15 replies to this topic

[jsgprod]

I know this is not the classified section .....and I'm not selling anything. But I might, and if I do I will post this there.

For now though I am curious about any and all other racers that I have not already contacted about the desire for some higher rate front torsion bars. I recently had some custom 31mm torsion bars made and before I did I contacted as many of the RPR members that I could think of, that I knew either raced, or Solo'd their cars. My reasoning for this was that I don't believe these things should be used in a street vehicle. For cryin' out loud, the 29's are stiff enough... or so I thought .

At any rate, before I started this I was hoping I could sell maybe six sets of these. I ended up selling all 10 sets that were made and have had a couple more people ask me about them since. Which is why I am posting this here now.

IF I can get enough CONFIRMED interest in having another run made, I am willing to do this again. But I will need at least 10 confirmed buyers prior to going ahead.

Oh yeah, the two most important aspects about them.
Price: as long as I have at least 10 made, $300 a set plus shipping.
spring rate: depends on how you actually do the measurements but I came up with ~ 650lb/in rate. Or right at 30% more than the 29mm bars, again depends on how you actually measure them.

I will monitor this.
Jay

[Greg Gauper]

I'd love to test my new 31mm bars Jay, but the glaciers haven't receded up here yet

First chance to test them will be at the end of April or first week in May.

I guess you get to be the guinea pig

Edited by Greg Gauper, 14 March 2007 - 08:39 PM.

[bamcrxgp]

Did you strengthen the torsion bar tube. I always thought about sleeving the outside of it.

[jsgprod]

I'd love to test my new 31mm bars Jay, but the glaciers haven't receded up here yet

First chance to test them will be at the end of April or first week in May.

I guess you get to be the guinea pig

What do you mean 'get to'? I already have ! I ran the race at Roebling Road with them in the car...........over a week ago. I guess I forgot to mention that.

I LIKE them! Wish I'd done them a long time ago. My first session out on Saturday AM I had three succesive laps that were within .3 sec of the track record... and I had no idea! Discovered that after I got home.

I was asked what I had done to my motor by a few people. They didn't believe me when I told them it was the same one I ran at the Runoffs, that all I'd done since then was work on the chassis. And get this, I had to use my stock gearbox, Jamie's not done with my new gears quite yet.

To say that I think the car REALLY works well with them is an understatement.

Blake, I'm using the stock tubes but will be checking them from time to time. I plan on making it to Atlanta in a week. Come on out!

Jay

[Greg Gauper]

Jamie may not be done with your gears yet, but he is done with my new final drive It shipped out today.

And no Jay, you didn't mention that you ran with the new bars.... I thought you didn't have time to install them before Roebling and that Atlanta was going to be your first race with them. Did you run with or without the front sway bar? Did you stick with the same rear rates?

Blake/Jay,

Any guestimates as to how much stiffening up the tubes would have on increasing the sprint rate up front?

[Doodson]

Jay maybe you could give a quick run down of your set-up

Shocks? revalved? Front / Back
Sway bars? Front / Back?
Rear spring rate?
31mm front torsion bars

The only reason I did not get a set of those bars is because I was affraid that I would have to get my Front KONI shocks revalved to work with those bars and then I will need to match the rears with higher spring rates and revalve those shocks aswell.
I would LOVE to do this but its not in the budget because I am planning on running a couple National SCCA races in GTL and thats taking some money. I still my be interested and will just hold on to them until I can afford to do the whole shock upgrade.

[iambhooper]

i think Doodson said it all... so i'll dito that one.

Also, as for strengthening the tubes... i wouild guess that wouldn't be "Improved Touring Legal"? But for Production, anything goes.

[jsgprod]

Jamie may not be done with your gears yet, but he is done with my new final drive It shipped out today.

Now, see, that’s just WRONG…. I’m the one that initiated all that work (including yours) and you’re still under a white blanket of frozen…whatever . I’ve already had three races (could have been four) yet YOU get your gears first? I’m just going to have to speak to Jamie about that.

And no Jay, you didn't mention that you ran with the new bars.... I thought you didn't have time to install them before Roebling and that Atlanta was going to be your first race with them. Did you run with or without the front sway bar? Did you stick with the same rear rates?

Actually, it was the Kershaw race in February I didn’t have time to install them for. It was a bit of a rush to get them in and adjusted for Roebling but since I did get them in time….
Ran with the front bar (stock box with a locked diff) and the same rear springs I’ve been running, the 850’s. I knew I needed to do something with the rear roll rate and didn’t have time to get new springs (sold them to you) so I looked into making a bigger rear bar. I thought I had some stock big enough in the garage but couldn’t find anything so I made a very strange looking, add-on, kluge, that I could bolt on. I had my doubts as to how well (or not) it would work but surprisingly, it worked quite well. FWIW, I picked up some 1” DOM tubing with 0.120 wall thickness the other day to make myself a real anti-roll bar .

