mr henry

i have a 71 911t that i am converting into a rs replica. the cosmetic stuff is done and i am now tackling the mechanicals. i have a built 2.7 and a 915 ready for install but i am at a loss for suspension/brake upgrades. my car has the "m" struts so i know those need to go. i have access (free) to a '74 suspension and turbo brakes. dont know if those will retro fit or not. also, would appreciate advice on where to by these parts. haven't seen alot of stuff advertised for the older cars. <img src="graemlins/jumper.gif" border="0" alt="[jumper]" />

Trak Ratt

You didn’t say if this was a street or track car so assuming it will be mostly a street car w/some track use… If the ’74 has Bilstein struts (green) send them back to Bilstein to have them re-bushed & rebuilt to “sport” specs. You can also talk to them about re-valveing the inserts to match what ever suspension set up you decide on. There’s a previous thread all about the process. If not I’d go w/the Bilstein sport inserts & rears. Of course if the struts are Koni then that’s what you have to use. I’d use the ’74 suspension front & rear w/S calipers on the front, w/competition pads all around. But since you can get the turbo set up cheep you can use it w/this suspension too (see earlier threads for more information). I’d use 22 & 28mm hollow torsion bars w/a complete set of poly bushes. The ‘71 is relatively light & any more bar & you will not like the ride on the street. Use the stock S’s 15mm front & 15mm rear sway bars to start. I’d keep the sway bars relatively small compared to the torsion bars if you are going to run on the street, the ride will be a lot better. Remember through the body sway bars are more efficient than the later style, so the stock set up is probally a good place to start. Add Turbo Tie Rods w/spacer kit, & a factory short shifter kit. Don’t forget an external oil cooler, even a stock 2.7 can use the help. Role the front & rear fender lips & run 225-50s on 7x16s front & 245-45s on 8x16s or 9x16s on the rear if they will fit. Set the ride height at about 24” back & 24-1/2” front measured at the top of the wheel arch. Hopefully your rear flares were installed correctly. Get a good alignment from a shop that knows how to do Porsches, then enjoy. Best place to buy parts is at swap meets but get a copies of “Excellence”, “Grass Roots Motor Sports” and “Pano” for a list of venders & shop around for pricing, service & support.

JackOlsen

David's pretty much on the money, although I think 22mm front torsion bars are too stiff for a car that light, and (in a difference of opinion with Bruce Anderson, even) I'd say 28 in the back is too soft.

I have an early tub with 21/30 torsion bars, Turbo brakes, 22/22 adjustable sway bars (no reason to go small since you can dial them down to nothing), Turbo tie rods, drop links to correct the steering geometry. I have Bilstein Sports front and rear, revalved by Bilstein in back to match the 30mm bars. I run 8x10x17 2-piece Fuchs (made with Fuchs centers) and fit 245/275 tires underneath, which makes a huge difference.

Your alignment settings will make worlds of difference on a track. I run -3 camber in back, -2 in front, with the strut tower mounts modified to allow more caster.

The difference between my car and yours is that my engine is heavier than a built 2.7, so you might not want quite as much torsion bar in the back. However, there is a whole school of track guys (Bruce Anderson acknowledges them in his book) who think you can't go stiff enough in the back. 21/29 would probably work real well on your car.



Now, I'm just giving you opinions. Before you start writing big checks, you might want to ride in some cars that have had these kinds of mods done. If you're only driving on the street, then you'll probably want your suspension settings a few steps more mild, and you don't really need the bigger brakes, unless you're getting brake fade on public roads (and if that's the case, you probably should get off the public roads).

You'll get better advice on this board (and you also might want to ask for suggestions on the <a href="http://forums.pelicanparts.com/forumdisplay.php?s=&forumid=8" target="_blank">Pelican board</a>), if you tell us exactly what the car is going to be used for.

mr henry

thanks guys. as far as use, this would be hard street driving and DE events. comfort can be sacrificed. i really haven't inspected the suspension stuff so i'll check and follow up with any other questions.