My alignment, for sake of discussion

Red Voodoo

So, disclosure first: I like to think I'm a car enthusiast, but once I start down the modification rabbit hole, I usually discover that I don't know as much as I like to think I do. That being said, please bear with my limited knowledge of the topic, much of what I picked up while snooping through various online "resources".

I had lowering springs installed, waited a few weeks for things to settle, and then had an alignment performed (see Fig. 1). The objective was to get a baseline of how close (or far) the car was to OE alignment specs. Overall, it wasn't terrible, but the resulting adjusted camber for the rear was a bit more negative than I expected with the Swift Spec-R's.

Since the unadjusted camber up front was even at -1.8*, and having some negative camber in the front wheels is seen as beneficial, I decided to take the wait-and-see approach before I invested into adjustable front arms. With the fronts at where they are at, I figured I'd add some positive camber to the rear wheels (to about -1.5*) with adjustable camber arms and toe bolts and keep the camber within .3* between the front and rear.

Then I thought about toe. What was dialed in at the shop seemed to be a little extreme, but well within spec. I see some of you run neutral toe all around, or 0* up front with a tad toe-in in the rear. I understand that poorly adjusted toe is a killer on tires, even more so than a lot of camber. It can also lead to twitchy steering on highways or snap oversteer in fast turns. I was thinking of going with neutral toe up front and .04* toe-in for the rear wheels. Would these adjustments result in decent handling on the street, or an unpredictable mess that would be tiresome to manage on a long highway drive?

Finally, I am also considering going with a square tire set-up for my Sport Rays, using a 275-width tire all around. I do not care for how the car has typically plowed through the corners, so I've read that this would be one way to help make the handling more neutral. I'm not sure if this would need to be factored in when considering an alignment, but I thought I would mention it.

I will add that the car will not be used for track or auto-x events.

I would love to hear the thoughts of those who spend a lot more time fine-tuning their suspensions and handling aspects and have experience with different settings.






Fig. 1: Alignment measurements, before and after

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OptionZero

Driving like a sane person on public roads, your alignment isn’t going to cause your car to explode or anything. Driver input would. For bumming around on the street, how much “neutral” feeling are you looking for? It doesn’t matter at legal street speeds.

Your toe is too high. Expect increased wear.

I think my feelings about swifts and no mods are pretty clear. You can do it right or you can do it cheap and easy and live with the compromise.

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Spooler

Your toe is the dead middle of spec for the most part. That is where I set mine. Your front left Toe is off a little. You are going to get some inside tire wear due to the camber. SPL stuff is in your future if you want to make it perfect.

Red Voodoo

When I take spirited drives on backroads, I experience the inherent understeer that comes with the staggered wheels. I had read that going with a square wheel set-up could help alleviate that a bit, or that a square tire set-up can also offer some of the same benefits. Am I off-base? I suppose another option could be a larger front sway bar, but tires will be the next upgrade, so I thought it might be able to make a difference there.

I thought so as well. I recall reading somewhere on this forum that zero toe up front and 1/16 inch toe-in in the rear might be an option, but that could be more geared for a track car.

Indeed! I expect increased inner wear on the fronts, but I'm hoping that the positives outweigh the negatives. It's the nature of the beast when you start making these kind of changes.

Thanks for you input, OptionZero!

- Sean

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Red Voodoo

I know! Funny, right?? It was the only thing that changed on the left front, and for the worse at that. Not sure what happened there.

Rear camber arms and toe bolts are on their way, so I'm halfway there. The jury is out on whether or not I will be investing in the SPL front arms. I don't mind a little extra camber on the steer tires, but if I burn through a set of medium-rated treadwear summer tires in less than 10k miles, I might be changing my tune!

Thanks for your input!

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OptionZero

IMO you can’t complain about you car’s handling and then us you don’t wanna … buy parts

Nissan gave us a platform without alignment ability, that’s just the reality of it. Pencil in adjustable arms as part of the cost of the platform

You want to change the handling? Pay up

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Red Voodoo

There's no debate over the need for adjustable front arms to help get the suspension geometry back to where it should be. What I'm understanding from your statement is that trying something else to neutralize understeer before optimizing the alignment is like putting the cart before the horse. So, with no pun intended, I'll pony up and will follow that advice before I do anything else.

Being somewhat of a novice to this, I appreciate the insight that folks like yourself bring to the discussion.