Blake/Jay,

Any guestimates as to how much stiffening up the tubes would have on increasing the sprint rate up front?

I measured the inside/outside diameters and lengths of the tube a few years ago and calculated the rate of the tube at well over 2000 lb/in. I have that data somewhere, I’ll see if I can find it.

Jay

[jsgprod]

Jay maybe you could give a quick run down of your set-up

Shocks? revalved? Front / Back
Sway bars? Front / Back?
Rear spring rate?

Chris, I understand why you didn’t get them after the last PM you sent. Believe me, I totally understand why you couldn’t do this at this time, it made perfect sense to me.

To answer your questions, I have the shortened front Koni’s, double adjustable, valved for the 29mm bars BTW (more on this in a minute). Rears are also Koni but stock length and only single adjustable, valved for 1000lb/in springs (true)!!!
Front bar is an Integra bar (found a wagon in a u-pull it nearby! I may go get the front bar from it this weekend). Rear bar is my homemade one, ¾” x 39” length with adjustable arms, in addition to the above mentioned, UUMM, enhancement.
I run 850 lb/in springs in the rear most of the time, I tried the 1000lb/in units at the 2004 Runoffs(hence the valving rate) but the car was bouncing a little on fast corner exits. Shock adjustment didn’t help so I put the 850’s back in and it went away. I still put the 600lb/in rears in for Sebring, and will probably NOT run the 31mm bars there either for the same reasons.

As for the front shock needing revalving, I also thought it was necessary, until I found Lee Grimes at Daytona during the 24hrs. I discussed what I was doing and he basically told me to run them as is currently to see how well they could handle it. The valving is done to cover a range of rates and it’s possible that they would be able to handle the spring rate of these with the firmer adjustment settings. I haven’t done any testing (like I can afford that) but from the limited track time I’ve had so far, I think they’ll be fine….for now.

Jay

[Greg Gauper]

FWIW, I picked up some 1” DOM tubing with 0.120 wall thickness the other day to make myself a real anti-roll bar .

Jay

I don't know Jay...sounds kinda wimpy to me

I'm leaning towards one of these babies:
http://1speedway.com...rd_swaybars.htm
http://1speedway.com/Swaybar_Arms.htm
Something in a hollow 1.25in hollow bar.

They have charts listing all of the spring rates for their different bars with different wall thicknesses. My biggest problem is I think my current mount for my 3/4" bar may not be stiff enough and might start to deflect.

Good to know that the front Koni's work okay with the new bars.
If I can get the sway bar to work properly, I suspect I can get rid of those kidney killer 1000# rear springs I bought from you and get down to something a little more reasonable like 800#.

Edited by Greg Gauper, 15 March 2007 - 09:54 AM.

[jsgprod]

I don't know Jay...sounds kinda wimpy to me


They have charts listing all of the spring rates for their different bars with different wall thicknesses. My biggest problem is I think my current mount for my 3/4" bar may not be stiff enough and might start to deflect.

wimpy huh?

Let's see;
my current 3/4" bar with a 6.7" arm length = 208 lb/in rate.
Using the 1"/ 0.120" wall tubing with the same 6.7" arm = 425 lb/in rate.

Considering the new torsion bars are only 30% stiffer than the 29's, I think that should work.

I know what you mean about the mount. I've been looking at mine for a couple of years now wanting to reinforce it.

Oh, and I found those figures I had done on the tube, I was close. It was more like 2600 lb/in, according to my measurements and calculations of course.

Jay

[bamcrxgp]

Jay I will be at Road A crewing for a 914 that I helped build the engine for. I will stop by and say hello.

[tom91ita]

are you guys planning on switching between the 29 mm and 31 mm for different tracks or is there a set of 29mm for sale somewhere around here?

the 31's just seem like too much for an ITB/H5 and sometime GP car. i currently have the 27ish ones.

[jsgprod]

I plan on keeping mine for when I run at Sebring. That track is bumpy enough with the 29's in the car.

Thankfully most of the other tracks down here in the Southeast are pretty smooth.

Jay

[duner]

i would be VERY interested in a set of 31mm's, but i wouldnt be able to purchase them until later this spring or even this summer.

Jay, am i remebering correctly about you saying these t-bars were shortened, or was that something else?

thanks,

tim