Front end darting around?
05-07-2005, 07:46 AM
#17
928 Barrister
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At my last alignment, the front tires were to be replaced BEFORE performing the alignment, but they were not. That meant the fronts were worn almost to the cords on the inside and almost new on the outer edge. I discovered it after I took delivery of the car and the tires were changed immediately, but no adjustment to the settings was made. The new tires did make a noticeable difference but the problem was still there. My question is how much did performing an alignment with unevenly worn front tires affect the result? I am really getting weary of doing alignments and paying for them over and over. 
I asked for maximum castor but was told it would remove the steering "feel". But I always thought caster controled self centering of the steering. I am up to my posterior in "feel" and think I will do the alignment myself next time.
Nicole, your car's tendency to wander is mild compared to mine. Night and day difference. You would become angered if you drove mine for any length of time, and I am about to set out on a 7000 mile adventure. Maybe I can find an alignment shop on the way. At the Boise parade, I found a great place to balance tires for only $25. It solved a high speed vibration all the "expensive experts" couldn't.
Porsche steering is one of the greatest aspects about the car; but not so with the 928. I give up jawboning about it to anyone. It is not possible for anyone else to correct it. You know what they say about doing things right = doing them yourself. Anyone who has set up Weber carbs knows that is the only way to get them right. The 911 guys do alignment at the track with string and a tape measure.
Think I'll get myself down to the store for some of that stuff and a protractor.
I asked for maximum castor but was told it would remove the steering "feel". But I always thought caster controled self centering of the steering. I am up to my posterior in "feel" and think I will do the alignment myself next time. Nicole, your car's tendency to wander is mild compared to mine. Night and day difference. You would become angered if you drove mine for any length of time, and I am about to set out on a 7000 mile adventure. Maybe I can find an alignment shop on the way. At the Boise parade, I found a great place to balance tires for only $25. It solved a high speed vibration all the "expensive experts" couldn't.
Porsche steering is one of the greatest aspects about the car; but not so with the 928. I give up jawboning about it to anyone. It is not possible for anyone else to correct it. You know what they say about doing things right = doing them yourself. Anyone who has set up Weber carbs knows that is the only way to get them right. The 911 guys do alignment at the track with string and a tape measure.
Think I'll get myself down to the store for some of that stuff and a protractor.
05-07-2005, 08:27 AM
#18
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A silly question - but have you reset the car to factory ride height? My GTS behaves very similarly (36,000 miles) and is much worse than my S4, which I had reset to 175mm ride height all round. I am no engineer so don't know what effect the ride height has on geometry but the there was a marked improvement in the S4 after I took out some of the sag in the springs. And that's on British roads which are narrow, potholed and heavily cambered. Worth a try.
Cheers
Mark
Cheers
Mark
05-07-2005, 08:55 AM
#19
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I noticed recently that the inside of my front tires was slightly more worn than the rest of the tire, and my car "tramlines" as well. The ride heigth is correct, the tires are fairly new, and the alignment was done at the Porsche dealer. I checked my front wheel bearings, and guess what? Plenty of play. I tightened them down [no pre-load, but nearly zero play as well] and the car feels a bit more stable now. Try that next.
N!
N!
05-07-2005, 09:10 AM
#20
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The problem with this sort of thing is that it could be anything... shocks, balljoints, bearings, tires, alignment, etc. etc..
Start with the cheap stuff and work up from there...
Cheapest thing: try adjusting your tire pressure.
Start with the cheap stuff and work up from there...
Cheapest thing: try adjusting your tire pressure.
05-07-2005, 10:42 AM
#21
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I've been through this song and dance before.
Ron H., your steering isn't right yet, in my opinion.
The thing that "scares" me, is the quote "figure out what tire to go with and then have them replaced and the entire car aligned." And I saw something like this in a few of the posts!
I've had an alignment done three times. The first one was done by a good year store, who had an alignment tech, who is recognized by a local Porsche specialists shop, who does their race cars' alignments. I believe, but don't quote me on this, as I have no verbal conformation or rumors to the effect, this tech may even have aligned Rahal's (sp?) cars, that shop is just down the road. That was not the shop that recommended this alignment place to me, BTW. This was before I had read about not lifting the car on Rennlist.
As he did the alignment, I watched him lift the car. After about a thousand miles, the insides of course, had worn out quite a bit, I took the car back to be checked out for why, and he lifted it again. After I had told him about the lifting problem I had by then read on Rennlist. He got angry at me, for trying to tell him a recognized fact. Nobody should have to put up with that. And he didn't center the steering rack, nor check the ride height. This guy obviously did NOT know 928's, so I started again looking for an alignment tech.
