BJ, thanks for the detailed response. I just wanted to really make sure that this is the same design that you use on the Grand Am car since my Z sees a lot of heavy track duty (although admittedly I am not (yet) competing in the GA cup). You have fully convinced me that the design works.

I'll be ordering a set from you guys sometime during the summer. I also have a couple of extra questions for you, that may be best taken off-line, but I'll ask anyway:
- What are you doing for rear camber?
- What front camber settings are you running? My hunch would be that -2 to -2.5 would be optimal for my setup (245 section width Hoosier R3S03 front and rear). However, my rear camber is at -1.8 right now. I'd like to kick that out a bit as well.

Thanks! Looking forward to the group buy/special pricing on these bad boys!

Jason

 

We run our own arms in the rear.
Those are next as far as production goes.
Camber depends where we go.......max setting of -3.5 in GAC
pre order special is coming very soon.
most likely next week.
Cheers
BJ

 

aluminum on aluminum has a very high coefficient of friction (about 1.35 depending on alloy). Almost double that of steel on steel.

If you figure the bolts used to tighten the plate down are torqued to 220 in-lb (I'm basing this on a 10mm bolt... I have no idea what they really are) 220 in-lb applies about 1100 psi of clamping pressure.

those plates appear to have several square inches of area. I'd say it would require in excess of 4,000 lb to slip them.

I would say the ball joint or inner attachment points would fail before then.

it's good to go in my book!

 

N74DV - good explanation. You're right I'm sure. I tend to do basic math/engineering calculations on my own when I know them, but I can't for the life of me remember the transfer equation from bolt torque to clamping force. Does it depend on the pitch of the bolt?

Either way, sounds like a great product - I just wish it wasn't $850! (even though I understand the economics of small production run fabrication - particularly if there are low fixed costs that can be spread out with things that have to be CNCed)

Jason

 

I think you will be happy with the preorder price with the monoballs. (The $850 will be retail price with mono ***** you will have the option of using the stock rubber bushings from you oem arms.

 

Got some qucik numbers back form the engineering firm....

"Basicly the calculation is pretty simple. You figure the clamp load of the bolt * the number of bolts. Then you multiple the result by the coeffeciant of friction of steel on aluminum. The result is the force it would take to slide the plate. The numbers he came up with is the four bolts torqued to 22 ft. lbs. equal a clamp force of about 35,000 lbs. The coeffeciant of friction is 1.05 to 1.4. So the ultimate force to make the plate slide is 36,750 to 49,000lbs. Now we would want to operate at a 2 to 1 safety factor so figure about 18,000 lbs of force to slide the plate."
hope that helps a little.
We ran at Daytona SPeedway with the bolts torqued to 12 ft/lbs

BJ

 

BJ, that makes sense. The part that is tricky and that I couldn't fully remember until I just did a quick google search is how you get from bolt torque to clamping force. Basically, there is no easy equation. You have to figure out how much bolt deformation you are causing (by figuring out the pitch of the thread times the number of turns from static and use the spring equation f=kx to solve for f (where k is bolt spring rate and x is distance). So you can only convert from bolt torque to clamping force once you solve for the above math for that particular bolt and draw up a curve (minus the percent of applied torque that goes into head friction and thread friction - about 80%).

Anyway, this is better explained at the following link:
http://www.gnttype.org/techarea/misc/bolts.html

Sorry for the engineering lesson (that no-one asked for). I typed this out more for myself than for any other reason (maybe I'll remember better from now on).

Jason

 

Jason,

its great information to know.
Actually thanks for asking.
BJ

 

Very interesting read! Like Jason, I had concerns about the direction of the load forces. I didn't see anyone mention surface finish and its effect on the equations. Wouldn't this affect the numbers?

And BJ, will you still be bringing some to Mid-Ohio?

 

Yes

 

alrite guys must ask a newb question since i am new to this whole thing. All the web sites with the camber arms or wutever say front adjustable... does that mean we need another set for the rear? or is the price for the entire set for a car? Another question, in all honesty I dont want the vendors to answer this one, is there a difference between all the different kits? I mean the kinetics one is only 300 and something and the other ones are just asking 2 much... yes the others may look better but if it does the same then id like to go wtih the cheapest option possible since unlike the people with all the money i have quite a tite budget when it comes to modding my car. Thx for any replys.

 

The end result of all the front adj. arms is the same, correcting/changing camber. The kinetics arms will require separating the upper ball joint form the upright for adjustment. The 2 more expensive arms only require loosening a couple bolts to slide the arm apart or closer together, then re-clamping. This is worthwhile for people that track their Z's, where 2-3 degrees of negative camber are benefitial for maintaining even tire temperatures across the tread under extreme cornering loads. When leaving the track, the camber can be returned to OEM spec.

