PDA

View Full Version : Vi-King shock for C4 Conversion



Fladiver64
07-08-2015, 11:47 AM
I have ordered a c4 conversion frame for Laszlo set up for coil overs. I have been looking at the Viking brand of shocks as they look to be a better deal than QA-1 401/402 as they are double adjustable.

Here is what they are recommending, prices are list may be available for less through distribution.:

Vehicle= 57 Chevy with C4 Corvette suspension

Fronts
Ride height=12” Lower mount=t-bar, Upper mount=eyelet
Shock= C205-T (-T indicates lower GM t-bar) $209.95 each
C205 shock takes a 9” spring
Spring= 9” 450lbs?? -9DP450 $43.95 each

Rear
Ride height=13.5” Lower mount=eyelet, Upper mount=eyelet
Shock= C207 $189.95 each
C207 shock takes a 10” spring
Spring= I don’t have a really have an accurate guess at a rear rate.

Accessories
7995-102- spanner wench and thrust bearing kit for 2 shocks- $44.95
7917-101 – thrust bearing kit for rear shocks- $27.95

How does this look

Mike

NickP
07-08-2015, 01:27 PM
Rebuildable? Can they be revalved?

Fladiver64
07-08-2015, 02:40 PM
Yes and Yes, or so they say

chevynut
07-08-2015, 06:26 PM
Fronts
Ride height=12” Lower mount=t-bar, Upper mount=eyelet
Shock= C205-T (-T indicates lower GM t-bar) $209.95 each
C205 shock takes a 9” spring
Spring= 9” 450lbs?? -9DP450 $43.95 each

What is the extended and compressed length on that shock? The QA-1 401/402 shocks take a 9" or 10" spring. A 9" spring might leave you with less adjustability and/or a higher spring rate since the nut would be higher on the shock at a given ride height.


Rear
Ride height=13.5” Lower mount=eyelet, Upper mount=eyelet
Shock= C207 $189.95 each
C207 shock takes a 10” spring
Spring= I don’t have a really have an accurate guess at a rear rate.



There are two ways to do the rear. One is with a 10" shock and one is with a 12" shock. I personally like the idea of using a longer shock, and run it on the more compressed side. That allows you to run a softer spring for a better ride, and helps when it comes to taking the wheel off. What's important is that you don't bottom the shock out so the compressed length is critical, as well as setting your axle bumpers correctly. I typically get 2" of upward travel at the wheel front and rear.

As for the rear spring rate, it all depends on the shock extended and compressed length, as well as shock angle. You need to support a certain load at a certain ride height. I have a spreadsheet that calculates the spring rate once the car weight and shock extended and compressed dimensions are known.

Fladiver64
07-08-2015, 09:06 PM
What is the extended and compressed length on that shock? The QA-1 401/402 shocks take a 9" or 10" spring. A 9" spring might leave you with less adjustability and/or a higher spring rate since the nut would be higher on the shock at a given ride height.
The C205 10.04 compressed and 13.86 extended ride height recommended is 11 5/8 to 12 1/4

Next step up is the c217 10.48 compressed and 14.30 extended ride height recommendation 12 to 12/34 10" spring

One of the things they mentioned was that their spring uses fewer coils for the same spring rate and a longer thread on the shock body for more adjust ability. Maybe the 217 shock is a better fit.




There are two ways to do the rear. One is with a 10" shock and one is with a 12" shock. I personally like the idea of using a longer shock, and run it on the more compressed side. That allows you to run a softer spring for a better ride, and helps when it comes to taking the wheel off. What's important is that you don't bottom the shock out so the compressed length is critical, as well as setting your axle bumpers correctly. I typically get 2" of upward travel at the wheel front and rear.

As for the rear spring rate, it all depends on the shock extended and compressed length, as well as shock angle. You need to support a certain load at a certain ride height. I have a spreadsheet that calculates the spring rate once the car weight and shock extended and compressed dimensions are known.

207 is 11.10 compressed and 14.92 extended

chevynut
07-08-2015, 10:10 PM
I think the C205 is probably the best choice for the front. We set the front end up for right at 12" ride height length. That gives about 2" up and down travel. I was just wondering about the spring length, but if the spring rate is right and it doesn't coil bind it shouldn't matter. For an LS engine we typically recommend starting with a 450 lb/in spring in front. My spreadsheet says 472 lb/in for your combo (early suspension), but I would go with 450. That seems to work for most people so far. You will likely have to adjust the nut up 1" or more (depending on actual weight) but that allows you to use a softer spring. It will still ride pretty firm.


