View Poll Results: When setting ride height I do:
It by the book and set it to exact specs.
27
72.97%
It by wheel well height.
10
27.03%
Not know what the hell this guys talking about I drive a 924
0
0%
Voters: 37. You may not vote on this poll
Simple ride height queastion and poll
06-14-2009 | 11:19 AM
#31
Drifting
Joined: Dec 2003
Posts: 2,902
Likes: 0
From: an unnatural suburban habitat
MK- isn't there a racing forum you could go and hang out at? This is a discussion for street cars.
You could have a decade behind the wheel racing a 928, I don't care.
P.S. since you already know everything why don't you just publish a dissertation on all things 928 and shut your computer off. It would save you all the aggravation of having to correct our homework.
You could have a decade behind the wheel racing a 928, I don't care.
P.S. since you already know everything why don't you just publish a dissertation on all things 928 and shut your computer off. It would save you all the aggravation of having to correct our homework.
06-14-2009 | 12:53 PM
#32
Chronic Tool Dropper
Lifetime Rennlist
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Joined: Oct 2001
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From: Bend, Oregon
Ouch.
-----
Mark, your own memory is failing you. In the last year or two, you've been in discussions here about alignment, specifically camber vs. toe settings, looking for the cause of the inner scrub wear on the front tires on the Holbert car. We've had extensive discussions on the need for accuracy in toe settings, and I've been moe than casually critical of the stick-and-crayon method you use to set race alignment in a dirt paddock. Bottom line is that what seems to work for you and your race car is not representative of what street-only drivers might be looking for. We aren't dumpster-diving for still-serviceable DOT-spec tires. At least not yet for me. Tire life and even wear are big considerations for us street drivers. Important thing to remember is that there are a lot of folks reading your posts, perhaps thinking about applying your low-buck racecar preachings to their street cars. You are misleading them if somehow these methods and theories are misinterpreted as applicable to us everyday Joes.
And PLEASE read to the end of the thread before replying to a post, especially if you've been away for a bit. Put the text you are replying to at the beginning of your reply so we don't need to read what you post, go read what you were responding to, then go back and read yours again. My simple brain just can't keep track of the multi-threaded responses.
-----
Mark, your own memory is failing you. In the last year or two, you've been in discussions here about alignment, specifically camber vs. toe settings, looking for the cause of the inner scrub wear on the front tires on the Holbert car. We've had extensive discussions on the need for accuracy in toe settings, and I've been moe than casually critical of the stick-and-crayon method you use to set race alignment in a dirt paddock. Bottom line is that what seems to work for you and your race car is not representative of what street-only drivers might be looking for. We aren't dumpster-diving for still-serviceable DOT-spec tires. At least not yet for me. Tire life and even wear are big considerations for us street drivers. Important thing to remember is that there are a lot of folks reading your posts, perhaps thinking about applying your low-buck racecar preachings to their street cars. You are misleading them if somehow these methods and theories are misinterpreted as applicable to us everyday Joes.
And PLEASE read to the end of the thread before replying to a post, especially if you've been away for a bit. Put the text you are replying to at the beginning of your reply so we don't need to read what you post, go read what you were responding to, then go back and read yours again. My simple brain just can't keep track of the multi-threaded responses.
06-14-2009 | 01:01 PM
#33
Owns the Streets
Needs Camber
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Needs Camber
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Joined: May 2003
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From: New York
Was wondering why cars were slowing down at the far end of the George Washington bridge yesterday.
Came across a tire tread/carcass lying on the road. Sorta like ones you find from retreads losing the tacked on retread outer tread section.
Interesting.
Then came across current gen BMW 7 series limping off the bridge with flashers on. Right rear tire gone.
Seems the current economy may have this top o' the line BMW fitting cheap tires on the car.
(Dumpster diving for used tires???)
Unless it was really badly underinflated tires blowing out the treads?
Back to 'As the 928 scraps it's nose'.
Came across a tire tread/carcass lying on the road. Sorta like ones you find from retreads losing the tacked on retread outer tread section.
Interesting.