 

Sorry, have to throw in my .02... The kinetics ones, like mentioned above, are a good cheap way to go for the guy who just wants to set up the front end on a street car and leave it alone. The "other two" on the market are for the guy who is going to demand more out of the product. Easy adjustability between track and street, also parts that are race proven.

 

I would also add that it is my strong belief that some of the more expensive ones (e.g., the 350 EVO) arms are more likely to be reliable than the inexpensive ones. I haven't seen any of these parts (so far) but I know that some have been race-tested and others have not. This is a good way to ensure that the parts are durable where they need to be. The other designs with no R&D on the track may be just as durable, but we have less data to prove it than seeing BJ's car run his arms in Grand Am Cup.

Having an A-Arm fail at 140mph in hard cornering a few feet away from some Armco would be a bad situation. I'm willing to pay an extra couple hundred $$$ to buy a design that I have seen operate under that type of stress.

It also doesn't hurt that we had this whole (above) discussion about the sheer forces and clamping loads.

Jason

 

This is a great point!! We use ours on our two Grand Am Cup cars as well. They have also been approved (as have 350 EVO's) for racing by the sanctioning body that regulates the cars.

 

This Race set of Front Upper A-Arms both Performance Brand and EV0350 solve the track problem.
Note the Number of Grand Am Cup Cars is small. = low sales of A-Arms.

Then BJ - Jeff what is required to solve the predominate problem
of Nissan 350Z cars eating tires in less than 9,000 miles. With the Feathering and Cupping on the inside tread blocks.
Note the Number of 350Z's eating tires in less than 9000 Miles is huge. Large sales of A-Arms
Effectively all 350Z's made in model year 2003 and most 2004 models.

Please don't tell me set the tow to TSB specs as this has not solve the tire wear issue. Our test mule has Feathering occuring in 2000 Miles after TSB Tow in set. You know him.

One of the posts in this thread said it's a Shock and Spring issue that eats tires. To cover that point, we have extrordinarily gone to great pains to address that point.

Koni Sports are on the boat from Holland. I'll have them in my hot little hands in a couple of weeks - The Koni engineers said the OEM Struts/Shocks were way out of tune for a road car.
( Actually the Dutch called the problem - Stupidly out of whack )

The OEM manufacture Tokico stated in thier defense, the Nissan Factory people were advised, that this valving was for Agressive use only (read skid pad testing). The G35C has the Tokico recommended valve rate. However, some have the Tire Roar issue.

Subject: Hey !

Now you guy's have the technology to get a 350Z stable on the track at 130 mph. Can't you guy's come up with the soulution for all the 350Z Owners that hate the Bounce, and are having premature tire wear?

This is a question...Please reply !

Cheers Amy -

P.S. the aligment people want Caster adjustment, not just Camber adjustment.

Do I have to build my own design? Capable of both Caster and Camber adjustability? In depth letter to follow.

 

here here amycroft! I concur! WE WANT CASTER TOO!!!

my car pulls to the right BAD. Always has, even after the compression rod TSB.

EVERY single alignment shop has said if they had the ability to adjust caster on my Z they could get the car aligned perfectly.

CASTER & CAMBER please!

 

N74DV..

I had a drift to the right.. On NNA replacement of front tires The Alignment was done manually - Old School. The steering wheel was straped down in the Center position. Then adjusted.

The Before Left Tow was Plus 1/4 Inch, the Before Right Tow was Negative 1/4 Inch

The car tracks straight, with hands off.. But not as darty as it was before. In Nascar terms the steering is tight.

( I hate to add this but - several said if the compression rod TSB is done. The alignment of the front can not be made properly. )

My car never had the compression rod TSB done.. I only have 1000 miles ( read two weeks freeway to work over a six week period ) I have my Maxima as a daily driver.

Question - Every time you go to Nissan - always ask for the removed parts... Suggestion too late.

With the original part, you could at least go back to where you where.

Cheers Amy -

I used to drive a kind of dirt track car in the 60's - Do you know what a sprint car is/was ?

We made all parts in a small shop in Lynwood California, Hollow Forged rods and all that stuff. Kieth Black was on our block. He did all our balancing. Ah for the good old day's

Today we have a Shop full of CNC machines - that are Idle.. What do you want made in mass quantities?

 

since there are only the fronts... how do you adjust the backs?

 

Camber and traction rods. Check out Kinetex.