Rear suspension

[JBlake]

Where to begin....

I'm new to the Cobra world and a first time member to of this site.
My Classic sits a live axle 9" Ford rear end. I expect the live axle to be a rough ride but never imagined it would be as stiff as it is.

The shocks currently installed are non-adjustable and take forever to return after compression. I'm looking for some advice on how to soften the ride but don't know the application for which I should be looking to buy replacement.

How do I go about determining shocks woudl fit and work? Don't have a clue where to begin.

Thanks for your patience.

[Jack21]

The post below this one, same subject, describes rear shock options.

The component procurement manual that came with your kit references a rear shock originally found on a VW, with VW part #. This is where the cross referencing begins.

I cross referenced it to a Koni shock which seems to work OK. Don Scott has a Pro-Shock which also works well. Also discussed were rear springs. Try your auto supply store for the Chevette replacement Moog springs, or Don's springs if the ones you're using are too stiff.

[JBlake]

Thanks Jack.

Koni and Pro Shock are two brands I've begun to look into. Any idea which model of each will work in my rear application?

I'll need a 12" length from bolt to bolt. The eyelets are one half inch in diameter at each end two and half inches wide.

How much travel should I be looking? I originally thought 3" but someone advise that I'd run risk of cracking the fiberglass.

Any and all insight would be appreciated.

FYI, does the VW part number match up to NAPA part # 20722?

[Jack21]

Don't use auto supply store shocks on this car. They are passenger car shocks, not sports car or street rod shocks. No NAPA or Monroe or Gabriel or K-Mart or Sears.

Ideally, use the same brand on the rear as you use on the front. Carerra is a good brand generally used on the front of these cars. Hal is another good one.

12" - 13" c/c at ride height, with 6" - 8" total travel sounds about right. I think the formula is 60% compression, 40% extension.

Either Don or DV can provide you with the right shock for this specific application. If I had this to do over, I'd try to get all my suspension, steering, and brake components from the same vendor. Bolt it together and it all works, instead of try it and see.

My experience is there are a lot of little specialty shops out there that just do front suspensions, or rear suspensions, or brakes, or steering, and few of them have ever heard of a Cobra. There is no way to determine in advance if the parts will all work together properly. You can go through 3 rear setups, and 5 front setups, and a year's worth of work before getting it right, wind up with a lot of expensive parts sitting on your shelf that won't/didn't work on your car.

Don, DV, are you listening?

[Double Venom]

Guys,
We worked with "Blue Coil" and "PRO" shocks for about 5 months to come up with a good all around rear suspension set up.

Coil overs are nice, but of course add quite a chunk to the over all build. The rear springs we use, and now CR's ships with the kits are 13 - 200's Blue Coils. If you really want a little softer ride then drop to the 175's. I'll have to get the PRO number for the rear shocks when I get to the shop this morning.

If you do a lot of drag racing or roadcourse, then we found the 200's do work better without giving to stiff a ride/ but if you're 99% street, then the 175's will work well.

I think Don has some part numbers for rear coil overs if you want to go that way.

Hope this helps.
DV

[JBlake]

Thanks once again for all the input. Great to speaking with guys in the know.

DV, to Jack21's point earlier, do you to believe it's better to go with matching front and rears?

Just to cover all the bases, could you provide a model number for the matching fronts to the rear Blue Coil 13-175's you suggested? I'm going with the 175's since nearly all my riding in street.

It would great if you could do the same for the Pro's. That is, model/part number for the rear, and now fronts as well.

As an FYI, I was under the car last night trying to look for info on the current shocks. They're beige/cream color, are made in the usa, and have a series of letters and nunmbers appearing as
PCE1CG1F. On the opposite side shock I found this number...5676.

Don't know if any of this help, but I thought I give you much detail as possible.

Thanks again for all of your help.

[dscott]

jblake, I answered your shock question on the CR site but I will answer here again for general info if anyone else is looking for the Pro-Shocks. I use an SM600 oil filled, chrome Pro-Shock. The have very light valving so they work great on the rear of the CR car. The only problem with them is the extended length. They don't make them as long as needed so the upper shock mounting hole must be redrilled about 1 1 /2 inches lower to accomodate this. Not a major problem unless you don't have the tools to drill a new 1/2 inch hole. I am a dealer for Pro-Shocks along with DV and many others I'm sure. The cost is $80 per pair. The shocks that are on your car are probably Monroe, the number sounds like the old Monroe gas#. They are extremely stiff for this car. You will notice that when you push down on the rear it takes along time for the car to return to normal ride height. This causes the rear to bottom and not rebound fast enough causing the rear to bang and clunk on bumpy roads. I'm sure there are other shocks like Koni available but I've never used them.
Don

[Double Venom]

J. !!!!

Don called me on this one and is 100% right. I did some quick checking - do not, I repeat do not use the 175's. I came back and read this and the only thing I can think of is a brain back up!