Then came across current gen BMW 7 series limping off the bridge with flashers on. Right rear tire gone.
Seems the current economy may have this top o' the line BMW fitting cheap tires on the car.
(Dumpster diving for used tires???)
Unless it was really badly underinflated tires blowing out the treads?
Back to 'As the 928 scraps it's nose'.
06-14-2009 | 01:54 PM
#34
Rennlist Member
Joined: Feb 2003
Posts: 29,817
Likes: 185
From: saratoga, ca
Look, SOMETIMES racing transfers over to street. 
Did you read my post. You have folks here trying to transfer their feelings to the science. Its not as intuitive as one might think. The only real thing that changes with ride hight changes is bump steer. I think Devek posted the actual measured bumpsteer curve. on a street car, its really a non issue unless you get the car REAL low, and then it could be a factor in tire wear on a street car. But, at 20mm lower, its a rounding error at best. Im trying to help someone out, and there is no need to be rude about it. Its a discussion. If you want the cold dry answers, just open the manuals. If you want experiece, lets talk. we all have something to contribute here. Im sure ive been helped more than I could ever contribute here.
Now, back to the show.
mk
Did you read my post. You have folks here trying to transfer their feelings to the science. Its not as intuitive as one might think. The only real thing that changes with ride hight changes is bump steer. I think Devek posted the actual measured bumpsteer curve. on a street car, its really a non issue unless you get the car REAL low, and then it could be a factor in tire wear on a street car. But, at 20mm lower, its a rounding error at best. Im trying to help someone out, and there is no need to be rude about it. Its a discussion. If you want the cold dry answers, just open the manuals. If you want experiece, lets talk. we all have something to contribute here. Im sure ive been helped more than I could ever contribute here.Now, back to the show.
mk
MK- isn't there a racing forum you could go and hang out at? This is a discussion for street cars.
You could have a decade behind the wheel racing a 928, I don't care.
P.S. since you already know everything why don't you just publish a dissertation on all things 928 and shut your computer off. It would save you all the aggravation of having to correct our homework.
You could have a decade behind the wheel racing a 928, I don't care.
P.S. since you already know everything why don't you just publish a dissertation on all things 928 and shut your computer off. It would save you all the aggravation of having to correct our homework.
Last edited by mark kibort; 06-14-2009 at 02:33 PM.
06-14-2009 | 02:15 PM
#35
Rennlist Member
Joined: Feb 2003
Posts: 29,817
Likes: 185
From: saratoga, ca
Bob,
I dont know what you are referring to here. But what I can say, I’m speaking to you and the group based on experience. I did not forget what we spoke about over the last month or so. my inner tire wear was due to a slight toe out. (remember I measured it with the "crayon" ?) I was 1/8th" towe'd out. My measurement, as crude as you THINK it is, is very repeatable and accurate. I toed the car in to 1/16 of an inch, and it stopped the issue. recently, I got hit at the track and the car got toed in even more by 1/2" !!! (as expected, it scrubbed the outside edge before I got home ) I adjusted it to 1/6" toe in and raced it. everything was good. when I finally, after 7 years, went to the shop to check my settings on a Hunter Machine, I predicted .5 degrees of toe in, and what did I find??? .55 degrees. Hmmm, pretty close to what I had measured. You keep on talking about width of the marker, etc, but you are forgetting that I’m measuring off a straight edge. If the thickness of the mark is uniform and straight the distance between them can be measured very accurately. (i.e. straight edge on the rim , front to rear marked on the ground at 19" separation. measure the distance difference of both sides and take that distance/19" INV TAN= degrees of toe.)
Now, my only points here were that you were advocating stock manual ride heights. There is no reason for this , as setting all corners perfectly even will not help the car handle as lowing the car 20mm. want it to handle even better, do some corner balancing, but even that is silly as it doesn’t account for different fuel or passenger loads.
Having as many hard street miles as anyone here, with 4 different 928s, I think my experience here on the topic can help. If you don’t want it, just ignore my advice. jack your 928 up to foolishly high ride heights and clear all the potholes, curbs and driveways possible. But, if you want to improve the handling of your car, get long mileage out of your tires, lower the car a bit.
