Square setup and Understeer - MY350Z.COM - Nissan 350Z and 370Z Forum Discussion



Autocross/Road SCCA Solo II, SCCA Club Racing, Redline Track Events, Speed Trial, Speed Ventures, Grand-Am Cup, JGTC, Procar Australia

Reply
 
 
 
Thread Tools Search this Thread
Old 09-29-2017, 12:08 PM   #1
cubic202
Registered User
Thread Starter
iTrader: (1)
 
Join Date: Nov 2009
Location: Los Angeles
Posts: 86
Thanked 0 Times in 0 Posts
Default Square setup and Understeer

Hello and a quick question as I try move my skill set to the next level. Iíve been tracking my Z for about two years on stock 17s with Sumitomo HTR ZII; a very hard and greasy tire. These have been a great learning platform; lots of understeer on the fast sweepers, and quick oversteer on the tighter corners. Iíve learnt throttle modulation when coming out of corners along with the limits of the car and the driver.

Iím ready to move on to a square set up; 18/10.5 wheels running 275/35 Federal 595 RS-RRs. Iím running a stock suspension and wish to get a feel for the car with these wheels before moving to shocks and springs.

I understand the square set-up will eliminate a lot of the understeer but does this also induce snap oversteer? Would an upgraded front sway bar on a soft setting provide me with a little safety understeer?

For reference I prefer the faster tracks in So Cal: Willow Springs, ACS Roval and Buttonwillow.

Many thanks guys!!

Neil
cubic202 is offline   Reply With Quote
Old 09-29-2017, 01:34 PM   #2
terrasmak
Super Moderator
MY350Z.COM
iTrader: (8)
 
terrasmak's Avatar
 
Join Date: Jan 2007
Location: Sin City
Posts: 23,958
Thanked 796 Times in 576 Posts
Default

Going square on stock suspension will still be an understeer car. If you are having issues at the track, pop off one of the rear sway bar endlinks
terrasmak is offline   Reply With Quote
Old 09-29-2017, 07:06 PM   #3
cubic202
Registered User
Thread Starter
iTrader: (1)
 
Join Date: Nov 2009
Location: Los Angeles
Posts: 86
Thanked 0 Times in 0 Posts
Default

Ok, keep the stock sway and play it by ear, gotta ya. Thanks! I'll report on the results, NASA event later in the month. Thanks again.
cubic202 is offline   Reply With Quote
Old 10-02-2017, 11:22 AM   #4
Blurvision
Registered User
iTrader: (4)
 
Join Date: Oct 2012
Location: Tuxedo, NY
Posts: 521
Thanked 36 Times in 31 Posts
Default

If will be more balanced for sure. No "snap" you are concerned about.
Blurvision is offline   Reply With Quote
The Following User Says Thank You to Blurvision For This Useful Post:
cubic202 (10-05-2017)
Old 10-11-2017, 06:16 AM   #5
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

I've been running a square set up for most of 5 years of driving on track so I cannot comment on whether it improves or worsens understeer compared to a staggered setup. But, the longer I do this the more obvious it becomes to me that a stock 350z understeers rather badly (either that or I've developed poor driving techniques that lead to understeer).

Anyway, as I watch comparable cars (3 series BMWs, etc) take a similar line but carve through corners faster than me it is becoming frustrating. Granted, I don't know what mods or tires those cars are running....but still.

I also compared notes with a young lady running a 370z at VIR who was running laps a full 8 seconds faster than me on the same tires but her setup was staggered 295 rears, 255 fronts. I'm on 265s square. She did have a Quaiffe LSD and some other mods but 8 seconds is huge and indicates that 1) she is probably a better driver and 2) some mods to decrease understeer could provide some real improvement.