We did one Cobra using the 175's and it was special order only.
200's are going to give you the right ride.

If you ordered 175's on my account and can't cancel, I will buy them from you! Sorry for the mistake..all mine!

We use the carrera coil overs up front - 350 for small blocks, up to 500 for big blocks.

Jack, I apologise again. The 175 Blue Coils will work, but I do not reccomend them.
DV

[JBlake]

Dscott, many thanks for the help. I'm not really up to drilling new holes in the car (no tools) so I think I'm going with DV's recommendation. The description of the rear end characteristics was right on. It's exactly what I'm experiencing.

DV, no worries on the Blue Coil 175's. Haven't made the purchase. In fact, I haven't been successful in finding them anywhere. Can you direct to a source for the 200's? I'm assuming their installation won't require any drilling. I'm also hoping DScott confirms their compatibility for my car.

As I said before, you guys are a godsend. Thanks

[Jack21]

You might want to consider buying a drill. Minor household repairs & stuff. And a die grinder too. Lets see, anything else? A few sockets wouldn't hurt.

[dscott]

The 200's will work great. I use the 225's on cars with a heavy driver and rider. The 200's will give the best ride. DV uses the Pro-Shock without drilling and they work good. I guess I'm a little anal when it comes to these cars that's why I redrill. I'm sure the shocks work great without moving the mounts.
Don

[jwinkler]

Don - you said that DV uses the pro-shocks without relocating the mounting location, but 1.5" sounds like a lot. How does this work?

Also, you mentioned you and DV are dealers for pro-shocks - are you also a source for the blue coils, and (always have an "and" ) would you also be a source for the front coil-overs that bolt in where the shock goes now?

Thanks,

JLW

PS - I was just checking through the CR site messages, and more detail was posted about the new engine mounts. The notes talk about new frame mounts that enable the use of late-model Mustang mounts. Any chance you or DV could post pictures of the new arrangement? Would this be an easy swap from the old-style mounts I've got now? And (there I go again) will the existing transmission brace work with the dropped motor? Would it just have to be shimmed to line up right?

[Jack21]

Here's a shot of a set of frame mounts I had made by my welding shop specifically to use new Energy Suspension SBF polyurethane motor mounts. Dramatic improvement in supporting engine and keeping it from flopping around over stock rubber mounts, particularly the MII mounts.

Sent drawings & photos to Pete Johnson at CR. Presumably, CR now sells them. Presumably, DV & DS have something similar. If not, I'll pull 'em back out and make a copy so you can.

Also grafted a BBK late Mustang clutch quadrant to CR clutch pedal, along with BBK cable & firewall adjuster. Cable is stronger & longer than OEM and stays out of the way of the header. Firewall adjuster lets you adj clutch from firewall, instead of having to crawl under car to do it.

[Jack21]

Forgot to mention. Setup is specific to 351W motor in that it drops engine 3/4"- 1" and enables air cleaner clearance (just barely) when using hi-rise intake such as Ede Perf RPM. (Single plane Victors still won't clear. Too tall.) You do have to shim trans mount down 3/4" - 1" also so sidepipes will line up.

[dscott]

jwinkler, I haven't tried the Pro-Shocks without redrilling the hole. I didn't like the height of the rebound and that's why I moved it. DV says they work good without but I feel better drilling a new hole. I am not a dealer for Blue Coil but I am checking into that. I do sell the Carrera coil overs for the front. The package for the CR is a chrome spring that sits in the stock perch on the top and the aluminum shock perch on the bottom. The shock is chrome and is custom for the CR (because of the extra length). I use a 375lb spring for the small block and a 500lb for the big block. You must also have a lower arm that will accept the coil overs.

