zer099

iTrader: (2)

I wanted to post some information a learned/gained during my quest to get my '09 X corner balanced. The biggest hurdle I had was the lack of any type of adjustable front sway link available for the AWD G. I imagine the aftermarket issue is due to lack of interest and also because the stock sway links are insanely short, making adjustability very difficult while keeping them strong. The answer I went with was to just custom up some of my own. I originally was going to replace both sides, and still might as I have the parts to do so, but instead opted to keep the stock on one side and make the other side custom to fit as needed.

On a side note, adjustable sway links are needed when corner balancing so that you can adjust the sway bar to remove all pre-load from the bar when the car is in a static state. Not removing the pre-load will leave the bar in a state of having tension on it. If designed correctly, the car from factory should be set with no pre-load, but the second you start messing with your suspension and ride height I promise you there is some type of load on it. The whole point of adjustable coilovers, at least as I see it, is that you can corner balance your car, adjust suspension droop, and adjust your car's center of gravity and roll center to a degree. Your car looking cooler by being lowered is all just a by-product of the intended purpose of the adjustable coilover system. Again, that's my opinion; but I too like the by-product of the car looking the sexy sitting all low and the sort.

Back on subject: I sourced out some pretty stout end links and components to make my own front end links and here are the results:







The shopping list for this project is as follows per link:

- Metric rod end retaining washers, 12mm x4 (#3068-M12) from Pegasus racing
- QA1-MXMR12 rod end x1
- QA1-MXFR12 rod end x1
- M12-1.25 x 70 Hex cap bolt, grade 8.8 or better x1
- M12-1.25 x 80 Hex cap bolt, grade 8.8 or better x1
- 12mm flat washers x4
- M12-1.25 nylon lock nut x2
- 12mm jam nut x1 (optional)
- At least 30mm of 12mm ID SS spacer tubing (will need a 15mm section and a 12mm section)

I bought these parts from a few different places, trying to keep price down and purchased enough for two end links. In the end I spent about $90 on the parts for the links.

For the spacers you need to cut a 15mm spacer for the up top (mount to the control arm) bolt and a 12mm spacer for the sway bar mounting bolt. Are the rod end failure washers required, no, but it gives me piece of mind.

I ended up just using one link and keeping the stock on the passenger side because I only needed to trim about 6mm off the male rod end threads to get the perfect length. Any more and I would have needed to shorten the female rod end, and honestly at that point I would have just opted to replace both sides to have full adjustability.

If you are a good DIY type of person, have the tools and time and own a X that you want to remove the preload off the front sway then I recommend this for you.


As for corner balancing: after two weeks of having to reschedule I finally got the car corner balanced yesterday. After trying three different lifts (we first were going to use the lift on the alignment rack but the car sits so low they couldn't get the lifts to turn over under it, the second lift was a much lower lift but had a wide platform that would have impacted the 2.5" FI exhaust, we went with the most obvious option then of driving up on 2x10s, using a normal car lift and then removing the wood and putting the scales under her) and a lunch break it took about 3 hours to dial her in but I finally got a perfect 50/50 with me in the car and half a tank of gas. I think it made a very notable difference. The height difference is slight, oddly, it sits a little lower on the drivers side now. Shes much more nimble in turns and highly more predictable in the turn-ins. I don't know if it's a result of everything being fine tuned or if its just my brain but she also seems to ride a little smoother too. It cost me roughly $350, that was for the balancing and the alignment afterwords. I forgot to take pictures of the setup, but I do have a copy of the numbers as we were changing things. In the beginning she was:

FL: 1044 FR: 1156
RL: 1018 RR: 850

That was with me in the car. Afterwards she was:

FL: 1078 FR: 1078
RL: 956 RR: 956

Again, with me in the car. Once we got her dialed we put the car on the alignment rack, performed the alignment, and finally I got in the car and we adjusted the sway bar end links to zero pre-load with me in the car and connected them to the sway bars.

I guess I should note my full suspension setup now as it matter:

- FA500 coil-overs, 10k/9k swift springs at +8/+11 dampening
-- Front preload is 5mm, and the rears have a 19mm droop
- Hotchkis sway bars, hardest setting up front, hardest in the rear
- Moonface roll center adjusters in the front and rear
- Moonface bump-adjusted tie-rod ends
- 370z forged rays 19" wheels
- 245/40 and 275/35 Michelin pilot super sports
- 20mm spacers up front
- Ultra Racing Rear Lower Bar and Rear Member Brace
- Z1 Front UCA (race version)
- SPC rear Camber arms
- SPL titanium mid link (swift springs part #Z65-178-090)
- SPL eccentric lockout kit
- Whiteline rear sway bar links
- Custom front sway bar link
- Front camber is @ -1.2; rear is -1.6
- Front toe is zeroed out, rear is 0.05 degrees toe-in
- Front caster is 8.7

Oddly, the car weighs 3884 pounds without me in it and with half a tank of gas, I was honestly expecting more. I still can't figure out what is weighing down the front passenger side so much but I guess the entire front drive system is on that side, plus the battery, the fuel pump and plumbing, so I guess it makes sense.

Was it worth it? For the way I drive and the fact I occasionally track her, yes. I live in a area with hills, twists, and turns; I want my car to be able to perform the best in it can in those scenarios and I think I've achieved that. Now it's time to work on other things. Would this be worth it to someone else? Hard to say. If your a handling snob then yes. If you think the G came from the factory handling like a boss, doubtful.

slartibartfast

iTrader: (7)

Awesome sauce, both for the DIY end-link and the reasons for your changes.

