Expert suspension opinions

gregg911 · 10:17 PM

I've been going round and round gathering opinions and I've come up with a list of suspension upgrades for my 1980SC coupe.

My goal is to max out the available 8 points in the IS class in PCA. The total for the changes proposed is 7 so I'm under the max. I'm looking for opinions and insight before I pull the trigger. I only want to do this once so I've got to get it right the first time.

Rear
Elephant Racing Polybronze spring plate bushing
Elephant Racing Cambermax
Sanders 28mm Torsion bars 1 point
Smart Racing anti roll bar 1 point
WEVO roll bar mount
factory trailing arm bushing

Front
Elephant Racing Polybronze control arm bushing
factory control arm mounting bushing
Elephant Racing De-cambered ball joints
Sanders 22mm Torsion bars 1 point
Smart Racing anti roll bar 1 point
Elephant Racing Bump steer kit
Turbo Tie Rods
Elephant Racing Triangulated strut brace 1 point

DOT50 tires 2 points

I appreciate any and all input. Please feel free to make any suggestions.

garmo · 06-03-2008, 11:28 AM

Subscribed - I have an 80 SC also and am interested in what you will do here.
Gary

Bill Verburg · Bill Verburg's Garage

What are you running for wheels? That would be where to start if you haven't already

gregg911 · 06-03-2008, 12:42 PM

Quote:

Originally Posted by Bill Verburg

What are you running for wheels? That would be where to start if you haven't already

I haven't decided yet but I've got (2) options

OPTION 1:
15x6 Cookie cutters (f)
15x7 Cookie cutters (r)

205/50/15 Yokohama ADVAN A048 heat cycled and shaved (f)
225/50/15 Yokohama ADVAN A048 heat cycled and shaved (r)

My thinking is a shorter lighter wheel assembly, faster to max rpms for autocross.

OPTION:2
16x7 Fuchs (f)
15x8 Fuchs (r)

205/55/16 Yokohama ADVAN A048 heat cycled and shaved (f)
225/50/16 Yokohama ADVAN A048 heat cycled and shaved (r)

I end up with about the same contact patch with either setup, the 15s are about an inch less in diameter (go figure

)

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by gregg911

I haven't decided yet but I've got (2) options

OPTION 1:
15x6 Cookie cutters (f)
15x7 Cookie cutters (r)

205/50/15 Yokohama ADVAN A048 heat cycled and shaved (f)
225/50/15 Yokohama ADVAN A048 heat cycled and shaved (r)

My thinking is a shorter lighter wheel assembly, faster to max rpms for autocross.

OPTION:2
16x7 Fuchs (f)
15x8 Fuchs (r)

205/55/16 Yokohama ADVAN A048 heat cycled and shaved (f)
225/50/16 Yokohama ADVAN A048 heat cycled and shaved (r)

I end up with about the same contact patch with either setup, the 15s are about an inch less in diameter (go figure

)

Would you use points to go to say 8 & 9 either in 15 or16"

For A/X the Advan may not be the best choice, that's a roadrace tire, but anyway
7 & 8 x16 225/45 x16 Advan A048 at all 4 corners is only going to be a tad(~.1") taller than a 225/50x15 and will have a better shape for max grip. 7 & 8 x16 Fuchs would be good choices as you don't really want a 9 w/ that size.

If you are going to do track stuff some more high speed understeer is desireable, here 8 & 9, 225/45 & 245/45 would be better choices.

If you can fit the wheels and tires along w/ your other choices you'll have a nice setup, loose as much weight as you can, especially from the ends of the car.

If the wheels cost points i'd rather have them and adjustable sways than bigger t-bars.

911st · 06-03-2008, 02:10 PM

Why stock control arm bushing? (Assume that is the rear arm inner bush.)

Why not monoballs? This will help limit toe and camber changes over a stock bushing in the back.

225/15's are really short tires but dose give up some width in the rear. I was thinking of running them in the front and back on 7&8 fuchs for a gearing advantage on my Carrera.

225/245- 16's is a max set up. Seems to works great on 7&8" fuchs. The Toyo 888's are not as tall as stock.

gregg911 · 06-03-2008, 02:50 PM

Quote:

Originally Posted by 911st

Why stock control arm bushing? (Assume that is the rear arm inner bush.)

Why not monoballs? This will help limit toe and camber changes over a stock bushing in the back.

225/15's are really short tires but dose give up some width in the rear. I was thinking of running them in the front and back on 7&8 fuchs for a gearing advantage on my Carrera.

225/245- 16's is a max set up. Seems to works great on 7&8" fuchs. The Toyo 888's are not as tall as stock.

