General Chat
Q:
Ive never really pushed my car to that hard to experience understeer, how good or bad is understeer in our S30's?
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
Depends on the car and the setup.
No two cars are the same.
Mario
1976 280Z - Dad's Z (turbo swap?)
1978 280Z - Stock Rebuild | 5 Speed | Twice Pipes | Gutted
1982 280ZX - Turbo | MSnS-E | 5 Speed | Large NPR IC
BROKE: Will build computers, webpages, networks, MS units, troubleshoot computers for money
A:
A lot depends on your tires.
Think of how heavy the engine is (ever try to lift one?), then imagine it moving at say 40mph, and then imagine the amount of force the tires need to overcome to deflect that much energy with only about 9 square inches of contact per tire to work with.
A:
stock stock stock, in general how do they fair with understeer
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
With only tociko struts and springs installed (the rest of the car basically completely bone stock), on stock wheels and old radial tires at the autocrosses I would fishtail into 180s and 360s before I would understeer.
Now at the autocross, after urethane bushings all around, front strut bar, 15 inch rewinds and kumhos, I find myself really having to get on the brakes to make the turns or I feel like I am getting some understeer. That said, once in the turn at a comfortable speed, understeer disappears and Ican steer with the throttle.
Just my 2 cents.
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1978 280Z - I wish I had this much money in my 401K.
A:
It depends on the turn you're making also (IMO). If you're trying to sling your car at 45mph around a 90 degree corner there is a good chance you'll feel the understeer. I find that in bigger more sweeping turns (mountain roads for example) understeer becomes less of an issue but still something to keep your eye on. It's definitely not enough of a bother for me to not love my car. Hope that helps, and others may disagree.
1972 240z w/L28, tokico shocks and springs, and a 5 speed waiting. Also running high performance ultra mega blinker fluid, that's at least an extra 50hp to the wheels.
1987 Toyota Supra Turbo 5-speed. Belongs to me until my friend get's back from Iraq.
A:
You have experienced understeer before but may not have known it. Any time a car "pushes" through a turn, that is, you find the car moving to the outside of the turn, the car is "understeering". Understeer is not exceeding the limits of your tires and "sliding" through the turn.
Oversteer is when the rear end comes around on you.
1972 Datsun 240z - Crane XR700 Electronic Ignition, E31 Head, 260z 4-Speed, 3.54 Differential, Tokico HP Struts and Springs, ST Sway Bars, Urethane Bushings, SS Brake Lines, Power Slot Rotors, Hawk HPS Pads, MSA Turbo Exhaust
A:
i get understeer in mine at times normally when yanking the 90 degree turns too fast - not normally a problem on the long sweeeps but im on some super shitty front tires and i beat the crap out of it - as long as you know what your doing and have plenty of room and in the right gear its not hard to correct
but i deff wouldnt recomend taking the 90s around yor house at 45 :P
70 yay!
77 parts
81 compressed parts
86 compressed it handles
00 mercury cougar omg wtf : \ girl has to have something to drive
- owned
74.5 why did i sell you
81 1st car $425 found out s130s dont handle stock
82 good
84 BMW 325e omg never again
A:
45! that sounds scary...
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
yeah I really did pick the wrong speed to use for an example. Lets go with.........163! That's a more intimidating number.
1972 240z w/L28, tokico shocks and springs, and a 5 speed waiting. Also running high performance ultra mega blinker fluid, that's at least an extra 50hp to the wheels.
1987 Toyota Supra Turbo 5-speed. Belongs to me until my friend get's back from Iraq.
A:
Must suck to have no handling lol!
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
must suck to weigh so much.
1972 240z w/L28, tokico shocks and springs, and a 5 speed waiting. Also running high performance ultra mega blinker fluid, that's at least an extra 50hp to the wheels.
1987 Toyota Supra Turbo 5-speed. Belongs to me until my friend get's back from Iraq.
A:
Bring it on... I'd rather weigh a bit more and be able to turn corners and go faster lol!
