"Twitchy" steering with new PS2s
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First, get an alignment. The ride height will need to be adjusted though! Dont go too low or the handling will suffer because there is no travel.
Good luck!
Thanks bro. At least I have a few ideas now to go after. Based on the input from this thread I think the alignment / ride hieght issue is the culprit. I trust the GMP guys will know what to do. I'll bring it down this week and let you all know what happens. Thanks everyone!Originally Posted by brockster
Are the wheels new as well? if they are new wheels and tires the car needs alignment> the 19s change the whole geometry of the cars suspension. I did the same, changed to JIC then new wheels 19 x 9.5 in front and 19 x 13 in rear. 245 in front and 315 in rear. As you can imagine the suspension was totally "confused" to say the least. First, get an alignment. The ride height will need to be adjusted though! Dont go too low or the handling will suffer because there is no travel.
Good luck!
Whenever suspension or alignment work is done, the steering sensor should be reset to the new calibrations. Have you done that? It is not necessary for changing shock settings.
Also, could the new tires still have the mold release compound on them causing the tires to lack grip for a couple hundred miles?
Also, could the new tires still have the mold release compound on them causing the tires to lack grip for a couple hundred miles?
I agree with the comments about alignment. I do my own, going between track setting with a lot of negative camber, and street which is GT2 stock setting. I got lazy earlier this year, and left the track setting with street tires. The car was twitchy, darty, whatever you want to call it. I drove it 60 miles on the interstate in a cross-wind, and i was worn out by the time I arrived.
After returning the alignment to stock, car handles well again.
Jon
After returning the alignment to stock, car handles well again.
Jon
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Also, could the new tires still have the mold release compound on them causing the tires to lack grip for a couple hundred miles?
I'll make sure they reset the steering sensor. It's been 500 miles or so, so I doubt the mold release compound is still an issue.Originally Posted by landjet
Whenever suspension or alignment work is done, the steering sensor should be reset to the new calibrations. Have you done that? It is not necessary for changing shock settings.Also, could the new tires still have the mold release compound on them causing the tires to lack grip for a couple hundred miles?
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After returning the alignment to stock, car handles well again.
Jon
Exactly what you're describing...making an appointment today.Originally Posted by FAST FWD
I agree with the comments about alignment. I do my own, going between track setting with a lot of negative camber, and street which is GT2 stock setting. I got lazy earlier this year, and left the track setting with street tires. The car was twitchy, darty, whatever you want to call it. I drove it 60 miles on the interstate in a cross-wind, and i was worn out by the time I arrived.After returning the alignment to stock, car handles well again.
Jon
How do you reset the steering sensor?
I'm putting on BBS CHR 19s" 235 35 and 315 25 with Conti S3s this week and usually do all my own work.
I don't have the equipment to mount tires or do an allignment but would like be smart enough that the steering sensor has been reset.
I'm putting on BBS CHR 19s" 235 35 and 315 25 with Conti S3s this week and usually do all my own work.
I don't have the equipment to mount tires or do an allignment but would like be smart enough that the steering sensor has been reset.
Ditto on the alignment. I once had an issue with brand new tires and the car being twitchy. I got a new rear tire and the issues were resolved. Turns out that the new tire was leaking air like a sieve.
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I'm putting on BBS CHR 19s" 235 35 and 315 25 with Conti S3s this week and usually do all my own work.
I don't have the equipment to mount tires or do an allignment but would like be smart enough that the steering sensor has been reset.
Yeah, I'm curious to know that too. I'm bringing mine in on Friday and hopefully I can look over their shoulder while they're under it so I get me some learnin'.Originally Posted by rolfjahn
How do you reset the steering sensor?I'm putting on BBS CHR 19s" 235 35 and 315 25 with Conti S3s this week and usually do all my own work.
I don't have the equipment to mount tires or do an allignment but would like be smart enough that the steering sensor has been reset.
OK I had the alignment done Friday and the specs for front camber are +/- .25 deg, (or +/-.3 deg as shown in another thread here). Although they weren't able to get the fronts 100% within spec because it was lowered so much (I learned it's down ~2" not .5" like I thought!) they got it close (-.47 deg) versus where it had been which was over 1 degree negative camber. I rides 100% better and I'm very satisfied with how it handles but I'm still going to price out adjustable camber plates which will allow for more adjustment so I can bring it back to OE spec regardless of ride height.
Thanks for the help here gents.
Thanks for the help here gents.
