968 M030 Anti-roll bar

74goldtarga · 06-16-2007, 03:49 PM

I put in the 968 M030 front anti-roll bar last weekend and have driven the car a few times since. The bar seems to improve the steering response and reduce roll without increasing ride harshness. This is a cheap upgrade that I would highly recommend. I have the turbo 18mm rear bar and the steady-state balance on the clover leaf is excellent (I have one by my house on which I can hold between 45 and 50 mph, the camber changes slightly on each of the 4 leaves). I am looking forward to the next track day to see if I can tell a difference there. I stuck with the stock rubber bushings for now. I considered doing the 19 mm adjustable rear bar as well but wasn't sure how much difference there would be between that and the 18mm bar.

Next mod - coilovers to replace stock bilsteins, any suggestions? I'm considering Bilstein Escort Cup, KW variant 3, H&R RSS club sport, JIC Cross.

DanAllen944 · 06-16-2007, 06:08 PM

I would get the 19mm rear bar too. Its easily adjustable so you can change it at thet track to suit your needs. also with your current setup you probibly have a bit to much understeer.

74goldtarga · 06-16-2007, 06:20 PM

Thanks Dan, you are probably right. It looks to me that the mount point on the rear 18mm bar is the same location as the stiffest setting on the 19mm bar. I would think that the loosest setting on the 19mm bar is similar to my bar but I am just guesstimating. I was thinking I might go to a hollow 22mm Weltmeister bar for the rear if I am going to be able to really adjust it. I'm not sure how much stiffer the 19mm bar is, maybe 10%?

vanwyk4257 · vanwyk4257's Garage

I just replaced the rear 18mm bar on my car (off a 951) with a 19mm adjustable M030, and it definitely helped make the car more neutral, with the big front sway there was a lot of understeer.

74goldtarga · 06-17-2007, 05:05 AM

Alright then, anyone know if I should use the 19mm bar or the 22mm adjustable?

vanwyk4257 · vanwyk4257's Garage

If you have stock spring rates front and rear I would go with whichever bar the factory matched with the front you are using. The nice thing is it only takes a few minutes to adjust the rear bar to your liking. My car has 250lb front springs and stock rear torsion bars so I compensated for that by setting my 19mm rear bar full stiff to offset the softer spring rate in the rear. I would think that you will find the 19mm at a stiffer setting or the 22mm at a softer setting probably won't be too much different. Ultimately it depends on whether you prefer the car to understeer or oversteer at the limit. I wanted mine to be neutral to slight oversteer since I have an open diff and the car is so well balanced at the limit. Hopefully that helps, but I'm sure others will chime in with their preferred setups.

8744S · 06-17-2007, 12:14 PM

Have you looked a Leda coilovers? I know alot of people who run those at the track.

74goldtarga · 06-20-2007, 03:58 PM

I have looked at the Leda coilovers, they are a good price but higher priced than the others I listed, also more strictly race oriented and for now I plan to keep the car streetable (barely). Vanwyk - can you get the car to oversteer with the rear bar at full stiff (you have the 30mm front bar right), if so the 19 should be fine, if not I would prefer the 22mm bar. Thanks again.

vanwyk4257 · vanwyk4257's Garage

I'll let you know after tomorrow evening, I will be doing an open track event at Gingerman Raceway. The last one I did a couple weeks ago with a bunch of my fellow GruppeB members there were only 5-6 cars most of the evening, so we got a lot of track time in. I probably did well over 100 miles on the track that night, I'm hoping to do that many tomorrow.

74goldtarga · 06-21-2007, 07:24 PM

Hey Van, my whole family is from Grand Rapids. Mom went to Grandville. I would love to come visit family sometime and spend a track day with you guys. Let me know how the balance was with the bars, thanks.

vanwyk4257 · vanwyk4257's Garage

Ha Ha, it's a small world!

I don't think my front bar is a 30mm, it looks smaller and is non-adjustable. The balance with the 19mm rear bar set full stiff was great. Before, the car just wanted to understeer, now it still understeers a bit under power but I can roll out of the throttle and get the back to rotate a bit. I'm much happier with the feel of the car. That said, I think if you are running the 30mm front you might want to consider the 22mm rear, you can always run it softer. I'm planning on doing coilovers with 400lb fronts and 30mm torsion bars over the winter, so that may change things for my car.

We will be at the track on July 5th and the following one or two Thursdays in July as well. If you make it out this way shoot me an email or PM to let me know you're coming out and I'll get you my phone number, I always like hanging out with fellow Porsche fanatics and drinking a beer!

74goldtarga · 06-23-2007, 04:58 AM

Thanks, I have my track day allowance already reserved for this year. More and I think I will break the spousal tolerance bank. Next year is a long way off but you may get a PM this winter about your track dates for next year since I have wanted to go to Gingerman and visiting the relatives is a good excuse.

