Another spin - lessson to be learned

[NSXGeek!]

It takes balls to post video of your track sessions, including posting your mistakes, because you know you will be judged and analyzed by all who read and watch. Personally, I feel this is very useful information and helpful to all, so thank you. I'm sure luck, some error, yet an equal amount of skill yielded the result you had. However most importantly, you're obviously learning from this and willing to share with others which I appreciate.

 

[YellowHaze]

I totally agree with NSXGeek's comments. As one who occasionally brings my NSX to the track, I enjoy seeing these and other videos and learning what I can. Thanks and nice driving!

 

[TURBO2GO]

Jim is your safety gear pretty much... your helmet? 13 events a year and you are on stock belts with no hans and a short sleeve T as your driving suit?

 

[CL65 Captain]

Jim is your safety gear pretty much... your helmet? 13 events a year and you are on stock belts with no hans and a short sleeve T as your driving suit?

And cheapest SA2005 helmet I could find. :wink:

 

[TURBO2GO]

And cheapest SA2005 helmet I could find. :wink:

lol I wanted to comment because it LOOKS cheap but I didn't want to insult you.

I suppose you never used condoms either.... hahaha remind me to not take safety advice from you.

 

[CL65 Captain]

lol I wanted to comment because it LOOKS cheap but I didn't want to insult you.

I suppose you never used condoms either....

Don't need to, my girlfriend doesn't put out.

hahaha remind me to not take safety advice from you.

I have never given safety advice. :tongue: But I will...

Dave if you going to have a harness, you sure as hell better have a roll cage so that roof doesn't collapse while your harness has you sitting up straight.

And before I ever bought a Hans I would buy this.

 

[NSX-Appeal]

Pretty intense. I watched it a few times, and I think my first instinct would have been to go inside, behind the 968. I could feel my imaginary wheel turning right instead of left.

 

[TURBO2GO]

Don't need to, my girlfriend doesn't put out.




I have never given safety advice. :tongue: But I will...

Dave if you going to have a harness, you sure as hell better have a roll cage so that roof doesn't collapse while your harness has you sitting up straight.

And before I ever bought a Hans I would buy this.

I swore I wouldn't take safety advice from you but man... that looks pretty cool! I can't figure out if it needs a harness bar to latch onto or not. Does it? If not I could get one right away.

 

[CL65 Captain]

I swore I wouldn't take safety advice from you but man... that looks pretty cool! I can't figure out if it needs a harness bar to latch onto or not. Does it? If not I could get one right away.

No it doesn't. The owner of the company gave a tech seminar at one of our events. Hans is old technology.... this is the new. Everyone is switching over as it is being approved by the sanctioning organizations.

It is really a nifty piece of equipment. I was told it can even be used with regular seat belts.

Call them as I don't know enough about it....

And BTW: Before spending money on harnesses and bar talk to someone who knows better than me - because it's really a complete system once you go down that road. ie - you can do more harm than good installing a harness without a cage and without disabling the airbag, etc, etc.

So you have to decide if you want your NSX to be a race car or a street car. I think this new Safety Solutions brace will give you some of the protection you are looking for while still keeping a OEM interior. But like I said, talk to the Safety Pros...

 

[TURBO2GO]

I know. Cage/disable airbag/harness/hans are all one step. After a lot of investigation I decided against just a harness bar. Need a proper custom fabricated rollbar/cage. But this device looks great because if it works with standard belt and doesn't nees a harness bar I am all over it. If the airbag is a problem that is even better because that will give me an excuse for a momo tuner.

 

[CL65 Captain]

I know. Cage/disable airbag/harness/hans are all one step. After a lot of investigation I decided against just a harness bar. Need a proper custom fabricated rollbar/cage. But this device looks great because if it works with standard belt and doesn't nees a harness bar I am all over it. If the airbag is a problem that is even better because that will give me an excuse for a momo tuner.

Give them a call. From what I remember they said it would work just fine with my OEM interior and just a seat belt. The whole purpose of the device is to protect the spine.

 

[nsxtreme91]

You said you have f600 r500 what happens if you had f500 r600 when you brake you wound allow more weight transfer more front grip? Or did tail loss grip?

