Square setup and Understeer
09-29-2017, 12:08 PM
#1
Square setup and Understeer
Hello and a quick question as I try move my skill set to the next level. I’ve 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. I’ve learnt throttle modulation when coming out of corners along with the limits of the car and the driver.
I’m ready to move on to a square set up; 18/10.5 wheels running 275/35 Federal 595 RS-RRs. I’m 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
I’m ready to move on to a square set up; 18/10.5 wheels running 275/35 Federal 595 RS-RRs. I’m 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
09-29-2017, 01:34 PM
#2
Super Moderator
MY350Z.COM
MY350Z.COM
iTrader: (8)
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
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cubic202 (10-05-2017)
10-11-2017, 06:16 AM
#5
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?
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?
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10-11-2017, 09:48 AM
#8
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?
10-11-2017, 10:01 AM
#9
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.
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.
10-11-2017, 11:02 AM
#11
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.
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.
10-12-2017, 12:10 PM
#12
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.
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.
10-12-2017, 12:23 PM
#13
Read books by Ross Bentley
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.
Ross Bently has actually addressed this issue in some of his blogs/emails.
10-12-2017, 03:38 PM
#14
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.
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.
10-12-2017, 04:24 PM
#15
But, the fact remains, track times don't lie.
10-12-2017, 05:35 PM
#17
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.
10-13-2017, 06:01 AM
#18
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.
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.
10-13-2017, 08:28 AM
#19
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:
For Fun...here is my stock Focus, which is closer to the hp/speeds you're talking about:
10-13-2017, 01:19 PM
#20
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.
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.