what spring rates for track coils? (g37)

w0ady · 05-04-2010, 11:42 AM

figured id post this here since theres not as much track experience on myg37. thanks in advance!

from my latest track thread @ roebling

Quote:

UPDATE: bad news: i need coilovers. good news: i need coilovers lol.

just came from infiniti, had my head tech do an oil change and a thorough inspection. looks like my plowing issues arent just the weight but my springs are too soft - the control arms are bottoming out on the sway bar. this is what killed my end link last time. the new yokohama tires are stickier and the extra traction is being taken out on the car. luckily levin was awesome enough to help me weigh the car so i have my 4 corner weights. i need to call and do some research with race spring manufacturers. hopefully i can get an idea for what rates i need. ive been debating ordering some adjustable bc coils and looks like theres no more debate. just need to figure out the specs and ill be set. its pay now or wait and hurt the car/wear through tires.

current setup is eibach pro

Quote:

Spring Rates:
Front: 228lbs/in initial, up to 548lbs/in
Rear: 371lbs/in initial, up to 531lbs/in

with 3/4 tank of gas, my curb weight is 3904 lbs and corner weights are:

lf 1094 rf 1026
lr 905 rr 879

so with my current understeer and bottoming out on the front springs - i need help on figuring out just what spring rates i should get if i buy coils. im going with a linear setup. it will only be for 4-5 track sessions a year at this time so i need something streetable that will still do the trick. any ideas?

klubbheads · 05-04-2010, 11:57 AM

300lb/in to 600lb/in is streetable. The improtant thing is the height. If you get coilovers, don't dump the car so the suspension has room to compress without bottoming out. Adjusting the dampening to stiffer settings will help you with bottoming out as well.

As far as the understeer goes, the general rule of thumb is stiffer rear springs/dampening/sway bar settings more oversteer. So according to that general idea you can adjust the behavior of the car along with some driving adjustments.

w0ady · 05-04-2010, 06:05 PM

thanks for the response.

im only lowered about an 1" all the way around and i plan on keeping the same drop. bc type br come 12kg front/8kg rear which is 672/448. everything i see for the g37 is around 9-14kg front and 7-12kg rear. usually they are a staggered setup with 2kg difference front to back which is why i was thinking more 14/12 or 12/10.

ya ive read all the suspension tuning advice. plan is to get the coils and start in the middle on the track, then adjust from there once i see how the car really behaves.

klubbheads · 05-04-2010, 06:12 PM

12/10 would be a good choice for a daily and track use. Higher spring rates might be overkill unless you are planning to use race rubber on every track day. I had BC 10/8kg on my sedan and was very happy with them. Make sure you get the coilovers corner balanced to use the full potential of your suspension.

w0ady · 05-04-2010, 06:20 PM

thanks again. narrowing down the rates has been the tough part lately and 12/10 is what i was leaning towards. im running yokohama s.drives and they're plenty sticky for where i am right now. i definitely plan to corner balance once i get them.

Mike · 05-04-2010, 07:37 PM

w0, I think you will be on race rubber before you know it, judging by how fast you are progressing!

gshb · 05-05-2010, 12:11 AM

have you done any weight reduction, particularly in the rear?

w0ady · 05-05-2010, 02:12 PM

Quote:

Originally Posted by Mike

w0, I think you will be on race rubber before you know it, judging by how fast you are progressing!

haha i wish bro. id love to have the meanest track g37 out there. 1 day...

Quote:

Originally Posted by gshb

have you done any weight reduction, particularly in the rear?

nope its still my daily. i run it as is with just minor suspension mods for now.

05-04-2010, 11:57 AM	#2 (permalink)
klubbheads Base Member Join Date: Jan 2009 Location: North Hollywood, CA Posts: 221 Drives: Very slow Nismo 370 Rep Power: 17	300lb/in to 600lb/in is streetable. The improtant thing is the height. If you get coilovers, don't dump the car so the suspension has room to compress without bottoming out. Adjusting the dampening to stiffer settings will help you with bottoming out as well. As far as the understeer goes, the general rule of thumb is stiffer rear springs/dampening/sway bar settings more oversteer. So according to that general idea you can adjust the behavior of the car along with some driving adjustments. __________________ g35driver OG.

05-04-2010, 06:05 PM	#3 (permalink)
w0ady Base Member Join Date: Apr 2010 Location: jacksonville, fl Posts: 191 Drives: 2009 g37 ab 7at Rep Power: 16	thanks for the response. im only lowered about an 1" all the way around and i plan on keeping the same drop. bc type br come 12kg front/8kg rear which is 672/448. everything i see for the g37 is around 9-14kg front and 7-12kg rear. usually they are a staggered setup with 2kg difference front to back which is why i was thinking more 14/12 or 12/10. ya ive read all the suspension tuning advice. plan is to get the coils and start in the middle on the track, then adjust from there once i see how the car really behaves. __________________ sold: 09 athens 7at g37s coupe 12/22/08; 05 athens 5at g35 coupe r.i.p. 5/13/05-10/29/08

05-04-2010, 06:12 PM	#4 (permalink)
klubbheads Base Member Join Date: Jan 2009 Location: North Hollywood, CA Posts: 221 Drives: Very slow Nismo 370 Rep Power: 17	12/10 would be a good choice for a daily and track use. Higher spring rates might be overkill unless you are planning to use race rubber on every track day. I had BC 10/8kg on my sedan and was very happy with them. Make sure you get the coilovers corner balanced to use the full potential of your suspension. __________________ g35driver OG.

05-04-2010, 06:20 PM	#5 (permalink)
w0ady Base Member Join Date: Apr 2010 Location: jacksonville, fl Posts: 191 Drives: 2009 g37 ab 7at Rep Power: 16	thanks again. narrowing down the rates has been the tough part lately and 12/10 is what i was leaning towards. im running yokohama s.drives and they're plenty sticky for where i am right now. i definitely plan to corner balance once i get them. __________________ sold: 09 athens 7at g37s coupe 12/22/08; 05 athens 5at g35 coupe r.i.p. 5/13/05-10/29/08

05-04-2010, 07:37 PM	#6 (permalink)
Mike The370Z.com Sponsor Join Date: Jun 2009 Location: Loganville, GA Posts: 5,944 Drives: 370z Rep Power: 2187	w0, I think you will be on race rubber before you know it, judging by how fast you are progressing! __________________ NISSAN: 75 280Z / 86 300ZX GLL /87 Sentra SE / 03 350Z / 23 Z Porsche: 93 968 / 23 Macan GTS / 93 968

05-05-2010, 12:11 AM	#7 (permalink)
gshb Base Member Join Date: Feb 2010 Location: SJ Bay Area Posts: 3 Drives: G37S 6MT Rep Power: 16	have you done any weight reduction, particularly in the rear?

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