Help: Explain Swift DB1 Front Torsion Bar Working to Me

[rickd]

I'm not even exactly sure where it is, I assume it's in the tube that is the pivot for shock rocker arms. Is that right? How does it work? How is it adjusted? Does anyone have a disassembled pic of the assembly? Pics of the bar/bars?

Thanks in Advance, Rick.

[fletch]

I'm not even exactly sure where it is, I assume it's in the tube that is the pivot for shock rocker arms. Is that right? How does it work? How is it adjusted? Does anyone have a disassembled pic of the assembly? Pics of the bar/bars?

Thanks in Advance, Rick.

You are correct about the location.
It’s a splined shaft and is not adjustable.
I believe there were different diameter splined shafts available?

[Extreme1]

I’m not sure where it is on your car, but a Torsion Bar is a round bar of steel, with splines on each end. The bar is made of a steel that twists evenly along its length, then untwists when unloaded.

[rickd]

You are correct about the location.
It’s a splined shaft and is not adjustable.
I believe there were different diameter splined shafts available?

Thanks for the reply. Any idea where there are some pics of these torsion bars? I've checked the adds here but no luck, I'll try again.

[tlracer]

This is the rocker assembly - the arb is the link between the two. Apologies for the poor condition of the parts, the picture was taken before refurbishment!

It is splined into the outer collars of the rockers then secured with the small clamp bolts. There have been various upgrades/revisions to this original design over the years so you may also see other rockers with different/longer collars.

[rickd]

This is the rocker assembly - the arb is the link between the two. Apologies for the poor condition of the parts, the picture was taken before refurbishment!

It is splined into the outer collars of the rockers then secured with the small clamp bolts. There have been various upgrades/revisions to this original design over the years so you may also see other rockers with different/longer collars.

Thanks for the pic. Was it easy to change bars on a race day, did you multiple bars? You wouldn't have a pic of a bar by chance?
Thanks for this one.

[tlracer]

IMG_20220808_143332.jpg

Couple of bars...tbh, I am still rebuilding the car (it was something of a train wreck when I bought it) so can't say how easy they would be to swap on a race day. Certainly not as easy as just moving links, like most others though!

[rickd]

Couple of bars...tbh, I am still rebuilding the car (it was something of a train wreck when I bought it) so can't say how easy they would be to swap on a race day. Certainly not as easy as just moving links, like most others though!

Thanks, again, tlracer. That's some thick metal for such a short distance. Are they hollow or solid.

[tlracer]

All mine are solid - the ones in the picture are the thickest and thinnest I have. Lever ratio is actually quite similar to my Van Diemen RF86, but yes, they do look kinda fat at first glance!

[rickd]

All mine are solid - the ones in the picture are the thickest and thinnest I have. Lever ratio is actually quite similar to my Van Diemen RF86, but yes, they do look kinda fat at first glance!

How many do you have. Is that ''typical''.

[Garey Guzman]

I never changed the one in my DB1 when I had the car but it was already setup for the soft slicks of 15 years ago. I did adjust the rear based on how the car was handling that day.

[rickd]

This is the rocker assembly - the arb is the link between the two. Apologies for the poor condition of the parts, the picture was taken before refurbishment!

It is splined into the outer collars of the rockers then secured with the small clamp bolts. There have been various upgrades/revisions to this original design over the years so you may also see other rockers with different/longer collars.

Another question regarding the rocker assembly: The links hanging down that attach to the upright rockers...is that how front ride height is adjusted?

[tlracer]

The two bars pictures are the ends of a range of around 8 that I have though, like Garey, I suspect the one already on the car is the original and has never been changed!

The drop links are used for adjusting ride height. I've not yet investigated their involvement in corner weight adjustment...

[-pru-]

Attached OEM Swift DB-1 Set Up Sheet that outlines how the drop links are to be used with regards to corner weights...

[-pru-]

Older thread on Swift DB-1 Roll/Sway Bars: Sway Bars

[John LaRue]

Ray Germaine built an update for these that utilized a hex end if I recall correctly. It had external adjusters so you could equalize the down-links. Swapping bars and making RH adjustments was a snap. There were a lot of cars converted to that system in the day.