Armed with the info from Rennlist, AND CaptEarls alignment procedure, I finally found an alignment tech, who would listen to me, and talk with me about my shark's alignment, of all places, at a local Sear's garage. They had the Hunter system, the tech had actually done a 928 before, and they'd actually let me watch and speak with the tech during the procedure. I saw many out of spec indications on the machine. He didn't lift the car at any time. He adjusted the car on the rack. My only complaint, was he could not check the ride height. Afterwards, the steering felt noticeably better. The tech told me that after I got the ride height "adjusted", to bring the car back, he would recheck the alignment, no charge. I need to find where the height check points are, make a set of go-nogo gauges, find a LEVEL area to check them out, adjust as needed, and go back for the recheck.....
THEN I went and had my Bridgestone SO-3's put on. I don't have a tramline problem or twitch in my steering, the car goes where I've got it pointed. Of course the steering tries to follow the wallows put in the freeways that over- heavy semi's have put in the road, or other dips or road cambers, but rain grooves have no effect. My shark's steering is the BEST steering I've ever felt!
And so far, I haven't noticed any inside extra tire wear.
And now, as I read the new added posts, before I add my post, more good info is put up. Ya GOTS ta find a tech, who will speak with you. Good luck to you all, in your area search!
P.S. I am building my own system, from CaptEarls' info, so I can check my own alignment out. Thanks CaptEarl!
Ron H., your steering isn't right yet, in my opinion.
The thing that "scares" me, is the quote "figure out what tire to go with and then have them replaced and the entire car aligned." And I saw something like this in a few of the posts!
I've had an alignment done three times. The first one was done by a good year store, who had an alignment tech, who is recognized by a local Porsche specialists shop, who does their race cars' alignments. I believe, but don't quote me on this, as I have no verbal conformation or rumors to the effect, this tech may even have aligned Rahal's (sp?) cars, that shop is just down the road. That was not the shop that recommended this alignment place to me, BTW. This was before I had read about not lifting the car on Rennlist.
As he did the alignment, I watched him lift the car. After about a thousand miles, the insides of course, had worn out quite a bit, I took the car back to be checked out for why, and he lifted it again. After I had told him about the lifting problem I had by then read on Rennlist. He got angry at me, for trying to tell him a recognized fact. Nobody should have to put up with that. And he didn't center the steering rack, nor check the ride height. This guy obviously did NOT know 928's, so I started again looking for an alignment tech.
Armed with the info from Rennlist, AND CaptEarls alignment procedure, I finally found an alignment tech, who would listen to me, and talk with me about my shark's alignment, of all places, at a local Sear's garage. They had the Hunter system, the tech had actually done a 928 before, and they'd actually let me watch and speak with the tech during the procedure. I saw many out of spec indications on the machine. He didn't lift the car at any time. He adjusted the car on the rack. My only complaint, was he could not check the ride height. Afterwards, the steering felt noticeably better. The tech told me that after I got the ride height "adjusted", to bring the car back, he would recheck the alignment, no charge. I need to find where the height check points are, make a set of go-nogo gauges, find a LEVEL area to check them out, adjust as needed, and go back for the recheck.....
THEN I went and had my Bridgestone SO-3's put on. I don't have a tramline problem or twitch in my steering, the car goes where I've got it pointed. Of course the steering tries to follow the wallows put in the freeways that over- heavy semi's have put in the road, or other dips or road cambers, but rain grooves have no effect. My shark's steering is the BEST steering I've ever felt!
And so far, I haven't noticed any inside extra tire wear.
And now, as I read the new added posts, before I add my post, more good info is put up. Ya GOTS ta find a tech, who will speak with you. Good luck to you all, in your area search!
P.S. I am building my own system, from CaptEarls' info, so I can check my own alignment out. Thanks CaptEarl!
05-07-2005, 01:24 PM
#22
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Brett,
My point about the new tires was that with the excessive wear on the inside of the tires and the fact that I will be needing new tires soon suggests that the best starting point is to have the tires replaced before an alignment.
In the past when I had them do an alignment, on previous Porsches, after they replaced the tires, they drove the car relatively hard through some turns and bumpy roads before beginning the alignment. Not quite 25 miles but Boge's are Boge's and I don't see why Boge's on 928's should be much different than Boge's on 911's. I have never had a problem with their alignments in the past. They drive the car onto the alignment machine without lifting. After completing the alignment they would test drive the car again on the same roads check it for proper driving characteristics and then check the alignment a second time.