Two questions:
1) roll center adjusters? Are these eccentric arm pivots?
2) Why didn't you try for a little more even front/rear weight distribution? Is there enough adjustment remaining in the rear to lower that end a smidge? You're at 55.5% front.

zer099

iTrader: (2)

1) No, they are replacements for the OEM spacers where the arms connect to the knuckles. It gives you a very small amount of change but if your lowered more then an inch and a half you will notice the roll center change.

2) Cross-weight is your main goal when corner balancing. I hit a perfect 50% and was happy with that. Just the fact I magically was able to get perfect left to right weight amazed me. But as you pointed out I would have had to raise the front a good deal (the back driver side was almost maxed out) to get 50/50 front to back. Yea, it will put more weight on the front when breaking, but when accelerating it will even out to close to 50/50 I hope.

blnewt

iTrader: (13)

Just an incredible DIY job there, those look like some extra stout links you DIYd, should hold up to just about anything you throw at them.


BTW, what is the OEM caster spec on the AWD, 8.7 sure seems high.

slartibartfast

iTrader: (7)

I had a little dissertation typed out which stated that roll axis position doesn't change with ride height, but a little bug in the back of my mind made me pull out my Chassis Design book, and sure enough, Milliken points out that many suspensions types do not have a fixed roll axis. It can move with ride height changes and suspension movement while driving. I'll have to look into the Moonface parts.

I would have done the same as you with the rear at the end of the adjustment range.

zer099

iTrader: (2)

Thank you! I think it will hold up fine as well but only time and the track will tell.

Stock caster is around 4.1 if I recall correctly. I was sitting around 5.5 when I had SPC arms on the car. Z1 really crank the dial to 11 with the caster on their arms. I haven't noticed any adverse effects from it at high speeds yet, but then again I haven't gotten much higher then flow of traffic highway speed as of late. No horrid under-steer has been introduced, so that's a good thing!

I use to track my B14 all the time. Spent most of my time tweaking the suspension. Cut out the rear Scott-Russel link and put in a panhard, cut the ends of the front LCAs to put in adjustable rod-ends. Anything to get the grocery getter that was lowered 2 inches to raise its roll axis in the front and lower it in the rear. Learned a lot about handling of car with those experiments. Don Alexander's High-Performance Handling for Street or Track was my bible for chassis tuning for a while there. That and Mike Kojima at Motoiq. Tons of good information in both.

The only thing on the G that I haven't looked into is raising the subframe in the rear. It should adjust the roll axis as well. However that, at worst, would put the subframe against the body and I'm not sure what kind of NVH that would introduce.

Honestly, right now I'm pretty pleased with the car's abilities.

slartibartfast

iTrader: (7)

I didn't get that far with my B13. I acquired offset urethane front bushings that increases caster for our LeMons B13 but we stopped racing before they went in.

Aaron Labeau has an account on here, he wrote a piece about Fast Intentions exhaust for MotoIQ. I bet I know you. Torry?

zer099

iTrader: (2)

I saw and read Aaron's piece, helped me decide on going with the FI exhaust. And sorry, I'm Jarrett; lol no worries though.

Did get to toss her around some this weekend and the difference is very noticeable for me. Is this a measurable thing that everyone would want? Again, that depends on the type of driver you are but if you like/want the best out of your G when doing high speed cornering I highly recommend it.

SonicVQ

Thanks for sharing your work on this!

One question:
Why 1.2 degrees of negative camber in the front? With your 8 degrees of caster it will greatly increase the inside wheel negative camber when turning in, resulting in 2+ degrees of negative camber in the front.

I would expect the steering feel to be much improved, almost like an old BMW.

VIVID

iTrader: (12)

Thanks, zer, for that. Really exciting. I can't wait to give it a go myself.

As I mentioned to you previously: this is what I've been waiting for, it's like the last important piece in the X suspension puzzle. Really, really, awesome.

You know, it's not the most important thing, but they are very visually appealing as well.

Nice work!!!

Sean

zer099

iTrader: (2)

Sonic, I'm sort of experimenting with what is the best camber up front now. I didn't expect to get so much caster from the Z1 arms. From lock to lock when static, currently at -1.2° camber and 8.7° caster, I go from -4.8° (lock) to -3.5° (50%) to -1.2° (straight/neutral) to +0.9° (50%) +3.2° (lock). I haven't been able to track her yet and get some temp readings. Once I do and get her dialed in I will post up my final alignment settings.

Thanks Sean!

My next fear is overheating the transfer-case now when tracking for prolonged periods. I have considered the possibilities of adding a small 9 or 13 row cooler and pump to the T-case if it becomes an issue. GT-R guys (r32s-r34s) do this so I figure it would be the same for us pretty much. However I'm hoping that will not become a issue.

SonicVQ

Sounds like you have a good plan.

It would be very interesting to see how much the corner weights change with the castor jacking/20mm hub spacers with the front wheels turned. Any chance you could measure this next time on the scale?

Lt8Che

iTrader: (6)

Awesome write up!!! I'm going to have to take a page out of your book here soon. Thank you!

jfisher

So no one makes an aftermarket sway bar end link for the AWD cars?

j50ny

iTrader: (8)

Amazing write up! I hope that you are just as pleased with the results once you hit the track.