I saw on SCCA forums you posted about some OTS koni's. I will have the front two for sale (cheap) in a month or so when my DA's get back from truechoice. I'm guessing you were looking for singles to send out to be converted to DA's? Let me know if you want 'em. They would have maybe 400mi on them by then.

 

Yes, save them for me...I am not in a rush...

 

Will do...I'll let you know when they are off the car.

 

No change in bushings and I'm on a shorter sidewall as well. I think the JRZ's are single contributiong factor to improved ride quality even when using higher rate spring.

Thing that amazes me is that the 370Z loses that ugly rear tail hop with lower spring rate in the rear and good coilover. I can drive the car with a lot more confidence now.

 

As little as ten years ago the supposed "fast" setup for production car racing included a lot of compression damping in the shock. It was almost a monkey-see, monkey-do thing that became self-perpetuating. You see it in a lot of the DTM, ETCC, and BTCC race videos from those days.

The Oreca Viper team at Le Mans started to go another way after some research with Penske (yes, even though they were sponsored by Dynamic, they ran Penske shocks anodized in Dynamic colors) and their success helped change racers attitudes about compression damping values.

Unfortunately, street drivers still equate stiff with good handling so a lot of shock manufacturers valve their street shocks with more compression damping then ideal.

 

Sub'd to read article in first post when I got more time.

Thanks!

 

Definitely true, my Tein Flex's performed best at almost full soft. They sure felt a lot faster at the stiffer settings but they absolutely led to reduced cornering speeds.

Also, thanks for the article. I found a link to a lot more of them which should help me learn a lot more.
http://www.eviltwinmotorsports.com/?page_id=204

 

Guys I have 275/35 front and 275/40 rear wheels, oem cambers, lowered by around 15mm. 7kg springs front and rear (Tein SS).

It turns very well now. Much more neutral than the oem setup. I'd like to take away some of the nasty lean I get during hard cornering.

I am planning to install:

Aftermarket front swaybars and A-arms while keeping the rear as they are. Basically my current front camber is -1.6 and rear is -1.8. With the aftermarket arms, I can adjust to a more aggressive front camber setting like -2.5 when attending trackdays.

Is this a good idea? ?

Your input will be much appreciated!!
TIA!

 

I always enjoy your trivia with the facts!

 

The Aussie V8 supercars run fairly low compression damping, not only is it fast but it allows for a lot of aggresive kurb hopping lol
'quickly scours the net for an example'
the first couple of mins in this vid shows what i mean, NFI whats going on with the dudes talking hahahah

<iframe width="560" height="315" src="http://www.youtube.com/embed/oK-GpsWphI0" frameborder="0" allowfullscreen></iframe>

they may be basic
pushrod 5.0L v8, live axel rear end etc which has earned them the nick name supertaxis but they have dam good suspension and alot of grip

 

For curb hopping there's additional valving in the shock sometimes called "blowoffs" that open at high shaft speeds. These are separate from the compression valving.

I had blowoffs in the Penskes I ran on my racing 240Z. I could slam curbs while still keeping my foot on the throttle and the car would hold its line and still put power down. The car behind me that tried to follow that line (most common place was exiting the Bus Stop at Buttonwillow CW) would launch itself into a lurid spin off track.

 

Those blowoff's, was that just a separate high-speed damping option... e.g. Low speed, High speed and Higher speed adjustment?

 

No adjustment on the blowoffs. They came into play when shaft speeds exceeded .5 mps. (if I remember correctly.) I had 8760 Penskes which were configured with high speed rebound and compression and low speed compression. I used low speed compression as kind of a substitute for anti-roll bars and was able to reduce my bar sizes by about 20%. Blowoffs are a separate option for the shocks.

EDIT: All this is from memory. The shocks were sold back in 2004 and are sitting on a friends shelf. Erik Messley at EMI Racing built the shocks for me and my car.

EDIT: I looked at the Penske VDP piston diagram and the "blowoffs" are a separate circuit to the compression shim stack.

 

a lot of good reading in this thread but it somehow went from sway bar 101 to compression damping

 

They are related. With ARBs you're controlling how the tires are loaded with lateral weight transfer. With low speed compression (and rebound if you have 4 ways) you can have even finer control of the lateral loading of the tires plus control over longitudinal loading (pitch). With this additional control you can reduce ARB sizes thus getting back some of the suspension independence that's lost with ARBs. In addition, you can reduce the mechanical anti-dive in the suspension and increase the car's compliance.

 

It's all about keeping the contact patch on the ground and at a useful angle?

 

Yes and about controlling how the tires are loaded. Keeping the contact patch optimized through alignment is easy. That's basic geometry. Keeping the contact patch providing enough grip for the entire race is much more difficult and that's where controlling how much and how quickly the tires are loaded comes in.

 

John, thanks for all the great info, great thread. I had a question in regards to sway bars that I asked sometime ago, but didn't get any answer. Specifically after my first track day I realized I was murdering the outsides of both my front and rear tires and my thinking was I either need more camber or less roll. I ended up stiffening up my hotchkis sway bars from soft to medium. This resulted in much better looking tires at my 2nd event (I didn't measure temp across the tire...really should have though). I was wondering whether this was the right approach, is stiffening sways and loosing some independence in the suspension a good 1st line of attack or are alignment changes i.e. more camber a better 1st choice ?

 

If it was your first track day then you are correct, you were murdering your tires by over driving them. The care and feeding of the tires is the most important thing a driver has to learn. More bar is a good direction to go if you're not willing to increase spring rate. But learning how to drive your car within its abilities is the most important thing.

 

Yup, im still learning, but as mentioned happy to report tires were much better during the second HPDE. Im glad you mentioned increasing the spring rate as I was thinking of doing just that to the front coils (go from 9kg to 10 or 11kg) as opposed to running more bar...I'll keep it as an option for now.