I don't really want to try solving the problem by inducing oversteer though. I'd like to do it by improving front traction. So what is the best way to do that? Camber?
N80 is offline   Reply With Quote
Old 10-11-2017, 06:54 AM   #6
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default

1) What is your lap time at VIR?
2) What is the setup on the car?
3) Tires?
03threefiftyz is offline   Reply With Quote
Old 10-11-2017, 08:03 AM   #7
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

Quote:
Originally Posted by 03threefiftyz View Post
1) What is your lap time at VIR?
2.25

Quote:
2)What is the setup on the car?
Stock

Quote:
3) Tires?
Yokohama Advan Neova (180twr)
N80 is offline   Reply With Quote
Old 10-11-2017, 09:48 AM   #8
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default

You need to embrace the slow in, fast out method my friend. In all due honesty...I would think a stock Z on decent tires should be a 2:16 car or so...just for fun I took my stock Focus ST down to VIR last year and it ran a 2:18. Are you still on 225/245 stock sized tires?
03threefiftyz is offline   Reply With Quote
Old 10-11-2017, 10:01 AM   #9
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

265s front and rear.

Might just be the driver. In defense of my driving skills I've only been there four times and two of them rained all weekend. Times at my home track are more in line with comparable cars....but I still feel slow.

Last edited by N80; 10-11-2017 at 10:04 AM.
N80 is offline   Reply With Quote
Old 10-11-2017, 10:17 AM   #10
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default

You take AiM data or anything?

I have some from other Z's that I can relay some insight. Probably not a great comparo to my car at this point (runs sub 2min)...
03threefiftyz is offline   Reply With Quote
Old 10-11-2017, 11:02 AM   #11
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

No. Harry's Lap Timer.

I probably need to pay for some coaching sessions. I think there are several issues at VIR: I need more practice there, I need more guts to stay flat up through the upper esses, I need to brake later on the back stretch, I need to carry more speed through hogpen, I need to remedy the understeer a little, stickier tires would be nice but not in the cards right now. But a lot of the VIR issues, I think, come down to trusting the car and having a little more guts.

The funny thing is, even though I'm not that fast, I've been able to help students (DE-1 and 2) get faster very effectively and I don't get nervous or rattled in student's cars at all, even when things are going south. So I generally know what to do and how to teach it, just not putting it into practice myself.

Again, I'm not quite so slow on my home track.
N80 is offline   Reply With Quote
Old 10-12-2017, 12:10 PM   #12
Blurvision
Registered User
iTrader: (4)
 
Join Date: Oct 2012
Location: Tuxedo, NY
Posts: 521
Thanked 36 Times in 31 Posts
Default

Just a word of advice on the best way to get faster. Don't go buying sticky tires and keep changing your setup. Focus on what you have right now and improve the way you self diagnose. Learn how to read your lap data. Read books by Ross Bentley and others, seek help from qualified instructors at the track. Spend the money on seat time.

Instructors are highly trained. Stick to the basics. Careful giving out advice to new drivers, especially if your not in the car with them. You can inadvertently inflate their head and give over confidence causing them to wreck.
Blurvision is offline   Reply With Quote
Old 10-12-2017, 12:23 PM   #13
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

Quote:
Originally Posted by Blurvision View Post
Just a word of advice on the best way to get faster. Don't go buying sticky tires and keep changing your setup. Focus on what you have right now and improve the way you self diagnose. Learn how to read your lap data.
Agree completely. My frustration is mostly with my performance at VIR. I love the track but only get up there once or twice a year. I need more practice there.

Quote:
Read books by Ross Bentley
Was thinking the same thing yesterday. I've got his book. Will pull it out tonight.

Quote:
seek help from qualified instructors at the track.
I've done that. It has helped some. Will continue to do so but considering a professional coach. Probably crazy money but might be worth a try.


Quote:
Spend the money on seat time.
Agreed.

Quote:
Instructors are highly trained. Stick to the basics. Careful giving out advice to new drivers, especially if your not in the car with them. You can inadvertently inflate their head and give over confidence causing them to wreck.
I am a NASA certified instructor. That was my point. I seem to be able to teach others to go faster but not as good at teaching myself. You know the old saying those who can do, those who can't.............