[rickd]

Ray Germaine built an update for these that utilized a hex end if I recall correctly. It had external adjusters so you could equalize the down-links. Swapping bars and making RH adjustments was a snap. There were a lot of cars converted to that system in the day.

Do you have a link or pics of this update.

[rickd]

Attached OEM Swift DB-1 Set Up Sheet that outlines how the drop links are to be used with regards to corner weights...

Thanks for the info.

[tlracer]

Do you have a link or pics of this update.

https://www.apexspeed.com/forums/sho...ank-differnces

[rickd]

https://www.apexspeed.com/forums/sho...ank-differnces

Thanks for the link. If what I see is correct, that was a mod to make the torsion bar adjustable with his blade style bars. Yes

[problemchild]

Thanks for the link. If what I see is correct, that was a mod to make the torsion bar adjustable with his blade style bars. Yes

As, or more important, it allows you to adjust more components to compensate for irregularities in those components as the car gets more used. The rockers get tweeked on a regular basis under normal use (curbs, wheel-banging, etc). By having more adjustments, you can quickly adjust components while keeping in the desirable range.

As a side note, try to pair up rockers by laying them on a flat surface, and matching those with the closest angles. Don't be alarmed if they are not perfectly matched, as they will change often. People had various tricks to equalize them including using a press, or dragging shock holes with a file and welding on washers to relocate the hole where desired. This was common with all 80s rocker cars. It is a performance detriment only if you ignore it. Stay on top of it and you can virtually match the performance of pushrod cars.

[rickd]

As, or more important, it allows you to adjust more components to compensate for irregularities in those components as the car gets more used. The rockers get tweeked on a regular basis under normal use (curbs, wheel-banging, etc). By having more adjustments, you can quickly adjust components while keeping in the desirable range.

As a side note, try to pair up rockers by laying them on a flat surface, and matching those with the closest angles. Don't be alarmed if they are not perfectly matched, as they will change often. People had various tricks to equalize them including using a press, or dragging shock holes with a file and welding on washers to relocate the hole where desired. This was common with all 80s rocker cars. It is a performance detriment only if you ignore it. Stay on top of it and you can virtually match the performance of pushrod cars.

Wow, something I hadn't even thought about, thanks.

[-pru-]

Via the Facebook group “Swift DB1 Owners”:

“Ray Germaine just made a set of his famous Bellcrank ARB Conversion to eliminate all preload when corner balancing DB1-DB5's. He has 4 other sets. Contact Ray if you are interested.”

[Roland V. Johnson]

Do you have current contact info for Ray?

[-pru-]

Do you have current contact info for Ray?

From an invoice dated Aug/18:

[rickd]

Via the Facebook group “Swift DB1 Owners”:

“Ray Germaine just made a set of his famous Bellcrank ARB Conversion to eliminate all preload when corner balancing DB1-DB5's. He has 4 other sets. Contact Ray if you are interested.”

If Swift had such problems with their splined bars, why do the circle track guys still use splines?

[tlracer]

If Swift had such problems with their splined bars, why do the circle track guys still use splines?

With the standard Swift rockers the bars are splined direct in. So unless the rockers are a perfect match, the drop links from the rockers to the upper front suspension arms are the only adjustment point for corner weight.

On Ray's adjustable rockers, the bars are splined into a non-fixed collar, that can be adjusted relative to the rocker. This avoids any 'twist' in the bar when adjusting other setup parameters.

On a 'conventional' bar, where it's operated by separate drop links & lever arms, this separates the ride height/corner weight adjustment from the bars.

Hope that makes sense!

[CARSHouston]

Or simply put on GT or circle track cars, our shocks aren't attached to the sway bar like yours's in a DB1. Those rockers are a great solution.

[Tim.R]

I'm the starter of one of the threads mentioned before
Due to the fact that i can't get unmodified bellcranks in case the modification goes wrong still haven’t tried to modify my original
ones.

Does anyone have a picture of a set of "disasembled" Protech rockers?
How is the "interface surface" between bellcrank and the adjustable part (which is fixed to the bar)? Just aluminium on steel, as the
only movement is while cornerbalancing and after that it is locked?
A needle-bearing would certainly be overkill.

And unfortunately i can't use the protech made ones as the european Swifts run longer ARBs!

Thanks in advance
Tim