Sway bar question

[74goldtarga]

I have a 951 with MO30 front hollow bar and stock rear bar which in my case is an 18mm bar (which I think is larger than the later bars).

I have contemplated getting the 19mm rear MO30 bars with links and solid mounts but was unsure how much difference there would be - I realize the MO30 bar is adjustable but relatively speaking the 18mm bar looks like the ends are as long as the shortest (stiffest) mounting hole on the 19mm bar.

Bottom line - I'm not convinced it is worth making a change, if anyone knows why it would be I would be interested to hear.

My other question is has anyone tried the weltmeister or tarret bar in the rear with the MO30 in the front, I would think you could adjust these to be neutral with the non-adjustable front bar in place but I'm not sure. I favor getting a Welt bar due to cost if this is a reasonable solution.

In a related question - is there really that much value in a camber strut brace in these cars, I'm not convinced there is but if there is really some value I will probably get one. I have been told by a master mechanic and 944 class record holder at my local track that they aren't worth much. What do you all think?

[flash968]

i've driven a couple of cars now with the weltmeister bars - not all that much to write home about - plenty adjustable, but that is a slippery slope, requiring a ton of tuning time to accurately set it up and not just be "how close can i guess?"

it's all about balance - the 19 works well with the 30mm hollow IF you have the springs and torsions to match - too much bar on too soft of a spring is a problem - you could easily end up with a car that feels like it's on marbles - it's very important to match bars to springs (torsions are springs too)

the 19mm bar is not a lot stiffer, but if you want to settle the rear down a bit more, it can help - depending on the rest of your setup though, it might induce oversteer - if you have 25.5mm torsions, you can go to the 19 without fear - if they are smaller that that, i wouldn't do it

yes, you can run even bigger bars, but you need to match everything else up too - for example, i am running a 22.25 on the rear of my car, with a 31.75 on the front, but i have the springs shocks and struts to accommodate them - i have also reinforced the extremely soft lower suspension mounts by bracing the castor blocks and running spherical bearings everywhere

again, it's all about balance

[74goldtarga]

I know you are right of course. I have weltmeister lowering springs 250lb on front and stock at the rear - I keep saying that I am going to a full coilover setup but that keeps getting put off while I do something else (Pantera) instead. I appreciate your input, I am trying to make some nice easy (inexpensive) upgrades before I go to the track next month and am trying to figure out what I should do and what to leave alone. Thanks again.

[smlporsche]

I agree with what's been said above but the other question to be asked is how good a driver are you really?

I'm assuming that you're referring to a track set up. Are you running in Black or Red run groups??

If you're not running in the top run groups you will not notice the 1 mm difference particularly if the rest of your suspension system is not correctly matched up to it.

Regarding the strut tower brace. In a car that is driven well (and fast) there is a huge amount of flex on our cars in the front.
A good friend of mine was the PCA national autocross champion for a few years back in the late 80's. He showed me pictures of his 944 in both a left hand and right hand hard corner and you could see the hood flex up about 1/2" on the inside corners without a brace...yeah it works!

[Dave L]

Originally Posted by 74goldtarga

I know you are right of course. I have weltmeister lowering springs 250lb on front and stock at the rear - I keep saying that I am going to a full coilover setup but that keeps getting put off while I do something else (Pantera) instead. I appreciate your input, I am trying to make some nice easy (inexpensive) upgrades before I go to the track next month and am trying to figure out what I should do and what to leave alone. Thanks again.

I have a similar set up with the 250lbs springs and stock 25.5mm (I belive) torsion bars. This will create more understeer. By adding a bigger rear bar (I went from 18mm to 19mm) this helped tame it a bit. I also have a KLA strut bar.

The IDEAL set up is to replace the rear torsion bars (anyone want to give me $1500?) and match the 19mm bar with the 30mm but we all sometimes have to make choices.

[flash968]

just to clarify, the brace i am talking about is not a strut tower brace, though that is a very good idea - the one i am talking about is a LOWER suspension brace - there is even more flex down there than up top, and the resultant geometrical change due to the flex is larger

imagine your lower ball joint flexing in and out over 1/4" - guess what? that's exactly what it does

that wrecks havoc on geometry, but makes for a very compliant ride, which is what these GT cars were designed for - they aren't sportscars, and to drive them like one you need to remove some of the things that make it soft and comfy

[74goldtarga]

How good of a driver am I really? Let's call me intermediate. However, entering turn 1 at BIR at 120-125 mph and turn 2 at 100+, balance and stability are a big deal no matter how good you are - you are at steady state from a suspension standpoint for a while during those corners. Sounds like the strut brace is a must have. We don't have black or red run groups but in any case my car is silver.
Flash - Are you referring to the Brey-Krause lower brace? - that is the only one I've seen, it looks well designed but is not an inexpensive upgrade.

[27Carrera]

One of the big benefits of the M030 bar is teh adjustment... If i had it to do over again I would have gotten the lindsey bar as it has even more adjustment.

[jkb58]

19mm rear bar is not a lot stiffer than the 18, although the adjustment is nice. Since you have 250 front springs, the car will be prone to very noticeable understeer, so you probably will want a somewhat dramatic increase in the rear stiffness to re-balance the car's handling.

20mm 944N/A & S M030 bar would be stiffer than the 18mm bar, but not sure its much if any more than the 968 bar on full stiff - its not adjustable either. 21mm TurboCup bars are impossible to find anymore and were big $$ even when available. So the 22mm welt adj bar is probably the best option for you.

Not ideal, as flash mentions, as you do preferably want to set the suspension balance with spring rates, but as an interim upgrade it will probably make the car feel a little more balanced at the limit.

[74goldtarga]

Thanks guys. I'm thinking the welt 22 at full soft should still allow some understeer and then work it stiffer until I feel a good balance, I wouldn't mind playing with this between run groups at the track. I would be concerned though if someone felt that the 22 was somehow too stiff a match for the 30 hollow on the front. If the consensus is that the 19 is the ideal match (ultimately) then that is what I should get - I just don't want to buy parts twice.

[flash968]

targa - no, but the concept is similar - won't work on a turbo though