Thanks for the response. Monoballs are a stiff riding option. I'll be driving the car to and from any track events, most likely with the tires delivered by the wife in the truck. I've heard that a long drive on a marginal road with monoballs is not desireable.

Regarding your wheel/tire suggestions, you're thinking is the same as mine in regard to acceleration/braking advantages with the shorter tire and less rolling mass.

gregg911 · 06-03-2008, 02:55 PM

Quote:

Originally Posted by Bill Verburg

Would you use points to go to say 8 & 9 either in 15 or16"

Bill, there are no penalties for tires as long as I stay under a 225 or less. A 230-245 tire adds 2 points and anything over 245 is 4 points.

Flieger · Flieger's Garage

I have option #2. I love the Yokos.

They are my only tires but my car is for fast weekend driving. They grip like there's no tomorrow. And they look really cool.

I think Fuchs will be the better option. They seem to be lighter and stronger than most of the other options. The Aluminum weighs less than the rubber and you get less sidewall flex.

The Yokos heat up nice and sticky and have a pretty progressive breakaway unless you are on a dirty part of the road. The tail comes out but can be put back in line and managed in a slide as the driver wishes.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally Posted by gregg911

Bill, there are no penalties for tires as long as I stay under a 225 or less. A 230-245 tire adds 2 points and anything over 245 is 4 points.

So start w/ 7 & 8x16 w/ 4x 225/45x16 tires. gear type lsd, lose weight, lower the car(I see you didn't forget the bump steer kit), performance align & corner balance. Your choices are all good ones.

rfloz · 06-03-2008, 07:45 PM

I make no claim of expert status, but I will venture that the three things that will make your car faster in auto-cross or track, in order of importance are:

1. Driver education/practice - no points, go for it at every opportunity.

2. Tires - DOT R tires, specifically Hoosier A6 (auto-cross) or R6 (track) or Kumho 710s, will give you more than just about any imaginable 2 points worth of suspension stuff. Get the good tires and eat the 4 points.

3. Everything else. You need more negative camber up front than the stock setup will get you. If decambered ball joints are no points, go for it. Then good shocks (re-valved to suit your new T-bars and sways - see below), no points (unless remote reservoirs). Do it. Do anything with no points, including maximum allowable weight loss in the rear. Then I'd spend your last 4 points on T-bars and sways - big ones, all you can stand. The T-bar 2 points allow machining and/or welding to lower the car for the same 2 points - figure it out because just lowering the car via the T-bars will screw up the geometry. Skip the front brace. It doesn't do all that much and it really costs you 2 points since there's nothing else worth doing for only 1 more point. Increase track (wider wheels) up to 2"" no points, max out tire size. Hint - if you can change the offset the right way, you can increase the wheel width more than 1" and remain legal.

Finally, get a good track or auto-cross alignment (not the same thing and nothing like a street alignment) and corner weight done.

BTW, the points set out above are PCA Zone 8. If you are in another zone, please mention it and all their specific points allowances.

Please note - the above assumes you want to compete seriously. If not, if you just want the car to handle better and still be comfy on the street - never mind.

911st · 06-03-2008, 08:24 PM

I do not think rear mono ball inner arm bushings effect ride much. They do not really the primary load from bumps. I think they more limit side and twisting load. They may add a bit to noise transmission like all hard or performance bushings do.

Again, they should help take some flex out of the rear suspension to help maintain your toe and camber settings.

Chuck Moreland · 06-03-2008, 09:46 PM

While your list would build a fine handling car, it is really impossible to comment on how well you are spending your points without seeing the whole menu. Can you paste the relevent section of the rules here? or post a link?

A couple comments;

You haven't stated your shock plans. This is very important.

I will second 911st ' s comments about the monoballs. They make a big difference in keeping the toe and camber in check, and thereby make the car more predictable and easier to drive fast. Ride quality will be fine, they will transmit a little more road noise - not a lot.

The products you listed are Elephant Racing, not ERP. Two different companies.

gregg911 · 06-03-2008, 10:16 PM

Quote:

Originally Posted by Chuck Moreland

Can you paste the relevent section of the rules here? or post a link?

You haven't stated your shock plans.

The products you listed are Elephant Racing, not ERP. Two different companies.

Zone 8 rules http://zone8.pca.org/rules/2008/Z8Driving2008.pdf

Bilstein HD

Sorry about that Chuck, I fixed the original post..my apologies.

rfn026 · 06-04-2008, 12:51 AM

A friend of mine once suggested that instead of spending money on parts the money should be spent on gas, food and motel bills to enter more events. The additional seat time will make you faster at the end of the year than any parts you might purchase.

That said I would put tires at the very top of the list. If you're serious you'll go through several sets in the course of the season. PCA events aren't very competitive compared to some of the regional SCCA events so you might be able to get by on just a couple sets of tires.

