lock to lock in relation to steering

[rennlistuser3]

Hey everyone,

I'm trying to get my head around something technical in cars and thought I'd get feedback here.

The FT86 steering is 2.5 Turns Lock To Lock (tltl). The FT86 steering is the best steering I've ever experienced in my life. The main attributes are feel/accuracy/speed. I assumed the latter two were mainly due to the 2.5 tltl. But recently I tested my 2016 Mazda CX-5 and it was approximately 2.7 tltl. The CX-5 steering feels like a boat in comparison. Very slow to change directions, requiring a lot of steering angle to rotate at higher speeds whereas the FT86 just requires a slight angle to turn like a scalpel at even higher speeds. It's very hard to believe they're that close in terms of tltl. Driving back to back feels night and day.

I thought tltl is the major factor here but am I missing something? the new 2020 Ford Focus ST boasts a 2.0 tltl and I can't even get my head around how that would even work given that the CX-5 is only slightly slower tltl yet feels like a boat in comparison to the FT86.

What am I missing?

[redphaser]

So from my admittedly limited understanding I think what you’re feeling is likely the difference in steering ratio and “type” as opposed to the “lock to lock” differences.

The twins have a fixed steering ratio of 13.12 to 1 whereas the CX-5 has an effective progressive ratio of 15.5 to 1.

The smaller the first number, the “faster” the steering will feel. The other bits I mentioned are fixed vs progressive steering. Fixed means that the wheel is always 13.12 to 1, no matter how far you have the wheel turned. Progressive steering (and I’ll admit this is where I’m a bit more fuzzy on the details) generally means the steering is “slower” off center then speeds up as you get closer to lock. This is likely to help a car feel less twitchy at speed/on the highway, which is probably fine for a non-sporty vehicle, but can make the steering feel sluggish off center.

So while the lock to lock numbers are very similar, there are some huge differences in the the ratios in both type and numbers.

The BRZ has one of the quickest racks available, especially at this price point. It’s one of the reasons I miss my old 2015 BRZ so much (damn you freak hail storm!). The steering was plain fantastic.

And if I got any of this incorrect someone please let me know. Always willing to learn and correct myself

Data sources:

https://www.mazdausa.com/siteassets/...ures-specs.pdf

http://subarumedia.iconicweb.com/med..._Specs_2.0.pdf


Sent from my iPhone using Tapatalk

[Stang70Fastback]

There are a lot of other factors that come into play here. Lock-to-Lock is only one small part of it.

Tire Size: A quick google shows that most CX-5s (unless it had the 19" wheels) come with 225/65R17 tires. Those tires have a much taller sidewall, which is over 50% taller than the stock tires on a BRZ. That taller sidewall will flex a lot more when you turn the steering wheel, and the more flex there is, the sloppier the steering will feel, and the less immediate the turn-in will be, as the tire basically has to flop over before the car itself will really begin to turn. In addition, the CX-5 also likely had whatever all-seasons on... rather than sport-oriented tires, which means an even softer, less responsive sidewall... and softer, less responsive tread blocks that themselves also deform under load.

Softer Suspension: The CX-5, I assume, is a more comfortable ride than the BRZ. That also means softer springs, usually, and more body roll. Both of those things contribute to a car that "feels" less precise as the vehicle rolls a bit more before "taking a set" in a corner. That rolling motion can feel sloppy.

Higher Weight: The CX-5 is 700+ lb heavier than the BRZ. Weight matters. Regardless of whether or not the car can corner at the same speed, you can ALWAYS feel added mass. A light car with skinny tires cornering at the same speeds as a heavy car with fat tires will always feel more willing, and eager to change direction.

Higher Center of Gravity: As above, this contributes to the vehicle feeling taller and less stable, even if it manages a similar skidpad rating.

Comfier Bushings: Dunno what kind of bushings the CX-5 has, but it's likely that they are cushier in order to provide a more refined, more comfortable, and less jarring ride. Softer bushings allow suspension components to have a bit more play, which is yet another thing that can make handling feel a bit sloppier.

...and many other differences in suspension setup, parts, materials, etc...

[maslin]

Let's not leave out camber, caster, SAI, power steering, steering angle, steering wheel diameter, etc etc etc.

There's a lot involved. Hard to compare two completely different cars based on one small fact.

A miata and a F350 both have 4 tires, alloy wheels, brakes and seats. They aren't the same.

[rennlistuser3]

Originally Posted by redphaser

So from my admittedly limited understanding I think what you’re feeling is likely the difference in steering ratio and “type” as opposed to the “lock to lock” differences.

The twins have a fixed steering ratio of 13.12 to 1 whereas the CX-5 has an effective progressive ratio of 15.5 to 1.

The smaller the first number, the “faster” the steering will feel. The other bits I mentioned are fixed vs progressive steering. Fixed means that the wheel is always 13.12 to 1, no matter how far you have the wheel turned. Progressive steering (and I’ll admit this is where I’m a bit more fuzzy on the details) generally means the steering is “slower” off center then speeds up as you get closer to lock. This is likely to help a car feel less twitchy at speed/on the highway, which is probably fine for a non-sporty vehicle, but can make the steering feel sluggish off center.

