Power Steering questions

[04TitaniumGrayPhilly]

So I've been thinking about doing the AC and PS delete for some time now, since I never use the AC in the car and am just hauling around weight. Removing PS supposedly yields better steering response, and would make my intercooler piping re-do in the summer much easier since I could go straight down and not through the fender. Would free up room for other things to get adjusted a bit too.

I seem to run into a 50/50 split of people who love their manual racks, and those who hate them and even some who converted back to PS. Since I am transitioning into more track fun stuff and away from street driving as much, I feel it might be worthwhile, but I want to see what you guys think

[SilverMiataRacer]

I've owned 4 Miatas.  1 with factory manual steering and the rest with PS.  The manual steering is far superior on the track.  On the street it's a little bit of an annoyance if you have to parallel park.  My choice for a street car with occasional track days is keep the PS.  If the car is a part time driver and heavy track car then I go for manual steering.  I would NOT do the manual conversion without modding the rack though.  JMHO.

https://www.flyinmiata.com/tech/depower.php

[04TitaniumGrayPhilly]

I've owned 4 Miatas.  1 with factory manual steering and the rest with PS.  The manual steering is far superior on the track.  On the street it's a little bit of an annoyance if you have to parallel park.  My choice for a street car with occasional track days is keep the PS.  If the car is a part time driver and heavy track car then I go for manual steering.  I would NOT do the manual conversion without modding the rack though.  JMHO.

https://www.flyinmiata.com/tech/depower.php

Thanks for the insight, and yes, if we did the Manual conversion, we would pull and do all the needed work to the inside of the rack (friend actually just did it for someone else)

[sprite63]

My understanding is that the MS power steering rack has a different turning radius than the standard NB rack. Given that you are going to "manualize" the rack is there an additional benefit to realized by using an NB rack or is the MS rack better for the intended use here?

[rotorglow]

My understanding is that the MS power steering rack has a different turning radius than the standard NB rack.

The only difference is the stops at the ends of the rack, to keep the wider tires (than other NBs) from hitting. That's what makes the radius longer. Ratio is the same.

[04TitaniumGrayPhilly]

So if I'm already on a 15x10 245 maxxis and may in the future to to a 15x11 275, should i keep the MSM rack with those stops in place? Can they be removed during the manual conversion? Should they be removed?

[SilverMiataRacer]

I'd say you need to keep them in place.  The only time those stops become an issue is on the street if your trying to do something like make a U Turn or that kind of excessively sharp turn.  On the track they don't some into play and even under regular driving they don't.

[rotorglow]

Rackstops for other cars with big tires are very common additions, so more people in/with your shoes add them than remove them.  I'd hate to need to think that hard about what's rubbing when I got close to full lock.

Edit, and for unnecessary effect, my 330xi has a ridiculously small turning radius considering the stress full lock puts the the front half-shaft boots.  Those who parallel park those cars go through axle boots every 25K.  They last 90K+ on cars that don't.  I cringe every time I get close to full lock, and I'm considering adding stops.

Thumbs up on the new (?) short sig, btw!

[04TitaniumGrayPhilly]

Rackstops for other cars with big tires are very common additions, so more people in/with your shoes add them than remove them.  I'd hate to need to think that hard about what's rubbing when I got close to full lock.

Thumbs up on the new (?) short sig, btw!

Haha, thanks. I kind of realized it might be a big long and annoying when scrolling through 

['95MSM]

There aren't any stops to remove. IIRC, the rack is narrower, but assembled into the same housing as any NB. The result is less range of motion. (I posted on this several years ago after physically comparing NB and MSM powered racks.)

Mazda claimed improved steering for the NB, and I think bumpsteer was specifically addressed. If NB bumpsteer is good, MSM bumpsteer most likely is not as good: that narrower rack requires longer links and disturbs the relationship between the control arm lengths and the steering link.

I would search for a manual NB rack (rare) or de-power a normal NB rack. I've toyed with the idea of adding spacers between the rack and ball & socket joint on the inside of the steering links, but haven't come up with a way to replace or extend the mechanical lock between the joint and the rack.

I've driven a properly de-powered rack (Mr. Hyde's) on the street and did not like it at all. I'm sure it lightens up quite a lot for track use, but around town it just sucked IMHO.