Early vs Late Suspension

[bamf3000]

I must be new at this whole search engine here but couldn't find anything on google either. I just purchased a 1986 944 to do Spec944 with. However, I was informed that the 86 had the updated supsesion/control arms etc, which it does but I have read it also does not.

 

They upgraded the control arm to aluminum but its still the same size and suspension as the early offset cars.

 

My question is, can you and if you can, update the early model suspension to be exactly like the late model suspension and offset(ie. 87+) If so, what is needed to do this swap? Is there any major benefit to do things also?

 

Feel free to link to as many pages as you have so I can learn as much as I can.

 

Thanks

[Big Dog]

You can update the suspension to the late offset if you really want to. There is some question about which is better.

 

Some say the later offset is better because it wider at the wheel pickup points and the geometry is "better". However, it also requires phone dial wheels which are 2+ pounds heavier each. Not only is it rotating mass, that slows down acceleration and braking, it is also unsprung mass, which I have been told is even worse than the weight.

 

Some think the effective result of the extra weight of the wheels is equal to 80 pounds of extra weight in the car and that is just the rotating mass part. The unsprung weight is an entirely different matter.

 

Is the geometry enough better to offset the problems from extra weight and unsprung weight? That is beyond my pay grade. If it was my car, I would leave it as is and develop the car, get seat time, drive other cars later when you can feel differences and, if you want to change it later, go ahead. No reason to spend any money not. Race what you have.

 

Big Dog

[944-Spec#94]

You are allowed to swap early offset vs late offset suspensions. The rules do allow for that. However nobody ever does. The best plan is to make sure what you have works properly and be done with it. I have never seen offset of the car and suspension type have any impact on the racing on track. I have seen bad set-ups have major impacts. Use what have and make sure it done right.

[Tim Comeau]

Bamf,

83-85.1 steel arms front and rear.

 

85.2-86 Same length arms, but aluminum front and rear.

Weak front ball joints due to angles incurred when lowered for racing, but much improved bearings in rear arms.

 

87-88 Aluminum arms front and rear. Offset changed to accomodate ABS system. Front spindles have bigger wheel bearing from the 928S, top bushing also larger(?). Offset of wheels is 30mm more to the inside. However, the stock track width of all 944's is the same at 58.1 front, and 57.1 rear. The chassis mounting points in 944's are all the same, so you can put an 88 ABS alum suspension on an 83 if you want. You just have to swap the entire corner because of differences in wheel hubs, spindle bolt hole width and spacing.

 

The aluminum front arms are the same weight as the steel. I prefer the steel arms because:

1. when hit, they will bend but not snap like the alum arms. This can save your chassis.

2. Ball joints are much stronger

3. Ball joints are replaceable in 10 minutes at the track.

4. Same arm can be flipped over to be used on the other side of the car.

 

If you switch to alum arms in the rear, you'll need to get the longer late axles and matching spring plates.

For the short term, I would make sure your front bushings aren't too sloppy so you can get a good alignment, and that your suspension can move freely. The faster your suspension can react to track surface changes, the more continuous contact your tire can have. Check your steering rack joints for play.

 

DON'T miss track time because the suspension isn't perfect yet!

 

p.s. The 924S has entirely early offset suspension, steel front arms, alum rear arms, but must use the 87-88 ABS offset phone dials because of it's narrow fenders.

[Chuck T.]

Bamf

where is home ?

[bamf3000]

I'm in utah. The main reason I want to switch to late offset is due to who I know and who I would be racing with. The parts they have are all late offset parts so if I did have an issue at the track they would have a part, etc.

 

Does anyone know what is all needed to switch over? Front I'm assuming the control arms, spindle, and MAYBE the tie rods? Sway bar?

 

What would the rear need? contol arms, spindle/axles?

 

Thanks

[Sterling Doc]

I've raced both early and late offset, and didn't notice any significant difference. The only suspension spares you'd need to carry yourself is one steel a-arm, and one ball joint. Cheap, light, and simple.

 

For the conversion, you need:

front a-arms, hubs, spindles, tie rods, brake rotors

rear spring plates, trailing arms, spindles, brake rotor.

late offset wheels to replace early offset

 

This is an expensive & time consuming proposition vs carrying a spare a-arm & balljoint!

[bamf3000]

Well I do plan on replacing the rotors anyway, the ball joints on my car need to be rebuilt also, I am getting new hubs and wheel bearings. Since I plan to replace a lot of the stuff anyway, it might not end up being that much more expensive to just swap the rest of the stuff since the aluminum control arms I have can't just snap in an ball joint as it is.

[Tim Comeau]

Bamf,

I wouldn't make the swap. If you're racing with other 944 guys, they'll have spares, too. I assume you're a NASA member?

Most of us carry at least some spares.

[944-Spec#94]

Consider this.

 

early steel front arms = $25 each + $11 for a ball joint. Both can be used on either left or right side.

 

Aluminum arms = Rebuilt $500, New $1200, Ball joint kits $200 for both.

 

The steel arm stuff is cheap since they are VW parts. The aluminum ones have "Porsche" cast into them so are much more expensive.

 

I converted my 84 944 to aluminum rear arms (early offset) because I had an 87 924S parts car laying around. Also brake rotors for the early offset cars can be had for $30 to $60 each, but are $100 for late offset. This is due to the way they are mounted up. The late ones are a little easier to change. Pads are simple to change in all cars.

 

The only advantage to late offset you all your buddies run late offset is swapping wheels/tires. I have had guys borrow a set of tires, trade a set or run an slightly old set to get through a weekend. That is easy with everyone on the same offset. Not so easy otherwise as you would need to remount the tires.

 

Even so I would get 75% of the 944 spec cars are early offset. That make sense give the production years and volumes from 83 to 88.

[bamf3000]

Ya, the more I look at the cost of switching the less it makes sense. Is everything else on the 86 the same as the 87 and up? I have read the brakes are better on later models, the electric stuff is better, etc.

 

Thanks for all your help.

[Chuck T.]

if you make it over the hills to race with RMR we have all the early spares !

[Sterling Doc]

Brakes are the same 83-88. Electrical is the same 85.5-88; 83-85 (and the 924S) have more primitive electrical systems.

 

I would not run the early aluminum a-arms on your car, though. Backdate to the steel arms and ball joints. It's cheaper than rebuilding the early aluminum ones, and safer.

[bamf3000]

Thanks for all your help. After looking at parts and how expensive it would be even if I was replacing a lot of the items anyway, I think I'll just stick with what I have and update or backdate rather to the steel a arms. Is there any other advanatage to having an 87+ car over an 86 besides the suspension? Is one more prone to breaking than the other? I just want to make sure I'm going with the year that I think I'll be happy with before tearing into this car and making it my first spec car

[Sterling Doc]

'88 motors have higher compression pistons. You can shave the head to get back the compression, or put '88 pistons in. No other advantages to a later car. You already have the larger plastic gas tank.

 

Get on with building that thing already!

[Al F.]

So what is required to go the other way, from late offset AL to early offset steel?

[Chuck T.]

So what is required to go the other way, from late offset AL to early offset steel?

 

not a bad question but Al your car has early offset AL. not late AL ...

[Sterling Doc]

So what is required to go the other way, from late offset AL to early offset steel?

 

Early offset steel arms are a direct bolt-in replacement for the troublesome early offset AL arms that you have (per Chuck). Only need to check the alingnment.

[Tim Comeau]

Don't forget about the bushings. When you get the new steel a arms, get the Weltmeister red rear bushings, then stock rubber or delrin crossmember bushings. The ball joints are cheap as well.

[Al F.]

Well, good to know!