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Suspension Geomery
Posted: Thu Jun 05, 2014 8:50 pm
by Engineer60
I thought I would post my findings regarding this subject with regard to tire wear concerns etc.
The following results indicate to me that excessive toe out has caused the excessive inner tire wear on the front and excessive negative camber has caused the same on the rear tires.
These type of suspension settings will nearly always be (depending on suspension type/design) detrimental to tire wear, while at the same time being excellent or very good for chassis handling.
RHD Kizashi Sport 2013 at 4000 miles showing @ 25% additional inside wear on all four tires.
RHD Kizashi Sport 2013 – Initial Readings.
Total Front Toe = -3mm, O/S/F -2mm, N/S/F -1mm, Off-Set to N/S/R = +0.75mm.
Camber = O/S/F -0.9°, N/S/F -1°
Total Rear Toe = +2MM, O/S/R 0mm, N/S/R +2mm, Off-Set to front 0mm.
Camber = O/S/R -2°, N/S/R -2°
RHD Kizashi Sport 2013 – Re-set.
Total Front Toe = 0mm, O/S/F -1mm, N/S/F +1mm, Off-Set to rear 0mm.
Camber = O/S/F -0.99°, N/S/F -1.1°
Total Rear Toe = O/S/R +0.75mm, N/S/R +0.50mm, Off-Set to front 0mm.
Camber = O/S/R -1°, N/S/R -1°
Forgot to add pulled car into the workshop today.
Re: Suspension Geomery
Posted: Thu Jun 05, 2014 9:11 pm
by KuroNekko
Indeed the toe setting is the culprit up front. I got my alignment fixed and asked for the tech sheet from the mechanic. I uploaded it on the thread dedicated to this topic of the Kizashi's alignment issue:
http://www.kizashiclub.com/forum/viewto ... 8&start=90
Not sure about the rear setting. I think most people see wear on the rears simply as a result of rotating the tires from the front to rear.
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 5:15 am
by SamirD
KuroNekko wrote:Not sure about the rear setting. I think most people see wear on the rears simply as a result of rotating the tires from the front to rear.
Toe will always cause this type of wear, even in the rear. Probably more on the awd version like we have since there is always some active forces between the tire and the road.
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 7:42 am
by bootymac
Good info and thanks for sharing. I believe this is the lowest mileage we've seen alignment measurements. This confirms that the factory alignment is out of spec, even on 2013 models. I've attached the alignment specs for quick reference
How does the car handle after the alignment?
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 12:15 pm
by Ronzuki
KuroNekko wrote: I think most people see wear on the rears simply as a result of rotating the tires from the front to rear.
Negative. The original tires were completely fine in the front. It was the rears wearing badly on the inside. Then the TSB came out with new settings. Other than not having the alignment dialed in dead center of the ranges after the new tires, I've experienced no issues since. I have increased my rotation from 7k to 5k miles since I put the Generals on. Seems to be working so far.
I always thought the car handled better w/ the original factory alignment, but it was killing the rear tires which is precisely what the OP has implied as the case with cars of greater handling ability.
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 6:59 pm
by Engineer60
bootymac wrote:Good info and thanks for sharing. I believe this is the lowest mileage we've seen alignment measurements. This confirms that the factory alignment is out of spec, even on 2013 models. I've attached the alignment specs for quick reference
How does the car handle after the alignment?
Thanks for the TSB.
The car handles safe and secure as it did before which will improve as the tires wear down more uniform following the revised adjustments.
This car is my better half's so will never be driven on the racing limit where the original settings will give you faster corner speeds due to less understeer, it will just be used for A-B trips, normal driving and around town trips where the decreased toe out on the front actually gives you a more positive turn in at normal road speeds but on the max limit increased understeer which is more relaxed for the average driver.
I also dropped the tire pressures all round to 32 psi for comfort as the standard settings are really for handling and possibly fuel economy, although she is getting 22 around town at the moment in FWD mode but for continued high speed cruising on the motorway I would/will raise them accordingly.
HTH
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 8:54 pm
by KuroNekko
Ronzuki wrote:KuroNekko wrote: I think most people see wear on the rears simply as a result of rotating the tires from the front to rear.
Negative. The original tires were completely fine in the front. It was the rears wearing badly on the inside. Then the TSB came out with new settings. Other than not having the alignment dialed in dead center of the ranges after the new tires, I've experienced no issues since. I have increased my rotation from 7k to 5k miles since I put the Generals on. Seems to be working so far.
I always thought the car handled better w/ the original factory alignment, but it was killing the rear tires which is precisely what the OP has implied as the case with cars of greater handling ability.
I wonder if whether you had AWD vs. FWD had an impact on the rear tire wear. I really did not see excessive rear tire wear compared to the front in my FWD Kizashi. However, it wasn't like I really paid special attention to tire wear until after they were rotated and the front alignment ruined all the tires.
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 9:30 pm
by bootymac
Just so we're all on the same page, the alignment specs in the TSB aren't actually new. The measurements are the same as what's in the owner's manual from 2010. The purpose of the TSB was to present the specs in a more universal format:
Please refer to the attached table for the Alignment Specification listings for the Suzuki Kizashi model, presented here in a more universal format. We at A.S.M.C. have made every effort to offer the required alignment specifications in a manner that will work with nearly all measuring standards being used currently in alignment systems.
Re: Suspension Geomery
Posted: Fri Jun 06, 2014 9:41 pm
by bootymac
bootymac wrote:Good info and thanks for sharing. I believe this is the lowest mileage we've seen alignment measurements. This confirms that the factory alignment is out of spec, even on 2013 models. I've attached the alignment specs for quick reference
Also, this confirms that the excessive tire wear issue is not specific to the Dunlop SP Sport 7000 tires that most of us have. Engineer60 has Dunlop SP Sport Maxx TT tires fitted.
I wonder if Suzuki purposely used more aggressive alignment specs for short term gains (better handling = better reviews). The blame for tire wear could be easily shifted to others such as the tire manufacturer or the owner for lack of maintenance.
Regardless, it looks like I'll be getting an alignment sooner rather than later. I'm currently at ~7,500 miles and I'll be sure to share my before and after measurements.
Re: Suspension Geomery
Posted: Sat Jun 07, 2014 4:32 pm
by SamirD
bootymac wrote:I wonder if Suzuki purposely used more aggressive alignment specs for short term gains (better handling = better reviews). The blame for tire wear could be easily shifted to others such as the tire manufacturer or the owner for lack of maintenance.
Personally, I think this might have been the case. Tires are almost never covered under warranty on new cars as they are a wear item, so the there was nothing to lose and everything to gain. They knew this car had to be a hit, which unfortunately for them, was the opposite.