I'm only teasing, you guys dish out bs about the Z31 alot so it doesn't hurt to playfully tease back :P
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
Post Edited (Oct 5, 5:25pm)
A:
must suck to...
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
Z31...
Weigh alot
Look like an 80s transformer
240...
Be made of thin rusted sheet metal hence light
Not handle at all
That's all I can think of right now haha.
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
"Look like an 80s transformer"
lol..i'm sorry that literally made me start laughing out loud!! no offense intended, just thought it was funny.
1980 280zx w/L28ET MSnS-Extra, framerails are toast...
1982 280zx...newest acquisition...
1983 Maxima - just sits in the driveway these days...
A:
Haha, no offense taken... I just thought i'd jump the gun before the regular Z31 haters come on and start bashing it because I insulted their poverty suspension. Everyone needs to lighten up around here in my opinion. Although I happen to like transformers! :)
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
s30's handles good foo
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
Cmon, get real... The stock suspension in the Z31 is balls even, drive something else with good suspension as a comparison. I got KONI's and custom lowered springs in my NA, it's a whole different world vs the stockers.
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
huh
73' 240z: F54 4.2L, OS Giken LY DOHC Crossflow head, 17:3comp.ratio, N33, Tripple SU's, T10 Hybrid Draw-Through TT @ 47pds, Roots&Centrifugal Type supercharger, 3-2-1 headers, Centerforce 4 clutch, 6oz flywheel, R300 differential, Super-Hicas
A:
The 280ZX is the same.... Good struts and springs and they are night and different in handling vs stock. Even at that they will tail out on you......don't even think of trail braking. The mere thought of touching the brake pedal when the fronts aren't straight will put you in the weeds. With some work you can settle them down though....well worth every minute spent.
Ken
'82ZX n/a 2+2
'02 Sportster XL1200C
A:
If your having a lot of understeer then either unhook or loosen your rear sway bar - at the end link. With an open diff you will hook up and handle better with the rear a little loose. This is provided you have decent suspension to start with.
If you still have all stock bushing & struts then those should be changed first.
Matt
A:
So on a 1st gen, would a big fat stiff sway bar in the front tightened down all the way...and a stock sway bar in the rear loosened all the way greatly reduce understear?
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1978 280Z - I wish I had this much money in my 401K.
A:
S30 Chapman struts make for a better rear suspension setup than the Z31's semi-trailing arms. WAY less camber change with bump. I wouldn't have the Z31's setup in my car, no-way no-how.
This is the first I've ever heard anyone claiming a Z31 handles better than an S30 (assuming equivalent tires, of course). 240Zs were always a better SCCA ITS car than Z31s, despite worse power/weight.
Regarding reducing understeer, you'd want to STIFFEN rear roll stiffness and/or SOFTEN front roll stiffness. Loosening or disconnecting the rear bar will INCREASE understeer. So would going with a stiffer front bar.
A:
>240Zs were always a better SCCA ITS car than Z31s
Where did you pull that stat from? I've got a Z history book here with all the SCCA race results and the Z31 won just as many if not more titles than the 240Z. I'll scan the page one day when I can be bothered.
It's nothing against either car anyway that the suspension wasn't good, it was just the technology at the time. Some of you 240Z nuts just cant bare to think that another car is better in any aspect when half of the time it's not even about that. Not alot can out handle ANY Z period with a good set of struts and stiff springs and the right swaybar placement depending on your application.
>S30 Chapman struts make for a better rear suspension setup than the Z31's semi-trailing arms
You're just speculating based on nothing but hot air now. Unless you have driven both cars one after the other comparing track times and steering responsiveness and other characteristics of the run you cant say which is better to certain fact, at best you're half as$ guessing. The fact that this topic is even about understeer says alot.
All I know is with my custom lowered springs and KONI sports suspension, I can turn corners at any speed I want! :P
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
Obviously you don't know much about SCCA ITS competition, where mods are VERY limited, 240Zs and Z31's compete against each other. The 240Z has proved itself superior in many regions, and it's not due to being more powerful or having better brakes. It OUTHANDLES the Z31. Nowadays 2nd gen Rx-7s and E36 Bmw's dominate the class, but throughout the 90s into the early 00's, the 240Z was THE car to have.
