DRM Coil Overs - Page 2 - ZR-1 Net Registry Forums

UKZR1 · 11-12-2008

There's a couple of pics of one of the rears installed on my site and some of the kit from DRM layed out on the floor prior to install. Dosent look like I got around to taking any photos of the fronts on the car. The ones of the Brembos were taken before the coilovers. Can't remember the cost pre UK import duty and tax and shipping would have been around 2500-3000. That was a couple of years ago mind you

UKZR1 · 11-12-2008

Just to add, if you do the poly bushes as well while you are at it - and you should when you consider the age of the exsisting rubber bushes. The a press will really help.

I originally decided against the purchase of a press. I started at the rear of the car and managed to remove all the old bushes by drilling through the rubber a few times with a drill and then pressing them out in a vice. This was time consuming. It wasn't until I got to the front upper A arms (they are 1 piece and too large to fit in even a large vice) that I had to buy a press. I couldn'ty believe how much easier the job was with the press and should have got it at the start.

I also fitted poly bushes at the diff carrier. The original bushes were a nightmare to get out. In the end I had an engineer where my mother works make be a copy of the special tool in the manual. That worked but they were still hard work to get out. The tool consisted of threaded rod, a short length of pipe, 1/4" plate of metal with hole in the middle and a solid metal cylinder with a hole drilled though in which to pass the threaded rod through. The pipe sits over the bushing up against the carrier with the 1/4 plate over the top, the solid piece on the bushing the other side. Then with the rod through the lot start turning the nuts. If you are lucky the bush will move out the carrier into the pipe. One of mine was a pig.

Pete · 11-12-2008

UK,i also did poly bushings,before the coilovers they gave it a bit of a firmer ride not harsh, like the car needed bushings.

Coilovers really made the big differance.

Pete

rkreigh · 11-13-2008

I went too stiff on my coil overs, I think I have 425 front 300 rear

what do you think a "reasonable" spring rate setup is for street driven 95 zr1

like to get the "cushy" ride of the stock springs but the improved handling of the coil overs I'm thinking 375 front, 275 rear would be about right.

also upgrading to the 95 shocks so I will be machining the grooves and letting you all know. I'll have a stock set of 91 shocks, grooves machined and the actuators ready to sell and I'll be cutting a deal on them to help someone out wanting to go coil over

I won't rape folks on the acuators or shocks. I might have a bad controller box as mine all "time out" all the way around. going down to SGC next week so I'll try and find out what's bad.

thanks for any input! I agree totally that coil overs are the bomb

what do you all think about shock tower reinforcing? when I talked to to dave m about it he said the stock towers are PLENTY strong as the loads dished out from the shocks are the majority and that even though they look thin, it's pretty strong stuff. the callaway guys like to reinforce them, and oddly enough, they don't do coil overs on the c6 hmmmm.....

like to get smarter on setting them up and tuning the "corner weighting" I guess each shock is pre loaded just a bit according to the weight on that corner of the car to get the car to handle better.

no doubt that tuning with the coil overs is great stuff! thanks

Pete · 11-13-2008

Ron,when i do the conversion from NM to inch lbs 1990-1991 have
96.2NM fronts 39.9NM rears 1992-1995 have 75.4NM fronts 33NM rears.

To equal 1990-1991 springs it would be 425/175
To equal 1992-1995 springs it would be 325/150

I like to go softer from 400/200
i think i would like to try 350/150.
The spring prices aren't too bad.

Ron,if your FX3 ECU is bad i'd buy it from you,or i can tell you how to fix it cheap, without having to bend over.

Pete

Aurora40 · 11-14-2008

I could be wrong and don't claim to be a suspension expert, but I'm not sure you can directly compare spring rates like that? The shocks don't move straight up and down, so the coilovers presumably won't move as many inches per inch of suspension travel as the leaf spring would.

That said, I didn't realize there was that big a difference between the '90s and later cars in terms of spring rates?

Pete · 11-14-2008

Quote:

Originally Posted by Aurora40

I could be wrong and don't claim to be a suspension expert, but I'm not sure you can directly compare spring rates like that? The shocks don't move straight up and down, so the coilovers presumably won't move as many inches per inch of suspension travel as the leaf spring would.

That said, I didn't realize there was that big a difference between the '90s and later cars in terms of spring rates?

I'm not a suspension expert either but if you look at the suspension chart in the ZR1NetRegistry you can see where the 1991 ZO7 suspension has almost twice the spring rate of the 1996 GS suspension.
If anybody has driving a GS you know it has a nice ride,not as harsh as the early ZR-1's.
Since i don't auto-X or RR i would rather have the comfortable ride then a harsh bumby ride.
JMO
Pete

rkreigh · 11-14-2008

wow, those spring rate are WAY softer than mine. no wonder the thing rides like a truck on the bump stops

it does corner nice, but with the "mean streets" of dc and nova, pot holes and rough pavement are a fact of life and the LSV is no garage queen.

took the ms on a ride to the beach and we went over a bad bump and we tweaked our spines and bumped heads off the roof. that was is for her!

croozin with the honey is more important to me than ultimate corners, but I draw the line on the b&b, that's music!!

