Front end rise, rebound bumpers and shock length??

Posted By: ZIPPY

Front end rise, rebound bumpers and shock length?? - 09/01/10 02:37 AM

Well I think I found something.

Located a pair of the long discontinued .840 B body drag torsion bars for sale and bought 'em. They showed up and have been kicking around here for a little while.

I wanted to set the front end height the same as before so...before pulling the old bars out I got to doing some measurements and looking at a few things, and then I noticed the damn front shocks are too short!

With the rebound bumpers taken completely out, the front end can only move up about 3/8" before the shocks run out of travel....the upper control arm never even touches the rebound bumper.

Gee whiz, maybe that's why my car has never picked the front end up worth beans? Maybe that's why I can adjust the shocks to full loose and they always feel the same?

Common problem?

I found some cheap shock extensions that look like they'll work if I cut them to length.

When I extend the shock, then it seems like it'd also help to have some shorter bump stops for the upper control arms? Does anybody have a part number or source for such an animal?

Can't believe I never noticed this before, but honestly I never took the time to look

Thx

Posted By: '72CudaRacer

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 02:43 AM

You efectively tied the front end down. Like a 4 link car. Were you having trouble with the front end starting to rise and then spining the tires?

Brian

Posted By: '72CudaRacer

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 02:45 AM

The first thing I'd do is go to a salvage yard and try to find the correct lenght shocks that are worn out and try it. If it starts working better, go buy some Calverts or other good shocks.
Brian

Posted By: ZIPPY

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 02:50 AM

Tape measure tells me the front could potentially rise a tiny bit, but I never felt a thing driving it. Far as I could tell while driving it, it just sat there and did nothing

Really feel like a dork for not looking at it sooner, but there are alot worse things to overlook I guess

Posted By: TMP66

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 03:24 AM

Quote:

When I extend the shock, then it seems like it'd also help to have some shorter bump stops for the upper control arms? Does anybody have a part number or source for such an animal?

Yes, the part number is called a hack saw, or remove them completely.

Posted By: 69CHARGERMD

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 03:31 AM

I was told the .840 bars in a big car (B body) could be an issue as far as longevity on the street ?

I "ground" my bump stops down on my grinder,,I know some guys remove them all together,,i wanted to have at least some portion of cushion/rubber there.

How much travel do you have on the front end,,,i was told you should have 4-5",,, for me,,to achieve this,,,I had to lower the front end. If i recall the front end ride height on the "X" is set up for the street,,but I love the stance myself...

I have QA-1's and some Caltrac's,,,if were ever at the track together,,,your welcome to swap them on your car and try em....

ps,,Huge fan of the "X"

Posted By: Locomotion

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 03:33 AM

Do you know if the "short" shocks were for your particular application? From an A-body perhaps?

Energy Suspension has a variety of bolt-in rubber bumpers, OEM sized and probably smaller ones that would work. You can also saw off the tips to shorten them a bit. But do have something there. A long time ago I was told that not only is metal-to-metal hard on all the parts, but that the suspension travel was designed with the OEM stops in place and that removing them can put extra stress, bind and/or beat out the arms and their bushings when they travel beyond their design parameters.

Posted By: torkrules

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 10:47 AM

Quote:

I was told the .840 bars in a big car (B body) could be an issue as far as longevity on the street ?

I "ground" my bump stops down on my grinder,,I know some guys remove them all together,,i wanted to have at least some portion of cushion/rubber there.

How much travel do you have on the front end,,,i was told you should have 4-5",,, for me,,to achieve this,,,I had to lower the front end. If i recall the front end ride height on the "X" is set up for the street,,but I love the stance myself...

I have QA-1's and some Caltrac's,,,if were ever at the track together,,,your welcome to swap them on your car and try em....

ps,,Huge fan of the "X"

I've also been told 5" is the magic number. I have a buddy with the same issue on a 67 Dart. It's a big block with a couple of tubes in the fender well. With small tires and deep pan, the front end is up a little higher than it should be and he doesn't have enough travel so the front end comes up and then back down too soon unloading the rear tires.

Posted By: MR_P_BODY

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 12:35 PM

Rich, your going to gain alot more stored energy
with the small bars... get some longer shocks(alot
of guys like the calvert fronts)... if you still need
a little more travel grind your snubbers down on a
belt sander(a little easier if you freeze them) but
dont take them out completely steel on steel tends
to upset the chassis... if you grind down the snubbers
try to keep a similar shape... the shape is to have
a stack up rate... but just make them shorter

Posted By: ZIPPY

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 02:33 PM

Finding that problem explains alot, because everything I tried with the front end has made no difference. I've tried both stock replacement Monroe and QA1 shocks with no change, took swaybar off, no change, etc. Wish I would have noticed it sooner.

Being that I've used two different kinds of shocks I just checked both Monroe and QA1s data, and sure enough they list the same shock for A/B/E body....so both pairs of shocks that I've got are probably the right length for an A body but not long enough for the others.

The QA1s cost enough to where I want to give them a fair shake, so I'll try them with some extensions before going too much further.

Posted By: BradH

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 04:36 PM

In order to get my travel up to 5+", I had to...
1. Lower the static ride height of the car... a lot. As a result, I also lowered the back of the car because it ended up w/ too much rake after getting the front end down enough.

2. Cut down the upper control arm bumpers. I sacrificed an extra one figuring out how much could be trimmed before hitting the metal stud in the bumper around which the rubber is molded.

3. Change the upper shock mount hardware to effectively increase the length and allow the suspension to extend to the cut-down bumper w/o topping out the shock itself.

The end result is the car does transfer load off the line much better and the "porpoise" problem I'd experienced on occasion went away.

Posted By: Locomotion

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 04:47 PM

I remember once double-nutting the top shock mounting stud higher on the stud which allowed 1/2"-1" extra rise before the shock actually "engaged". It gave the shock that extra length before topping out. But it may have been before I learned that removing bumpers was not a good idea.

Posted By: cudarex

Re: Front end rise, rebound bumpers and shock length?? - 09/01/10 04:53 PM

To get my 5" of travel I had to lower frontend 2" and go to a 28" front tire to get ride ht. backup because oil pan was too close to ground.

Posted By: ZIPPY

Re: Front end rise, rebound bumpers and shock length?? - 09/04/10 02:36 AM

Front tires are 27.5, though it says 28" on the sidewall...

I might have to settle for 3" of rise because (like lots of others) I've got the front end set kind of high for the time being. Even 3" of rise should be an improvement over the tiny bit it had before, though not as good as 5+".

After the shock extensions show up, I'll see what's left of the jounce travel...if that's used up then will have to go to a thicker jounce bumper like this or this. No sense punching the shocks through the inner fenders (roads around here are rough) and want to play it safe there. The stock jounce bumpers are only 1.5" tall and are pillow soft so a taller/stronger bumper should save it from itself.

Then I think I'll go with these rebound bumpers to get all the rise I can get out of it. The stockers are 1.5" tall, and mine are showing a little weathering so might as well replace them rather than cut 'em down.

That's the plan for now anyway...If that doesn't get it then I'll chase more travel later on I guess. Too many irons in the fire right now.