Proper ride height for Track

wrxrcr · 12-28-2013, 09:54 PM

Motion ratio is like .63 front and .50 rear , that might be flipped. What alignment settings do you guys recommend for autox, street tires probably z2s in a square 275 setup?

synolimit · 12-29-2013, 01:27 AM

Quote:

Originally Posted by SPOHN

Took mine off the street also.

Pussy haha

Car Maniacs : Life With Le Mans' - XJ220LM 962C 767B

"We own racing cars, so we may as well use them in our everyday lives, it's only natural."

cossie1600 · 12-29-2013, 02:05 AM

Are you really comparing a street car with a bunch of aftermarket add-ons to a full blown race car at LeMans?

synolimit · 12-29-2013, 02:42 AM

Quote:

Originally Posted by cossie1600

Are you really comparing a street car with a bunch of aftermarket add-ons to a full blown race car at LeMans?

Kind of an insult to spohn no?

cossie1600 · 12-29-2013, 03:44 AM

Not insulting anyone, just saying there is a huge difference between something that is nearly impossible to drive on the street vs. something that is not fun to drive on the street

synolimit · 12-29-2013, 04:05 AM

Quote:

Originally Posted by cossie1600

Not insulting anyone, just saying there is a huge difference between something that is nearly impossible to drive on the street vs. something that is not fun to drive on the street

Not fun? I think that's in the opinion of the person. Wear a helmet and have fun.

GSS138 · 12-29-2013, 03:09 PM

@Mike, with 783 up front and rear in a coilover you have:

front ride rate: 2.3 Hz
and rear rate: 2.1 Hz

2.3/2.1 = 1.09 I think this ratio is one of the most important things when doing the suspension voodoo math. I am using a number really close to that ratio with just lower spring rates and the OEM motion ratios. The hope is to get the same under/oversteer feel. Our OEM ratio is like .90 which is pretty standard OEM street car setup.

BY using 672 front and 504(OEM rears)

I will get 2.13 Hz/ 1.95 Hz = 1.09.

This will prolly be a little loose till I throw a wing on. I use .62 for front motion ratio, and .62 rear(oem), or .73(Coil position) as my motion ratios. If I was going full track I would prolly move higher like you guys, but it's gonna be a while before that happens.

03threefiftyz · 12-29-2013, 04:10 PM

Last I checked the front M/R was closer to .67 and .63 in the back (350z). .2hz front/rear is pretty safe. Keep in mind, most of the weight you drop off these cars comes from the back. Even playing around with ride heights, you'll still likely be 55/45 WD, at best.

GSS138 · 12-29-2013, 08:11 PM

You could be right 350. It is really hard to measure though with just a jack a flashlight and a tape measure. I am also trying to fluff it a little with the 285 square setup I have.

Had a request for the math on Frequencies, I am attaching a spreadsheet. It is protected(so that I don't f up the equations) but it is not password protected so everyone can see the math behind it.

You can change motion ratios, rates, etc. I am completely guessing on the corner weights though FYI. If you find a math problem in it let me know.

03threefiftyz · 12-29-2013, 08:49 PM

Another calculator option:

Autocross to Win (DGs Autocross Secrets) - Dynamics Calculator

wrxrcr · 12-29-2013, 09:29 PM

The motion ratio in the rear for independent spring shock is .5.

03threefiftyz · 12-29-2013, 10:01 PM

No, it isn't.

wrxrcr · 12-30-2013, 07:56 AM

Quote:

Originally Posted by 03threefiftyz

No, it isn't.

For 370z, 350z or both. I often get confused with your posts as to which car your talking about, no disrespect intended.

03threefiftyz · 12-30-2013, 08:16 AM

The rear suspension is largely the same...

GSS138 · 12-30-2013, 02:09 PM

I thought it was .5 at first as well, but you have to measure all the way to the end of the wheel hub. It is closer to .6

That is a great link will have to play around with it.

12-29-2013, 03:09 PM	#97 (permalink)
GSS138 Track Member Join Date: Mar 2013 Location: Mission Viejo, CA Posts: 769 Drives: '12 370Z 6M Sport Rep Power: 13	@Mike, with 783 up front and rear in a coilover you have: front ride rate: 2.3 Hz and rear rate: 2.1 Hz 2.3/2.1 = 1.09 I think this ratio is one of the most important things when doing the suspension voodoo math. I am using a number really close to that ratio with just lower spring rates and the OEM motion ratios. The hope is to get the same under/oversteer feel. Our OEM ratio is like .90 which is pretty standard OEM street car setup. BY using 672 front and 504(OEM rears) I will get 2.13 Hz/ 1.95 Hz = 1.09. This will prolly be a little loose till I throw a wing on. I use .62 for front motion ratio, and .62 rear(oem), or .73(Coil position) as my motion ratios. If I was going full track I would prolly move higher like you guys, but it's gonna be a while before that happens. __________________ Current Mods: Vorpal Weapon +5.

12-30-2013, 02:09 PM	#105 (permalink)
GSS138 Track Member Join Date: Mar 2013 Location: Mission Viejo, CA Posts: 769 Drives: '12 370Z 6M Sport Rep Power: 13	I thought it was .5 at first as well, but you have to measure all the way to the end of the wheel hub. It is closer to .6 That is a great link will have to play around with it. __________________ Current Mods: Vorpal Weapon +5.

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12-28-2013, 09:54 PM	#91 (permalink)
wrxrcr Base Member Join Date: Nov 2013 Location: columbus Posts: 74 Drives: 12 370z,09 Wrx Rep Power: 11	Motion ratio is like .63 front and .50 rear , that might be flipped. What alignment settings do you guys recommend for autox, street tires probably z2s in a square 275 setup?

12-29-2013, 02:05 AM	#93 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	Are you really comparing a street car with a bunch of aftermarket add-ons to a full blown race car at LeMans?

12-29-2013, 03:44 AM	#95 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	Not insulting anyone, just saying there is a huge difference between something that is nearly impossible to drive on the street vs. something that is not fun to drive on the street

12-29-2013, 04:10 PM	#98 (permalink)
03threefiftyz Track Member Join Date: Apr 2010 Location: MD Posts: 536 Drives: 03 350z 6mt Rep Power: 16	Last I checked the front M/R was closer to .67 and .63 in the back (350z). .2hz front/rear is pretty safe. Keep in mind, most of the weight you drop off these cars comes from the back. Even playing around with ride heights, you'll still likely be 55/45 WD, at best.

12-29-2013, 08:49 PM	#100 (permalink)
03threefiftyz Track Member Join Date: Apr 2010 Location: MD Posts: 536 Drives: 03 350z 6mt Rep Power: 16	Another calculator option: Autocross to Win (DGs Autocross Secrets) - Dynamics Calculator

12-29-2013, 09:29 PM	#101 (permalink)
wrxrcr Base Member Join Date: Nov 2013 Location: columbus Posts: 74 Drives: 12 370z,09 Wrx Rep Power: 11	The motion ratio in the rear for independent spring shock is .5.

12-29-2013, 10:01 PM	#102 (permalink)
03threefiftyz Track Member Join Date: Apr 2010 Location: MD Posts: 536 Drives: 03 350z 6mt Rep Power: 16	No, it isn't.

12-30-2013, 08:16 AM	#104 (permalink)
03threefiftyz Track Member Join Date: Apr 2010 Location: MD Posts: 536 Drives: 03 350z 6mt Rep Power: 16	The rear suspension is largely the same...