posted on May 02, 2011 22:00
The Ultimate Guide to Suspension and Handling: Part Seven - Tuning your Toe
By Mike Kojima
Previously in our series we were talking about general tips for you to follow when tuning your suspension. In our last installment we talked about adjusting your camber to gain more grip. Today we will talk about an easier and more basic adjustment that has a great influence in handling, adjusting your toe settings.
To read the rest of the series, click here!
Tune Your Toe
Toe refers to the direction a car’s tires are pointed relative to each other when viewed from above. Toe in means the front of the tires are closer to each other than the rears. The opposite is toe out.
|From the left to right, toe in, toe out and zero toe as shown from above looking downward. Of course this is the front wheels but you can also tune toe on the rear wheels with good effect as well.
Fine tuning toe settings will allow a measure of control that is often overlooked. It also has a significant effect on how a car behaves in a corner. Front toe settings make a big difference in how a car handles in the first third of the turn, the critical turn in phase where cornering force is initiated. Rear toe settings can be critical for helping a RWD car get on the gas on the exit of a corner harder and sooner.
|Toe adjustments are not well understood but can make a big difference and can be used to help you go faster in all motorsports from autocross, to road racing, to rally and drifting.
The cool thing is that toe settings are probably one of the easiest alignment settings to do and all cars are toe adjustable with the exception of rear toe in cars with beam and solid rear axles. This makes it so you can experiment with different toe settings and get a feel for how they affect chassis balance.
Monday, May 02, 2011 11:19 PM
Thank you Mike for another excellent article! I have been waiting to read this
Tuesday, May 03, 2011 12:00 AM
" particularly AWD cars with transverse engines based on FWD cars like the EVO and STI"
Might want to double check the last bit of that sentence...
Tuesday, May 03, 2011 2:22 AM
Great article, this is one of my favorite series.
anxiously awaiting one on anti-geometry.
Tuesday, May 03, 2011 6:11 AM
I run a Chevy HHR in SCCA Autocross, and last time I went in to the tire shop, I had them set 1 degree of front toe-out (compared to the stock 0.0-0.4deg). I was expecting gains, but I wasn't expecting a completely different car. I actually ran into oversteer at the season opener. So far all of my modifications have been aimed at killing understeer, and the toe setting had a more tangible effect than Dunlop Star Specs and an Eibach front anti-roll bar. In terms of performance per dollar, it's hard to do better.
Tuesday, May 03, 2011 8:27 AM
I read recently about some MR2 racers who run toe out on the rear of their cars with good results.
Tuesday, May 03, 2011 11:42 AM
@ Mad_Science: Updated caption for you. The spirit of things remains the same as an STI is a front heavy AWD car.
Tuesday, May 03, 2011 4:30 PM
Ockham: My memory may be a little faulty, but I believe Mike had mentioned in one of the earlier parts that FWD cars benefit most from an adjustable rear anti-sway bar as opposed to a front one. I believe he had mentioned you could find that balance between oversteer and understeer you were looking for, without toe adjustment.
Mike: Excellent info as usual! This is a little beyond me, but I thought you could set the Ackerman to get some dynamic "toe out" as opposed to what I think you're reffering to, static "toe out"? Doesn't that mean you could still run zero toe out for better tirewear and then increase dynamic toe out by adjuating Ackerman?
Tuesday, May 03, 2011 4:53 PM
No production car that I can think of has adjustable Ackerman and there are not too many aftermarket ways to do it either. On race cars we custom fabricated parts to change the Ackerman.
Tuesday, May 03, 2011 10:18 PM
And my naivety pokes through again! For some reason I thought there was the ability to adjust production cars, kind of like you adjust a sandrail. Although, now that I think about it, I think most Ackerman problems are solved by completely reworking the steering. I think I mispoke, I think a LOT of this is beyond me but this sponge is still soaking! Thanks Mike.
Tuesday, May 03, 2011 10:23 PM
Adjusting toe is very simple though, don't be afraid to experiment.
Thursday, May 05, 2011 12:10 AM
Can you install a rear bar on an SCCA auto-X car in the stock classes w/o being bumped to a modified one?
Thursday, May 05, 2011 5:08 AM
No, only a front bar.
Thursday, May 05, 2011 4:40 PM
I still remembered back in ~1987 at the parking lot of the TRD store, Mike told me to set the rear toe of my MKII Supra to 1/8" toe in and fronts to 0. That setting with the race-spec TRD springs and dampers worked like magic. It was great advice at that time and still great now.
Wednesday, May 11, 2011 10:02 AM
Another thing to take into account when using toe to set up your car, especially in the rear, is what kind of suspension kinematics does it possess? Does it toe in or out under compression? I like to run a couple minutes toe-in in the rear of GD/GC Imprezas, for example. Under compression, the rear suspension toe's out and isn't as stable as I like at the limit, mid corner. So with static toe-in the car comes to about zero toe under compression.
Wednesday, June 15, 2011 12:52 PM
very good writeup, one question i had was in regards to your toe dimensions.. are you saying combined toe or toe on one corner?
can't wait to read more of your writeups.
Sunday, October 30, 2011 10:51 PM
I understand bending a beam axle on the rear of a FWD car to fix the toe, but won't bending a solid axle housing on a RWD car (the AE86 example) cause horrible things to happen inside it, followed shortly by horrible things happening outside it? It would bind, break the axle shafts, mess up the bearings, and/or blow the dif. Bending the axle flange would give your wheels a nice wobble, just like my Ford Ranger that once lost a wheel. With a solid drive axle, you're pretty much stuck with 0 toe and camber.
Sunday, October 30, 2011 10:53 PM
I am not talking about bending it 10 degrees, just 1-2 degrees which is commonly done in racing.
Sunday, October 30, 2011 11:34 PM
Fair enough, but I would think even that would wear the bearings quicker, although in a race car that's probably fine.
Thursday, November 03, 2011 10:52 PM
is there a specific distance from the center of the hub that you measure the toe at? i understand its the difference in the distance between the fronts of the tires and the rears but that really doesn't take into account the different wheel diameters out there. can you clarify?
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