single adjustable shock-compression or extension adjust?

[High Plains Mopars]

I've been shopping around for a single adjustable shocks and notice there are some that offer compression adjustment and others that offer extension adjustment. What are some pros/cons of the two different approaches in a street application? Does that criteria change when used in an autocross where transitional control is of huge importance?

[Bryce]

compression

short answer I know. I will add more later.

[79T/Aman]

Who offersa compression adjustable only shock? most are rebound adjustable

[68sixspeed]

QA1's are adjustable on compression. (on my 68)

[JRouche]

Well beyond the scope of my knowledge but I would think if I had to pick one I would want it adjustable in bump. I just picture the bump as being the more active side of the stroke and I would want more control over that. Ideally it would be double adjustable. Cause on rebound the springs will want to slam the tire back down pretty hard. So maybe they have a fairly stiff valve for rebound on a single adjustable shock. Are the DA shocks that much more? I think I had to pay an additional 200 bones (maybe less, I forget) per shock for mine. They are air ride tech spring/shocks (shockwaves) though. JR

[The WidowMaker]

maybe mark will chime in, but i thought that the CA single adjustable adjusted both the bump and rebound. the doubles allowed them to be adjusted seperately, but the singles still did both at once.

Tim

[79T/Aman]

I need to look into the single adj. more but 3 way shocks adjust the rebound but wher some get confused is how they are listed in comp/reb. %, the comp. stays the same it's just the % from comp. to reb. that changes.

[BMR Tech]

QA1's are adjustable on compression. (on my 68)

QA1 single adjustable (Stocker Star) shocks change both compression and rebound at the same time when they are adjusted. This is fairly typical of most single adjustable "Street" shocks as Tim mentioned earlier.

[High Plains Mopars]

Who offersa compression adjustable only shock? most are rebound adjustable

Spax and Afco both offer shocks in single adjustable models that can be made in either compression or rebound modes.

Yes, double adjustables certainly are the schiznit for the application, but at $150-200 more per shock, that is just a bit hard on the budget right now.

So QA1 have an incremental increases on both rebound and compression for each click. Is that a more reasonable performance compromise to having a shock with one mode with fixed valving and the other motion adjustable?

[Marcus SC&C]

Almost all single adj. shocks are rebound only. This applies to both onroad and offroad. QA1 and Chassisworks Varishocks are exceptions and both adj. compression and rebound. The DA versions of both obviously adj. comp./rebound individually. The QA1 use linear curves, Varishock are progressive/digressive which I find gives them more usable settings. It`s hard to explain well in this "online post it note" format but it makes them a little like a poor mans double adj. by altering the comp. and rebound rates differently at comparable points in their respective curves. A little dampening slight of hand as it were. ;) Mark SC&C

[68sixspeed]

QA1 single adjustable (Stocker Star) shocks change both compression and rebound at the same time when they are adjusted. This is fairly typical of most single adjustable "Street" shocks as Tim mentioned earlier.

you are correct, I thought of that after posting!

[amx2334]

QA1 Proma Star, Stocker Star, Pro Coil are compression and rebound.
QA1 Ultra Ride, Aluma Matic, Street Star are rebound only.

[High Plains Mopars]

Hadn't look at Vari-shock before. Very nice set up. I really like that they have a variety of lenghts to fit non stock ride heights. That is very cool since my car sits quite a bit lower than stock and the twin tube design should be decent for the street. I'd like to find some more technical info on them since their online catalog kinda sucks.

Another option I came across is Strange. They have a double adjustable mono-tube shock for around $250. That is considerably lower than any other double adjustable I've seen out there and jsut a little bit more than most single adjustables. Anyone have any expereince with Strange?

Something I've also noticed in a couple of catalogs in a price difference in drag shocsk vs an ovaltrack or road race shock. I could see this in a single adjudtable version, but if you have a shock with double adjustable options, what would the big differences between a drag shock and oval track shock be?

[Marcus SC&C]

Feel free to give a call for more info on the Varishocks. We`ve been using and selling them for quite a while now so we know them very well.

