RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   Race Car Tech (https://www.rx7club.com/race-car-tech-103/)
-   -   FC Steering Rack opinion (Man/Pwr) (https://www.rx7club.com/race-car-tech-103/fc-steering-rack-opinion-man-pwr-434743/)

Infini IV 06-17-05 07:41 AM

FC Steering Rack opinion (Man/Pwr)
 
I was given the opportunity to drive my friend's '87 TII with a manual steering rack. From what I know, the car is also fitted with Tein HA coilovers (8fr/6rr combo), 205/55/16 A032R tires up front (35-40psi?), ~2* camber, and front strut tower bar.

Effort in turning the steering wheel is not as great as a car with a P/S rack looped, but still great enough that it takes decent strength to turn it at speed. Even at speeds of over 100mph, the effort required to turn the steering would affect one's ability to relax and feel the reactions of the car. BTW, I'm sure we all agree that a relaxed person has a greater ability to "feel" movements. At this point, I'm wondering why people who enjoy driving fast (not just going straight) discard their P/S racks for a manual rack. I'll honestly admit there is a slightly better feedback on the steering wheel of the manual rack car as compared to S4 and especially S5 P/S racks. However, with a car sprung stiff as my friend's car was, I find that the overall feel of what the chassis is doing is greater than the slight advantage you can feel of the steering with a manual rack. I would have had much greater confidence in pushing his car further if his car was fitted with an S4 P/S rack.

I've given my opinion based on my experience... please discuss with effort on how you feel about the different steering racks of the FC.

RETed 06-17-05 09:06 AM

I take road feel ANYDAY over overboosted steering.
I don't understand your experience...
As speeds get faster, the effort to turn the wheel should go down.
At triple digit speeds, you should have no effort turning the wheel.
What are you trying to do? High speed drift???


-Ted

Gene 06-17-05 10:52 AM

My TII is converted to manual. The only thing I don't like (besides parking) is the increased turning travel required when going around low-speed turns like on city streets.

Bad2ndgen 06-17-05 11:01 AM

Are the ratio's differant? Does anyone have a kit to just eliminate the pump on a ps rack like they have for fd's? If the ratio is tighter on the ps rack this is what I would want to do.

RX-Heven 06-17-05 12:49 PM

The ratio is tighter on the ps rack.
I cannot stand the way ps feels in any car.
My vert and all other fc's I've owned, with one exception that was manual, have had a converted ps rack and I like it much better. It's all personal preference though.
Anyone that complains they are hard to park after being converted is a pussy imho.

Ratios:
Manual S4- 20.3:1 Power Assist- 15.2:1
Manual S5- 17.4:1
Lock to lock:
Manual- 3.6 Power Assist- 2.7

Infini IV 06-17-05 03:58 PM

RETed - As speeds get higher, steering effort did go down. However, it still required enough effort to turn that I wouldn't be as relaxed as I could be. Are you sure it requires "no" effort? Even an S4 P/S rack requires a little effort to turn. The only one of the FC steering racks that require close to "no" effort is the S5 P/S rack. Honestly, I don't feel an S4 P/S rack loses much in terms of feel to the manual rack. BTW, where did you come up with the "high speed drift" thing? It's often interesting to read the things you come up with to question people... almost as if your mind wonders to far greater places than we know.

RX-Heven - Of course it's personal preference, but I was wondering what about PS that you didn't like? I thought all S5 steering racks were power assisted. According to "Sport Car Color History: Mazda Rx7" by John Matras, S5 steering racks were either 15.2:1, or 17.2:1, or 17.4:1... all power assisted.

Most of you guys probably have an idea of how S2000's and M3's have a very "edgy" feel when trying to get the most out of the cars (getting the most grip out of them...no "high speed drifting" ;) ). Putting coilovers (of the rates I had mentioned above since this is what I have experience of) on the FC chassis prompted the car to become just one step closer to having that "edgy" feel as the S2k and M3 does. On a track, you can constantly ride that limit on those cars and make the real quick and precise steering corrections needed to keep the car in check partly because the road conditions are smooth. However, on a road with bumps, it is indefinitely harder to make those steering corrections as precise. Add to the fact that the rack is slower and requires more effort and I'd find it damn near impossible to make as quick a steering input to react to the chassis.

ProjectRESuperG 06-17-05 04:32 PM

I have a S4, with a converted PS rack. With my RT215, and lowered via JIC FLTA2, yeah, I admit, turning at a dead stop, and "parking lot" speeds can be some what of a pain, but freeway? No way. Like Ted mentioned, it requires minimum effort. Heck, even my wife can drive my FC (despite complaining about the effort).