Ross Bently has actually addressed this issue in some of his blogs/emails.
N80 is offline   Reply With Quote
Old 10-12-2017, 03:38 PM   #14
guitman32
Professional
iTrader: (14)
 
guitman32's Avatar
 
Join Date: Jul 2005
Location: South FL
Posts: 1,661
Thanked 42 Times in 36 Posts
Default

Get some other guys in your car with you. There are people out there that have had enough coaching and experience that can probably take you to the next level, just like you do the 1 & 2 guys. The circle of track life.

At some point it really just becomes how much you want to push (and spend), so you just have to get comfortable in your own skin.
guitman32 is offline   Reply With Quote
Old 10-12-2017, 04:24 PM   #15
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

Quote:
Originally Posted by guitman32 View Post
At some point it really just becomes how much you want to push (and spend), so you just have to get comfortable in your own skin.
Agree. I usually have a better time when I'm not watching lap times. And the most fun I have is chasing or running from similar paced cars, especially in a group. To me, a session of 'racing' similar paced cars is the holy grail for DE4.

But, the fact remains, track times don't lie.
N80 is offline   Reply With Quote
Old 10-12-2017, 05:25 PM   #16
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default

I don't ride right seat, but if you get an AiM Solo I can walk you through where you need to pick it up and such.

I usually am at VIR for NASA events and a CHIN or Trackdaze event here and there. I was not there for the last event, though.
03threefiftyz is offline   Reply With Quote
Old 10-12-2017, 05:35 PM   #17
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default


I have a bunch of data from 350z's of different prep levels. I know it is a few hundred up front, but getting an AiM solo is worth it...if for no other reason than just about everyone else in grid has one and the data is easily shareable and overlayed.
03threefiftyz is offline   Reply With Quote
Old 10-13-2017, 06:01 AM   #18
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

A couple of observations from that video:

Your speeds on the front and back stretch and through the upper esses are way higher than mine.

On the front stretch I'm topping out around 125.---I think the only way I can improve on that is carrying more speed out of hog pen...which I think I can do, but I had a big off there last weekend that set me back a little.

Through the upper esses I'm at about 100. --- I lift entering the esses dropping from about 115 to less than 100. Other drivers riding with me say I don't need to do it, or at least not as much. I just don't have the ***** for more speed through there on these tires. I might just need to slowly increase my speed through there until I'm more confident.

On the back stretch I'm topping out around 135.---Again, the only remedy I know for that is to carry more speed through Oak Tree. I've got the guts for that, just can't find a line that is just the right line for my car.

I know that doesn't tell you much but you are way faster in all those segments. I'm sure you are way faster in the other corners too but I don't have good data there.

Again, my car is essentially bone stock.
N80 is offline   Reply With Quote
Old 10-13-2017, 08:28 AM   #19
03threefiftyz
350Z-holic
iTrader: (25)
 
03threefiftyz's Avatar
 
Join Date: Aug 2007
Location: Frederick, MD
Posts: 9,814
Thanked 87 Times in 48 Posts
Default

Keep in mind the car in the vid makes ~150whp more than yours, has aero, Hoosier A7's, etc....but I have a bunch of data from other Z's, too. Same car at 300whp was completely flat through the esses, even up top until checking up for SouthBend.

For Fun...here is my stock Focus, which is closer to the hp/speeds you're talking about:
03threefiftyz is offline   Reply With Quote
Old 10-13-2017, 01:19 PM   #20
N80
Registered User
 
Join Date: Mar 2011
Location: SC
Posts: 680
Thanked 16 Times in 11 Posts
Default

Apologies to OP for the thread high jacking but the discussion is probably still relevant.

Anyway, my laps look more like your Ford laps but you still went a bit faster through the upper esses than I do. I think it is just a matter of guts there.
N80 is offline   Reply With Quote
 
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -8. The time now is 07:10 PM.


Copyright ©2002 - 2017, MY350Z.COM All Rights Reserved.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: