SLR Mini-Kit with Z3 rack - Anyone running this combo?

[Inflame]

I am seeking some insight/input from people running a similar setup.

The car in question is my LS6 swapped 95 M3. I have the Z3 rack w/ the GM P/S pump running on a 10% under drive ATI pulley, so it is no where near the stock BMW feel.

Is there anyone running the SLR mini-kit (RC and BS correction) with the Z3 rack? Is it too fast? I did not get a chance to drive my car much with the Z3 rack as I ran into a few issues that put the car out of commission but the rack felt pretty quick.

I ask because the SLR kit is of higher quality (to me) than the GC kit and worth the $150 premium. Though my fear is the advertised 40% quicker steering may actually be too fast with the Z3 rack.

I spoke with Sean about this and he sent me an in-car video of a racer in Mid-O, but you can barely see the drivers steering inputs.

Thank you in advanced.

[TXBDan]

I think I'd be a little hesitant. I'm hesitant about the 40% reduction with a stock rack. seems pretty extreme. I've been interested in their kit for awhile, but that 40% reduction is holding me back.

[Amir@AvusAutosport]

The 40% reduction is awesome. The steering stock is school bus like, and the SLR kits really makes it feel like a touring car. I plan on doing the Z3 rack when I get my car back since the stock rack is leaking. 100% would do. I also drive the car too and from the track, and on the street it's perfectly fine even with an aggressive alignment.

[Inflame]

That goes hand in hand with what user Jakermac says. He has a few in car videos, but they're not forward facing on a race track, which is what I'm looking for. Amir, when do you plan on having your car back?

[Amir@AvusAutosport]

That goes hand in hand with what user Jakermac says. He has a few in car videos, but they're not forward facing on a race track, which is what I'm looking for. Amir, when do you plan on having your car back?

I'm sorry, I wish I had some in car. I can say that it took no getting used to. The car just felt better and required much less input to get the desired inputs which was a huge plus to the bump steer and RC correction.

I'm hoping to have it back late this month or early Feb.

[0100]

What is the Z3 rack ratio? I am getting all kinds of different numbers when I search.

So what would these ratio's be if 40% faster?

Z3 rack ?13.9 : 1.
ZHP rack 13.7 : 1
Z4M Coupe 12.8 : 1

40% faster (Did I do the math right?)

Z3 rack ?8.34 : 1.
ZHP rack 8.22 : 1
Z4M coupe 7.68 : 1

I have a ZHP rack ready to install and was thinking about these arms...

[Inflame]

I believe z3 non-m is 13.9:1

[aeronaut]

I was also thinking that 40% would be too much. I assume it increases steering effort by 40% too, so maybe from a 'feel' viewpoint that counters the quickness of the ratio and the 'experience' is good.

I don't recall really wanting quicker steering ratio while HPDE-ing, but certainly DO find myself crossing-over quite a bit while doing hoolgany stuff. (I have the ZHP rack).

Amir's positive opinion certainly makes me rethink all this.

[jakermac]

I made the jump from the OEM rack to the Z3 rack about 2 weeks after I got the car, which happened to be about 2 days after I did my 1st autocross with it. I could not live with the slow steering. Then about 2 years ago, I decided that I wanted to correct the roll center and bumpsteer from having the car pretty low so added the SLR mini kit. I was also excited about reducing the steering input even more. I could not be more pleased with the current setup, and honestly could use faster steering sometimes.

Anyone that dismisses this mod as being "too fast" or "undrivable" has not tried it for themselves. There are NO downsides. The steering does not get too twitchy, unless you're a crackhead that can't settle down. And the steering weight does not get too heavy unless you're a 100lb fembot with zero upper body strength. The feel is just as good as ever, even more so because of the immediate feedback produced by the much faster ratio. Like I said to inflame in a PM, I'm rub to rub (lock to lock) in a bit less than 2 turns, and I wouldnt have it any other way.

[TXBDan]

Hrmm I'm not a crackhead or a fembot. Thanks for breaking down the wall of rationale I was so successfully using to avoid this expenditure.