Two things happen here. the car will handle better because it is lower. more g loading, for less weight transfer. PLUS, because of this, you get less compression of the suspension for the same g loading, which gets less body roll, which then keeps the tire flatter on the ground, reducing tire wear.
I drove my 84 to 185,000miles , only 50k of that racing, and I never wore my tires out prematurely.
Just trying to help and provide solid reasoning of why I’m advocating 10-20mm lowering of the sport minded street driver that might even want to take their car on the track, or drive it real hard on a mountain road.
mk
I dont know what you are referring to here. But what I can say, I’m speaking to you and the group based on experience. I did not forget what we spoke about over the last month or so. my inner tire wear was due to a slight toe out. (remember I measured it with the "crayon" ?) I was 1/8th" towe'd out. My measurement, as crude as you THINK it is, is very repeatable and accurate. I toed the car in to 1/16 of an inch, and it stopped the issue. recently, I got hit at the track and the car got toed in even more by 1/2" !!! (as expected, it scrubbed the outside edge before I got home
) I adjusted it to 1/6" toe in and raced it. everything was good. when I finally, after 7 years, went to the shop to check my settings on a Hunter Machine, I predicted .5 degrees of toe in, and what did I find??? .55 degrees. Hmmm, pretty close to what I had measured. You keep on talking about width of the marker, etc, but you are forgetting that I’m measuring off a straight edge. If the thickness of the mark is uniform and straight the distance between them can be measured very accurately. (i.e. straight edge on the rim , front to rear marked on the ground at 19" separation. measure the distance difference of both sides and take that distance/19" INV TAN= degrees of toe.)Now, my only points here were that you were advocating stock manual ride heights. There is no reason for this , as setting all corners perfectly even will not help the car handle as lowing the car 20mm. want it to handle even better, do some corner balancing, but even that is silly as it doesn’t account for different fuel or passenger loads.
Having as many hard street miles as anyone here, with 4 different 928s, I think my experience here on the topic can help. If you don’t want it, just ignore my advice. jack your 928 up to foolishly high ride heights and clear all the potholes, curbs and driveways possible. But, if you want to improve the handling of your car, get long mileage out of your tires, lower the car a bit.
Two things happen here. the car will handle better because it is lower. more g loading, for less weight transfer. PLUS, because of this, you get less compression of the suspension for the same g loading, which gets less body roll, which then keeps the tire flatter on the ground, reducing tire wear.
I drove my 84 to 185,000miles , only 50k of that racing, and I never wore my tires out prematurely.
Just trying to help and provide solid reasoning of why I’m advocating 10-20mm lowering of the sport minded street driver that might even want to take their car on the track, or drive it real hard on a mountain road.
mk
Ouch.
-----
Mark, your own memory is failing you. In the last year or two, you've been in discussions here about alignment, specifically camber vs. toe settings, looking for the cause of the inner scrub wear on the front tires on the Holbert car. We've had extensive discussions on the need for accuracy in toe settings, and I've been moe than casually critical of the stick-and-crayon method you use to set race alignment in a dirt paddock. Bottom line is that what seems to work for you and your race car is not representative of what street-only drivers might be looking for. We aren't dumpster-diving for still-serviceable DOT-spec tires. At least not yet for me. Tire life and even wear are big considerations for us street drivers. Important thing to remember is that there are a lot of folks reading your posts, perhaps thinking about applying your low-buck racecar preachings to their street cars. You are misleading them if somehow these methods and theories are misinterpreted as applicable to us everyday Joes.
And PLEASE read to the end of the thread before replying to a post, especially if you've been away for a bit. Put the text you are replying to at the beginning of your reply so we don't need to read what you post, go read what you were responding to, then go back and read yours again. My simple brain just can't keep track of the multi-threaded responses.