207 is 11.10 compressed and 14.92 extended

So that's a 3.82" stroke which is pretty short for a rear shock, but about the same as the front. Since the shock sits at an angle, you should have a little more stroke than that. The QA-1 403/404 is just about the same shock, and that's the 10" one I mentioned above for the rear.

The C4 IRS has some interesting geometry going on and the calculations for spring rate aren't so straightforward. I have used empirical data from customers to adjust my calculations. With the 207 shock my calculator says you need about a 550 lb/in spring in the rear and the adjuster will be 1-1.5" above the bottom.

I would start with the rates above and make adjustments only when the car is completely assembled and drivable. If you run out of adjustment at the top and the car still sits too low, you need to go up one spring rate. If it's too high and the adjuster is at the bottom, you need to go down one spring rate.

JT56
07-09-2015, 04:39 AM
Have you checked with Ride Tech Coil overs?

chevynut
07-09-2015, 07:02 AM
Have you checked with Ride Tech Coil overs?

$$$$$$$$$$

JT56
07-09-2015, 08:07 AM
$$$$$$$$$$


Agreed, but they have some nice products.

NickP
07-09-2015, 12:08 PM
I can't personally speak for the OP Brand but, I can speak to QA1. I know JT56 can speak to Ride Tech. My personal opinion, what ever the brand, it needs to be rebuildable and re-valveable if you want to garner all of the performance from this type of suspension modification. If the design intent of the completed car is to make good use of that, then a quality shock might be something to consider.

chevynut
07-09-2015, 12:16 PM
Personally I think you can easily go overboard on shocks. Not many of us are going to tune our cars to the max, so we just need a shock that's adjustable (at least rebound adjustable) and rebuildable is a good feature, although I'm not sure you can even do that yourself. How often do these things need to be rebuilt? Even if it's 50K miles it's going to be 10 years or more for most of us.

Why do you need re-valvable? Who's going to mess with different valving on these? I personally think even dual adjustable is overkill, unless you intend to autocross the car.

Fladiver64
07-09-2015, 07:51 PM
I guess I am somewhere in the middle on all of this. One of the problems when building cars is that each component/system can be over done and scope creep quickly gets out of hand. The goal for me is a good quality driver car with an eye on performance. What I liked about the Viking shocks was the double adjust ability at about the same price point of the Q1A shocks. Looking at the Ride Tech stuff it is clear that they have a very good product, I just don't think I would put them to good use and money is better spend somewhere else.

My experience in adjusting shocks has mostly been on motorcycles and having separate compression and rebound setting invaluable to getting the bike setup correctly. I will have to say that once the settings where made I rarely changed them for different uses but it was very nice to get it to perform the way you wanted. I am not sure this is critical with a car but if you can have double adjustable shocks for the same price why not.

I also need to see what real world pricing for each setup is configured similarly as that could make a difference. Lots of parts left to go :)

WagonCrazy
07-10-2015, 05:28 PM
Back around June of last year, I called up Vi-King shocks and discussed my needs and ordered a complete set of double adjustable coil overs. $1098 shipped to my door, including spanner wrench, thrust bearing kit for each shock, and "t-bars" for the bottom of the front shocks (mount to the lower a-arm)
I have a 57 Nomad build, with a Laszlo frame, and C4 setup too.

Went with a C-218 Front shock body, with 500# springs. 12.5 inch ride height.
Went with a C-210 Rear shock body, with 400# springs. 14 inch ride height.

You can see more at my post here at http://www.trifivechevys.com/showthread.php/606-57-Nomad-C4-LS1-called-quot-Ozzy-quot/page3

My Nomad is not out on the road yet, and I think I may have the rear springs either too stiff, or too long. Read the post and then throw me your questions and I'll try to be helpful.
Paul

Fladiver64
07-10-2015, 08:10 PM
Paul,

Thanks for your feedback, I read your thread and lots of good information in there. I wish I had read it a few weeks ago as I was in Santa Clarita. We had a memorial service for my father as his sisters live out here and could not travel easily. I grew up in Newbury Park and had not been back for about 20 years, your town grew up a bunch in that time.

Sound like your shocks ended up a bit long so the recommendations they gave me may work out well. I think spring rate is just a guess until to gets all assembled. The Vi-King shocks to seem like a good value for what you are getting. I still have some time as my chassis will not be here until Mid October, and I still have to build a place to put it.

Next time I am out maybe we can get together and you can show off your project.

WagonCrazy
07-10-2015, 09:03 PM
Doors open for like minded folks. Come on over.
When i get back under the nomad ill give more feedback on my shock situation. Really cant tell on the spring rate untill all the glass and interior is in.

chevynut
07-11-2015, 07:59 AM
Really cant tell on the spring rate untill all the glass and interior is in.

Except for the fact that I have TWO customers who gave me feedback on their spring rates. ;) Both had LS engines, and one was a 57 Nomad while the other was a 55 sedan (pics on my website). Both of them went with my recommendation of 450 lb/in in front (Aldan American Eagle coilovers), and as far as I know that worked well for both of them. In front the body style doesn't have a lot of bearing on spring rate, but accessories can. My Nomad with the BBC currently has 600 lb/in springs and I think they're going to work fine although if I can I'm going to drop the rate a bit.

Both of the customers had issues in the rear. A typical spring rate calculation said that a 250-300 lb/in spring would work so they both tried 250. If you go through the calculations for a solid axle car (no motion ratio, only shock angle), that's about what you would get. At first glance, you wouldn't think an IRS has a motion ratio because the shock is connected directly to the knuckle that the wheel is bolted to. However, it turns out that it's more complicated than that due to the IRS geometry.

Anyhow, with the 250 lb/in springs both of the cars sat too low in the rear and they ran out of adjustment. They both had to go to a 600 lb/in spring in the rear to make it work. Since then I have modified the shock angle to make them sit more upright in the rear by relocating the upper shock mount further outboard....we've been building them like that for several years now. The rear shock angle now is 25 degrees at ride height. I got some information on their shock angles, car weights, etc. and added a correction factor to my spreadsheet to match both cars when I plug in their numbers.

A wagon is about 170 pounds heavier than a sedan in stock form with the difference being mostly in the rear of the car. Here's what my spreadsheet says for your cars, with one person in the car and with an LS engine and a 200 lb aluminum tranny:

Front:

Viking C205 (10.04"C/13.86"E) 12" RH, 1.5" AH, early C4 susp. Sedan - 445 lb/in Wagon - 408 lb/in
Viking C217 (11.1"C/14.92"E) 12.5" RH, 1.5" AH, early C4 susp. Sedan - 388 lb/in Wagon 356 lb/in
Viking C218 (10.48"C/14.3"E) 12.4" RH, 1.5" AH, early C4 susp. Sedan 445 lb/in Wagon 408 lb/in

Rear:

Viking C207 (11.1"C/14.92"E) 13.4" RH, 1.5" AH Sedan - 592 lb/in Wagon - 656 lb/in
Viking C210 (11.57"C/16.76"E) 13.6" RH, 1.5" AH Sedan - 378 lb/in Wagon - 410 lb/in

If you want to run the adjuster height (AH) higher, you can run a lower spring rate. If you want to run it lower, you can run a higher spring rate. Personally I don't recommend using the 217 in front because I think it's a bit too long, depending on where you actually want to run the ride height. I would set the car up where you want it to sit and measure the eye to eye distance and pick a shock that is 1/3 to 1/2 compressed at that length. As I said, we set it up at 12" ride height.

You can clearly see the effects of a longer shock in the rear which allows you to run the lower spring rate. That's because the spring is compressed further. The thing to watch out for when using a longer shock is bottoming the shock out. I would install the axle bumper, push the suspension up to the bumper, and measure the eye to eye distance. This is the longest compressed length you should use. Note that the C4 Corvette didn't use an axle bumper in the front.

So all of this is more than "just a guess", it's a calculated estimate. I think these calculations get you to at least within one spring rate. I can run any calculations you want me to if you give me all the parameters.

BTW, Wade's Nomad ended up at 3686 lb. 1870 in front and 1816 in the rear. My spreadsheet predicted 3578 lb. so I may have been light on accessories. I also ended up with a slightly different weight distribution so maybe some tweaking is in order. Wish I could get more info on finished cars. ;)

Fladiver64
07-12-2015, 12:07 AM
What I meant by just a guess, has more to do with the builder, me, than your calculations. Your information and estimates are invaluable for getting in the ballpark but your numbers are only as good as the data we provide. These builds suffer from a lot of, while I'm here, its only a little more, and that's a great idea, that all have an effect on the different systems in the car. For example with the ls motor, aluminum or iron blocks can be 80 to 100 lbs different. Building cars for me is a prototyping process that we expect a finished product at the end. I build most of the prototypes for new systems for my company and almost always at the end I have version 2 designed in my head because of what you learned in building the first.

I agree that at most your estimate is probably off by one spring rate, most probably is within the adjust ability of the shock, your advice on the challenge of adjusting the stock traverse leaf spring was the reason I went with coil overs in the first place. I think your right the 205 shock is the best for the front and the rear I think is just going to have to wait to get measured on the car.

NickP
07-12-2015, 06:35 AM
the rear I think is just going to have to wait to get measured on the car.HUH? Why would you have to wait? You're building a chassis with know dimensions and inserting a suspension system with known dimensions and and desired ride height, what's left to measure? Assembled or otherwise, the rear suspension rides at its original designed attitude with the same weight applied to the rear half. You have two points of attachment, both of which you control. You have the specified attitude of all components at rest with the applied corner weight. It's not going to change when assembled. I'm confused. Maybe I'm just overthinking the noted problem.

chevynut
07-12-2015, 08:55 AM
Nick, there is a "design" ride height and a "desired" ride height, which can differ a little. We set up the front suspension with the lower a-arms level, which also results in the steering tie rods being level. In the rear we set it up with the halfshafts level. Some have argued that the halfshafts should be slightly high in the center but I don't think it matters. I think you have at least an inch up/down range of adjustment from where the suspension sits. We offer a 3" standard suspension drop and 2" is optional. The 3" drop puts the frame about 4" off the ground at the front of the door, depending on final tire size.

I think what fladiver is saying is that he may want to mock up the car at the ride height he wants, then select the shock length by taking a measurement. Sounds like that's what Paul did in the rear of his Nomad. At designed ride height I believe the rear shock should be about 13.5" long. That could be adjusted by using a different lower shock mount.

Fladiver64
07-12-2015, 01:47 PM
I think what fladiver is saying is that he may want to mock up the car at the ride height he wants, then select the shock length by taking a measurement.

Exactly, I think the front is a given but the rear is close and the next size shock is close, it would only take and inch or so to make a difference in the shock size and I think that is too close to call without a mock up.

Fladiver64
07-12-2015, 06:59 PM
Laszlo, what do you think about making a rear sway bar with a kit like this http://www.welderseries.com/blog/store/#!/Universal-Sway-Bar-Kit/p/49762034/category=12921497
Could you run this through the frame and then eliminate the interference with the fuel tank. Just an idea, it is hard to tell how this would work.

chevynut
07-12-2015, 07:13 PM
The issue with the fuel tank interference is the length of the swaybar arms. I'm pretty sure that just about any swaybar is going to interfere with the stock gas tank location since the tank is so far forward. If the stock tank was moved back to the rear crossmember, you have more room but the C4 swaybar still won't fit. IMO the Speedway Engineering swaybars with splines on both ends are a better choice. I don't know if putting the tube through the frame really buys you anything.

Fladiver64
07-13-2015, 01:34 AM
My thought with that kit was the spline cups are separate from the arms and you weld them up. That way you could adjust the arm length to move the bar forward. The sleeve bar could go on top of the frame or through it if needed. You would have to order the splined shaft the correct width and then make the arms to fit the location.

Rick_L
07-13-2015, 04:55 AM
As you consider this, remember that the arm length on the swaybar affects the leverage on the bar - shortening the arms loses leverage and will make the bar act stiffer.

chevynut
07-13-2015, 08:17 AM
My thought with that kit was the spline cups are separate from the arms and you weld them up.

It looks to me like that's the case on one end only. The other end is splined. It does give you more flexibility on length of the bar.


That way you could adjust the arm length to move the bar forward.

Yes the arm length would have to be determined and cut off accordingly. The SE swaybar also allows you to do that. As Rick said, the shorter the arms the stiffer the swaybar at a given diameter. Most C4 swaybars are around 1" (24-26mm) with some being hollow and some solid. The arms are fairly long. We can discuss the preferred path when we get to your build. ;)