Euro-tire has many years of experience aligning Porsches and high end sports cars I am sure they will do the job correctly. Although from all I have read I will be sure to discuss this with them in depth before proceeding.
My point about the new tires was that with the excessive wear on the inside of the tires and the fact that I will be needing new tires soon suggests that the best starting point is to have the tires replaced before an alignment.
In the past when I had them do an alignment, on previous Porsches, after they replaced the tires, they drove the car relatively hard through some turns and bumpy roads before beginning the alignment. Not quite 25 miles but Boge's are Boge's and I don't see why Boge's on 928's should be much different than Boge's on 911's. I have never had a problem with their alignments in the past. They drive the car onto the alignment machine without lifting. After completing the alignment they would test drive the car again on the same roads check it for proper driving characteristics and then check the alignment a second time.
Euro-tire has many years of experience aligning Porsches and high end sports cars I am sure they will do the job correctly. Although from all I have read I will be sure to discuss this with them in depth before proceeding.
05-07-2005, 03:44 PM
#24
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928 is special case among cars in regarding alignment. Simple fact is that front end is totally wrong if it's lifted. It will look just right on second measurement if car was lifted during it also. For some reason this is extremely hard to get through to people working with them (and even to some owners).
05-07-2005, 03:53 PM
#25
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Thanks Dave and Erkka,
That was the point(s) I had a hard time pointing out to alignment techs. No, I don't know why, but the conditions are the conditions! So, its best to follow past hard earned experience, mentioned all too often, on our Rennlist.
Yes, I'm glad I'm a paid member, my dues are due, and yep, you bet I'm gonna re-up!
That was the point(s) I had a hard time pointing out to alignment techs. No, I don't know why, but the conditions are the conditions! So, its best to follow past hard earned experience, mentioned all too often, on our Rennlist.
Yes, I'm glad I'm a paid member, my dues are due, and yep, you bet I'm gonna re-up!
05-07-2005, 04:20 PM
#26
Drifting
ive had so many crap alignement jobs done but what a difference when its done right. i thought the 928 suffered terminaly from bump-steer, that it had to have 4x4 ride height, and i thought that reduced offset wheels with big rubber meant tramlining was inevitable - bull sh*t.
a good alignement sorts it all out. you can run less than stock ride height and carry wider rubber on low offset rims and the car will drive very nicely, with a good alignement. maxing out the castor really does help.
a good alignement sorts it all out. you can run less than stock ride height and carry wider rubber on low offset rims and the car will drive very nicely, with a good alignement. maxing out the castor really does help.
05-07-2005, 05:26 PM
#27
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Originally Posted by drnick
ive had so many crap alignement jobs done but what a difference when its done right. i thought the 928 suffered terminaly from bump-steer, that it had to have 4x4 ride height, and i thought that reduced offset wheels with big rubber meant tramlining was inevitable - bull sh*t.
a good alignement sorts it all out. you can run less than stock ride height and carry wider rubber on low offset rims and the car will drive very nicely, with a good alignement. maxing out the castor really does help.
a good alignement sorts it all out. you can run less than stock ride height and carry wider rubber on low offset rims and the car will drive very nicely, with a good alignement. maxing out the castor really does help.
I'm in the midst of fine tuning the alignment on the S4, after installing Konis. Using a Hunter DP400 (no lifting), we've set castor @ 4.7 deg at a suspension height of 173mm at all four corners.
Toe and camber are set at stock (0.12 deg & -0.5 deg respectively): The on-center feel is still not as rock solid as with my '80, even after playing with tire pressures. We are going to tweak toe a bit more ....
Any indications which to try - less ... or more ??? 225/45R17 on front over 7x17 ET 55.
05-07-2005, 05:51 PM
#28
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Anthony -
As we speak, I just drove home from Motorsport after having new rear tires put on. I swear, I think they gave me a brand new car! My new tires are Bridgestone Potenza RE 750's front and rear. I replaced the fronts maybe 4-5 months ago since the previous fronts were almost bald (from bad alignment). The previous rears had a moderate amount of tread left, so I didn't change them at the time.
