Time for the 10s.

G37Sam

It's a multi-link suspension in which caster, camber and toe vary as the links move. You'd literally have to get the arm lengths (distance between mounting points) model them on CAD or some suspension software (unless you feel like deriving the system model mathetically - Phunk probably did that already haha) and see how it behaves. From there you'll discover that you'll have to redesign the arms which will basically force you to rework the entire subframe. Please correct me if I'm wrong.

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clintfocus

ALL THIS TO COUNTER WHAT IS GOOD WITH THE Z!!!! :P (FlameSuit engaged by Road race guy :P )

phunk

I have wondered this entire time if what the alignment is doing is actually the most optimized for road racing or not. I am no road race setup expert, but I think its a conversation worth having.

Could the outside tire be cambering more than the chassis is leaning, and taking rubber off the pavement for no good reason? Perhaps "yes" with a very stiff and flat setup, and "no" with a more stock setup? Or would the answer be "no way not even close"?

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wstar

I think in general the answer is that yes, the 370's suspension is more optimized for road-racing than it is for for drag-racing. Not that it doesn't need tweaking and parts upgrades for road-racing too, but even without those it's generally in the ballpark of doing the right thing. I *want* camber as the rear loads up on weight transfer, because that set of conditions (low-gear + heavy throttle -> weight transfer to rear) only tends to happen during mid-corner through to the exit, where the car is already trying to fly sideways at a full G or more before I even started laying into that throttle pedal.

It seems it would be difficult in general to simultaneously optimize a rear suspension's response for both road-racing and drag-racing.

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7AT Track Car!
Journal thread / Car setup details

phunk

I agree that the setup is much more optimized for road racing than drag racing. But I believe you misread my question you quoted. Simplified: does the 370z camber too much during compression *even* for road racing? Or maybe with some setups "yes" and some setups "no". There has to be a point where its too much, I am wondering if the 370z could have crossed that line in some applications, or is it not even close to being too much? Could adjusting the control arm nodes to reduce compression camber slightly even aid a road race 370z that wants a lot of compression camber?

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Super Werty

might be easier to swap in a live axle and let er rip

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The Build

AlexRaymond19

So even if you stopped the suspension from going any further down from the desired point which camber would be perfect for traction? There isn't a way to stop the suspension travel prematurely?

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2010 370Z Touring MT | Stillen | Motordyne | Momentum| Z1 | Fast Intentions | Advant Garde | RE11 | Swift | SPC | Quaife | Whiteline | Evo R | 322RWHP 259ft-lb Mustang

phunk

The desired point is HIGHER (decompressed) than where you started, so you couldnt go down (compress) at all. You would have to take out the shocks and put in solid metal bars and defeat the whole suspension... which would result in an unstable and dangerous car.

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phunk

I ask because if I keep the car much longer, we have played around with the idea of a custom rear crossmember. We could then change the curve by using custom control arm lengths, or possibly a few different positions. If it would only cater to drag racing, then I would figure on building just one, in which cause would be easier to fabricate and modify off the stock one. But if there was benefits to be found for the much more common road course racers here, then it could possibly justify a full custom rear crossmember. But it sounds like you guys are plenty happy with how it is already.

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wstar

My rear static/dynamic camber ends up doing the right thing on the outside wheel. It gets a little iffy on the inside wheel, but I suspect I'm going to iron that out over the next two events. This weekend I'm trying just a downgrade to the stock rear sway, and then for the next event I'll probably be upping my spring rates all around (but esp in front) to reduce body roll. Depending on lots of things, I'm not sure which rear bar I'll end up running with the stiffer springs. But either way, I don't think we need a major geometry change in the rear for road racing.

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7AT Track Car!
Journal thread / Car setup details

GSS138

You should be able to find a spring setup that works for track and street. I am currently putting a pair of BC's on for daily/track use. I am going with a 10K/12K setup which is similar to OEM setup. You could probably do the same but depending on your corner weights might have to up the front(sure your front is heavier than mine).

Are you doing true types in the rear or OEM?

The diff is a no brainer. Switch to solid diff bushings and just throw any of the reputable diffs in there-Quaife, Geiken, Cusco. I bet that alone takes off .5 second.

For front wheels , I would just get an el cheapo pair of 18"x8" wheelsand throw some 100 dollar Goodyear touring/eco low rolling resistance tires on there. They don't have to be top fuel eliminator bicycle tires, but there's no reason to be running grippy 275's up front if you are going in a straight line.



Using spare tires rated to 55MPH sounds a little sketchy .

Also running 4.08 gears at 600 HP would just make your problem worse. The problem is traction, not HP. There's literally nothing else to the equation.

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