I haven`t used the Strange shocks but as a rule nothing violates the old standby that you get what you pay for, ;)

The difference between the ranges of adjustment. Ie. if a drag shock may allow less rebound dampening adj. than a circle track shock. A Circle track shock will have adj. ranges starting firmer and ending firmer than a street shock etc. You can probebly get a middle of the road setting with any of them but they`ll allow more adj. in the range that that discipline uses most. Mark SC&C

[silver69camaro]

Unless if you are paying $800+ for a shock, each adjustment will change both compression and rebound, even if the manufacturer states only one is changed. What happens is say one click adds 10% to rebound, but also happens to add maybe 5% to compression.

[silver69camaro]

Another option I came across is Strange. They have a double adjustable mono-tube shock for around $250. That is considerably lower than any other double adjustable I've seen out there and jsut a little bit more than most single adjustables. Anyone have any expereince with Strange?

Strange makes very good shocks, and their valve type is almost identical to a Koni. Problem is, most are designed for drag racing. The Strange units we use are valved for our specs.

I'm going to be a bit blunt here, but it sounds like you aren't very familiar with dampers which would make any more than a single adjustable out of your league. My advice to you is to get a single adjustable shock of decent quality, set it then forget it. Properly adjusting compression and rebound individually isn't easy.

[JRouche]

Unless if you are paying $800+ for a shock, each adjustment will change both compression and rebound, even if the manufacturer states only one is changed. What happens is say one click adds 10% to rebound, but also happens to add maybe 5% to compression.

Wow, really? 800 each. I bought some shockwaves for 800 a pair and thats with an air spring and double adjustable shocks. They look surprising close to varishocks too so I wouldnt be surprised if they were.

I just couldnt imagine paying 3200 buck for a set of shocks. Really?? Anyone paying that much here?? Where is that money tree, I am gonna change jobs from being retired to a gardener JR

[Twentyover]

Wow, really? 800 each. I bought some shockwaves for 800 a pair and thats with an air spring and double adjustable shocks. They look surprising close to varishocks too so I wouldnt be surprised if they were.

I just couldnt imagine paying 3200 buck for a set of shocks. Really?? Anyone paying that much here?? Where is that money tree, I am gonna change jobs from being retired to a gardener JR

Penske motorcycle shocks are $1200-1600 each. They do come with a spring.

Yes, they contain essentially the same parts as a $10 pep boy shock, but are 4 way adjustable (adjustable for low speed, high speed (shock speeed, speed of linear compression and extension) dampening in jounce and rebound)

But where the $10 shock is put to gether by a piece of automated assembly equipment in a dark greasy factory from whatever parts the previous machine spat out, the Penske is assembled by nubile beauties to custom specification (yours) from precision parts fabricated to close tolerances in well lit clean rooms accented with the light aroma of smoldering incense.

Or something like that

[Rhino]

...They look surprising close to varishocks too so I wouldnt be surprised if they were...

As far as I know, they are Varishocks as of this moment. I've been told they're varishock components that ridetech builds and dynos in house. It doesn't really matter in regards to the rebound/compression/both discussion, but I figured I would let you know.

[High Plains Mopars]

I'm going to be a bit blunt here, but it sounds like you aren't very familiar with dampers which would make any more than a single adjustable out of your league. My advice to you is to get a single adjustable shock of decent quality, set it then forget it. Properly adjusting compression and rebound individually isn't easy.

Very observant and very close to the truth. My experience with shocks has all been in highly restricted, stock type racing classes that did not allow adjustable capability. If we needed more or less control, we swapped the whole shock, which got expensive fast and became a limiting factor since the budget was tight and we had to sometimes compromise on the best set up in order to buy tires or gas instead of another shock.

So on my street car 'd rather pay more up front for more capability that I can grow in to than swap shocks every few years. My car will not only see street duty but will also be doing an occasional autocross and and regular Nasa HPDE. So yes, my initial choice was a very good, high quality single adjustable unit that may last me a long time before I get tuned in enough to the set up to get double adjustables. I doubt I'll just set it and forget it since in addition to those activities, I also hit the drag strip once or twice a year, hence the whole idea behind adjustables.

So, knowing the above and referencing a single adjustable unit, would you lean more towards a rebound or compression adjustment? I can see merits of both, but like you said, lots of margin for error in there if I head off in the wrong direction with a double adjustable unit. Before making the purchase, I probably will also call the manufacturer to talk about where I am at with my wheel rates and intended applications to see if an off the shelf valving will work or if I need to get something custom set up.