Seeking sway bar advice

Crusty · 03-02-2013, 09:25 PM

Hi all. I'm relatively new to SCCA autocross though I do have several years of experience in my well prepared 240z with a small club in northern CA. Last April I bought a new 370z and thus far my nephew (co-driver) and i have run the car at about 6 scca events and about 7 or 8 small club events. My intention with buying a new car was to run in a stock class with SCCA (CS-T1 road tire class San Francisco Region), because i felt the level of competition is higher with SCCA than what i'm used to, and after taking a hard honest look at my driving i decided my skills needed improvement as I felt like to some degree, I had been hiding behind a very fast car while not necessarily improving my driving as much as i had improved the car. So my ultimate goal is to go much faster by way of improving my driving first. To date, my driving is probably not yet where i want it (sound familiar?), but i have been practicing and i am getting faster consistently. While I'm not planning on buying any parts until i feel better about the driving, i'm tempted to start doing homework on go faster parts. What i notice about the 370 is that it seems to be a bit tail happy during on throttle corner exit and with the viscous LSD it seems to have difficulty putting power down to the inside wheel as you unwind the steering and accelerate. I'm wondering what kind of results others have had with by installing a larger front sway bar. Are other folks experiencing the same thing, and does the front bar change help? Thanks.

VoBoy · 03-05-2013, 06:32 PM

Just a suggestion before you spend some money you could always see if disconnecting the rear sway bar helps.

Crusty · 03-05-2013, 07:13 PM

OOps! That last question was meant for shamu. Been starring at the screen for to long:/

Boss_302 · 03-05-2013, 07:44 PM

The sway bars on a Nismo are stiffer than the standard bars and are factory, this may help getting around the rule limitations. Maybe going with an Nismo factory barat the front and an aftermarket rear adjustable might give you the combination you are looking for.
Its trial and error.

gomer_110 · 03-05-2013, 07:54 PM

Quote:

Originally Posted by Boss_302

The sway bars on a Nismo are stiffer than the standard bars and are factory, this may help getting around the rule limitations. Maybe going with an Nismo factory barat the front and an aftermarket rear adjustable might give you the combination you are looking for.
Its trial and error.

What you're suggesting breaks the rules. This is why the Nismo runs B-stock and non-Nismo runs C-stock. SCCA does not consider the two to be equal.

Crusty · 03-05-2013, 08:10 PM

Thanks Boss_302. I actually had the same thought, so today i called the dealer (parts dept.) and they tell me that the only difference in bars is between the touring model and sport package. My car has the sport package. Not sure where the confusion lies and So far i haven't found detailed info on the NISMO bars on-line. They also gave me a functioning phone number (though they were closed) for nissan motorsports. Apparently NISMO is "no longer part of nissan", but perhaps nissan motorsports is actually racing zcars. Haven't heard anything about NM in years, but back in the day they always had the best parts and most experience (for the most part) with my 240z. Be interesting to see when i call them back.

Crusty · 03-05-2013, 08:12 PM

Agreed Gomer_110. I'm only interested in changing the front bar.

gomer_110 · 03-05-2013, 08:26 PM

Here's a chart someone showed me when I was looking at sway bars. Hope it helps.

Crusty · 03-06-2013, 10:37 AM

Quote:

Originally Posted by gomer_110

Here's a chart someone showed me when I was looking at sway bars. Hope it helps.

WOW!! That's great, and it definately is a good reference. Thanks!

ChipsWithDips · 03-06-2013, 08:47 PM

Quote:

Originally Posted by gomer_110

Here's a chart someone showed me when I was looking at sway bars. Hope it helps.

I installed Eibachs recently, and measured the weights. For what it's worth the weight calculations in that chart are a bit off. According to my measurements the weight ratio eibach/stock is 128% for front(pretty close to that chart calculation) but 193% for the rear, which is pretty far off from the 140% listed in the chart.

Eibach Front Sway: 4.52 kg
Eibach Rear Sway: 3.80 kg

Stock Front Sway: 3.51 kg
Stock Rear Sway: 1.97 kg

Also you could theoretically do a more detailed calculation if you measured the "lever arm" length of the various endlink setting holes and added that into the calculation. Shorter lever arm means less mechanical advantage, making it effectively stiffer. Though I don't know how much value there is in trying doing these calculations when really the inner diameter is only a guess.