Anybody that knows squat about suspension design knows that semi-trailing arms are a pretty poor solution for IRS. Chapman struts can be driven at the limit much more easily, and when the back end does step out you don't lose NEARLY as much time gathering it back as you do with a semi-trailing arm setup like the Z31. Generally speaking, semi-trailing arms have to be setup to understeer initially to prevent the tendancy for them to increase oversteer once the back end begins to step out from being a huge problem. A good multilink setup is better still, but Chapman struts are generally considered superior to semi-trailing arms.
If you really think you can turn corners at any speed you want, you should try to follow me sometime;)
A:
The 240Z out handles the Z31, I'ld love to see the proven facts. The Z31 would whip arse a 240Z stock for stock in new condition. Lol. You thing Nissan would go backwards in performance, i don't think so.
Being a NZR forum i'll add "try following a GTR skyline :) in your pussy 240Z" makes for a pussy race doesn't it!
A:
Now I suppose I'm inclined to crap on about how slow the 240Z is in comparison, and how much carbs suck, no power steering etc... lol I have friends who have owned both a 240Z and a Z31 and say that the Z31 handles better, stops better, goes faster hands down. So let the flaming begin...
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
You can argue all day about which car is the better platform for the track, but in the Z world that doesn't mean anything.
Generally, our Z-cars are all so modifed that what was stock doesn't matter.
WannaBREz and I got whooped by a VW Rabit diesel pickup truck this year at an autocross. You can argue that a VW Rabit pickup is a bad platform for an autocrosser, but I believe he came in 2nd in SM2.
Doesn't matter if it's a 240Z, 280Z 2+2, 300ZX...whatever. They all kinda suck in stock form, but all of the Z-cars are great starting points for a track car, IMHO.
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1976 Datsun 280Z 2+2:
-'81 L28ET with 1984 Z31 ECCS
-'81 Turbo snowflakes
-205/60/15 BFG G-Force Sports
-Tokico springs and HP shocks
A:
That's what I was trying to get at before, on the general scale of things any Z with aftermarket suspension handles great and would give any car a run for it's money around the twistys whilst still hard on the gas. I dont know why it has to turn into a "my Z is better than yours" arguement that's why I was poking fun at it before.
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
_____________________________________________
'05 350Z Chrome Silver Touring
'73 240Z
A:
Haha, there's a video of a 350Z "trying" to drift and drives into a tree aswell... Even the very latest cars in the wrong hands can go bad, but what the hell a tree was doing on the side of a track I dont know... lol
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
"The 240Z out handles the Z31, I'ld love to see the proven facts. The Z31 would whip arse a 240Z stock for stock in new condition. Lol. You thing Nissan would go backwards in performance, i don't think so."
Believe it or not, between 1970 and 1984, going backwards in performance was what practically every manufacturer did.
"Being a NZR forum i'll add "try following a GTR skyline :) in your ----- 240Z" makes for a ----- race doesn't it!"
I've said it before and I'll say it again: Bring one on and I'll give it a shot! Not saying I'd run with a 500hp+ one, but against a similar or even slightly better power/weight GTR, I wouldn't bet against me.
I'd love to hold hands and sing "kumba-yah" and say all Z's are wonderful and equivalent, but having driven both at the limit on the track, I have to say that on equivalent tires, with equivalent suspension mods (springs/struts/swaybars), the 240Z outhandles the z31. ITS competitors figured that out as well, the 240Z when well-prepared and well-driven is (or was for number of years) a championship-capable platform. The Z31 never was up to snuff in ITS, which is about as straight a fight between the two as you could ask for.
A:
I'm assuming you mean both non turbos that is, which are slow period.
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
Lol mate you wouldn't beat a skyline GT-R LMFAO! and especially when it comes to handling!