What tire pressures are you using? I have the same 19 with the same tire sizes and I go with lower pressures, like 33F and 37R. Seems to work really good.
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Hmm. I was going with the factory spec, which i believe is 40/44? I may try softening them a tad to see but right now it feels pretty good.Originally Posted by OCNYPORSCHE
What tire pressures are you using? I have the same 19 with the same tire sizes and I go with lower pressures, like 33F and 37R. Seems to work really good.
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Good to know...I'll fix that today. Thanks.Originally Posted by GT3 Chuck
those pressures (40/44) seem too high to me...my ps-2's used to lose grip at 40pds hot...33-37 cold sounds more reasonable for the street
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In the quest for more grip, your first move should be Sway Bars and Drop-Links. Once you have an appropriate set of Sway Bars, you can start adding camber, and really working on some serious grip. This is done with a set of adjustable toe links, then some spring upgrades to your shocks. The next upgrade would be proper adjustable lower control arms to get some camber into the front of the car. However, you cannot simply swap an Adjustable LCA and get a better setup. When we perform these swaps, we custom machine each control arm for its specific application. This way we can guarantee that we are not negatively affecting other suspension aspects such as the overall wheelbase and castor angles. Using upper dog bones is not the appropriate way to gain camber because while you are increasing your camber, you are also decreasing your front track, which is imperative to maintaining a good solid, planted feel when braking very hard. A wider front track provided by appropriate adjustable lower control arms will really allow you to stand on the brakes. Using wheel spacers is not the proper way to gain front track because as you space the wheel out from the hub, you are effectively making a longer lever arm, thus decreasing your spring rates.
I know this is a lot of information. If you have any questions about how/why some things work, I'll be more than happy to help!
Josh Bers
TPC Racing
410-799-7223
jbers@tpcracing,com
Hey Josh,Originally Posted by Josh@TPCRACING
One of your issues here is that you have gone from the optimum 18" wheel to the larger 19". If handling is what you are looking for, you should go back to the 18"s. By using a larger wheel you have taken side wall away from your tires. This stiffer side wall decreases your overall grip causing the car to get "squirrelly". What suspension components do you currently have? Usually if your car's suspension is stock, you should keep your alignment as close to stock as possible. A 1/2" drop is not too much for your Bilstiens. HOWEVER, if your car is dropped without a set of Adjustable Toe Links, your alignment could be out already because often times it is not possible to get back into factory alignment specs. This could also be adding to your squirrelly feeling. In the quest for more grip, your first move should be Sway Bars and Drop-Links. Once you have an appropriate set of Sway Bars, you can start adding camber, and really working on some serious grip. This is done with a set of adjustable toe links, then some spring upgrades to your shocks. The next upgrade would be proper adjustable lower control arms to get some camber into the front of the car. However, you cannot simply swap an Adjustable LCA and get a better setup. When we perform these swaps, we custom machine each control arm for its specific application. This way we can guarantee that we are not negatively affecting other suspension aspects such as the overall wheelbase and castor angles. Using upper dog bones is not the appropriate way to gain camber because while you are increasing your camber, you are also decreasing your front track, which is imperative to maintaining a good solid, planted feel when braking very hard. A wider front track provided by appropriate adjustable lower control arms will really allow you to stand on the brakes. Using wheel spacers is not the proper way to gain front track because as you space the wheel out from the hub, you are effectively making a longer lever arm, thus decreasing your spring rates.
I know this is a lot of information. If you have any questions about how/why some things work, I'll be more than happy to help!
Josh Bers
TPC Racing
410-799-7223
jbers@tpcracing,com
Wow. All that because of a wheel size change!!! And i was told that this was the "hot setup"!
It has 3-way adustable sway bars front and rear, with the PSS10s. It turns out the car is a lot lower than I previously thought, it is about 2" below stock. They were able to get the rears 100% within factory spec, and the caster and toe in the front as well. Just the camber is still a bit negative by about .25 degrees. I am told that new camber plates with more adjustment room will allow me to get that last piece of the puzzle back in spec. Agree? Disagree?
I will say that with just the alignment as-is the car handles very well...light years better than it did when I brought it in. I'm also told that my tires are a bit over-inflated as well, so I'll remedy that prior to my next drive.
I once had a set of PS2's on my GT3 that I ordered new from tire rack. They looked exactly the same, had the same amount of tread in them but the manufactured date/month on them was different (on the rear tires). The car was all over the place and drove like the alignment was off by a significant factor. They sent me 2 new tires with matching #'s on them and the probelm was solved.