Next work with your alignment settings. The tires won't work unless you can maximize the amount of rubber you have on the pavement. Also, keep in mind that the tires are really springs. Getting the correct tire pressure (the correct spring rate) is critical.

The bottom line is don't spend quite so much time worrying about the parts. Drive the car. Enter as many events as you can possibly find. Go to every Test and Tune day you can locate. Seat time is the critical factor here. That's what's going to make you fast.

Richard Newton

Autocross Performance Handbook

Wheel and Tire Performance Handbook

Quicksilver · 06-04-2008, 04:03 AM

The rear monoballs aren't a point so they are really an easy choice...

As mentioned above: Tires are the number one consideration. All the suspension mods in the world won't beat the raw grip of the best tires. The next question is can you deal with the speed that a really good tire will wear out? A lot of these tires will "cycle out" (get hard) a long time before the tread wears out.

If you are serious about improving the auto-x performance and are planning on taking the points for a T-bar change you should seriously think of going with 23 - 30s.

You haven't mentioned sway bars. There is a serious improvement to be found there. Auto-x is about trying to minimize quick transitions and the sway bars and t-bars are the key here.

- - -
That all being said. . . (and not knowing your level of experience)
To add to Richard's suggestion of thinking about investing in the driver instead of investing in the car (an adaptation of a Carroll Smith quote):
"Smooth" is required to really use a car to its limit. It is much easier to learn to be smooth in a softly sprung car with street tires then in a stiff, harsh car with gumball race tires. "Smooth" is really hard to see and feel in a harshly sprung car that has grippy tires that let go with a 'snap'.

I have run auto-x in cars from one end of the spectrum to the other since I was 21. If I didn't have a sporty car I would run anything that was available. Hands down I learned much more about running slaloms (evenly spaced line of cones) by running a stock 76 Corolla wagon then I did from running any other car. (It kind of beat you over the head with 'rhythm'.) If you can run a string of cones smoothly and quickly in that car you can easily do it in something sprung like a roller skate.

I know people (with $$$!) that have extremely seriously setup cars that are no where near 'smooth', they haven't progressed towards 'smooth', they don't realize where the 'smooth' is missing, and you can't explain it to them. You can be smooth in a very violent car but the 'smooth' bits happen so fast you won't see them unless you work your way up to them slowly with a softer car.

A softly sprung car talks to you in big obvious gestures. A violent harsh car says the exact same things but it is much harder to notice them unless you slowly work up to it.

JeremyD · JeremyD's Garage

Quote:

Originally Posted by gregg911

Thanks for the response. Monoballs are a stiff riding option. I'll be driving the car to and from any track events, most likely with the tires delivered by the wife in the truck. I've heard that a long drive on a marginal road with monoballs is not desireable..

Not true - you might year a little more road noise, but really monoballs will have minimal effects on stiffness. You will get more steering response. Bigger torsion bars will make much more of an impact on stiff riding

911st · 06-04-2008, 07:40 AM

+1 on Richards comments.

I had an instructor at a club event in an old warn 74 911. All he had was sticky tires. Still had a stock suspension w the original shocks. Man that guy was smooth and fast! All the other guys in his class had suspension kits but he usually still had top time.

I know, it is hard to not to want to get all the goodies...

However, it is rewarding to beat the guy with all that money tied up in his car.

KTL · 06-04-2008, 10:52 AM

You say you don't want to deal with the harshness of the monoballs. Others have stated their experience with their feel, I cannot attest to that myself. But the other issue you should consider in relation to monoballs is the effect they have on your alignment and therefore on your tires.

Like others said, the monoballs do a better job of managing your alignment. Additionally, and this is a component you don't have on your list, you need to consider the upper strut mounts of the offset type. These are your best bet to gain the additional negative camber the front tires desperately need. Without the large amount of neg. camber, your front tires will suffer a lot of outboard wear. Tires aren't cheap and these strut mounts will pay for themselves with the performance gain and reduced tire wear over time. And you'll notice in part III.R that there are no points assessed for the use of these monoball camber plates. Seems like "free" gains to me.

I'll have to disagree on the strut brace issue. These things do provide a benefit if you've got a triangulated one. I've seen (by mistake) the stiffness they can provide at the track. It's only 1 point and if you've got leftovers, then it's an easy point to install.

The weight restrictions are rather amusing: "Curb weight is defined as the weight of the car ready to drive with all fluids (gas, oil, etc) full, tools, spare tire, jack, etc in the car but no driver. These items do not have to be in the car while participating in the event. Anything removed for purposes of Section XIII Part K may be replaced and all fluids may be topped off, as needed, before weighing."

At these events are people taking apart and putting their cars back together all the time to gain an advantage?