SASSER

I have a 1986 parts car and a few weeks ago my PS pump stopped working. Instead of replacing it I was wondering would the manual rack from the 1986 work on a 1990 with little trouble? I havn't started takening the 86 rack out to check if there's a difference yet. Kinda wanted to see if someone has or knows someone who has put one of these in an S5. Thanks in advance.

Valkyrie

If you don't mind heavy steering, you could convert your PS rack into a non-PS rack.

The manual rack is a 20:1 steering ratio versus 15 or 17:1 depending on what model, for the PS rack...

in other words, it's SLOOOOOOOW. Heavier, with heavier steering than the manual rack though (for obvious reasons).

papiogxl

iTrader: (6)

check the archive for the writeup on how to properly remove PS, I don't even have that done, and I have a 15:1 ratio, and its not too bad for me. I'm not even strong, my bench is only around 150ish. Slow speeds its a little difficult, but moving, there is no difference.

Sideways7

iTrader: (7)

Yeah, you can jsut de-power your rack. It will be pretty hard to move when stopped (parking can be a bitch!) but you will get used to it pretty soon. I didn't even notice it on my car after driving it regularly.

Bama420

iTrader: (1)

I'm in the middle of removing my ps pump. I've been driving it without a belt for about a week and a half. I'm already used to it. The only time it causes a problem is when I'm smoking a cigarette, holding a drink, talking on the phone, driving a stick and following a damn minivan around a sharp turn at 5 mph in a 15 recomended turn. It gets a little tricky, but if I can do it, you can. And yes, I know that just removing the belt can harm the rack after a while. I just haven't had the time to remove the pump and I need the extra poewr for those damn civics and cavys that like to rev their fart cans at me at red lights. Some of those little knats are pretty quick. I mean, yeah I drive an rx7 but it's a 17 year old near stock GTU. And no, I don't have an lsd.

Bama420

iTrader: (1)

Hmm, I just realized that didn't answer your question at all. Hmm, If I were you, I would just remove the pump and reroute the lines off of the rack. From what Valkyrie says, it'll be easier to turn while moving with a converted power rack rather than an actual manual rack anyway. And it does the same thing either way on the lines of power.

Valkyrie

The proper way to do it involves taking the rack apart, grinding out the seals, and putting it back together with grease, and sealing up the line fittings (don't need to do any loops since the internal seals are gone).

The manual rack will be much easier to turn when stopped than a depowered rack, but the 20:1 ratio (3.6 turns lock to lock) will be extremely un sports car-like (too slow)... you'll have to pass the wheel for anything sharper than an average turn, and it'll be more like driving a truck than an FC. Ideally, I'd want the ratio closer to like...13:1... which is closer to what a sports car should be like, imo... (the Lancer Evo is like 12.5:1)

You definately want a depowered rack if you have the 17:1 ratio PS rack, for autocross... 20:1 would be horrifically slow, and I find that the 17:1 PS rack tends to hydrolock a lot when you steer really fast (ie, gymkhana or drifting).

I'm gonna get a 15:1 rack...some day...

drft_180sx

ok, so how can we tell if we have a 15:! or 17:1? I have a GXL.

KhanArtisT

iTrader: (2)

Very informative post, do you know which models came with which racks?

Valkyrie

The manual rack will say FB01, the 17:1 rack will say FC01, and the 15:1 rack will say FB...somethingorother... plus it'll obviously look different from a manual rack since it'll have lines and be twice as thick.

All S4's either had 15:1 PS racks, or 20:1 manual racks. Almost all of the S5's except the turbos had the 17:1 cheap-*** RPM-sensing ones.

If you have a PS S4 with a working speed-sensor, you should just leave it alone because you've got the best of both worlds (low-speed assist and high-speed feel, and probably less prone to hydrolocking).

Ashyukun

iTrader: (3)

The thread in the archives about de-powering the rack (https://www.rx7club.com/2nd-gen-archive-72/how-de-power-your-steering-rack-right-way-440198/) also contains the information on which models had which ratio rack in them.

I'm going to be de-powering mine (well, doing the mod on my parts car's rack and swapping it in) when I have the engine out to replace it. For better or worse, it has never run since I've had it so I won't have a frame of reference for how much more difficult it is to drive without the power assist. :P