Help Car floating when going straight
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Instructor
Joined: Apr 2002
Posts: 131
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From: NY
Help Car floating when going straight
I recently find it difficult to keep it straight on the highway over 60mph. It seems little unstable where it tries to change lanes, so I got concentrate a lot.
I am not sure if tie rods are gone or could be something else.
I did put on 964 rims on the 993 just recently, which have 7 inch width vs 7.5 stock but the wheel calculator did not raise any issues in regard to offsets etc.
Under 50mph seems solid.
Looking for guidance in determining the problem. If simple I like to fix it my self otherwise take to shop.
Thanks in advance for your help.
-Kadeer
I am not sure if tie rods are gone or could be something else.
I did put on 964 rims on the 993 just recently, which have 7 inch width vs 7.5 stock but the wheel calculator did not raise any issues in regard to offsets etc.
Under 50mph seems solid.
Looking for guidance in determining the problem. If simple I like to fix it my self otherwise take to shop.
Thanks in advance for your help.
-Kadeer
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Joined: Jan 2004
Posts: 8,634
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From: Boston, MA
Could be a toe issue (likely), could be a broken cord in one of the front tires, could be bad tie rods, could be a blown shock, could be significant drop in tire pressure in one of the front tires. I'd start with checking simple things. If at all possible, I'd try to put two different tires on the front and check, eliminating either tires or the suspension as a possible culprit.
Intermediate
Joined: Mar 2008
Posts: 26
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From: UK
Well I've had my car 12 months & in that time it's cost me £5000 excluding petrol. That includes a service, HD suspension, insurance, HIDs, 4 new tyres, new radio/MP3, & a few other little trinkets. About what I budgeted for the 1st year.
So last month saw the final spend on 2 new front tyres. When I bought the car it would tramline quite badly & the advise I'd sought suggested the basic structure was OK (bushes etc) but the tyres were old (PZERO Rosso in the rear & P ZERO Asimmetrico in the front), the dampers past their best & there was also a slow puncture at the rear.
1st step was to replace the rear tyres (PZERO Rosso ), fit HD's & get the alignment sorted. This solved 80% of the problem but the car still followed the camber; the crown of the road being the most unpleasant place to be. OK on well surfaced roads but anything else wasn't too good.
With PZERO Rosso on all 4 corners it's a complete car. It doesn't matter how poor the surface, how deep the truck tramlines or how cambered, it just goes where I point it with commendable ease.
I write this to show that it can be a combination of errors contributing to this rather common problem. I suspect though that it is rather essential to have 4 tyres same make/tread pattern.
So last month saw the final spend on 2 new front tyres. When I bought the car it would tramline quite badly & the advise I'd sought suggested the basic structure was OK (bushes etc) but the tyres were old (PZERO Rosso in the rear & P ZERO Asimmetrico in the front), the dampers past their best & there was also a slow puncture at the rear.
1st step was to replace the rear tyres (PZERO Rosso ), fit HD's & get the alignment sorted. This solved 80% of the problem but the car still followed the camber; the crown of the road being the most unpleasant place to be. OK on well surfaced roads but anything else wasn't too good.
With PZERO Rosso on all 4 corners it's a complete car. It doesn't matter how poor the surface, how deep the truck tramlines or how cambered, it just goes where I point it with commendable ease.
I write this to show that it can be a combination of errors contributing to this rather common problem. I suspect though that it is rather essential to have 4 tyres same make/tread pattern.
Thread Starter
Instructor
Joined: Apr 2002
Posts: 131
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From: NY
I do have different tread patterns in the front and back, basically I have winter tires on now.
Btw, also the tread depth is different on the left front vs right front (slightly). Could this also cause issue? I was being cheap so I used a tire from my another car of the same specs.
As recommended I will try putting on another set of wheels in the front to isolate if its a bad tire issue.
Btw, also the tread depth is different on the left front vs right front (slightly). Could this also cause issue? I was being cheap so I used a tire from my another car of the same specs.
As recommended I will try putting on another set of wheels in the front to isolate if its a bad tire issue.
Racer
Joined: Jun 2001
Posts: 398
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From: Bay Area, CA
I do have different tread patterns in the front and back, basically I have winter tires on now.
Btw, also the tread depth is different on the left front vs right front (slightly). Could this also cause issue? I was being cheap so I used a tire from my another car of the same specs.
Btw, also the tread depth is different on the left front vs right front (slightly). Could this also cause issue? I was being cheap so I used a tire from my another car of the same specs.