So while the lock to lock numbers are very similar, there are some huge differences in the the ratios in both type and numbers.

The BRZ has one of the quickest racks available, especially at this price point. It’s one of the reasons I miss my old 2015 BRZ so much (damn you freak hail storm!). The steering was plain fantastic.

And if I got any of this incorrect someone please let me know. Always willing to learn and correct myself

Data sources:

https://www.mazdausa.com/siteassets/...ures-specs.pdf

http://subarumedia.iconicweb.com/med..._Specs_2.0.pdf


Sent from my iPhone using Tapatalk

Sorry for the late reply. I wanted to scratch my head over this for a bit.

If I understood this correctly, the only thing stated in the Mazda manual is variable assist. This basically changes the power steering assistance making the steering sometimes lighter sometimes heavier but does not effect the steering ratio which is as far as I know fixed for the CX-5. I actually patiently hate variable steering ratio and I avoid cars that have this. Hondas tend to have this and I hate driving them for this reason. I think if the CX-5 has a variable ratio, I would've sensed it the same way I do in Honda but maybe I'm missing something here?

[rennlistuser3]

Originally Posted by Stang70Fastback

There are a lot of other factors that come into play here. Lock-to-Lock is only one small part of it.

Tire Size: A quick google shows that most CX-5s (unless it had the 19" wheels) come with 225/65R17 tires. Those tires have a much taller sidewall, which is over 50% taller than the stock tires on a BRZ. That taller sidewall will flex a lot more when you turn the steering wheel, and the more flex there is, the sloppier the steering will feel, and the less immediate the turn-in will be, as the tire basically has to flop over before the car itself will really begin to turn. In addition, the CX-5 also likely had whatever all-seasons on... rather than sport-oriented tires, which means an even softer, less responsive sidewall... and softer, less responsive tread blocks that themselves also deform under load.

Softer Suspension: The CX-5, I assume, is a more comfortable ride than the BRZ. That also means softer springs, usually, and more body roll. Both of those things contribute to a car that "feels" less precise as the vehicle rolls a bit more before "taking a set" in a corner. That rolling motion can feel sloppy.

Higher Weight: The CX-5 is 700+ lb heavier than the BRZ. Weight matters. Regardless of whether or not the car can corner at the same speed, you can ALWAYS feel added mass. A light car with skinny tires cornering at the same speeds as a heavy car with fat tires will always feel more willing, and eager to change direction.

Higher Center of Gravity: As above, this contributes to the vehicle feeling taller and less stable, even if it manages a similar skidpad rating.

Comfier Bushings: Dunno what kind of bushings the CX-5 has, but it's likely that they are cushier in order to provide a more refined, more comfortable, and less jarring ride. Softer bushings allow suspension components to have a bit more play, which is yet another thing that can make handling feel a bit sloppier.

...and many other differences in suspension setup, parts, materials, etc...

All very good points.

I was sort of contemplating the idea that you would need more steering angle in an SUV to account for more slippage of the steering tires compared to a sports car but wanted to hear more from others if this makes sense.

Really good stuff to learn

[mav1178]

lock to lock doesn't mean anything without the same variables, i.e. the steering angle is the same between two cars you're trying to compare.

just view it this way:

S13 240SX had a 17:1 steering rack
S13 240SX with Super HICAS had a 13:1 steering rack. this was pretty much the holy grail of drifting, because you had a super responsive steering rack that made the car very nimble. most people ended up buying a HICAS canceller to disable the system (it was really just a plain metal plate that fixed the rear toe links and capped the hydraulic system)

Normal vehicles have higher ratio (i.e. more turns to achieve same angle) so it's easier to turn your steering wheel. The only definitive way to compare is if you physically got out, measured the same steering angle of the wheels, and then determined how many turn(s) to get to that angle.

[strat61caster]

^ that

Turning the steering wheel one revolution results in a different wheel angle on pretty much every different car due to all the differences in mechanisms and geometry.

tltl is a neat stat, but ultimately next to meaningless to how the car feels to drive, steering rack ratio is more meaningful to describe the responsiveness available, but the weight and feel can be totally warped by suspension geometry and power steering tuning.

[maslin]

Originally Posted by mav1178

lock to lock doesn't mean anything without the same variables, i.e. the steering angle is the same between two cars you're trying to compare.

just view it this way:

S13 240SX had a 17:1 steering rack
S13 240SX with Super HICAS had a 13:1 steering rack. this was pretty much the holy grail of drifting, because you had a super responsive steering rack that made the car very nimble. most people ended up buying a HICAS canceller to disable the system (it was really just a plain metal plate that fixed the rear toe links and capped the hydraulic system)

Normal vehicles have higher ratio (i.e. more turns to achieve same angle) so it's easier to turn your steering wheel. The only definitive way to compare is if you physically got out, measured the same steering angle of the wheels, and then determined how many turn(s) to get to that angle.

I swapped a super hicas rack on to my ‘90 s13. Absolutely loved it.