11-12-2008	#11
UKZR1 Join Date: Feb 2004 Location: South East England Posts: 172	Re: DRM Coil Overs There's a couple of pics of one of the rears installed on my site and some of the kit from DRM layed out on the floor prior to install. Dosent look like I got around to taking any photos of the fronts on the car. The ones of the Brembos were taken before the coilovers. Can't remember the cost pre UK import duty and tax and shipping would have been around 2500-3000. That was a couple of years ago mind you __________________ Red/red 90 #1281 (UK) Marc Haibeck 368 B&B, Brembos DRM suspension Known as 'Gixer' on corvettechat.co.uk www.corvetteclips.co.uk

11-12-2008	#12
UKZR1 Join Date: Feb 2004 Location: South East England Posts: 172	Re: DRM Coil Overs Just to add, if you do the poly bushes as well while you are at it - and you should when you consider the age of the exsisting rubber bushes. The a press will really help. I originally decided against the purchase of a press. I started at the rear of the car and managed to remove all the old bushes by drilling through the rubber a few times with a drill and then pressing them out in a vice. This was time consuming. It wasn't until I got to the front upper A arms (they are 1 piece and too large to fit in even a large vice) that I had to buy a press. I couldn'ty believe how much easier the job was with the press and should have got it at the start. I also fitted poly bushes at the diff carrier. The original bushes were a nightmare to get out. In the end I had an engineer where my mother works make be a copy of the special tool in the manual. That worked but they were still hard work to get out. The tool consisted of threaded rod, a short length of pipe, 1/4" plate of metal with hole in the middle and a solid metal cylinder with a hole drilled though in which to pass the threaded rod through. The pipe sits over the bushing up against the carrier with the 1/4 plate over the top, the solid piece on the bushing the other side. Then with the rod through the lot start turning the nuts. If you are lucky the bush will move out the carrier into the pipe. One of mine was a pig. __________________ Red/red 90 #1281 (UK) Marc Haibeck 368 B&B, Brembos DRM suspension Known as 'Gixer' on corvettechat.co.uk www.corvetteclips.co.uk

11-12-2008	#13
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,667	Re: DRM Coil Overs UK,i also did poly bushings,before the coilovers they gave it a bit of a firmer ride not harsh, like the car needed bushings. Coilovers really made the big differance. Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage Last edited by Pete; 11-12-2008 at 04:55 PM.

11-13-2008	#14
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,080	Re: DRM Coil Overs I went too stiff on my coil overs, I think I have 425 front 300 rear what do you think a "reasonable" spring rate setup is for street driven 95 zr1 like to get the "cushy" ride of the stock springs but the improved handling of the coil overs I'm thinking 375 front, 275 rear would be about right. also upgrading to the 95 shocks so I will be machining the grooves and letting you all know. I'll have a stock set of 91 shocks, grooves machined and the actuators ready to sell and I'll be cutting a deal on them to help someone out wanting to go coil over I won't rape folks on the acuators or shocks. I might have a bad controller box as mine all "time out" all the way around. going down to SGC next week so I'll try and find out what's bad. thanks for any input! I agree totally that coil overs are the bomb what do you all think about shock tower reinforcing? when I talked to to dave m about it he said the stock towers are PLENTY strong as the loads dished out from the shocks are the majority and that even though they look thin, it's pretty strong stuff. the callaway guys like to reinforce them, and oddly enough, they don't do coil overs on the c6 hmmmm..... like to get smarter on setting them up and tuning the "corner weighting" I guess each shock is pre loaded just a bit according to the weight on that corner of the car to get the car to handle better. no doubt that tuning with the coil overs is great stuff! thanks

11-13-2008	#15
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,667	Re: DRM Coil Overs Ron,when i do the conversion from NM to inch lbs 1990-1991 have 96.2NM fronts 39.9NM rears 1992-1995 have 75.4NM fronts 33NM rears. To equal 1990-1991 springs it would be 425/175 To equal 1992-1995 springs it would be 325/150 I like to go softer from 400/200 i think i would like to try 350/150. The spring prices aren't too bad. Ron,if your FX3 ECU is bad i'd buy it from you,or i can tell you how to fix it cheap, without having to bend over. Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage Last edited by Pete; 11-14-2008 at 05:36 AM.

11-14-2008	#16
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,704	Re: DRM Coil Overs I could be wrong and don't claim to be a suspension expert, but I'm not sure you can directly compare spring rates like that? The shocks don't move straight up and down, so the coilovers presumably won't move as many inches per inch of suspension travel as the leaf spring would. That said, I didn't realize there was that big a difference between the '90s and later cars in terms of spring rates?

11-14-2008	#18
rkreigh Join Date: Jan 2004 Location: Alex VA Posts: 1,080	Re: DRM Coil Overs wow, those spring rate are WAY softer than mine. no wonder the thing rides like a truck on the bump stops it does corner nice, but with the "mean streets" of dc and nova, pot holes and rough pavement are a fact of life and the LSV is no garage queen. took the ms on a ride to the beach and we went over a bad bump and we tweaked our spines and bumped heads off the roof. that was is for her! croozin with the honey is more important to me than ultimate corners, but I draw the line on the b&b, that's music!!