I think many people like manuals, or converted PS due to the fact that at high speeds, sensitivity to steering input becomes greater, so a manual rack will offer more "feel" which translates into more control. Many people with PS can over-correct at high speeds due to PS's "artificial" feel.

Modern cars tend to do better in this dept. Never driven a M3 or S2K, but have driven WRX's, and it feels better than some of the late 80s, early 90s Japanese cars, which tends to have over-boosted PS systems.

Just want to add, I have never driven a FC with PS, or manual rack, so I can't compare as far as being car specific. I do remember loving my old 86 VW Scirocco with a manual rack, I can feel every "pebble" on the road, and that allows me to push that car to the edge without going over it very easily. That same feel exists in my 87 TII with a coverted PS rack. Wouldn't trade it for a PS anyday.

Bad2ndgen 06-17-05 04:39 PM

Converted ps rack? How are you doing this please? thx.

tims 06-17-05 08:07 PM

As for why I don't run power steering. simply put for simplicity and reliability. My car is a race only car and power steering on the race track needs to be more than just the OEM setup(at minimum a cooler should be used). So to make the car simpler and more reliable the ps has been eliminated. As for the "feel" I can take it or leave it. I don't feel a loss of feel, but I also always remove the stock steering column and use a very solid connection. The effort required to operate is like the "feel" thing. If it is to hard for you to steer then you will need to be stronger or use the power steering. I personally don't have a problem. I just finished a 3 hour enduro and I drove 2 hours with no ps . I am using a power rack with hydraulics disconnected. why? because it was in the car.

RETed 06-17-05 11:13 PM


Originally Posted by Infini IV
RETed - As speeds get higher, steering effort did go down. However, it still required enough effort to turn that I wouldn't be as relaxed as I could be. Are you sure it requires "no" effort? Even an S4 P/S rack requires a little effort to turn. The only one of the FC steering racks that require close to "no" effort is the S5 P/S rack. Honestly, I don't feel an S4 P/S rack loses much in terms of feel to the manual rack.

Do you know what your alignment settings are?
I have this funny feeling your alignment is set funny...



BTW, where did you come up with the "high speed drift" thing? It's often interesting to read the things you come up with to question people... almost as if your mind wonders to far greater places than we know.
Well, I'm involved with a drift FC project, and I'm getting to know what works and what doesn't.
The drifters like to have very fast steering as a number 1 priority, so that kinda just popped up. :)


-Ted

hypothermix79 06-18-05 02:48 AM

I had to disengage my PS last drift event and talk about hard work. I was having a time trying to hit my countersteer right. I had to double arm it to get it to go fast enough around. and then try to shift while all that was going on. I'm repairng that right now. Definately not some thing I want to do again. When drifting I definately like the wheel speed. but light the feed back for driving regular. I guess I need a few more sevens. one for each type of driving I like to do. If I only had the funds....

Infini IV 06-19-05 01:31 AM

RETed - I'll have to check with my friend on alignment settings. His car feels quite twitchy under braking or anytime I'm not touching the throttle.

its66 06-20-05 10:43 AM

Infini,
Race car, street car, autocross, dual purpose?? What are you trying to get out of the car? That will help in deciding which might be better for your application.

Jim

gnx7 06-20-05 10:54 AM

I had manual racks in my FC's and loved the feedback. On the road race course it felt great but it was a little tiring.

If you plan to AutoX (yawn) keep the p/s rack. Aside from parallel parking once you go 5mph I hardly notice it.

I have 285/30/18's up front and don't mind it one bit.

Infini IV 06-20-05 04:11 PM

its66 - My friend is just using his car for street-driving purposes. However, he wants to be quick enough to beat me on the track, and I want him to have as much advantage as he can get ;)

rotarygod 06-20-05 04:32 PM

I only ditched my power steering on my 2nd gen due to the fact that I had a line leak and then later a pump fail. I instlled a manual rack purely since I was sick of fixing it. The only time there is any steering issue is when I am trying to turn at very slow speeds such as parking the car. My 1st gen has harder steering than the 2nd gen so it isn't bad to me. I have no problems relaxing whatsoever when cruising. At highway speeds, the steering is no harder than it is with power.