Those who use a preferred street alignment that improves upon the conservative OE specs, please comment!

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Rusty

You want a street set-up that won't burn through tires.

Front camber -1.8, caster +6, toe .06 in

Rear camber -1.5, toe .06 in.

Hotchkis front sway bar.

If you want street/track set-up. This is my specs.

Front camber -2.2, caster +6.5, toe .06 in

Rear camber -1.7, toe .06 in.

This takes SPL arms and the Hotchkis bar.

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浪人 - 殺し屋
"The Difficult Anytime, The Impossible By Appointment Only"
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Red Voodoo

Thanks, Rusty... I have decided to go with the SPL front and rear arms for full adjustability, along with the SPL eccentric lockout kit to keep things in check in the rear. I have SPC toe bolts as well, but I assume that they will go back on the shelf once the lockout kit is used.

Your recommendation for street alignment is right in line with what I was considering initially, with exception of caster (which was unadjustable before OZ drove some sense into me to get the front arms). I will likely go with that and have the caster adjusted as recommended.

You suggest the Hotchkis front bar. It seems like a popular choice here due to its reputation as one of the largest diameter bars on the market for the Z34. A lot of what I've read online stresses the importance to having some adjustability with sway bars, yet this bar does not come with that. The price point for a Hotchkis front bar isn't far off from the competition. In your opinion, has Hotchkis engineered a sway bar so good that it makes no sense to look at alternatives that allow you to adjust the stiffness for different environments?

And, while we are on the subject of sway bars, I was considering just keeping the OE rear sway bar based on testimony from some of you that prefer to have no rear sway bar in track (fast) conditions for better rear end control through turns. (Not that I'm going to be navigating public roads with controlled oversteer... LOL!) Would not touching the rear bar be the wise thing to do on a street car when electing for a stiff bar up front?

Love the ideas and recommendations. Thank you!

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Red Voodoo

Rusty... Almost forgot to ask, just to clarify: The toe-in as shown in your recommendations is in degrees, not inches, correct? So, total toe-in per axle would be 0.12°?

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Rusty

Degrees. If is was in inches. It would be about 1/16". And yes, total toe.

Keep your rear bar.

The Z needs a stiff bar in the front.

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"The Difficult Anytime, The Impossible By Appointment Only"
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Red Voodoo

Great... Thank you!!

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Tractionless

Rusty,

What is the result of running so little toe and equal amounts front/rear?

I've read the rear number should be double the front or you're looking at "rear end stepping out" troubles.

I'm at .094 front / .188 Rear on my street car with -1* camber which is REALLY saving the insides of my rear 305's and still provides for plenty of spirited driving handling. Camber goes more negative under acceleration (weight transfer) so trying to keep more rubber on the road in straight line situations. Watching the technician pull down on the rear end while on the rack even changes it significantly! Front suspension is OE, ride height OE.

I've also seen .125/.250 mentioned for toe.

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Rusty

You never want negative toe in the rear. That will give you snap-oversteer. Only full blown race car with a experienced driver will benefit from it. Keeping the toe front and rear just positive will make the car react quicker. To some, it may feel nervous. Camber on the rear. I don't like to go over -1.8. Some will set it at -2.0 or more. That is more for using full slicks. The camber curve on the rear suspension is quite steep. The more you compress it. The more negative camber you will get. As you have seen. My tire set up is 285/35-19 front and 345/30-19 rear. The outside edge of my rear tires barely make contact with the ground at -1.8 camber. I'm at -1.7 now. Soon as the fronts wear out. I'm putting 295/35-19 on. Really want to try 325's in the front.

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"The Difficult Anytime, The Impossible By Appointment Only"
http://www.the370z.com/members-370z-...o-journal.html

Tractionless

Gotcha, the toe numbers I quoted above are positive. Not sure the benefit of running double rear toe in comparison with the front as posted and reflected in Nissans factory data. Any ideas?

Meaty tire setup there. I noticed a big seat of pants power gain stepping down from 325/30/19 to 305/35/19 most likely due to lower overall gearing, weight and less friction on the road with the 305's. Loved the 325 look but can't justify the "power loss." At -1* rear camber I have maybe 1/2 of outer tread not on the road which is fine as it contacts in corners and I don't get on the sidewalls.

Still love getting behind the big body Chargers, Challengers and Mustangs and seeing their OE tires/wheels that look like spares compared with our Z's.

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