Evill Ed

This has been a 2+ year restoration. The car is done but needs final tweaking. My main gripe is the very heavy steering feel and to a lesser degree ride quality. I am looking for suggestions on ride height and suspension set up. The car will be used mainly for Street and a few DE events per year. Here are the details on my car.

The body is a 1977 911S. I added Carrera Rear Flares to it. These are butt welded and dead even side to side as measured from several locations. The suspension has been completely rebuilt. Torsion bars have been increased to 21mm and 28mm F&R. The bushings have been replaced with Weltmeister plastic. The struts are Bilstein Sports, new turbo tie rods were added and Weltmeister Steering Rack Spacers. The wheel bearings F&R, and ball joints are new. Weltmeister sway bars front and rear were added. Brakes were upgraded to Carrera calipers and rotors. Wheels are 7 and 8 by 15 Fuchs with 205/55/15 and 225/50/15 Yokohama AVS.

When I set the car up, I set ride height at the wheel well centers at 24.5-in front and 24-in rear. The measurements from the wheel centerlines to the torsion bar centerlines are 179mm front and 49mm rear, even on both sides. This is far off from the factory settings of 108mm front and 12mm rear. While the car looks good, I am convinced that it is way too low. At higher speeds or on rough roads I experience bump steer and then harshness when I believe the struts bottom out. The initial suspension is smooth, but gets hard quickly. BTW – the front strut spacers (thick steel washers) are removed.

The other day I raised the front and rear of the car 1-in higher with floor jacks. At Euro Spec, 25.5-in front and 25-in rear at the wheel wells, the wheel to torsion bar centers decrease to 154mm front and 21mm rear. These are still a way off from 108mm and 12mm. According to Bruce Anderson’s book, the rears can work well as low as 1.25-in, so I think the 21mm setting would be fine. I’m hoping that the increased ride height of 1-in in front will provide adequate strut travel. I realize that original tire diameter for this car was 25-in and my current set up is just under 24-in (23.8-in) but to get to the factory spec of 108mm in front, I would need to raise the front up another 1.6-in. (Rally Car?) When viewed from the front, the control arms angle upward a few degrees on the ball joint side. The tie rod ends also angle upward, hence the bump steer.

Now to my heavy steering. First I found that the Weltmeister spacers move the rack up to where the rubber bushing (under the steering shaft u-joints) binds. The inside of the rubber bushing has a groove in it; the shaft has a ring on it that rides in that groove. The rack spacers move the shaft up to where the ring and groove are not aligned. The rubber bushing nests into the clamp, so there is no adjustment to compensate for this change. I removed the clamp on the bushing and found the steering felt a bit easier. As an experiment, I added 1//4-in spacer under the bushing clamp to reduce friction against the shaft. I also checked the rack with the front end jacked up, it is smooth and easy with no binding. My alignment specs are Front: .7° Camber L/R, 6.1° Caster L, 6.2° Caster R, 0 toe. Rear: 1.4° Camber L/R and .03° toe. I am wondering if the caster is contributing to the heavy steering feel. I also have a Momo steering wheel which is a smaller diameter (350mm) than stock so that is a contributing factor as well as the wider front tires, 205mm vs. 185mm.

So my intention is to raise the suspension 1-in front and rear and remove the rack spacers if possible or maybe replace with adjustable toe rod ends if necessary. I want to reduce the heaviness of the steering. I like a firm planted feeling and I do not mind slightly heavy steering. Your thoughts and suggestions are welcomed.

Regards,
Ed

John D.

Awesome looking car, Ed..!

As well - you might want to invest in a call to Steve at Rennsport - 503-244-0990. Say "Hi" for me if you do, OK??

Best to ya'!

John D.

rusnak

The steering rack arms should be roughly parallel to the ground. They should also be equal in terms of angle left to right in relation to the ground (level). It sounds like you could benefit from raised spindles in the front. Did you leave the rubber snubbers in the front struts? If so, you might want to cut them down by about half.

FranzBlamRacing

Franz suggests you take the spacers completely out and get a bump steer kit for the front end. Make sure that a professional bump steers the car for you.

Set the front toe to 0 and in the rear to 1.5mm in per side.

Next, try going to 24.75 in the front and 25 in the rear.

Take some caster out to between 5.7 and 5.8 degrees.

Finally, the rear 28mm torsion bar may be too stiff for the rear. We typically put 26mm on cars that will be used for both street and track.

If you have any more questions please do not hesitate to call us.

Evill Ed

Thanks Johnny, good to hear from you. Hope all is well with you and Jenn.

Rusnak, I will cut the snubbers if necessary.

Franz- Thank you for the advice. You are suggesting a slightly higher height in the rear than the front, I thought the rule was higher in front. Is the higher rear to provide more foward rake? I have to double check my rear bars, I thought that they were 26mm's but my receipt says 28mm, I will have to look at and measure one.

So you do not think I have the suspension too low? There will be adequate travel at these settings?

Any advice on adjustable bump steer kits?

Regards,
Ed

John D.

And right back to you and yours!! Your sons have got to be in college by now, right??

Seriously - Jenn & I miss all the great times on all the rambles, even though you drove like a maniac (what the heck was that hill-climb..?? )

Anyway - back On Topic.. A really stunning car, Ed... Your workmanship skills have always been wonderful - and we'd like more pics, of course! Sorry I can't provide any suggestions on your set-up, tho' - but it looks like you are in good hands with the comments back...

Best to you my friend! Let's plan on getting together, OK?

John

Evill Ed

John, Dylan is 13 yrs old, he is into Boxing, he has been training with professional fighters for 2 years now. Also into cars, motorcycles and building things.

Eddie is 10 yrs old and totally into baseball, wants to be a pro one day. He is inot cars too, he really likes Mustangs.

Kali is good and still tolerating me, so all is good.

Yes, I really miss the Rambles too, we did have good, crazy and slightly dangerous times. We really should try to plan some type of gathering.

Thank you for the comments. This project was a labor of love and IMO the finest car that I have built to date. This is the green 911S that I sold my 914 to purchase.

Your boys must actully be in college (or out by now) right?

You can see the build up of my 911 on my page at http://community.webshots.com/user/evill914 as well as the 914-6 I built for Nick Cole.

Stay Well.

Ed

RoninLB

my car 1977

I set my rake at 1% w/stock dia tires, 3/4 tank gas, drivers weight in seat, and correct tire psi and alignment.

I run 21/27 t-bars, turbo tie rods, Bilstiens HD x 4, stock 1977 sway bars, rack spacer, BA "euro" ride height, and Welt street bushings.

Not the softest street ride but great suspension travel and control when unforseen situations arise. It's a relaxing and safe cross country go-cart with Bridgestone S-03s.

I needed a perfectly level floor for settings.

and nice project you built

FranzBlamRacing

Sorry for not getting back to you quicker, Ed. We hope you had a nice weekend.

The goal here is to add just a tad more rake, keeping in mind that the fenders aren't 100% symmetrical. Your suspension is not too low in our opinion.

Please check your pm for bump steer info.

Thanks,

FBR