high travel rf/lr

[Mr.Kennedy777]

If you can take 275 or 300 pounds off the bump and store it in the spring that’s more energy in a useable form over more travel than 1/4” or 1/2” inside a bump

[TheJet-09]

I saw Eckrich (Iowa) selling a Barry Wright on line, and in the pics there is a screw jack set-up for the RF upper shock mount. I assume that is how one could go about raising the RF without changing the pre-load on that spring. But you'd still need to be able to get it to compress down to the same end point in order for it to benefit the height of the LR, right?

[a25rjr]

Why are we not worried about getting the rr up in the air? I remember a modified and dlm had great success during Speedweeks, several years ago!

[Mr.Kennedy777]

I saw Eckrich (Iowa) selling a Barry Wright on line, and in the pics there is a screw jack set-up for the RF upper shock mount. I assume that is how one could go about raising the RF without changing the pre-load on that spring. But you'd still need to be able to get it to compress down to the same end point in order for it to benefit the height of the LR, right?

It would change pre load on the spring if the spring was on the shock. You’re not adjusting the pre load on the adjuster nut, but you’re pushing down on the shock which would raise the car you would still change your spring pre load. I think with the amount of pre load built into some of the springs this is a nicer option because they can get a little tight on the adjuster if you’re running a bump setup. Being able to make fine adjustments in shock height at static is nice and you can always re set pre load if desired or decrease it and adjust the shock height for different things going into the RF. I think personally it would just make quick adjustments and fine tuning easier, my personal opinion but I could be way wrong.

[Mr.Kennedy777]

Why are we not worried about getting the rr up in the air? I remember a modified and dlm had great success during Speedweeks, several years ago!

Are you talking about hiking the RR?

[a25rjr]

Are you talking about hiking the RR?

Yes.......

[Kromulous]

I seen that Barry Wright car, that adjuster is cool. Nice to have if you wanted to really boost up the LR for a feature, or different track, crank it down say an inch, lower the LR and the raise the deck back up. You could work it out in the shop on your smasher numbers for the LR, probably the LF and RR too i guess to get back to your set up, and change the whole attitude of the car dynamically.

Overall thats what i am trying to do, make more room for the RF shock to expose more shaft for available travel. Plus not lose to much shaft trying to maintain a higher static ride height, aka the preloading question.

One thing i find intriguing, Bloomquist doesn't run all that crazy camber. His car lifts high, but the nose inst burred in the ground like the longhorns or the disco mobiles either. He seems to make it work without going to the extremes.

[billetbirdcage]

Anyway, i am in the process of mapping my RF shock spring set up and i noticed to get ride height up 1" over std how are they doing this? Only thing i can think of is pre-loading the spring?

So say i have 425lbs on the RF corner static, and i have a 275 lb normal spring. At ride height you would need to compress said spring 1.54". 7" shock would show 5.46" remaining travel. That's if your shock mount can handle that much travel, basically zero droop, most cars have 1" or so? So that puts it down to 4.46" remaining travel. I think thats close to a standard set up.

Anyway is my thinking completely off here?

Not 100% sure if this is what your asking:

Can you run the car with the RF shock basically extended all the way at ride hieght? meaning when the car is setting on the ground in the pits the 7" stroke shock has 7" of exposed shaft? Not saying it's ideal, but we'd won 5K+ races like that. The car is never in that position except in the pits.

[Mr.Kennedy777]

Yes.......

I know quite a few mod guys that have been running 4 left and Z right for that reason. Even with relatively tame static bar angles that don’t move the tire rearwards much, the drive angle is always really good and coming off the corner you can see the RR coming up on the gas.

[Kromulous]

Yes Billet that's what i am after, maybe not the full 7, but 6 would be nice. Then i would probably have to work on rack or cross member clearance.

On the RR thing, on the slick tracks i go to, if i notice the RR doesn't compress coming off the corner or just stays the same ride HGT, the car is usually slow. Most of the fast guys from the middle off compress the RR a little. We race a lot at Florence that's where i notice it.

[Mr.Kennedy777]

Yes Billet that's what i am after, maybe not the full 7, but 6 would be nice. Then i would probably have to work on rack or cross member clearance. On the RR thing, on the slick tracks i go to, if i notice the RR doesn't compress coming off the corner or just stays the same ride HGT, the car is usually slow. Most of the fast guys from the middle off compress the RR a little. We race a lot at Florence that's where i notice it.

I’ve never had any personal success with running the higher drive angles in the RR on slick. But perhaps the drivers doing this kind of thing and making it work for them don’t use up as much of the RR tire capacity on entry to mid, perhaps more roll steer on throttle, maybe running higher bite and softer springs like old school, and then are able to use more of the RR on exit?

[Mr.Kennedy777]

I dunno. I’ve seen some guys be really fast and sounds like they’re ripping pretty hard even on a slick. Maybe it’s a brake floater on the left rear deal while trail braking with more throttle or something. Really not sure about that one lol

[billetbirdcage]

Yes Billet that's what i am after, maybe not the full 7, but 6 would be nice. Then i would probably have to work on rack or cross member clearance.

Just to be clear, I'm saying we've ran with 6 to 7" of exposed shaft when at ride height but we aren't using all of that up in travel. Meaning I'm not traveling close to 6" to 7" from standard ride height. There was another reason I needed the shaft exposure and it wasn't travel related in my case which I don't want to get into. I Just didn't want people to misconstrue I was traveling that far.

[riddle28]

this may sound dumb but how are you raising the rf 1" above ride height and holding the car up in the pits? like say youre an 1" above and your static ride height wheel weight is usually 450 a 3.5", meaning it takes 450 lbs to hold that corner up. If it takes that much to hold it up, wouldnt you wind up being like 600 lbs at 3.5" wheel weight when the car gets to the normal static ride height? that may be my problem im trying to make the high travel stuff logical with my old way of weighing a car

[Kromulous]

Cant use the quotes thing, but yes i wanted to have more shaft available to make room for a bump stop or bump spring, and a stack.

Riddle28, not dumb at all i am tring to put all together myself, if you boost your ride height up to 4.5" (over the 3.5") your going to have to decrease your LR the same amount 1" at min. Still you might carry a little more weight on the RF, not sure. So in essence your rocking the car back on the LR, using the LF and RR as the pivot axis.

I think the key would be with all that travel you added, is to keep the spring rate soft enough initially to travel thru it and get the nose down on the track before you add to much weight to the RF corner.