I did help in the development of the new engine mounts. We used the Mustang GT mount and dropped it 3/4 of an inch for better hood clearance. I haven't noticed much change in the trans or sidepipes so the same parts apply. I should note that the trans mount was dropped before the motor mounts so if you are using the old trans mount from Ford it is to high. I use a Napa mount #602-1334. The engine mounts are a Napa #602-1639. You will need to change the frame brackets also. They come from Classic. I don't have any of the mounts in right now but I think the pictures jack21 has are very similar. I don't think the mount he used is the same as the one CR uses. The poly mounts are stronger but the cost was much higher. If you wanted the poly mounts the CR mounts won't work unless the Napa mounts cross to a poly mount. There are several mounts for the Mustang GT and we picked one that allowed for good clearance and was a common part#.

jack21 has built his car the way he likes it. It isn't always easy to change things as he has. Many of the customers building their cars don't have the ability or the tools to do custom mods. I sell to many people that have never done much of anything to a car let alone build one. This is why many things are kept as simple as possible. My suggestions are for the builder who can do minor changes without major mods. The changes I make to the Classic car are for the customer that has purchased a turnkey. I have the ability and the tools to do this. This doesn't make my car any better or worse but it does give me peace of mind and time savings. Many of the parts that were so readily available when the car was introduced are now becoming obsolete. That's why the changes are coming about. It is also availabilty of parts that must be considered. The person building his car doesn't normally have parts available other than sources such as Napa. That's why off the shelf parts are used. This also allows the repair of the car at just about any shop. Many of my customers want the look and prestige of a Cobra or Sebring but have zero mechanical ability and must rely on the repair shop of choice.

I have been involved with a few body shops lately that are trying to rebuild wrecked cars for their customers. Many of them have previous owner built cars with major mods to headers, sidepipes, steering columns, mounts, etc. This causes prolems in duplicating parts or trying to figure out what the part is from. So any factory mods are done in a way to allow all customers ease of repair and replacement. If you have the ability to change your car and add expensive parts that's great, but, the car must be easy for the novice or the expert.
Don

[Jack21]

Sorry if I tend to be an opinionated old geezer sometimes. That's just me. I appreciate your position, Don, & DV, in that simplicity and reproduceability for the average builder/owner are important.

I also appreciate your experience and expertise in this, and your willingness to share them on this forum. You put a lot of thought into that response Don.

Yes, I'm an engineer that happens to be building a Cobra and as such can tackle jobs the average builder wouldn't, but I'm not in the business of making or selling parts, or cars. If I come across something that appears to have usefulness, I'll share it. If something I've come across solves someone elces build problem, then I've contributed...paid my dues...for the priviledge of picking your brains when I'm stumped. (Like these front brakes.)

The E.S. motor mounts are direct replacements for late Mustang 5.0's. A little pricey, but they work. After butchering the MII mounts and still being unhappy with them, I bought a set of prototypes from Pete at CR. They didn't fit. I redesigned them, built a set for myself, and sent them back along with the shop drawings. The frame mounts should work for either OEM late Mustang, or E.S. Using the E.S. trans mount requires dropping the trans frame about an inch. If there's a shorter trans mount to be had, then it shouldn't be necessary.

I'm decent with electrical systems, typically the bane of most hot rodders. Anybody thinking of ditching the Chevette column, but unsure of moving the stalk mounted controls to the dash? I did.

[dscott]

jack, I don't take any offense to your responses. I think it's great to have other opinions for everyone looking for information. I have such a broad spectrum of knowledge from the customer that I have to keep things is terms they can understand and work with. DV runs into this all the time also. I think back to some of the things I did to my own muscle cars when I was younger and I hang my head in shame but that was all I knew at the time and I thought it was right. So many people try and build these cars on a very limited budget that cost is a major factor for them. So again, I am not offended or upset with you or your responses. That's why this forum is great for sharing knowledge. I'm sure some of the responses I give make people think I must have my head up my butt. I can only relate what I know and you do the same. People will decide what is best for them and we are all smarter because of it.
Don

[JBlake]

Quick update on the rear shock saga. I learned that ProShocks also makes SM500's that provide 12" ride height without requiring the drilling of any new wholes. They're on order, should arrive this week and with any luck be installed this Friday. I'll let you know how it works out.

[JBlake]

I'm happy to report that the Proshock 500's went in without a hitch. Now I've got a sense of what this driving experience is all about. What a difference!

[jdean]

Long time viewer, first time poster....

It looks like the rear spring area on the CR would be easy to put an airbag suspension in. If properly done, these are known to give a smooth ride, even in a light car.

Good points are ride quality, easily adjustable. What are the not-so-good points? Would handling suffer?