Dan Wheeler's Rear 4-Link Thread

DanWheeler · Sep 11, 2017

Thanks, Steve. That will be the plan.

That said, I just got back from a test drive after really dialing in the shocks at a lower ride height and I think I'm going to hold off until the weather turns before pulling it apart. It's pretty drivable down lower. Still some brake dive but much less.

Only problem is that the ride is pretty firm in the rear. The older ST struts I have, want to be sitting right in the middle of the shock length so 8" of chrome on s 16" shock. I've got 4" showing. I talked to ORI and they said something about the STs sitting on or in the oil that causes a firm ride. I need to order STX or send these in for upgrade. The STX can run at any ride height due to some valving changes.

I Gotta one of those dual-fill nitrogen hookups and something with a long hose so the bottle can stay on the floor. I'm going nuts trying to hold that heavy bottle up, connect the shrader fitting, open the shrader fitting, open the nitro bottle then turn the regulator handle. I need 4 more arms for all that. The air shocks really play off each other. It'll be nothing, nothing, nothing then go over to the other side, put a little air in then suddenly it shoots up way past ride height. Ive been going incrementally on each side so dual fill would be great to bring one end up as s pair.

Here's a pic at lower ride height. Doesn't look as fun =D

nvrstuk · Sep 11, 2017

Hmmmm, finds "is" a good buy on a dual full hose Dan...sounds like I'll be needing one too...

nvrstuk · Sep 14, 2017

Are you braided line for everything on your rig? I just posted on my build thread what to text at Summit told me about using braided line for the whole system. Don't do it or spongy pedal especially with hydroboost

DanWheeler · Sep 21, 2017

Just from the upper link frame mount back it's all hose. That is really interesting what they are saying. Well I suppose that wouldn't be hard to go back to steel tube. Hmmm

I've decided to leave it at the lower ride height for now and not cut things up. I'm liking the way it drives the few times I've had it out. Only issue so far is some loud and embarrassing tire rubbing at full lock so I'm doing some clearancing.

Still need to re-attach the sway bar in the rear then I'll trust it in the corners, that Currie antirock makes all the difference in the world.

DanWheeler · Oct 4, 2017

got new exhaust done at shop today - much quieter and less melty/smelly.

Also got the antisway bar cut down tonight and re-installed... I forgot what a massive improvement that makes. I have been tip-toeing around corners without it and with it back in, there's almost zero body roll and the tires start slipping long before it gets unstable. (if it even would)

I ordered some link brackets to raise the upper axle mounts and I also have ORI STX upgrade kits on the way to improve the valving on my ST struts. It's still a really bumpy ride.

Brakes are still spongy and front/rear bias is out of whack. Need to order a new Astro h-boost unit and matching master cylinder (mine are both junkyard and have somehow lasted 5+ years) to replace the Corvette MC which I only installed to rule out the Astro MC on the spongy pedal. I think it's probably just the long runs of hose. Brakes OK just feels soft.

Still diving on brake and squatting on accel at the lower ride hide but tolerable. I got a tire chirp on the 2nd to 3rd shift the other day when I was really getting on it - that's a first.

I also get a little bit of left-side lift on acceleration from a stop. Didn't used to do that with leafs but I guess things are a little more slushy now riding on air.

overall, things are definitely getting better - for a while there I wanted to drive it off a cliff but now I think I'll keep it

Apogee · Oct 5, 2017

The problem with driving it off a cliff is that that's kinda what you built it to do, so it would probably just keep on driving. Glad you're getting the bugs shook out though and good luck with getting the brake feel sorted out.

nvrstuk · Oct 5, 2017

DanWheeler said:
got new exhaust...

Brakes are still spongy and front/rear bias is out of whack. Need to order a new Astro h-boost unit and matching master cylinder (mine are both junkyard and have somehow lasted 5+ years) to replace the Corvette MC which I only installed to rule out the Astro MC on the spongy pedal. I think it's probably just the long runs of hose. Brakes OK just feels soft.

Dan, I think I mentioned this up at the top of Blewett the other day but for others reading this I will post up that I also called MasterPowerBrakes and asked them about using nothing but braided hose and they cut me short in my description of wanting to run all braided line and said "don't do it"...

So I ran as much hard line as possible...will find out real soon...

OX1 · Oct 5, 2017

DanWheeler said:
- for a while there I wanted to drive it off a cliff

Uuuuh, I thought that was the whole point??

DanWheeler said:
but now I think I'll keep it

Glad to hear you are getting close. What size is that vette master?

Yeller · Oct 5, 2017

The 2/3 shift chirp is due to the very low AS numbers. The geometry is not forcing the torque to generate traction so it slips a tire instead.

I do have a question. Now that you've driven it more when launching does the rear noticeably squat? Or is the ride height too low and/or compression valving too stiff to notice?

DanWheeler · Oct 5, 2017

OX1 said:
Uuuuh, I thought that was the whole point??

Glad to hear you are getting close. What size is that vette master?

UP, not OFF

I think that MC is a 1980 which says 1.125" bore.

I took a slow motion video when I was bench bleeding it because I thought I noticed the forward port was squirting before the front port and the video confirmed that. From what I've heard, you want the back brakes to lock up first to straighten the vehicle in a panic brake so if that's true, the forward port goes to the tears which is how I have it set up.