97 Nissan Laurel, drift it up! New Zealand.
Post Edited (Oct 7, 6:01pm)
A:
I'm assuming he doesn't realize they're AWD... Oh well, let him dream.
Go drum brakes y0! lol Perfect for the track! *yeah right*
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
vrrooooom
_____________________________________________
'05 350Z Chrome Silver Touring
'73 240Z
A:
*vroooom*
lol
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
that vid's been posted many times.
_____________________________________________
'05 350Z Chrome Silver Touring
'73 240Z
A:
I know, it was just posted again too for good luck...
85' 300ZX NA
86' 300ZX Turbo
88' 300ZX Turbo
89' 300ZX Turbo
300ZX Turbo Project
A:
Bring
It
:)
A:
"Regarding reducing understeer, you'd want to STIFFEN rear roll stiffness and/or SOFTEN front roll stiffness. Loosening or disconnecting the rear bar will INCREASE understeer. So would going with a stiffer front bar."
We did just the opposite per a skip barber instructor on my friends 75. He's all new urethane, illumina's, basic upgrade stuff. 14X7 hoosiers.
Anyway at the last autoX he was pushing all over. This guy came over and said drop the rear bar. We thought he was crazy, but we tried it. He dropped 2 seconds on a 36 second track and had very little if any understeer. With LSD it is opposite and like you said as that is how my car is setup. I broke my LSD and now am back to the open 3.90 and I understeer bad, loosened rear bar now the front bites and it is much easier to control with the throttle.
I don't know maybe were backwerds! At the time I was thinking like you said Dan, but then the times came back, my friend didn't learn to drive that much better between 2 runs.
How many times has it been proven that ZX's of any year do not handle as well as 1st gens - with suspensions on both cars in new condition. Sure a revamped 300 will outhandle a 78 280 with almost 20 year suspension. The semi trailing arm design rides a little smoother and is simpler it was more suited for the GT cruiser than a track car.
Matt
A:
Funny. When I dropped my rear bar (WEAK 3.70 lsd in back btw), the reduction in oversteer (increase in understeer) was DRAMATIC. It felt slower, but was MUCH faster (like 1.5 seconds) around NHIS and Lime Rock. Got better drive out of slower corners as well (less inside wheelspin).
Before losing the rear bar, the car would turn in VERY readily, and then I'd actually have to reduce the torque I applied to the steering wheel as it drifted around corners. It felt like it was self-servosteering through the turns, effort at the wheel was MINIMAL. Pretty neat, and totally controllable, but going around the south oval turn at NHIS (or any other corner) at a ~7degree sideslip angle is apparently not the quickest way around! Now I easily hang with well-prepared Spec Miatae through the corners (eat them up and rocket away on the straights).
In the end, whatever works, WORKS, whether it's "supposed to" or not.
No doubt a Skip Barber instructor knows more about setting up a Z for autoX than I do...
A:
I'm not saying your wrong, I'm just confused. I know you know what your doing and would hope the driving instructor does but the info conflicts. I'm just trying to figure out what's right.
Matt
A:
The GENERAL rule in roadracing is you reduce the roll stiffness at the end where you need grip. This unloads the outside tire at that end of the car, and increases total lateral grip at that end.
The only thing I can figure is that for a stiffly sprung/sway-bar'd car with [edit] little caster [re-edit: or maybe a lot of caster! Little caster would give worse camber of the inside wheel with a lot of steering input, and a lot would act to load the inside tire more.] and a lot of camber and wide tires, on very slow corners where there's a lot of steering input, you might be relatively reducing the load on the outside front and increasing it on the inside front (planting the inside front, lifting the outside front). Since the inside front will be radically cambered the wrong way for the turn, it's not going to contribute its fair share of cornering grip.
I can see how this *might* be a case where INCREASING the amount of lateral weight transfer at the front (stiffer front bar or softer rear bar) might actually increase cornering grip at the front.
Maybe...
Post Edited (Oct 13, 9:26am)
A:
Thank you, that is helpful. I think a good portion of his understeer issues are related to his point and shoot driving style!
Matt