Factory Five Racing Forum banner
1 - 20 of 149 Posts

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #1 · (Edited)
I've already mentioned setting the Koni's to their softest settings as a start on improving the ride of the '33. ( http://www.ffcars.com/forums/showthread.php?t=228221 ) This week I got a chance to get the next phase started. I spent some time on the phone with the folks from Eibach and then ordered some "Tender Springs" from one of their dealers.

These things are actually more expensive than the standard springs, but what the heck, it's my butt I'm trying to protect so maybe making my wallet thinner will also help!

<u>Front Shocks/Springs</u>

Here's what the suspension looks like with stock parts:
<center><img src="http://www.aim-users.com/frontspring03.gif"></center>
Two 8" long 500#/in rated linear springs. The front shocks have a 4" stroke.

The pressure on the spring in the FFR suspension configuration is about 450 to 500 pounds at proper ride height. The standard spring compresses about an inch, just as you would expect. Further compression starts to build spring load rather dramatically. The spring would potentially be loaded to 2000 lbs if the full stroke of the shock were used.

Eibach can come up with a "progressive" springing arrangement by stacking two springs of different rating. Because the original spring used up essentially the entire length available, I chose to buy new 500#/in springs that were 6" long to gain the overall length needed. In this case, the tender spring needed to be reacting first with the main spring taking over when the tender spring reaches full bind or "block height."

<center><img src="http://www.aim-users.com/frontspring01.gif"></center>
Image shows assembly "unloaded" with the car on jack stands.

Even as the lighter rated spring is being compressed, it's transferring some load to the main spring. Eibach recommends the tender spring be mounted at the "frame" end of the shock absorber, so in the case of the '33, that meant at the lower end. A nice coupler fits between the main and tender springs to keep them aligned. I plan on putting a nylon tie around both springs and the coupler to keep them from separating unintentionally. The 6" spring gives us room for the tender and the tender spring gives a more compliant ride but allows the heavier spring to do its work under hard cornering. There's still a nominal amount of ride height adjustment (lowering) available.

When the car was back on the pavement, I could push down on the car's frame and see the tender spring flexing and see the red main spring responding, too. Most of the motion was being absorbed by the black tender spring. In this case, the red main spring is compressed about 1" as before while the tender compresses between 1 1/2" and 1 5/8". The tender spring reaches full bind at 675# with a compression of 2 1/4". The additional ~3/4" of travel on the "softer" spring is where the comfort is improved.

<center><img src="http://www.aim-users.com/frontspring02.gif"></center>

Next, Rear Shocks/springs........................
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #3 · (Edited)
Rear Shock/spring change....

<u>Rear Shocks/Springs</u>

At the back end I was able to re-use the original 8" 350#/in linear springs as there was lots of room for adjustment. The rear shocks have a 5.47" stroke and the extended length is 17.63". Assembled, the "upper" groove for the spring retainer is used and there's still lots of room. To be sure, however, we moved the retainer to the bottom groove in the shock body and then stacked the tender spring on top of the main 8" spring.

<center><img src="http://www.aim-users.com/rearspring01.gif"></center>
(left rear coil-over shock)

On the left side of the car it was impossible to make the switch without removing the shock assembly from the car. It's fussy work getting the top bold out. As you can see, there's still plenty of adjustability here even with the tender spring in place. Again at Eibach's suggestion, the tender spring is added at the "frame" end of the shock. Here it's on top. A nylon tie will be used to keep the coupler and two springs from separating.

<center><img src="http://www.aim-users.com/rearspring02.gif"></center>

The right side assembly I was able to do without removing the shock from the car. Only the bottom bolt needed to be removed.

I've only had a quick ride around the block (over some pretty old pavement) and the outside temp was just 8°F, but I can verify this has improved the ride comfort at both ends of the car. It's removed the "nervous" aspect of the ride and I would imagine it being quite a bit better when the outside temperature is more civilized!

This car's never going to glide over potholes with aplomb, but at least with this setup, each pavement joint isn't going to jar your teeth. Unfortunately with the winter weather closed in around Wisconsin, I don't believe I'll get a really good chance to fully evaluate the changes for a while.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #4 ·
Thanks Kyle, I hope I'm not being a sissy about the car's ride. I don't want to compromise the handling of the car but sure would like the tires to stay planted on the pavement. Before I reset the shocks, I'd swear the front end lost traction over larger bumps.

Hitting pavement seams with both front tires wasn't too bad before this change. It was when one front tire hit something while the other was on smoother pavement. The feedback to the steering wheel was pretty rugged.

I've been driving the #007 car around on my 17" rain tires I use on the Challenge car. They're basic street tires 245/45-17. I wanted to see if the car rode better than on the 18" rims/tires. It drives better on the rains, and the ride improved slightly. (the 18" tires followed every crack in the pavement.)

I'm still leaning toward taller tires and smaller rim diameters. But, before I bought, I wanted to see if I could remedy the ride a bit. This improvement has opened up some more options on wheels/tires.

Best regards,
 

·
Registered
Joined
·
59 Posts
Setting the chassis heights by FFR, I noticed the upper control arm is close to frame sitting still. Will you bottom the control arm to frame getting this additional movement from this spring combination or are you raising the ride heights?
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #7 ·
Hi Duane, I only checked to make sure the ride height was the same as before I started. I've not noticed any interference with the upper control arm when driving. I have the nose height set to the factory height.

Overall spring length is a bit longer than the factory 8" piece, but part of it compresses rather quickly. So I don't see any problem so far.

I've only driven it once around the block because of the winter weather. I'll report more later on this.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #8 ·
Olli, I'll list the parts and where I used them as soon as I've finished up the project and feel it's working the way I had hoped. I bought two different size tenders and I've tried them one way (one size at the front, another at the rear) but I want to swap them out, end to end and try it the other way, too.

There's one more spring option I may try if I don't get everything I want from these I've been trying.

I should know by mid week or next weekend which way and with what parts it's going to work best.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #9 · (Edited)
List of part numbers and data

NOTE Added 11/22/2010: The car now has around 3500 miles on it with the new spring setup. When I changed front Wheels the new ones had more offset and put that end of the lever further from the fulcrum of the front suspension. This essentially "flattened" the front Tender Springs.

To save yourself some effort and money, I now suggest not using the method described below on the Front End of the car. There's just not enough improvement there with the suggested springs. The optional "progressive rate" springs I've not yet tried. They might work on the front end and would work okay on the rear as well. If I do more testing with the progressive tender, I'll post the info here.
----------------------------------------------------------------------------
Original Note Below:
----------------------------------------------------------------------------
Here's the Eibach parts I ordered and the info to make sense of it all:

<b>Front</b>

Part #................Spring......Rate.....Free Length......Travel......Block (bind) Height......Max Load at Block Height

Koni Shock......................................15.15".........4" stroke

Original 8"............Main.....500#/in........8".................?.....................?.......................2000 lbs (full shock stroke)
(Not used with this modification)

---------------------------------------------------------------------------------------------------------

<b>Replacement combo from Eibach</b>
..........................Spring......Rate.....Free Length......Travel......Block (bind) Height......Max Load at Block Height

0600.250.0500.......Main......500#/in.........6"...............3.62"............2.39"........................1810 lbs

0225.250.300.......Tender....300#/in........3.94".............2.25"...........1.69"..........................675 lbs

Combination----------------Variable------9.96in--------5.87in-------4.08in-----------------1810 lbs

Expected result, combination should allow Tender spring to be useful before full bind.
Tender will be compressed to about 67% of capacity under static load.
Should leave 225 lbs of additional load and 3/4" travel before full bind of the tender.
----------------------------------------------------------------------------------------------------

<b>Rear </b>

Part #
Koni Shock...........................................17.63"..........5.47" stroke

Reuse original 8"....Spring......Rate.....Free Length......Travel......Block (bind) Height......Max Load at Block Height

............................Main.....350#/in.........8in................?..................?........................1641 lbs (full shock stroke)

Add
..........................Spring......Rate.....Free Length......Travel......Block (bind) Height......Max Load at Block Height
0175.250.300.........Tender...300#/in........3.77"............1.75".............2.02"........................525 lbs

Combination.......................Variable.......11.77"............5.47"max.........?...........................1641 lbs max.

Expected result is partial compression of Tender spring and Main to static load. The 300#/In spring will compress most under normal driving while the main will carry heavier acceleration and cornering loads.

Vehicle Weight

Front axle = 1160 lbs; Rear axle = 1260 lbs (weights are with 190 driver in car)
------------------------------------------------------------------------------------------------------

There's one possible part that could work at both ends of the car. It's a variable rate spring #0200.250.0550. It's a progressive rate from 250#/in up to 550#/in. It's 3.5" tall free height, travel of 2" with a block height of 1.5". It has a max. loading at full bind of 865 lbs. It looks like it might be a good unit for both ends of the car, but I didn't try this one.

The short bit of driving I've done shows improvement over the individual linear rate springs. Unfortunately the weather's closed in for much more testing before next year.

Since these springs aren't exactly "free" and this change is pretty simple even after the car's fully assembled, I'd suggest you try driving your Street Rod before spending the $$$. If it seems to ride like a go-kart, then this is a reasonable solution for taming the ride a bit.
Total cost of part: $690.00 including shipping.

Here's a link to Eibach's complete spring catalog PDF file:
http://eibach.com/eibach/img/ers-2010-catalog.pdf

If anyone else does try this, I'd like to hear your own opinion of the change in ride character.
<center><img src="http://www.aim-users.com/Cousins.jpg"></center>

Best regards,
P.S. - the only way I could get the columns to line up was to put a photo in here wide enough to keep the text from wrapping!!! :)
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #10 · (Edited)
Judgement Day!

We had our January Thaw, but it came with a lot of rain two weeks ago. That's both the good news and the bad. The bad was that I couldn't get the car out to try the suspension changes because of the foul weather, the good news is the rain rinsed off essentially all the road salt.

So, today with the weather around 24°F, clear, dry and salt free roads everywhere I ventured out in the '33 to see how the combination spring set-up works on the car. The BondMobile (#007) had been in a 60°F garage at Salvaggio Automotive Design on Maritime Drive in Port Washington, WI so the shocks weren't stone cold. (But I'm sure they didn't get any warmer as I drove!) First I took it around the block on mostly good pavement with minor frost heave from the winter so far. It drives just fine on this stuff and really didn't seem much different from before. Maybe a bit kinder to the hinder, but at 25 MPH it's hard to tell.

Next I headed down WI State Hwy 32 toward Grafton on pavement which is 15 year old concrete. This is 55 MPH roadway and the joints this time of year are bumpy and noisy even in "your father's oldsmobile." Frost is amazing stuff. The ride here was far better than before - even though the roadway is seasonally worse than the last time I drove on it. The car's still remotely nervous, but no where near as it was before. The car still tracks and steers very well; no change in manners. The main thing is that it doesn't come unglued from the pavement over bumps as it did before.

From the Grafton intersection of Hwy 32 and I-43 I headed north on the Interstate. This section of road has significant joint bumps at this time of year (again, frost heave) and even my Passat complains. At around 70 MPH the car stays nicely settled, the nose stays better planted and the car drives more like a modern sports car - firm but not a kidney bleeder. Before I'd watch the front edge of the hood bobble up and down over every bump and pavement joint.

At Exit 100 at the north end of Port Washington I got back onto State Hwy 32 at the north end of the town. Most of this road is 25 MPH and very new and smooth. However, once into downtown, I headed out of town again via Chestnut road (probably the worst pavement in town) and down County "C" toward Sunset Drive, then back to Maritime Drive in the industrial park. Both Chestnut and Division (Cty "C") are near the end of their useful lives and are scheduled for complete reconstruction next year. Needless to say that at 25 MPH this isn't kind even in a Suburban, let alone the '33. That said, the car took the bumps WAY better than before. The car used to barely handle this section, bumping over all the potholes, sunken pavement and "gator back" ancient asphalt. Every bump was felt all the way to one's elbows through the steering.

Round trip - about 15 to 20 miles at speeds from 25 to around 75, on aged asphalt to new concrete.

I can't see any downside to the changes made. The ride and general comfort improvement don't seem to have any handling drawbacks. Unlike changing to a softer anti-sway bar, or reducing spring rate there doesn't seem to be any additional body roll. A day at the track before and after would have been nice, but "Winter" happens!

If I keep the '03 Pumpkin Racer and use it as a Street car, I'll probably give its suspension the same sort of treatment. There's a lot of difference in how these two cars drive with the extra 22" of wheelbase, but linear springs in both cars produce a level of uncivilized and unnecessary harshness.

So, in conclusion, if the '33 Street Rod's ride isn't what you always wanted, these Eibach tender springs are a very reasonable solution. I would love to hear from some others on this topic relative to their own perception of the car's ride. Further, if you know anyone with an FFR street snake in need of better ride, this concept should work there as well. The part numbers might not be the same, but for any given diameter spring, Eibach seems to have tender springs available.

Best regards,
 

·
FFCobra Fanatic
Joined
·
2,656 Posts
Thanks Tom. I appreciate your research, time spent, and write-up.

I am tempted to do as you have done.

Olli
 

·
Registered
Joined
·
3,317 Posts
Under hard acceleration is there any problem with wheelhop? I found that I get a softer (better)ride since I switched from Bilstin shocks to Koni shocks.With the Koni's The car gets a slight lift in the front end and the rear drops down just a slight bit under hard acceleration.The car plants the rear end real solid now.I get no wheelhop no matter how hard I shock the rear tires. I would like to keep it that way,but a little softer ride and keep the body roll down to a minuim would be great. The roads here in Michigan are some of the most bone jarring in the country.It sound like this may be something that I might be intrested in.Roger
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #13 · (Edited)
Hi Roger, I didn't try a standing start dump of the clutch but got pretty aggressive in 2nd gear a couple of times. Roads were very cold, but dry. I did get some wheel spin, but I've not had any wheel hop in the car since it first hit the street - before or after the change. Note that I have the three link rear axle location.

The Konis (come standard with the '33 kit) give nice control and have four settings from softest to most firm. I'm currently running them on their softest setting.

Now that the ride has been civilized, I've been able to focus on the tire/wheel combination for the final end of the car's work. I'd been considering 15" rims to get more sidewall and maybe some better comfort. I've now chosen 16" rims as a compromise based upon improved ride comfort. The tires are going to be 50 series so there will be some sidewall, but probably less flex than a 60 series on a 15" rim. If I want to play on the track, I can always borrow the 17" wheels/tires off my Pumpkin Racer.

No matter what the tire/wheels this combo spring setup should help the ride.

For the short ride I took I didn't notice any significant change in squat or lift at the back or front with the tender springs. The Konis seem to be more in control of that.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #14 ·
Hi Olli, I was frustrated in November when I first installed the new springs because Winter closed in and I couldn't really try them out. I had put enough miles on the car last Fall to know that the ride needed some refinement or I needed more sidewall in my tires (or both!).

Since this is a simple retrofit, you should probably drive it in summer weather some to see how it rides before doing the change. If it seems harsh to you, then this is less than an afternoon's work to change things around.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #15 ·
Weather!

I'm glad I got the ride in yesterday! 3" of snow overnight and the salt trucks were out in force.

So, I guess Play Time is over for a while.........

TV
 

·
Premium Member
Joined
·
3,804 Posts
It's too bad we couldn't find progressive springs. that would be the hot setup I bet. You think your rode stiff, try my 20 and 22" wheels! I still have a blast driving it, in fact me and John George just got back from cruising down Hampton Beach and then into downtown Portsmouth, Nh in it.
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #17 ·
Longer Rides...............

I, too, am enjoying the heck out of my car. Every time I fill the tank and realize I've put another 200+ miles on it, I smile. Tank for tank on the highway it is getting around 21MPG, I believe. That's civilized. I have 3.55:1 rear gears. It smells a bit on the rich side, so don't know if reflashing the computer would be of help. I may run it over to a fellow who does a lot of Ford stuff with his dyno and have him profile the Air/Fuel ratio through the whole range. Maybe that will be telling of a need to re-map the computer.