The rears are locking up super easy on hard braking even though I have the prop valve cranked down. I've been reluctant to slam the brakes really hard at speed to get the fronts to lock up because of the lack of antidive so I don't know if the fronts would ever lock up but my previous experience with this corvette MC the last time I used it was that I couldn't lock the fronts no matter what.

DanWheeler · Oct 5, 2017

Yeller said:
The 2/3 shift chirp is due to the very low AS numbers. The geometry is not forcing the torque to generate traction so it slips a tire instead.

I do have a question. Now that you've driven it more when launching does the rear noticeably squat? Or is the ride height too low and/or compression valving too stiff to notice?

Yeah it squats on launch and like I said, the left side picks up a little too. I remember when I added the traction bar to my old leaf setup - launches suddenly felt very "flat" there was no movement, it just went forward immediately. It doesn't have that feeling anymore, it feels a little sloppy like it's trying to figure out which direction to go.

DanWheeler · Oct 11, 2017

A few parts arrived to make Bronco go more better. ORI STX strut upgrade kit and some taller upper link mounts on the axle from Artec.

I've been doing some figuring and measuring on my rear brake lines and here is what I've come up with:

- I had 62" of rubber hose before the 4-link (frame to axle tee + hoses to each caliper)

- I now have 102" of -3AN stainless braided hose after 4-link (from frame at upper link all the way to calipers)

- I could reduce to 48" of -3 AN stainless braided hose after brake line re-do by using (4) 12" hoses, two on the upper link and two at the calipers.

just need a bunch of these to adapt from 3/8-24 female inverted flare to the -3 AN lines:

so that's the plan to reduce the amount of hose and firm up the pedal.

nvrstuk · Oct 12, 2017

Those are the fittings I used btw hard line and AN ends on my PTFE stainless braided lines...not helping me with my brake issue tho...

I'm bleeding my brakes and can't get a pedal for two pumps in a row...weird...spend 2 full 14 hr/days on it...oh well, not trying to hi-jack... : ) Got 3 shops in town twisting their heads trying to figure it out too! Used to do brakes for a living...good thing I'm not anymore!

Keep us posted on how it goes Dan!

DanWheeler · Oct 18, 2017

Got the old upper link mounts cut off the axle truss and the new taller ones welded on. Still considering more gussets but I don’t think they are going anywhere.

I have all new brake lines to install with less hose and more tube.

I have a new Astro M/C and reman H-boost on the way to replace the junkyard parts that have somehow managed to last 6+ years

It’s actually going pretty quickly should be done with Bronco 4-link v1.1 next week

DanWheeler · Oct 18, 2017

Had to redo the gussets between the mounts tonight, it was ugly. Also found a good use for those sticker sheets Summit Racing sends in every box. Welded on a proper brake line mount where I’m transitioning from tube to hose at the upper mount.

nvrstuk · Oct 18, 2017

Looking good Dan!

Shoot me a text when you can in the am...my ORI's are causing me a fit...

DanWheeler · Oct 23, 2017

Lots of pain, gain and spilled fluids this weekend

Rear brakes are now hard line except for four 12” hose pieces. First I had several leaks caused by bad double flares (need to order the high quality flare tool) but once I got those all worked out my pedal was still bottoming out completely. I used some plugs to isolate the problem to the calipers. I plugged the lines right before the calipers and pedal was just as firm as with plugs in the master cylinder so I knew my lines were good. Reconnected one caliper with other caliper still plugged and pedal was firm but only after some travel. I connected the other caliper and pedal bottomed out and zero braking power. I got all the air out of that caliper and got some firmness back in the pedal but still more pedal travel than I would like.

I’m pretty sure my oversized rear calipers (3” pistons) are too big for my 1.25” bore master. I need to step up the MC or reduce the rear calipers. I have a couple options I may try later. I’m not sure all that hose I had previously was really an issue or if it was, it was minor compared to the calipers.

I got the ORIs upgraded to STX. If my floors weren’t already covered in brake fluid they are now covered in fork oil. That stuff comes gushing out of the bottom of the outer case with no warning when you remove the top cap. The ride seems MUCH better now.

As for the rear end popping up on hard braking after raising the rear mount 2”... well, it’s still doing it =D My tears are still locking up first and my damping is set to the lowest setting so I will experiment with that tomorrow.

Overall, something about how it drives feels way better but I can’t describe it. Not sure if it’s the geometry fix or the ORIs but something just feels more normal now. Acceleration seems more stable and confident than before.

Lots more test driving and tuning to do

DanWheeler · Nov 3, 2017

Switched back to the hoses for the rear brakes tonight. Pedal feel seems good and brakes feel strong. This is with the new master and new h-boost. Way better for hose routing. I really didn’t like the hard line and hose transitions on top of the upper link. Seemed like there was some possibility of the steel tube bending back and forth on suspension cycle rather than the hose sections doing the flexing.

nvrstuk · Nov 4, 2017

Glad you've got things working better! No fun bleeding brakes over and over and over...

Dan Wheeler's Rear 4-Link Thread

Bronco Guru

Attachments

Just a Bronco driver for over 50 yrs!

Just a Bronco driver for over 50 yrs!

Bronco Guru

Attachments

Bronco Guru

Bronco Guru

Just a Bronco driver for over 50 yrs!

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Bronco Guru

Attachments

Just a Bronco driver for over 50 yrs!

Bronco Guru

Attachments

Bronco Guru

Attachments

Just a Bronco driver for over 50 yrs!

Bronco Guru

Attachments

Bronco Guru

Attachments

Just a Bronco driver for over 50 yrs!

Similar threads