ChipsWithDips · 03-06-2013, 08:54 PM

Anyways, I like the feel of the eibachs, so far I have only tried it on soft setting on front and middle setting on rear.

I was a little concerned when reading the eibach install guide, it basically said don't use the stiffest settings front or rear in the rain. My Z is my daily driver so it sees rain on occasion, should I be concerned about going stiffer in front? I guess I don't really see how less roll is going to make rainy conditions more dangerous.

gomer_110 · 03-06-2013, 08:55 PM

Quote:

Originally Posted by ChipsWithDips

I installed Eibachs recently, and measured the weights. For what it's worth the weight calculations in that chart are a bit off. According to my measurements the weight ratio eibach/stock is 128% for front(pretty close to that chart calculation) but 193% for the rear, which is pretty far off from the 140% listed in the chart.

Eibach Front Sway: 4.52 kg
Eibach Rear Sway: 3.80 kg

Stock Front Sway: 3.51 kg
Stock Rear Sway: 1.97 kg

Also you could theoretically do a more detailed calculation if you measured the "lever arm" length of the various endlink setting holes and added that into the calculation. Shorter lever arm means less mechanical advantage, making it effectively stiffer. Though I don't know how much value there is in trying doing these calculations when really the inner diameter is only a guess.

Just sharing what another member shared with me. Guess from now on I'll have to post a disclaimer that there may be errors. Thanks for pointing out the error though.

ChipsWithDips · 03-06-2013, 08:58 PM

Quote:

Originally Posted by gomer_110

Just sharing what another member shared with me. Guess from now on I'll have to post a disclaimer that there may be errors. Thanks for pointing out the error though.

Yeah I know, I saw that chart before I bought my sways also. I took it with a grain of salt knowing that the inner diameter was a guess(it says so on chart). Not sure who the original creator was. Its still a neat comparison given the limited data available.

Boss_302 · 03-05-2013, 09:22 PM

Yea, I understand about the rules. Use to run formula fords. Sometimes we just drop the rear bar, but than we had other things to adjust,
One thing you can do is play with the tire pressures front to back, a couple of pounds either way could make a difference, alignment is important. You can get a tire pyrometer and measure the temperature across the thread and see if you are making full contact and fine tune the alignment accordantly

Shamu · 03-05-2013, 10:35 PM

For AX 245 font is way too skinny for our weight. Minimum of 265 or 275 up front. 295 or 285 rear on stockers is going to be best bet.

03-02-2013, 09:25 PM	#1 (permalink)
Crusty Base Member Join Date: Mar 2013 Location: Santa Rosa Posts: 19 Drives: 2012 370Z CS T1 Rep Power: 13	Seeking sway bar advice Hi all. I'm relatively new to SCCA autocross though I do have several years of experience in my well prepared 240z with a small club in northern CA. Last April I bought a new 370z and thus far my nephew (co-driver) and i have run the car at about 6 scca events and about 7 or 8 small club events. My intention with buying a new car was to run in a stock class with SCCA (CS-T1 road tire class San Francisco Region), because i felt the level of competition is higher with SCCA than what i'm used to, and after taking a hard honest look at my driving i decided my skills needed improvement as I felt like to some degree, I had been hiding behind a very fast car while not necessarily improving my driving as much as i had improved the car. So my ultimate goal is to go much faster by way of improving my driving first. To date, my driving is probably not yet where i want it (sound familiar?), but i have been practicing and i am getting faster consistently. While I'm not planning on buying any parts until i feel better about the driving, i'm tempted to start doing homework on go faster parts. What i notice about the 370 is that it seems to be a bit tail happy during on throttle corner exit and with the viscous LSD it seems to have difficulty putting power down to the inside wheel as you unwind the steering and accelerate. I'm wondering what kind of results others have had with by installing a larger front sway bar. Are other folks experiencing the same thing, and does the front bar change help? Thanks.