-----
Mark, your own memory is failing you. In the last year or two, you've been in discussions here about alignment, specifically camber vs. toe settings, looking for the cause of the inner scrub wear on the front tires on the Holbert car. We've had extensive discussions on the need for accuracy in toe settings, and I've been moe than casually critical of the stick-and-crayon method you use to set race alignment in a dirt paddock. Bottom line is that what seems to work for you and your race car is not representative of what street-only drivers might be looking for. We aren't dumpster-diving for still-serviceable DOT-spec tires. At least not yet for me. Tire life and even wear are big considerations for us street drivers. Important thing to remember is that there are a lot of folks reading your posts, perhaps thinking about applying your low-buck racecar preachings to their street cars. You are misleading them if somehow these methods and theories are misinterpreted as applicable to us everyday Joes.
And PLEASE read to the end of the thread before replying to a post, especially if you've been away for a bit. Put the text you are replying to at the beginning of your reply so we don't need to read what you post, go read what you were responding to, then go back and read yours again. My simple brain just can't keep track of the multi-threaded responses.
Last edited by mark kibort; 06-14-2009 at 02:36 PM.
06-14-2009 | 02:18 PM
#36
Rennlist Member
Joined: Feb 2003
Posts: 29,817
Likes: 185
From: saratoga, ca
EXACTLY! Bill always has a way of producing the messages I like to make, in 10% of the text. Thanks bill.
mk
mk
The factory spec for front ride height is 180 +/-20mm and 180 +20/-30mm once the car leaves the factory. So, the low end of the range is 150mm. At 150 I found no problems with everyday driving, but tossing the car around some twisty roads lead to a lot of spoiler-road contact which fractured the uprights in the grill.
06-14-2009 | 03:00 PM
#37
Drifting
Joined: Dec 2003
Posts: 2,902
Likes: 0
From: an unnatural suburban habitat
MK- just so long as you are willing to set some money aside to pay for other people's low ride height related problems- broken belly pans, front spoilers, cracked oil pans, broken alternator blocks, and worn out front tires.
06-14-2009 | 04:22 PM
#38
Thread Starter
Race Car
Joined: Sep 2007
Posts: 3,663
Likes: 0
From: No where Oklahoma AKA "The Dust Bowl" In The Arm pit Of Hell
928andRC51 since I started this thread I would ask that you refrain from being so negative with people that disagree with your views. I value all advice on this forum. Some facts I understand and agree with and others I don't and disagree with. The truth is rarely black and white we generally formulate our truth from our own personal experience mixed with some technical fact. I appreciate all views since most drivers here have more experience with the 928 than I. Lets all try to work together for the good of the 928 even if we don't see eye to eye.
06-14-2009 | 08:37 PM
#40
Burning Brakes
Joined: Mar 2006
Posts: 1,003
Likes: 1
From: Nashua New hampshire.
i can say mines way too low, that and very wide/taller then stock tires (245-50/16)make for issues. i have hypercoils and the bump stop is set too low...rubs bad on drivers front and passangers rear (ice skating accident most likly the issue) looks great ..lol i do need to raise it about 15mm ..i know that my specs are too low....but realy the stock setting is WAY too tall.
On a side note, anyone know the ride height of the cup cars?
PS i should note i dont have 500 dollar spoiler up front = )
On a side note, anyone know the ride height of the cup cars?
PS i should note i dont have 500 dollar spoiler up front = )
06-14-2009 | 09:08 PM
#41
Rennlist Member
Joined: Feb 2003
Posts: 29,817
Likes: 185
From: saratoga, ca
250,000 combinded miles, 200 race /DE days, 4 chassis, and helping a few others with same type of settings. no issues, but a few scraped oil pans, spoilers, but NO worn out front tires, ever. You also have to remember, my ride hight has been very low. 110mm to 135mm currently, to 120-130s 10 years and before. I have already said, you have to look at how you drive the car and where you drive it. if you want to pull into parking places blindly, with no regard, yes, stock ride hight is good. If you take a little care, like you are driving a performance car and not a rental car, then get the car in the 150-160mm range, as it looks better, will handle better, and will not burn up street tires if it is aligned properly.