 

[stuntman]

You said you have f600 r500 what happens if you had f500 r600 when you brake you wound allow more weight transfer more front grip? Or did tail loss grip?

The NSX has different motion ratios front and rear. Given the same spring rates, the the rear will have a higher wheel rate.

Arbitrary Example): 500/500lb front/rear spring rates could have 275/350lb wheel rates.

A 600/500 setup will have the wheel rates closer to the same, but having a 500/600 setup will have a MUCH higher rear wheel rate relative to front which will tend to oversteer relative to the first setup.


Billy

 

[TURBO2GO]

What's a wheel rate if you don't mind my asking...

 

[RYU]

What's a wheel rate if you don't mind my asking...

I believe it's the actual rate as measured farther out at the end of the A-arm vs. the rate at the shock/spring pivot point. The longer the A-arm the greater the leverage the lower the wheel rate. If the spring/shock pivot point was at the exact location as the wheel then they would effectively have the same rate.

This is my stab at it anyway...

 

[Ponyboy]

wheel rate = spring rate/leverage^2

 

[TURBO2GO]

It sounds like that is the important number then and not spring rates... why don't we always talk about wheel rates? Sounds like a complex thing to figure out exactly. I guess its different on every car and every wheel and spring rates are uniform.

 

[ChopsJazz]

Jim that was close as hell. And knowing your buddy had to get his car repainted from the shower of rocks in the gravel trap REEEEEALLY makes me want to take my freshly painted car to the track!

Instead, give it a couple weeks and take your freshly painted car to get a clear bra. Then take it to the track!

 

[CL65 Captain]

It sounds like that is the important number then and not spring rates... why don't we always talk about wheel rates? Sounds like a complex thing to figure out exactly. I guess its different on every car and every wheel and spring rates are uniform.

bingo... that's why we can compare spring rates amongst ourselves but comparing them to say a 911 GT3 doesn't mean much.

 

[stuntman]

I believe it's the actual rate as measured farther out at the end of the A-arm vs. the rate at the shock/spring pivot point. The longer the A-arm the greater the leverage the lower the wheel rate. If the spring/shock pivot point was at the exact location as the wheel then they would effectively have the same rate.

This is my stab at it anyway...

It's basically what the name implies: the rate at the wheel. If you have a 500lb spring, it takes 500lbs to compress it 1". But mounted on the front of the NSX, it only takes (arbitrary): 275lbs of force pressing on the tire to compress the spring 1" due to leverage.

While the concept of longer A-arms giving more leverage and thus a lower spring rate is true (for the front of the NSX), the rear pick-up point is on the hub/upright itself. The suspension geometry (pick-up points, control arms, etc...) dictate the motion ratio and thus the leverage difference between the spring and wheel.

A strut-type front suspension has closer to a 1:1 ratio, where 1" of wheel travel = 1" of spring/shock travel.

It sounds like that is the important number then and not spring rates... why don't we always talk about wheel rates? Sounds like a complex thing to figure out exactly. I guess its different on every car and every wheel and spring rates are uniform.

Most people don't talk about wheel rates because either they don't know about it, or because they just focus on the spring rates and how spring changes affect the car (because they just work on 1 car and are specialists on that 1 platform). Swaybar rates are also often overlooked and is just as important as a component as the springs. It's important to know about the entire system of a suspension. Suspension is called a "black art" by some because they don't understand the fundamentals of the suspension package as a whole. While spring and wheel rates are new and more advanced concepts for many, it is still very fundamental and elementary compared to the infinite whole picture.

bingo... that's why we can compare spring rates amongst ourselves but comparing them to say a 911 GT3 doesn't mean much.

Exactly, but if you know the motion ratios of both cars then you can compare their wheel rates.

 

[wneal]

Jim,
This is the spin I had going into turn 1 in 2007.

http://www.youtube.com/watch?v=v1PDTL6jIp8


Watch the car suddenly veer left, I over corrected and that is all she wrote.

The "rocks" in the runoff ruined the paint on the right side of my car to the point I had the entire car painted.
Track car = MAACO paint job