I also very recently had new Bilsteins installed on all four corners. Handling improved quite a bit with the new shocks, but I was still a little disappointed with road noise and a fairly loud "clunking" sound over small road bumps. Those issues seemed to be coming from the rear. So I decided it was time for new rear tires. The difference is amazing! The car tracks perfectly at all speeds, corners on rails, and the ride is now showroom smooth, supple, and tight.
I wonder if my old tires had become hardened and noncompliant simply due to age. I have no idea how long ago the PO put them on. But the Bilsteins and the new tires have given me a new car.
BTW, Dave at Motorsport talked me into using 275's on the rear - a little wider tire than stock. Very nice, aggressive look and even better cornering! My ride height is stock.
One last thought... The other thing that markedly improved my handling was installing new motor mounts. The old ones were so squashed that, again, there was no compliance in the front of the car. Every little bump seemed to cause the front of the car to jiggle or bounce a little from the jar of the bumps being transmitted directly to the weight of the engine. New motor mounts made a world of difference.
My car has also been aligned not too long ago by knowledgeable people. So, it's been a little long and expensive journey, what with alignment, all new tires, new motor mounts, and new shocks...
But, man, I've got me a brand new PORSCHE now!
Edit: Hey, I just noticed your location on your avatar. My car was originally a New Joisey car. First sold out of a dealer in Trenton.
As we speak, I just drove home from Motorsport after having new rear tires put on. I swear, I think they gave me a brand new car! My new tires are Bridgestone Potenza RE 750's front and rear. I replaced the fronts maybe 4-5 months ago since the previous fronts were almost bald (from bad alignment). The previous rears had a moderate amount of tread left, so I didn't change them at the time.
I also very recently had new Bilsteins installed on all four corners. Handling improved quite a bit with the new shocks, but I was still a little disappointed with road noise and a fairly loud "clunking" sound over small road bumps. Those issues seemed to be coming from the rear. So I decided it was time for new rear tires. The difference is amazing! The car tracks perfectly at all speeds, corners on rails, and the ride is now showroom smooth, supple, and tight.
I wonder if my old tires had become hardened and noncompliant simply due to age. I have no idea how long ago the PO put them on. But the Bilsteins and the new tires have given me a new car.
BTW, Dave at Motorsport talked me into using 275's on the rear - a little wider tire than stock. Very nice, aggressive look and even better cornering! My ride height is stock.
One last thought... The other thing that markedly improved my handling was installing new motor mounts. The old ones were so squashed that, again, there was no compliance in the front of the car. Every little bump seemed to cause the front of the car to jiggle or bounce a little from the jar of the bumps being transmitted directly to the weight of the engine. New motor mounts made a world of difference.
My car has also been aligned not too long ago by knowledgeable people. So, it's been a little long and expensive journey, what with alignment, all new tires, new motor mounts, and new shocks...
But, man, I've got me a brand new PORSCHE now!
Edit: Hey, I just noticed your location on your avatar. My car was originally a New Joisey car. First sold out of a dealer in Trenton.
05-07-2005, 05:58 PM
#29
Drifting
front - ride height is set at about 160mm, camber about -1.00, total toe (left + right) 0.12, caster 4.40
rear - toe 0.05, camber -2.20
i will dial in more negative front camber next time and slightly less rear. mark kibbort has posted his settings in the past which he used as a compromise between track and road. changing the castor really helped for me and i think ?reducing? the toe as well - toe allways confuses me, especialy in relation to the rack and which way the tyres get pulled when under way...
rear - toe 0.05, camber -2.20
i will dial in more negative front camber next time and slightly less rear. mark kibbort has posted his settings in the past which he used as a compromise between track and road. changing the castor really helped for me and i think ?reducing? the toe as well - toe allways confuses me, especialy in relation to the rack and which way the tyres get pulled when under way...
05-07-2005, 06:16 PM
#30
928 Barrister
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One other trait has cropped up in the past which I can share: on an old Rabbit that has long since died, I had some cheap tires. The car would never go straight, and instead would wander back and forth. Ultimately, the problem was solved by installing Michelin tires and the tire rep told me the belts in cheap tires become loose and move around inside the tire. I am not sure that is exactly true, but the problem went away and I always use Michelin tires on my Rabbit now.
On the 928, I use Bridgestone 750s as does Bigs, and he reports that he is satisfied with his car's steering so mine should be do-able. Maybe someone at the Parade will be able to recommend a shop in Pennsylvania.
On the 928, I use Bridgestone 750s as does Bigs, and he reports that he is satisfied with his car's steering so mine should be do-able. Maybe someone at the Parade will be able to recommend a shop in Pennsylvania.