mr2peak

Has anyone swapped in a faster rack from another car?

FD is stock 16.5:1

E36 M3 is 15:1, E46 M3 is 14.5:1, Z3 1.9 is the fastest at 13.9:1
Porsche is 14:1 or 15:1 depending on the model.
Miata is 15:1 for powered racks

My MK1 MR2 had a very fast quaife rack 2.2 turns lock to lock, a bit too fast for a car with FD levels of power. I don't want to use a 1.5:1 or 2:1 steering quickener.

Has anyone tried to fit a rack with a bit faster ratio? Definitely want to keep a powered rack, much easier to throw a car around with a little assist.

ptrhahn

iTrader: (9)

The Atomic/Minotaur rack was/is quicker. 2.4 vs 2.9 lock to lock. I love mine. Tough to find anymore tho.

mr2peak

But that's a manual rack, yes? I want to keep a powered rack, much safer when the tail steps out

ptrhahn

iTrader: (9)

I don't know about "much safer when the tail steps out".... but I also don't see the work to benefit ratio on a faster rack for power steering. What problem are you trying to solve?

What you could do is get a faster manual rack and add electric assist to it. That's going to be a helluva lot shorter distance between two points than trying to retrofit a hydraulic rack I think.

mr2peak

Faster steering is nice. Once you've driven a car with faster steering you notice how slow the FD rack feels.

Slapping electric assist into the FD could be a fast way to lose the steering feel. OEMs struggle with this with massive budgets, I doubt I'd get close with a home brew option. There's a place on a show FD for electric assist, but this isn't that.

Try spinning out with manual steering vs power assist, it's much easier to catch and correct with power steering, especially if you run a small steering wheel and much larger wheel/tire like a lot of us do.

DaveW

My F2000 Citation racecar has very fast steering with a lot of steering lock angle. I drove a different F2000 racecar for a couple of races and was caught out a couple of times (spinning) by its slow and low max-angle steering. I often get sideways driving, and with my Citation's steering setup I almost always am able to save it. So I agree completely with mr2peak's opinion.

Esser

iTrader: (2)

Miata appears to be the closest to fitting dimensionally

ptrhahn

iTrader: (9)

My opinion of course, but power steering isn't needed for "driving" and won't help in controlling oversteer. Its for garages, parking lots, and traffic. Once you're moving (as you'd need to be for the back to step out), its not really needed. Might even hurt, it can make sharp movements more chaotic or exagerated.

c0rbin9

iTrader: (2)

I think it's very hard to argue that power steering doesn't make the car more controllable in performance driving. I've driven cars without it and frankly I'm not sure how you're supposed to go fast on a backroad without it. As other posters mentioned, it makes it much harder to countersteer.

mr2peak

I'll have a look at it. Published numbers take suspension geometry into account, I need to find raw degree turned = rack travel length info. Looks like a few people have swapped it in the past, but usually unpowered.

mr2peak

Here's an article by Jason Cammisa about power steering vs feel and how the lack of power assist can add to a crash / spin

https://www.roadandtrack.com/car-cul...hing-you-want/

ptrhahn

iTrader: (9)

I mean, I've been tracking this car for 25 years, the majority of it without power steering. I removed it on purpose. What I see more often than not in spins isn't slow correction of initial slide, but over-correction, leading to tank-slappers and the sort of stuff you see coming out of cars and coffee events on youtube. Only instance where I'd maybe amend my previous statement is autocrossing, but not so much for catching slides as hustling it around really tight corners.

mr2peak

I spend the majority of my time on the street. Power steering is good for that. I'm not interested in a de-powered rack.

Ceylon

iTrader: (3)

I'd be interested in a rack swap. Are there any electric-powered racks that have good ratios and feel? It'd make the engine bay cleaner, I'd love to bin the pump .

j9fd3s

iTrader: (3)

there are sort of two types of electric racks, one where the motor is ON the rack, like the Rx8

or ND Mx5


then everything else seems to have the electric motor on the steering column and then use a really plain looking manual rack,
this one is a Mazda 3


i feel like Mazda has kept the spline to the column the same, and the tie rods are probably the same thread, but the racks do mount differently so that is a thing too.
i'm sure there is something that would work, although it would take some time to find the good candidates

oh and Mazda's all have the same-ish steering ratio, so if you want something faster you'd need to figure that out too

i drove a Lancia Scorpion a bit and that steering is so fast i had the opposite problem from DaveW, my Mazda sized steering inputs were way too much for that car.

mr2peak

Yeah that's why I don't want to go with a steering quickener at 1.5 / 2 :1 it's just way too much. I'll have a look outside Mazda and see what I can find. Something in that 14:1 area would definitely modernize the car without being crazy. I'll measure a stock rack and see what the actual rack travel is.

TeamRX8

iTrader: (2)

The FD3 is 16.6 overall ratio with 2.9 turns to lock @ 15” steering wheel diameter

The RX8 is 16.4 overall ratio with 3.0 turns to lock at 14” steering wheel diameter

because you have to consider both rack ratio and the steering lever arm length on the front knuckle

steering wheel diameter also comes into play as well, since a larger OD will have a larger circumferential travel distance for a given rotation angle input. A smaller diameter provides a heavier, but quicker feel by requiring less input to achieve the same angular rotation change.

Having owned and autocrossed a variety of vehicles since when the FD3 originally debuted in 1992, which autocross is about as dynamic wrt steering as it gets for motorsport activities, I consider the RX8 ratio perfect, very controllable at the limit and never any issue to either catch or over-input. Which I prefer a loose/oversteer chassis setup as well. If it were me I’d just go for one of the under-dash add-on EPS kits with a depowered rack and associated OE support parts removed. Retrofitting a rack etc. would be a much bigger headache and more likely to have issues imo.

in my general experience, the people who most often go on about steering ratio either lack driving skill and/or understanding. They read or heard something somewhere and got hooked on an idea. You can sort of pick up on who they are, because it generally trends with that same person over and over again for a variety of similar carrying-on scenarios ...
.

mr2peak

Please expand on this for us. It seems like once again you are commenting on something just to be an *** to me. Every time dude. What are you so incredibly butthurt about?