Lowering IRS Suspension

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MyBlueBuggy
Posts: 99
Joined: Mon Mar 29, 2010 5:00 am

Lowering IRS Suspension

Post by MyBlueBuggy »

I would like to equalize the ride height front to rear in my buggy.  As it sits the buggy is 2" higher in the rear than the front.  While I can easily raise the front suspension, I have an adjustable beam, I would rather lower the rear because I like the way the front sits.  I have an IRS suspension and I know that to lower it I have to remove the torsion caps and relocate them on the splines of the torsion bar.  Yes I realize it's a bit more complicated but  my question is this...

If I want to lower the buggy in the rear, turning the end cap on the torsion bar will equate to what drop in height?  Also, if I rotate the bar in the housing,what does that equate to?

Also, any tips?  Recommendations?
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jsturtlebuggy
Posts: 652
Joined: Wed Apr 07, 2010 5:00 am

Lowering IRS Suspension

Post by jsturtlebuggy »

Tom,

I sent you a PM.
Joseph
Manx Club #1095
Having fun with Buggies since 1970
Worked in VWs in shops since 1970
louisb
Posts: 300
Joined: Wed May 05, 2010 5:00 am

Lowering IRS Suspension

Post by louisb »

Ed-Chenal
Posts: 382
Joined: Thu Apr 08, 2010 5:00 am
Location: SoCal

Lowering IRS Suspension

Post by Ed-Chenal »

Ed
MyBlueBuggy
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Joined: Mon Mar 29, 2010 5:00 am

Lowering IRS Suspension

Post by MyBlueBuggy »

OK,



So I decided to just go for it. I took some before measurements and the front ride height just behind the front wheels was approx 9" of ground clearance. Rear ride height measured just in front of the rear wheels was approx 11". So the 2" was what I was trying to eliminate and even out the ride. After taking a look at the table Louis linked I figured that just turning the torsion spring plate one spline would get me in the ballpark.



I took the rear wheels off, shocks off, removed the bolts holding the spring plate to the trailing arm and realized the side pods were in the way of the plate caps. It took a little garage engineering to get them off , aka sawsall and die grinder to the side pods, but eventually I was able to remove the spring plates and turn them one spline. After it was all put together and on the ground I stepped back in amazement as the buggy stance looked really low.



I knew this would be a trial-and-error job so I took additional measurements. I jounced the rear end by jumping up and down on the rear bumper then also made sure the front end was settled. I took more measurements at the same spot. 9" front ride height, 9" rear. I'm never this lucky. It looks great. I promise to post before and after pics as soon as I can.

Image
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5150bossman
Posts: 606
Joined: Thu Apr 01, 2010 5:00 am
Location: So Cal

Lowering IRS Suspension

Post by 5150bossman »

Be sure to let it settle in a bit and drive it around the block (or at least down the driveway and back), then take your final measurement.
MyBlueBuggy
Posts: 99
Joined: Mon Mar 29, 2010 5:00 am

Lowering IRS Suspension

Post by MyBlueBuggy »

I plan on it. I have a couple errands to run tonight after work. I'll give it a good workout then, check the handling, alignment, etc..
MyBlueBuggy
Posts: 99
Joined: Mon Mar 29, 2010 5:00 am

Lowering IRS Suspension

Post by MyBlueBuggy »

Post errand report:



Looks good. Handled well, a bit more balanced. No clunks or loud scary noises. I do think I need to sync my carbs though. Anyhow, I measured the car once I got it back into the garage. Looks like it settled about a 1/2" or so, it's measuring 8 1/2" front and rear.
Gene-C
Posts: 2949
Joined: Fri Feb 12, 2010 6:00 am

Lowering IRS Suspension

Post by Gene-C »

Tom
I just did mine
and it was actually pretty quick but then I did have a lift and air
One thing that you may want to look at is the inner and outer plastic  grommets or what ever they are called
Mine were really worn
Ed-Chenal
Posts: 382
Joined: Thu Apr 08, 2010 5:00 am
Location: SoCal

Lowering IRS Suspension

Post by Ed-Chenal »

The spring plate grommets from "Energy Suspensions" work real well.  I and others have had good success with the black polyurethane version of these grommets.  Unlike the old urethane grommets, if you use the lubricant they supply, they don't squeak.  They install easier if you gently round off the corners a little with a wire wheel. 

http://manxclub.yuku.com/editor/bypass/ ... =15%2E2109

Image

For Independent Rear Suspensions. Two 1-7/8 Inch Inner Diameter Round Style and Two 1-7/8 Inch Inner Diameter Knobby Style.
Last edited by Ed-Chenal on Fri Feb 11, 2011 8:46 pm, edited 1 time in total.
Ed
MyBlueBuggy
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Joined: Mon Mar 29, 2010 5:00 am

Lowering IRS Suspension

Post by MyBlueBuggy »

I replaced the bushings when I built the car. I did look at them when I had the torsion plates off and they looked just fine.



It didn't take me as long as I thought it would. I did most of the work at night for an hour or so. I guess total time involved was maybe one and a half to two hours a side, maybe. I still need to do an alignment and make sure nothing has worked loose. That may take an extra hour or so.



It wasn't too difficult. The key for me was to remove the rear shocks and once the trailing arm was separated from the torsion plate I used a floor jack to raise it up out of the way and secure it to the top shock mount to hold it out of the way. Most of the problems I encountered revolved around the side pods. They sit back on the pan just enough to cause interference with removing the outer torsion plate cap.
Lee-Hoffer
Posts: 69
Joined: Thu Apr 01, 2010 5:00 am

Lowering IRS Suspension

Post by Lee-Hoffer »

Tom,



I know exactly what you mean about the side pods interferring with the torsion caps. I always have to remove the side pods for this job, which adds a considerable amount of time to the process.
Carltons
Posts: 53
Joined: Tue Apr 20, 2010 5:00 am

Lowering IRS Suspension

Post by Carltons »

Tom
If you have the rubber ones they  do shrink, or harden a bit so that may be what is making the noise. On my 69 bug I replaced them in 96 and they did harden a bit after a few years.
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