Reconsidering the Factory Alignment
10-21-10, 09:30 AM
#31
Note its also going to change if you are lowered as the car will toe in further due to the steering link angle. I will try to derive the equivalent when lowered 1" up front. right now my toe settings were at 0.0 and 0.5.
__________________
Redefining Lexus Aftermarket Parts Since 2001
-- We are your Lexus suspension experts--
BCR - KW - PENSKE - OHLINS - HKS - GREDDY - STANCEPARTS
Links - Arms - SuperPro Poly Bushings - Solid Bearing Conversions - Motor Mounts
RB BBK's and 2P Rotors, G-Loc pads, Radium Fuel Systems
Custom Fabrication Design and Machining - Industrial 3D Printing - Laser Cutting
2018 USTCC Sportsman Class Champions - 2018 NASA ST5 National Champions
Redefining Lexus Aftermarket Parts Since 2001
-- We are your Lexus suspension experts--
BCR - KW - PENSKE - OHLINS - HKS - GREDDY - STANCEPARTS
Links - Arms - SuperPro Poly Bushings - Solid Bearing Conversions - Motor Mounts
RB BBK's and 2P Rotors, G-Loc pads, Radium Fuel Systems
Custom Fabrication Design and Machining - Industrial 3D Printing - Laser Cutting
2018 USTCC Sportsman Class Champions - 2018 NASA ST5 National Champions
10-21-10, 11:11 AM
#32
Pole Position
Join Date: Apr 2010
Location: TX
Posts: 399
Likes: 0
Received 0 Likes
on
0 Posts
I'll let you guys know when I get the results.
10-21-10, 03:58 PM
#33
Tech Info Resource
Thread Starter
iTrader: (2)
Okay, so I measured a rolling diameter of 26.75" on my front RE050A's. Assuming that:
1) the 1/32" to 1/16" of toe out is measured at the tread radius, and
2) the 1/32" to 1/16" of toe is PER WHEEL and not total
then that equates to .13° to .26° of toe out at each wheel.
lobux, thanks a lot for creating this thread. I'll be taking your alignment spec PDF to Speedware this week and have them align to those specs.
1) the 1/32" to 1/16" of toe out is measured at the tread radius, and
2) the 1/32" to 1/16" of toe is PER WHEEL and not total
then that equates to .13° to .26° of toe out at each wheel.
lobux, thanks a lot for creating this thread. I'll be taking your alignment spec PDF to Speedware this week and have them align to those specs.
How did you measure 26.75"? By specification it should be very close to 26.09".
10-21-10, 10:07 PM
#35
Tech Info Resource
Thread Starter
iTrader: (2)
I wouldn't trust that tape measurement for this.
10-22-10, 05:20 AM
#36
Lead Lap
iTrader: (9)
Join Date: Apr 2007
Location: MD
Posts: 481
Likes: 0
Received 0 Likes
on
0 Posts
Since we have the experts on this thread, when should I look to do an Alignment on my car?
My car has almost 34k miles on it, not seeing any issues with uneven tire wear (on 2nd set of tires). I don't track the car, it just sees alot of highway driving. On the highway I do notice it pulls alot to the right, more then it did when new. Tire pressure is in check and the tires look good. No bubbles or other irregularities.
My car has almost 34k miles on it, not seeing any issues with uneven tire wear (on 2nd set of tires). I don't track the car, it just sees alot of highway driving. On the highway I do notice it pulls alot to the right, more then it did when new. Tire pressure is in check and the tires look good. No bubbles or other irregularities.
10-24-10, 03:17 PM
#38
ok getting new tires soon..can someone just tell me what to tell the alignment monkeys to set it to....dont wanna ruin a new set of tires...my car has stock 18" wheels and is not lowerd..and it is a is350...thanks
10-24-10, 04:05 PM
#39
Tech Info Resource
Thread Starter
iTrader: (2)
10-31-10, 12:17 PM
#40
im on 19s and lowered with megan coils
i just checked my front tires yesterday and the inner is like 50% left and the outer still has like 90%. i have falken fk452s, and just bought these tires brand new about 4-5 months ago.
10-31-10, 04:56 PM
#41
So here's the spec sheet. It had 1/8" toe out from the factory, which is great for performance and terrible for tire wear. I had Jeff at Gran Turismo cut it back to 1/16" or from a little over 3mm to about 1.5mm. I'm going to see how this wears for street driving. Jeff also put some match marks on the toe links so I can toe it back out for track days.
FYI - one full turn equates to 3mm toe change on the side you adjust. I'll be resetting my toe to the factory spec on track days by lengthening the link 1/2 turn.
My cross camber is excellent, and with the car static, both sides read -1.0 degrees. I'd rather have -2.0, but at least they're the same. Rear cross camber isn't quite as good with -1.0 on one side and -0.7 on the other. Oddly enough, Jeff told me the right rear was actually toed out, so they corrected the rear toe, and reset the front toe to arrive at the numbers on the attached pdf.
I'm going to see how this wears, but I suspect it will be dramatically better. In theory, dynamic toe should be inward, so with a very slight outward toe, it might actually go to zero while cruising the freeway. In any case, I'll be monitoring it and reporting back what I find. I'm making an 1800 mile trip over the weekend, so I'll have some initial findings pretty quickly.
FYI - one full turn equates to 3mm toe change on the side you adjust. I'll be resetting my toe to the factory spec on track days by lengthening the link 1/2 turn.
My cross camber is excellent, and with the car static, both sides read -1.0 degrees. I'd rather have -2.0, but at least they're the same. Rear cross camber isn't quite as good with -1.0 on one side and -0.7 on the other. Oddly enough, Jeff told me the right rear was actually toed out, so they corrected the rear toe, and reset the front toe to arrive at the numbers on the attached pdf.
I'm going to see how this wears, but I suspect it will be dramatically better. In theory, dynamic toe should be inward, so with a very slight outward toe, it might actually go to zero while cruising the freeway. In any case, I'll be monitoring it and reporting back what I find. I'm making an 1800 mile trip over the weekend, so I'll have some initial findings pretty quickly.
01-20-11, 10:08 AM
#45
Tech Info Resource
Thread Starter
iTrader: (2)
^^the car is too low in the back. Caster should not exceed the OEM spec. When it does, the relationship between front and rear ride height is wrong. In your case, the rear is too low.
The amount of camber you have in the rear is also problematic. Anything over -2.5 can induce inside edge wear regardless of toe.
Since you are making a fashion statement with how low your car is, you can expect you'll have to pay for it with accelerated tire wear, and handling significantly diminished from a stock vehicle - I guarantee you with roll centers as low as you have, the car does not successfully negotiate a timed course faster than a stock IS F. I'd bet money your roll centers are below ground level and your roll couple is massive compared to stock.
The amount of camber you have in the rear is also problematic. Anything over -2.5 can induce inside edge wear regardless of toe.
Since you are making a fashion statement with how low your car is, you can expect you'll have to pay for it with accelerated tire wear, and handling significantly diminished from a stock vehicle - I guarantee you with roll centers as low as you have, the car does not successfully negotiate a timed course faster than a stock IS F. I'd bet money your roll centers are below ground level and your roll couple is massive compared to stock.