My opinion and experience only.
set the toe .5degrees toed-in in front, around 1 degree camber and you are good to go. check your toe after an alignment. it will be about 1/6" of an inch toed in. (based on 19" spaced marks front to rear of tire)
My opinion and experience only.
set the toe .5degrees toed-in in front, around 1 degree camber and you are good to go. check your toe after an alignment. it will be about 1/6" of an inch toed in. (based on 19" spaced marks front to rear of tire)
06-15-2009 | 11:16 AM
#42
Drifting
Joined: Dec 2003
Posts: 2,902
Likes: 0
From: an unnatural suburban habitat
Sorry to get testy, but I think the point I am trying to make is being missed:
On a stock suspension 928 (=mush, 20 year old shocks and sagged springs) a low ride height will eat tires (depending on how hard you drive) and leaves you more at risk for damage from ground contact- whether it's driveways, pot holes, manhole covers or whatever.
Every 928 I have seen (owned by the typical non-rennlist enthusiast) is low from springs sagging and has never been cranked back up, just re-aligned.
I am not going to get in a debate about this, it's been discussed to death and the search function should bring up enough information to choke a horse.
As far as my car, that pic is from '07, and my suspension is not stock. I don't have the same risk of grounding out and don't have much suspension movement either. Once my toe is set, I'm good. My car does not apply to what I'm saying.
On a stock suspension 928 (=mush, 20 year old shocks and sagged springs) a low ride height will eat tires (depending on how hard you drive) and leaves you more at risk for damage from ground contact- whether it's driveways, pot holes, manhole covers or whatever.
Every 928 I have seen (owned by the typical non-rennlist enthusiast) is low from springs sagging and has never been cranked back up, just re-aligned.
I am not going to get in a debate about this, it's been discussed to death and the search function should bring up enough information to choke a horse.
As far as my car, that pic is from '07, and my suspension is not stock. I don't have the same risk of grounding out and don't have much suspension movement either. Once my toe is set, I'm good. My car does not apply to what I'm saying.
06-15-2009 | 11:45 AM
#43
Rennlist Member
Joined: May 2001
Posts: 5,236
Likes: 5
From: Austin, TX
I've decided to lower the ride height, maintaining proper suspension geometer by installing 14" wheels and low profile tires.
Since the "finger" approach to measuring tire to fender ride height works so well, I will also be utilizing the traditional measurement methodology for horses, and measure in "hands."
Since the "finger" approach to measuring tire to fender ride height works so well, I will also be utilizing the traditional measurement methodology for horses, and measure in "hands."
06-15-2009 | 11:46 AM
#44
Rennlist Member
Joined: Oct 2004
Posts: 4,987
Likes: 14
From: In a tizzy
I have not owned a Porsche that I didn't lower. However it was not until I got my SUV drive over anything practices in check. AND I upgraded the springs first. These cars and others I found had American and ROW (Rest of World) ride heights where ROW is lower. If you take the time to check it out, you will also find that where there is a difference in ride heights there is also a difference in both springs and sometimes even swaybars and shocks.
An example is the 2005 Passat I had. The car as delivered was very cumfy driving, but at speeds above 90 it was scarily soft, drifted around and wandered. For only $400 VW would upgrade the springs and alignment to "Euro" Spec. After the stiffer springs, lowered right height and alignment it was a little less cushy around town, but handled much much better at higher speeds.
An example is the 2005 Passat I had. The car as delivered was very cumfy driving, but at speeds above 90 it was scarily soft, drifted around and wandered. For only $400 VW would upgrade the springs and alignment to "Euro" Spec. After the stiffer springs, lowered right height and alignment it was a little less cushy around town, but handled much much better at higher speeds.
06-15-2009 | 12:04 PM
#45
Thread Starter
Race Car
Joined: Sep 2007
Posts: 3,663
Likes: 0
From: No where Oklahoma AKA "The Dust Bowl" In The Arm pit Of Hell
This is a great discussion. I just want to say I'm still adjusting the suspension. What a hassle. Adjust drive adjust drive this process is rediculous! The real bad part is I can't adjust my sleeves without jacking the car.