that. I also think the car might be bottoming out. I removed the stock "rubber biscuit's" at the top of the shocks and used the poly bushings from DRM, and also removed the stock rubber at the top of stock shock shaft (bottom out cushion) to provide more shock travel. maybe the shock is bottoming out internally?? the car is pretty low and looks great, so I'm going to raise it back up a bit to both provide more travel and lower the spring rates a bit. so much for my expensive "upgrade" I'll need to eventually get the car realigned and corner balanced which isn't cheap. sheesh, my c5 with coil overs rides like a cadillac compared to the ZR-1 but something is definitely wrong. ride is WAY stiff and jarring over bumps, not complaint. I'm also checking to see if I didn't "over torque" some of the bolts causing the suspension to bind up. I replaced the stock dog bone control arm brackets with the drm camber brackets to hopefully get better traction and handling. I'll keep you all posted with what I find.

01-27-2009	#2
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,120	Re: problems with new fx3 coil over Id go back to the rubber bushings and Biscuits first before going any further on modifications to see if thats the problem. Start one at a time Ron as you changed out quite a bit there from the get go. From the new DRM brackets, To the new Coils rates, To the new Shocks, to the new bushings. Id start with the easiest to change back and go from there. Dont forget the brackets are susposed to change the factory setpoints to remove some of the squat during a launch and reduce lateral roll as well. Just some ideas. BTW I have never heard of a Marlin valving option? Daryll __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 01-27-2009 at 09:59 AM.

01-27-2009	#3
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,156	Re: problems with new fx3 coil over could be the valving too.. i was going to revalve my shocks to the moracca valving, but after driving my car this last month on a couple crappy roads, I decided the OEM valving is fine.. caddy like ride in touring mode and sport and performance for when I want it.. __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Shelby Series 1 - Wilwood Brakes Custom Interior NCM Lifetime Member #978

01-27-2009	#4
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,406	Re: problems with new fx3 coil over you might want to give corey a call and see what he thinks he has a pretty good grasp of the coilover set up .if nothing else to get another opinion.

01-27-2009	#5
WVZR-1 Join Date: Oct 2004 Posts: 1,884	Re: problems with new fx3 coil over Ron, There's one shop in NOVA that comes to mind that has a "shock dyno" and I would think the diagnostics could be done "locally" and you could determine the issue and then move on the fix! The guys I have in mind do a good bit of the Porsche stuff in the area. If they've got fixtures the diagnostics I would think reasonable and maybe the valving you're looking for also! It would certainly be worth a "conversation" I would think!! I've considered them for some Carrera "diagnostics"!! -Dave

01-27-2009	#6
Jeffvette Guest Posts: n/a	Re: problems with new fx3 coil over Ron, have you had the sway bar off?