Three Wheelin'
Joined: Oct 2006
Posts: 1,394
Likes: 3
From: Tampa, FL
Like others said, be sure to check simple stuff like tire pressure.
Had a tire replaced recently and they inflated the tires to the 16" wheel spec from their computers (42psi rear). Drove around for a week with the car hunting all over the place before I checked.
dave
Had a tire replaced recently and they inflated the tires to the 16" wheel spec from their computers (42psi rear). Drove around for a week with the car hunting all over the place before I checked.
dave
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Thread Starter
Instructor
Joined: Apr 2002
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From: NY
when you guys refer to toe issue. Is there a test for me to confirm, and what is generally the remedy. Alignment? tie rods?
More context, I have PSS9 with less then 5K on them, most that mileage was to AX and couple of DE events, the car is lowered to RS spec and aligned. My steering is off to the left couple of degree since.
Thanks I really appreciate the suggestion so far.
More context, I have PSS9 with less then 5K on them, most that mileage was to AX and couple of DE events, the car is lowered to RS spec and aligned. My steering is off to the left couple of degree since.
Thanks I really appreciate the suggestion so far.
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From: Boston, MA
Both the test and the remedy would be an alignment.
Steering being off is a red herring - just cosmetic. But depending on the alignment, it would track with the ruts in the road surface, hunt left and right and do other unwanted things... there is a compromise between street and autocross alignment and it's a very subjective thing.
Steering being off is a red herring - just cosmetic. But depending on the alignment, it would track with the ruts in the road surface, hunt left and right and do other unwanted things... there is a compromise between street and autocross alignment and it's a very subjective thing.
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Joined: Sep 2005
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From: South Florida
Aged hardened rubber causes a lot of problems like this. New shoes will have you walking a straight path again!
I had tires that looked brand new but they were ancient stock checking the date code. When I was ready to sell my old RUF I put a new set of Bridgestones on and I almost changed my mind about selling it, it was completely a different ride even though they where the same model tires.
~Chris
I had tires that looked brand new but they were ancient stock checking the date code. When I was ready to sell my old RUF I put a new set of Bridgestones on and I almost changed my mind about selling it, it was completely a different ride even though they where the same model tires.
~Chris
Race Car
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From: Calgary...Under my car... :)
[QUOTE=kadeer;6406755]I do have different tread patterns in the front and back, basically I have winter tires on now.
QUOTE]
What was the temperature out when you went for a drive? If was at all warm and the tire pressures were off only slightly, the winter tires are probably your culprit. All winter tires are soft so they work when its cold. My BMW is great in the cold with the winter tires on, as soon as it warms up and I am at highway speed the car does exactly what yours does. When it cools off the car is great again.....
QUOTE]
What was the temperature out when you went for a drive? If was at all warm and the tire pressures were off only slightly, the winter tires are probably your culprit. All winter tires are soft so they work when its cold. My BMW is great in the cold with the winter tires on, as soon as it warms up and I am at highway speed the car does exactly what yours does. When it cools off the car is great again.....
Thread Starter
Instructor
Joined: Apr 2002
Posts: 131
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From: NY
I just dicovered something really disturbing when I went to change wheels. I noticed the shop I took to put the front tires on the rear wheels, and rear tires on the front wheels. My 7x9 w/245 are riding in the back, and 8x10 w/225 in the front. I mounted based on the tire size so did not check which wheels the mounted the tires on. Idiots.
I have driven 500-1000miles like this, any damage I may have caused since the offset are screwed the way its placed.
I bet this has something to do with it acting up.
I have driven 500-1000miles like this, any damage I may have caused since the offset are screwed the way its placed.
I bet this has something to do with it acting up.
Drifting
Joined: Sep 2006
Posts: 2,413
Likes: 8
From: San Diego, CA
I just dicovered something really disturbing when I went to change wheels. I noticed the shop I took to put the front tires on the rear wheels, and rear tires on the front wheels. My 7x9 w/245 are riding in the back, and 8x10 w/225 in the front. I mounted based on the tire size so did not check which wheels the mounted the tires on. Idiots.
I have driven 500-1000miles like this, any damage I may have caused since the offset are screwed the way its placed.
I bet this has something to do with it acting up.
I have driven 500-1000miles like this, any damage I may have caused since the offset are screwed the way its placed.
I bet this has something to do with it acting up.
This is probably a large portion of your issue.... Take it back to them and have them make it right. Then find another tire place to use for the next time, as this is inexcusable.