The 968 M030 setup is a factory setup and I am guessing it errs on the side of understeer. If you have a smaller front bar it is probably perfect. I think if I get an adjustable bar I want to be able to dial in a little oversteer for tighter tracks or AX courses which is why I am considering the 22mm bar. I will probably call the local 944 race shop and get some additional input, but I appreciate you giving yours.

vanwyk4257 · vanwyk4257's Garage

No problem. For what it's worth I'm sure we will probably do the same thing with the Test & Tunes every other week at Gingerman next season as well.

I think you are probably right about using a larger rear bar relative to the front bar you have. Here's a video clip from Thursday night at Gingerman.

http://www.youtube.com/watch?v=k_EChAyAKXM

flash968 · 06-23-2007, 03:27 PM

on the turbo cup cars, the 22mm rear with a 30mm front led to dramatic oversteer, particularly on power

on the 968, i have found the 30mm M030 bar to be completely inadequate, and ended up designing a new bar that is 31.75mm, complimented with a 22mm rear - very balanced, and much flatter in the corners

vnarma · 06-28-2007, 04:34 AM

Quote:

on the turbo cup cars, the 22mm rear with a 30mm front led to dramatic oversteer, particularly on power

I run my 968 with the stock 26.8mm front bar, and the Tarret Engineering 22mm rear bar set to 25%. Suspension is the KW Variant 3. The car is corner balanced and weighs in at 2900lb empty, and I don't find it to be tail happy at all. There is a tendency toward oversteer, but nothing bad. Certainly better than the plow the stock configuration had. Realize the Turbo Cup cars had a much better power to weight, and under power, one can pretty much make any configuration oversteer when applied at the wrong time.

968 Suspension Upgrade

I've very happy with the configuration overall. Nice at the track, runing 255/50-17's all round. With a little more rear bar dialed at autocross and 245/275s it has nice rotation. I'm likely going to upgrade the front to the 30mm, and up the rear bar to 50%. The stock combination of 30/19 is neutral to slight understeer, even at full stiff. 30/22 should be a nice combination. I ran the 26.8/19 combination on my 924S and found it to be an excellent combination, although some thought it was a bit "loose". The 924S had a 48/52% rear weight bias.

YMMV

flash968 · 06-28-2007, 07:08 AM

well, at 25%, sure (though i'm not sure how you figured that out - did you measure and calculate?) with an adjustable bar like that you can reduce the rear stiffness until you eliminate the oversteer - call pete at rs barn - he'll tell you all about the ills of running the 22mm bar - he ran those cars for quite a while, and is quite well known for it

i had the M030 bars front and rear on my 968 and found the 30mm to be WAY too small - entirely too much body roll, even with 400# springs up front on konis and 600# springs in the rear with no torsions, yada yada - and this was just for street use - track was just out of the question - i don't know how guys tolerate it - i am used to a much stiffer and lighter car that just doesn't lean at all - these things are ridiculous - but, it was the only game in town, so i had to design something different myself

now i have a custom made 31.75 bar up front and with 22.25mm bar in the rear and allowed me to go with 300# springs up front and with 500# springs in the rear - MUCH better - smooth, flat, nimble, no wallowing, and a very nice ride with none of the normal bouncing and jarring

it's all about balance

vnarma · 04:20 AM

Flash,
Absolutely agree on the balance, that is the goal. I actually have the engineering specs, and the calculations for the Tareet Rear Bar. I also did the calculations on the Stock and the Weltmeister bar. Not to difficult. The Tarett 22mm bar, by design is substantially stiffer than the Weltmeister. As the stiffeness is a function of diameter, material, distance beween bearing surfaces, and the length of the arms. At 25%, the Tarrett is equal in rate to the Weltmesiter at 75%. Full soft is over 450in/lbs on the Tarett.

I talked to Pete about the bars. The Tarett is very similar to the Kelly Moss bars from the Firehawk series.

flash968 · 06-29-2007, 05:44 AM

wow - ira let that stuff out? nice - that would have made my job a bit easier when i was designing mine

lol - yeah - pete and i have been doing a lot of that lately too - he is going to be carrying my bars as soon as i run a batch - he already carries a few things i have come up with

vnarma · 06-29-2007, 09:27 AM

Flash, Looking forward to your bar being available. Been holding off the purchase of the front bar until your's was available. PM'ed you with some questions.

The spec's aren't difficult to calculate in any case. I like the bar alot, but would have preferred not having to engineer changes around the bar, like the exhaust.

Curious on your new front bar. Are you going hollow or solid? I saw the delrin mounting, and the rod-end links. Looks nice. No problems with clearance against the a-arms during full motion changes?

flash968 · 06-29-2007, 09:40 AM

lol - thanks - no problems anywhere with clearance on my lowered car - mounts pretty much like stock - it did require that i made some addtional braces though, and those will be availble soon too - not sure about clearnce on a stock ride height car though - haven't fitted one to see yet, as i only have the prototype right now - this bar is really for the nut like me who just can't stand the ridiculous body roll of these cars - putting it on an average street car is serious overkill, so keep that in mind - you really need stiff springs, and other suspension mods to make them work right - you know the drill - it's all a symphony

ok - where did you see it? have we met?

oh - and it's hollow up front and solid in the rear