[chikinhed]

Lol!

Sent from my GTX3582R

[Inflame]

Haha yeah, I'm pretty much sold on it. I'll be ordering it in a week or two.

[944CS]

I have this combo, in addition to a solid steering guibo. Wouldn't have it any other way.

[ckpitt55]

Do any of you guys have recommendations on where to source a z3 rack from? Looking to do these mods as well.

[Inflame]

I found mine locally by using http://www.car-part.com/ paid $100

BTW, ordered the SLR Mini-Kit!

[ckpitt55]

Just ordered as well.

Are you / will you guys be running rack limiters with this setup?

[Inflame]

No but I've been considering it since I rub pretty bad on the frame rail.

[Inflame]

Update regarding this setup.... it's freaking insanely awesome. I've only street driven the car so far, first track event is next weekend. So far I love the minimal amount of steering input needed to make massive changes.

I also installed steering rack limiters.

[Amir@AvusAutosport]

Update regarding this setup.... it's freaking insanely awesome. I've only street driven the car so far, first track event is next weekend. So far I love the minimal amount of steering input needed to make massive changes.

I also installed steering rack limiters.

Awesome to hear. I had the same response when I put them in. Feels like a touring car haha! You're going to love it on track, so much more precise.

[Inflame]

Awesome to hear. I had the same response when I put them in. Feels like a touring car haha! You're going to love it on track, so much more precise.

It is wicked quick, still hard for me to gauge exactly how much my tires have turned. I'm used to making 1.5-2 turns in my garage to get out, but at .755 turns now I'm at full lock!

Out of all the upgrades I've made over winter, this steering mod is #1 that I'm most curious about it's track feel... Next would be the new coilovers and then the Porsche 911 brakes.

[Inflame]

Yesterday I made a trip out to Gingerman Raceway, 2.14 mile course, 11 corner. Here is a track map.



Turn 3, 6 and 10B are the tightest turns on the track but are fairly quick. Turn 3 ~ 50mph, Turn 6 ~ 60mph and Turn 10B ~55mph. Prior to the SLR upgrade and Z3 track, at Turn 3 I would've had to input nearly 120* of steering to go around, yesterday I'd say it was closer to 80* or so looking at the video. The same goes for the test of the track, I don't believe I turned the wheel more than 90* for any turn. I never had to spaghetti my hands or take them off 9-and-3. The input was phenomenal, I HIGHLY HIGHLY recommend the Z3 rack + SLR mini-kit for ANY AND ALL E36 race cars.

[TXBDan]

I'm still skeptical. Do you feel like you have enough accuracy with the wheel? What about on long fast sweepers? Is it overly sensitive? Seems to me the difference between not enough and too much steering input could be like 3degrees now. Can you still feel and find the sweet spot?

My fear is that it feels tight and responsive and fast, but are you actually able to find the best tire slip angle?

[Inflame]

From Turn 7 to Turn 10B it's a 70mph+ right to left sweeper, I had plenty of feel, sensitivity and accuracy to navigate that section of the course with ease. I can not emphasis how much easier this car is to drive. At instance of oversteer is corrected extremely quickly with minor steering input.

For reference, on the exact same tires from last year, I beat my PR from last year within 3 laps and overall I beat my PR from last year by 1.6 seconds, I did not even touch the suspension settings yet and still getting used to the new brakes (same pads).

I'm not very good at expressing what I felt, how I felt it, etc into words.

The car has a new level of finesse, the quick ratio instilled confidence and control. I am in Group 1, open passing group, with multiple passes happening per lap, on the main straights, etc and at speeds of 120mph, it was not too sensitive. On center the car darts to your direction of desired travel. The SLR KIT + Z3 rack coupled with the E34 solid steering u-joint are must do mods.

[TXBDan]

Interesting indeed!

I just got the E34 Ujoint installed but am waiting on an alignment before i drive it. Maybe some day i'll try the SLR kit with the stock M3 rack and go from there.

[aeronaut]

VERY interesting.
Do you think your lap time best was due to the roll center/bump steer changes, the steering ratio, or ... other?