RSR type raised struts

echocanyons · echocanyons's Garage

I would like to know the process that people are using to raise the spindles on the strut in order to lower the car.

Is there any saftey issues with this?

I am thinking about having this done to my struts but I am interested in more info.

How much are they raising it or better yet how low can they make the front of your car?

Kelly

derek_sf · 12-04-2002, 12:15 PM

I have some struts with raised spindles, they were raised 20mm I believe. I don't have them on a car yet, so can't tell/show you what the end result looks like.

mike mueller · 12-04-2002, 12:16 PM

it's easier with 911 struts than 914 struts, but 914 struts can be done.....I think if running a stock 15" wheel 18mm was the limit.

Larger diameter wheels allow more modification.

derek_sf · 12-04-2002, 12:31 PM

oh yeah, should have been more clear, mine are 911 SC boge struts.

echocanyons · echocanyons's Garage

I never thought about havin it done to my stock struts I guess you could though.
I guess I shoulda clarified I will be using carrera struts specifically boge

Is it just a matter of rewelding the spindle?

Derek who raised your struts for you(assuming you had the work done by someone ohter than yourself)?

Kelly

derek_sf · 12-04-2002, 12:58 PM

yeah the spindle is cut off and then welded back on higher. rich johnson did mine. I can show you pics later if you want.

campbellcj · 12-04-2002, 01:04 PM

FWIW the true 911RSR type struts are coil-over (threaded) types. But with the right equipment and know-how, the spindle can be raised on regular torsion bar 911 and 914 struts too. From what I recall the normal range is about 19mm-21mm or so.

The main advantage is that you can lower the front of the car that much more without detrimental impact to steering geometry.

You can also modify (bend) the struts for more negative camber - a possible alternative to cutting up the top mount area.

echocanyons · echocanyons's Garage

Coilovers...
So would you lose the torsion bars altogether or run with them as well?

Very interesting

Kelly

mike mueller · 12-04-2002, 01:42 PM

If you go with coil-overs, the torsion bars are no longer needed.
However, the cars are not designed to take that kind of load on the fender housings so they will be to be re-enforced.

Brad Roberts · 12-04-2002, 02:27 PM

You cant raise the spindles on a 914 strut. The tube is tapered. You have to cut the strut and add material at the bottom and cut the same amount from the top (leaving the threads). This ruins a set of struts to make one pair.

B

Jeroen · 12-04-2002, 03:49 PM

"The main advantage is that you can lower the front of the car that much more without detrimental impact to steering geometry"

I know you keep full suspension travel by raising the the spindle, but wouldn't it affect your bumpsteer in the same way as when you lower the car the usual way?

I thought that on RSR type struts the "knuckles" (dunno the name, the arms to which the tie-rods connect) were bent back down to compensate for this.

Cheers,

Jeroen

DDS · 04:43 PM

I thought this allowed lowering the (stock, torsion bar) suspension without causing bump steer?

So, how do you do it on a 911 strut? Is it just welded at that dimpled area on one side of the casting? Grind that out, move the casting, then re-weld?

Brad Roberts · 12-04-2002, 04:39 PM

Some of the arms have been bent down in the past. I have a set of RSR factory struts and they are not bent any different from the regular Bilstein struts sitting next to them.

Too answer DDS question:

Yes. No matter how you lower the car, you will need to set the bump steer.

3 methods for bump setting (rack spacers,bend arms, spacers on heim joints out on arm)

B

JWest · 12-05-2002, 04:55 AM

Quote:

I have a set of RSR factory struts and they are not bent any different from the regular Bilstein struts sitting next to them.

Thanks Brad.

Ha, Ha. I got ripped on the 911 board about a year ago because they said that the factory struts ALWAYS had the arm bent back down.

I was trying to tell them that bump steer would still need to be adjusted when lowering using raised spindles.

Racer Chris · Racer Chris's Garage

Quote:

Originally posted by Brad Roberts
You cant raise the spindles on a 914 strut. The tube is tapered. You have to cut the strut and add material at the bottom and cut the same amount from the top (leaving the threads). This ruins a set of struts to make one pair.

B

That's not entirely accurate. Raising the spindles on 914 and early (tapered) 911 struts is done by cutting and rewelding the shock tube, but it doesn't require a second set of struts, just the right size DOM tubing. If not done correctly, the shocks won't fit back into the tube.
I perform this service, and have raised spindles from 16mm up to 22mm, depending on application. I also bend the steering arm to offset the moved spindle. Final bump steer correction is done with rack spacers.

Brad Roberts · 12-06-2002, 11:04 AM

When dealing with newbies to fab work... you SPELL it out completely for them. Had I said "use the same size DOM".. they would have been asking me "what is DOM ??" ha ha.

I promise, I hold back about 80% of the details when asnwering questions. Much like a magazine doing a tech article.

B

914timo · 12-08-2002, 10:10 AM

Yes, and that´s the reason why it is sometimes so frustrating to read these "tech stories"....

Brad Roberts · 12-08-2002, 11:43 AM

Timo,

I also adjust the information according to whom I'm answering originally. I know you can find a second set of 914 struts to cut, but for you to find the proper sized DOM and try to purchase 4 feet of it.... its not worth it. I'll tell the guy who works in his garage with minimal tools how to do it with minimal pain. Chris is a fabricator and had he been my only audience, I would have said "replace" the strut tube completely.

I seriously try to adjust my answers to the audience.

If you came to the shop, and asked me to do it, I would show you both ways and let you decide which way you wanted me to do it.

B

sacook · 12-08-2002, 02:38 PM

Yeah.......but what's DOM ?

Brad Roberts · 12-08-2002, 02:46 PM

Drawn Over Mandrel

Its the way the tube is made:

A procedure for producing specialty tubing using a drawbench to pull tubing through a die and over a mandrel, giving excellent control over the inside diameter and wall thickness. Advantages of this technique are its inside and outside surface quality and gauge tolerance. Major markets include automotive applications and hydraulic cylinders.

Bottom line: its strong and is used extensively in fabrication.

B