03-05-2013, 08:26 PM	#8 (permalink)
gomer_110 A True Z Fanatic Join Date: Aug 2011 Location: Perrysburg, OH Posts: 17,992 Drives: '11 Nismo #528 GM Rep Power: 36941	Here's a chart someone showed me when I was looking at sway bars. Hope it helps. __________________ '11 370Z Nismo #528 Fast Intentions \| Stillen \| Motordyne \| Uprev \| CSF \| Zspeed \| Z1 Motorsports \| AST \| Swift \| SPC \| SPL \| Whiteline \| Hotchkis \| Bride \| Schroth \| Robispec \| Cusco \| Nismo \| Volk \| Forgestar \| Hoosier \| RJM '17 Titan Bone Stock

03-06-2013, 08:54 PM	#11 (permalink)
ChipsWithDips Enthusiast Member Join Date: Mar 2011 Location: Austin, TX Posts: 279 Drives: '11 Gunmetal 370Z MT Rep Power: 15	Anyways, I like the feel of the eibachs, so far I have only tried it on soft setting on front and middle setting on rear. I was a little concerned when reading the eibach install guide, it basically said don't use the stiffest settings front or rear in the rain. My Z is my daily driver so it sees rain on occasion, should I be concerned about going stiffer in front? I guess I don't really see how less roll is going to make rainy conditions more dangerous. __________________ PPE Headers SS/Coated/Wrapped \| Ebay y-pipe \| Custom 3" single exhaust w/ Magnaflows \| UpRev \| Racingbrake 2pc Rotors \| 40th calipers \| Eibach sways \| SPL endlinks, diff mounts \| RJM pedal \| Stillen Intakes, UDP, Flywheel \| M370 Manifold \| Z1 engine mounts, CSC-EK, Clutch \| Forgestar F14 18x10 \| Conti DWs \| Quaife diff/4.08 gears \| Nismo diff cover

03-05-2013, 10:35 PM	#15 (permalink)
Shamu A True Z Fanatic Join Date: Jan 2011 Location: Nor Cal Posts: 1,059 Drives: 370Z Racecar Rep Power: 20	For AX 245 font is way too skinny for our weight. Minimum of 265 or 275 up front. 295 or 285 rear on stockers is going to be best bet. __________________ Grant

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03-05-2013, 06:32 PM	#2 (permalink)
VoBoy Base Member Join Date: Mar 2009 Location: Chicago/Houston Posts: 37 Drives: 06 350z Rep Power: 17	Just a suggestion before you spend some money you could always see if disconnecting the rear sway bar helps.

03-05-2013, 07:13 PM	#3 (permalink)
Crusty Base Member Join Date: Mar 2013 Location: Santa Rosa Posts: 19 Drives: 2012 370Z CS T1 Rep Power: 13	OOps! That last question was meant for shamu. Been starring at the screen for to long:/

03-05-2013, 07:44 PM	#4 (permalink)
Boss_302 Base Member Join Date: Feb 2013 Location: NY NY Posts: 150 Drives: 11 Nissan 370z S Mt Rep Power: 13	The sway bars on a Nismo are stiffer than the standard bars and are factory, this may help getting around the rule limitations. Maybe going with an Nismo factory barat the front and an aftermarket rear adjustable might give you the combination you are looking for. Its trial and error.

03-05-2013, 08:10 PM	#6 (permalink)
Crusty Base Member Join Date: Mar 2013 Location: Santa Rosa Posts: 19 Drives: 2012 370Z CS T1 Rep Power: 13	Thanks Boss_302. I actually had the same thought, so today i called the dealer (parts dept.) and they tell me that the only difference in bars is between the touring model and sport package. My car has the sport package. Not sure where the confusion lies and So far i haven't found detailed info on the NISMO bars on-line. They also gave me a functioning phone number (though they were closed) for nissan motorsports. Apparently NISMO is "no longer part of nissan", but perhaps nissan motorsports is actually racing zcars. Haven't heard anything about NM in years, but back in the day they always had the best parts and most experience (for the most part) with my 240z. Be interesting to see when i call them back.

03-05-2013, 08:12 PM	#7 (permalink)
Crusty Base Member Join Date: Mar 2013 Location: Santa Rosa Posts: 19 Drives: 2012 370Z CS T1 Rep Power: 13	Agreed Gomer_110. I'm only interested in changing the front bar.

03-05-2013, 09:22 PM	#14 (permalink)
Boss_302 Base Member Join Date: Feb 2013 Location: NY NY Posts: 150 Drives: 11 Nissan 370z S Mt Rep Power: 13	Yea, I understand about the rules. Use to run formula fords. Sometimes we just drop the rear bar, but than we had other things to adjust, One thing you can do is play with the tire pressures front to back, a couple of pounds either way could make a difference, alignment is important. You can get a tire pyrometer and measure the temperature across the thread and see if you are making full contact and fine tune the alignment accordantly