coil overs and cutting torsion

Gang,
I'm working on a VW based car (not my speedster)and I'm installing a 915 tranny with an EJ25 engine and I need to move the combo up and forward. In order to do that I'll have to cut the center out of the torsion housing and ditch the torsion bars. Can I run the trailing arm plates without the torsion bars? Anyone know of some good yet cheap (I am a teacher you know) set of coilovers that will fit the IRS arms? Thanks.
Jeff

Don't know the precise fitment with your setup, but remember that Porsche 914 is coilover at the rear. Maybe you can gather some "affordable" ideas from some discarded 914 bits.

angela

You do need the torsion plates to prevent sideway movement. You will someting like this
http://www2.cip1.com/ProductDetails....de=C26-501-360

As far as the coil over go you get what you pay for . Cheaper coil overs give you a cheap hard ride

If Joe's link doesn't work, try this:

http://www2.cip1.com/SearchResults.asp?Search=C26-501-360&Search1=Search

The torsion bar is held in position at 2 points, one us vua the splines on the spring plate and the second is a set of splines located within the middle of the torsion bar tube. The spring plate is held in position by 4 bolts and supported by thick bushings. This mass is made to rotate up and down in an arc and, if you remove or cut the torsion bars then the mass can move sideways causing a huge alignment problem with the rear suspension and, without a doubt, something will break. If you proceed, it will be a danger to you and to others.

I might go the way of the plates but the coilovers is the hard part. Finding some for free is even too expensive! I'm not cheap, just broke. :)
I'll get the engine and tranny set up and see how things fit then go from there. I have to get custom axles yet too. ugh.......
Jeff

"I'm not cheap, just broke"

I like the way you put that.

If you are worried about $$$ stick with the standard VW set up. If you need extra spring buy the JCwhitney coil overs. You do not want to go cheap on a coil over rear suspension w/o the torsionbars. It can be dangerous . I ended up paying $400 for a set of QA's for therear of my Volkrod.

You could look at some sites like racejunk .com for used coil over. You will need to but different springs for them with a lower spring rate 140 - 180# based on the rear weight of you car.

Larry, i am not sure i understand your explanation. the bushing is used to locate the pivot point of the swing arm, if the splines are greased (as they should be) the splines are going to allow the torsion bar to move left and right, in addition to this the torsion bar would certainly flex if the bushes were worn, pleas explain to this "moron" what would be the danger, as i see it, as long as the bush is in good condition what else could move and be dangerous.


I do accept that spring rates and shock rates are not something that you will get right first time, in fact will probably accept a compromise after 5 or 6 tries (gets expensive)

I am using the same set up with coil overs

You do not need to cut the torsion tube if you use a 915 fitting kit c/w shorter nose cone from Bug@5-speed. The box will then fit right in with a bit of grinding on the fork flanges. The kit includes a nice trans rear mount and front mount to the fork ends. Using this method no torsion tube cutting is needed hence you do not need to buy coil overs but cost was about 350 Euros for the kit

I used Carrera QA-1 4855P coil overs and springs from Summit. I think the shocks were about 180 USD ea and springs around 40.00 Rear spring rate guesstimation is 300 - 325 in/lbs. Weigh the car when finished to get the spring rate right but this will be close. You can check the prices on line easily enough

In retrospect, I would now cut the torsion tube and spend the money on the coil overs. This will allow moving the engine/box forward to reduce polar moment of inertia.

The best (and most expensive) way is to use the Bug@5-speed nose cone only and move it even further forward taking advantage of the shorter nose cone. You will have to fabricate both front and rear box mounts as you are now too far forward for the kit parts.

Yes you will need uniball plates in place of the stock spring plates if going for coil overs. I used Eagle Racing in the USA at around 250.00 - check on line.

If money is the issue, you can see how coil overs done right can add up in a hurry.

Be careful moving the whole mess too far forward. I know Henry at IM has had some CV boot issues in his 911 six powered cars. These cars have the motor/trans pushed forward to allow fitting the six where a four would be.

Greg,
Basically it's like this. If you cut or remove the torsion bar and rely solely on the spring plate to control the axle, the spring plate will wobble side ways, up and down and any direction it wants to move as the only thing supporting the spring plate would be the busings.

In a normal application, the torsion bar is held in place by the splines of the torsion bar at the inside of the tube and the outside by the spring plate. The spring plate is held in place by the bushings (1 inside and 1 outside. The spring plate cap is held in position by 4 bolts.

911 racer guys remove the torsion bars all the time. They don't have to cut the housing, though. Then they install coilovers and a monoball kit, which is a heim joint that replaces the spring plate cover. I think the trailing arms are special too, but the bananas(nickname for trailing arms) are cast aluminum.

See my post above re made in USA uniball plates. I had it wrong and it is Eagle Performance:
http://eagleperformance.com/CoilOverKits.html
As other posters have noted you NEED these and cannot use the spring plates

If you want aluminium trailing arms, use Porsche 944 turbo but see my earlier posts re pre-post 96 and either 25 or 50mm wider per side. Make sure you get the matching axles.

As noted you can only push the motor fwd within the range of the CV joint. Misalignment on the CV joints is limited and 930's are the max at 25 Degrees but require a 108mm output flange. Type 2 x 100 mm flanges @17 degrees or Type 4 x 100mm at 22 Degrees are reasonably priced.
T-1 flanges are 94mm

PS
Forgot to mention that the axle splines are different on the 930 at 28

T-1, 2 and 4 are 33

robert ,
The coil over shock mount comversion bolts are not cheap either.I 'm using the 944T arms on my Rat rod chassis. found a cheaper method for the shock mounts. I'll post some pictures soon.
Joe

The visual of that Eagle kit explains why you can't just cut the torsion bar out of the system. That appears to be for an IRS system but, I bet it could easily be adapted for a swing arm transaxle

Here's a photo link of my rear suspension minus torsion bar
[IMG]http://i241.photobucket.com/albums/ff42/Jogyver/IMG_2530.jpg[/IMG]
[IMG]http://i241.photobucket.com/albums/ff42/Jogyver/IMG_2521.jpg[/IMG]

Bad link - try these
http://i241.photobucket.com/albums/ff42/Jogyver/IMG_2521-1.jpg
http://i241.photobucket.com/albums/ff42/Jogyver/IMG_2530.jpg

Joe

How are you doing the top shock mount. I am thinking of designing a double shear bracket.

Joe, Although it's not a torsion bar removal as was commented on in the original post it appears to be VERY NICE work. Have you figured out how you will adjust Camber?? Some people shim between the trailing arm and the wheel.

In regard to the top shock mount, with out a doubt, do as was suggested and fabricate a double shear bracket to take the load. Most of the rear weight will be on that bracket and I wouldn't trust a single mount to take the wear and beating it will receive.

Joe,
Never mind, I guess I missed one photo showing that your using a control arm and a trailing arm