I am glad for the 500# spring rates in the front. I've notice heading into driveway ramps that it needs that much spring to not bottom when one wheel hits the ramp first.

The use of the tender spring at the back has helped the back end nicely. Did you also set your shocks down to the lowest setting? At Road America's track a few weeks back I enjoyed putting a bit of cornering pressure on the car. R.A. is about as smooth as one can find for pavement, so ride was not an issue. Putting some throttle into the car in a safe environment and using the brakes helped me fine tune the brake bias as well as get an idea of how the car's going to handle. Getting through R.A.'s huge carrossel turn and pushing the tires a bit was very pleasant.

I've meant to check the rear fenders to see if there was any rubbing when cornering hard. There is some body roll, but not excessive. And, with the roll there's not apparent change in steering attitude, so it's a very controlled feeling. Unfortunately it wasn't possible to get the car to near the tires' potential as there were a lot of cars out for touring and they were controlling things pretty tightly.

So, I still don't know if it wants to "push" or "wag" with the setup I have. Since I have smaller tires on the front, my guess is it will push a bit. With plenty of throttle available, it should control easily. My guess is that adding a simple anti-sway bar at the rear would be the answer if "push" turns out to be the main characteristic. Should it be tail happy, it would surprise me. It would be more difficult (and less pretty) to add a bar to the front end to correct that. I think before I did that, I'd probably change spring rates slightly; drop from 500#/in to say, 450#/in. That would be enough to shift the "looseness" toward the back.

I'll get some decent track time with either NASA "HDPE" or Northwoods Shelby Club sometime this summer. When I do, I'll report back on the car's track manners.

Best regards,
 

·
Registered
Joined
·
1,235 Posts
Discussion Starter · #19 · (Edited)
Adjusting Shocks.............

Hi AK,

Here's from the Koni site on the #30 shocks:

<i>30 Series

NOTE: Do not place shock absorber in a vice (except at the lower eye).

The Rebound adjustment is made with the shock fully extended. First remove
the shock absorber from the vehicle. Raise the black plastic dust cap covering the adjuster button. Hold the shock body where the piston rod emerges from the cylinder. Depress the button fully and hold it down while adjusting. The adjuster has 3 distinct stops (clicks), each of which marks an adjustment position. There are a total of 4 adjustment positions. The shock may have been adjusted previously. Check if the shock is in the zero-position by turning the piston rod counter-clockwise until the zero-stop is felt. DO NOT FORCE.

To increase the rebound forces, turn the piston rod clockwise. Once the correct adjustment has been reached, release the button and make sure that it fully springs back into position before installing the shock again."</i>

These shocks are set to the 2nd softest setting prior to shipping. Counter-clockwise will set the shock softer, clockwise makes the rebound firmer. They caution not to over do the rebound adjustment as the car will tend to "jack down" over a series of bumps if set with too much rebound control.

So, if you find the rebound to be too harsh, then you probably can soften it up a bit. And, you can maybe get two full adjustments for firmer settings.

I was able to adjust all but one shock by detaching just one end and extending it full length. Seems to me it was the left rear that I had to remove from the car completely to get it adjusted. It took two of us to do the front shocks. I took the bolts out of the lower end (rod end) of the shocks and extended it. My buddy held the button in and I twisted the rod to click down to the soft setting (from under the car). Later I moved the radiator and reversed the bolts at the body (upper end) end of the shock so if I ever need to adjust again, it will be easier. (My bolts were installed with the "bolt" end toward the radiator and I couldn't pull them without moving the radiator.)

(more comments at: http://www.ffcars.com/forums/showthread.php?t=228221 )
 

·
Registered
Joined
·
156 Posts
rough ride

Well I agree with and appreciate the posts from Tom and Ray and will, I am sure change the springs on the rear, [as it is way to harsh] and maybe even the shocks, but will wait a little and see if it becomes even more clear the best way to go. Thanks for all the great info guys.
 
1 - 20 of 149 Posts
Top