slpin 06-25-05 01:05 PM

haha so it is true that people in texas are poor and cant properly maintain a car

rotarygod 06-26-05 02:27 AM

In the early '90s after I just graduated high school and didn't know crap about cars like everyone else at that age, I did remove the power steering to make maintanence easier. I didn't get carried away like alot of others though. Lack of power steering is nothing special. It's not even that hard to turn. It was actually an option in '87. Lots of cars have manual racks. If you ever get your car on a track you may find that you like manual steering better. It seems to give better feedback to me but others like the power steering better. It's all personal preference. Both of my RX-7's are still quite streetable. The 1st gen GSL-SE being the most fun. It didn't come with power steering. The streetport is quite streetable as I didn't go too large like others like to do. Unlike alot of others I still have my a/c, working auxiliary ports and VDI (yes there is an S5 manifold on my 1st gen), and all of my interior is still in place. I don't even have any fluid leaks. And thank god I'm not using one of those SAFC (Stupid Air Fuel Computer) pieces of junk. Standlone all the way here. That's the proper way to do it! Reliable as a brick, properly maintained in Texas.

Nihilanthic 07-06-05 12:10 PM

One thing Ive wondered is that with manual racks you turn the wheel a lot more times - the hand over hand thing. Do you get used to that or is that a bit of an issue?

The fastest rack Ive ever used is a 14:1 (or somewhere near it) on a 1LE 3rd gen Camaro my stepdad has. VERY quick, plus it has a smaller aftermarket steering wheel. Its really quite a feeling to shove that big car around, and it corners pretty good for a camaro, I just hate the feeling of 'bouncing' off the sidewalls when I corner - unless thats the bushings being worn out or the stamped steel pan hard bar flexing, that is.

I can say trying to steer that wheel with the engine off is pretty freaking hard with the 235 tires up front and the engine weight pressing down on it, and not something Id try to do moving.

Infini IV 07-15-05 06:29 AM

He put on some shitty Bridgestone tires and the steering feels lighter now...? Car drives straight as well, with much less tension at high speed turns. This confuses me... how could a structurally stiffer and "squarer" tire as the A032R make steering harder than a soft/rounder-sidewalled tire? Shouldn't it be the other way around?

Dan H 07-16-05 02:15 AM

Tire pressure the same?

Infini IV 07-18-05 02:52 AM

^^ 33psi in front... I think?

Carl Byck 07-18-05 12:19 PM

Right now I have PS, The PS was disconnected for several months, as my PS pump had to be relocated to clear my IC pipes, with ~11' slicks in front it absolutely sucks trying to turn the car around. If was on track, and got in an off track situation, it would take a bunch of extra time to get the car turned around. I am no weakling, but there is a reason why most GT cars have PS. With proper ratios, and a good race PS system, you can't help but be faster, it becomes much more of a touch vs muscle thing. It's like left foot braking, pivoting on your heel, instead of using your thigh muscle, fine motor movements from muscle groups used for precise movements will be more accurate. Perhaps if you've learned to race in a non-ps car. Even then, you drive a car every day, the more your race car is like your DD, the more you can refine your skills everytime you drive. I will replace the stock set-up with a race set-up, there are a million choices with regard to ratio, and feel, that are IMHO the best of both worlds. I'll tell you this, if you are old(40 ;)) like me, and you happen to have a bad back on race day, you might as well sit and watch if your trying to drive my car with no PS, it plain sucks. Anyway, I'd say it is for sure personal preference, but if Dave(rxheaven) wants, I'll disconnect the PS, and then you can try to get my car on the trailer, I wish you luck;) Have fun, Carl

JEC-31 07-25-05 09:41 PM


Originally Posted by Infini IV
He put on some shitty Bridgestone tires and the steering feels lighter now...? Car drives straight as well, with much less tension at high speed turns. This confuses me... how could a structurally stiffer and "squarer" tire as the A032R make steering harder than a soft/rounder-sidewalled tire? Shouldn't it be the other way around?


Wild Guess #2,456 from JEC_31:

Maybe the stickies have enough grip to get something in the suspension to bind, causing the freakiness, whereas the shitty Bridgestones give more before hitting the bind and allow you to have un-interuppted smooth feedback.

Does this car have the rear-steer eliminators?

jgrewe 07-25-05 10:17 PM

There are so many variables that affect steering feel the rack is only a small part of it. Caster, camber, toe in/out, tire size, tire design, tire pressure, steering wheel diameter, anti-roll bar plus some others I'm probably forgetting. They all affect what the driver feels. There are things you can do with a PS car that are tiresome with a non-PS car; alignment differences are one thing you can mess with to get the "feel" back in a PS car. Run what you have unless you really want to make a change for the sake of making a change.

Hey Carl, if you have smooth areas to roll around on I highly recommend Go-Jacks, although I don't think they make them to fit that one big tire across the back of the whole car that you have :D


All times are GMT -5. The time now is 06:13 PM.


© 2024 MH Sub I, LLC dba Internet Brands