MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: GT4thomas on August 1, 2014, 18:58

Title: Under steer ?
Post by: GT4thomas on August 1, 2014, 18:58
I have stock wheels and tyres (sizes) yet i get a fair bit of under steer, and even more so in the wet.

Tyres are pretty old, have plenty of tred but are different makes front and back. at 28/32 psi.

Is this normal ?.
Title: Re: Under steer ?
Post by: AndyM on August 1, 2014, 19:06
Quote from: "GT4thomas"Is this normal ?.

It is common given your current tyre situation but isn't a handling trait of the car when setup properly/has decent tyres on all round. If you get some decent rubber on it I think you'll see it disappear.  s:) :) s:)
Title: Re: Under steer ?
Post by: maybeturbo on August 1, 2014, 20:46
I'll get shot down for this but I don't care it's my feelings.
Though I don't currently own an mr2 I have owned 5 in the past, and driven every type apart from a mk1 sc and my favourite handling set up was when I had my mk3 pfl with yokohama parada spec 2's on the front and some black round tyres on the back (think they were called sport one-cheapos) the balance was perfect, would get a little loose on heavy breaking into bends and transition to composed oversteer so sweet. When I replaced them with good rubber I was really disappointed.  

Now somebody shout at me for advocating cheap tyres.   s:scared: :scared: s:scared:
Title: Re: Under steer ?
Post by: AndyM on August 1, 2014, 21:12
I'm not going to shoot you down. I'd be a hypocrite as I ran a Yokohama/Bridgestone mix for a while when I first had the car and it felt great, however... while mixed tyres may inadvertently end up giving you a great handling car, there is no doubt that it is putting some faith in a lady luck and you could equally end up with something horrible.

Having a set of matched tyres gives you a stable and consistent base to start from. Plus, with mixed tyres when you get into adverse conditions they can act differently and massively unbalance the car, at least with the same on each corner they will generally react the same to a given situation so become more predictable.

Going back to the main topic... I think the 'old' comment is probably the key here, the rubber on the front has probably have gone off.
Title: Re: Under steer ?
Post by: maybeturbo on August 1, 2014, 21:25
Diplomatic way of saying- no that's wrong. Lol.

The tyres are trying to do very different things though, two of them are pushing forwards (ore sideways) and two of em are telling it where it's going.

There's a lot to be said for not having to push to silly levels to get it on the limit too. My old mk2 turbo with about 320 hp and big eagle f1's on the back, when you got on the power through a round about and slid a bit, when it corrected you'd be propelled at your exit at warp speed. Was insanely scary.
Title: Re: Under steer ?
Post by: AndyM on August 1, 2014, 21:38
 s:lol: :lol: s:lol:  I'm just saying that, in my opinion, I wouldn't do it again personally.

I completely agree that the tyres are doing different things, my point is that unless you know the qualities and characteristics of all the major tyres in the market to make an informed choice to match them up then there is the potential for getting it wrong and, in the worst case, making it dangerous.

Also all car manufacturers/race teams/etc use matching tyres makes (even if the compound and sizing is tweaked) and I don't think I know more than them.  s;) ;) s;)

It's all personal preference though, I like having lots of progressive grip for road driving to corner fast (and avoid idiots) and I'm not that bothered about actually getting the rear to break away (although granted it can make roundabouts more fun). If I wanted to drift my way to work I'd probably get myself a Skyline or GT86 though.  s:D :D s:D
Title: Re: Under steer ?
Post by: Anonymous on August 1, 2014, 21:41
I had toyo t1r on standard wheels and it still had a fair amount of under steer, that's how it's designed, for safety.

I've fitted an underbrace, front upper brace and wider front tyres and the transformation is amazing, absolutely no under steer, feels pretty amazing actually
Title: Re: Under steer ?
Post by: maybeturbo on August 1, 2014, 21:52
Oh yeah, completely agree, total pot luck.

I always found the pre face lift under steered a bit if you weren't forcing grip to the front by lifting off and the face lift was just an understeer machine! I know it's probably only geometry changes but felt totally different to me.
Title: Re: Under steer ?
Post by: GT4thomas on August 2, 2014, 06:57
If i approach a t-junction fairly quickly, turn in then accelerate mid corner it will just go straight regardless of lock lol.

But as soon as i lift off the grip is back and the rear snaps into place.

Or it could just be my bad driving lol.

How do to correct if the rear is really out without spinning ?.
Title: Re: Under steer ?
Post by: Wabbitkilla on August 2, 2014, 07:55
Sounds like a combination of things.

1. Old rubber is as bad as cheap and nasty tyres and mixed tyres, you will be mega surprised by the difference new rubber makes.
2. Driving style, if you are used to driving front wheel drive you essentially need to relearn cornering and make note and feel your way around turns.
3. Maybe you are just plain going too fast for the tyres and conditions, again adjust driving style to meet.
4. Might be worth getting a 4wheel geo/alignment check and adjust, these cars really should be checked at least every 2 years.

I have actually experienced the same as you in my early days of ownership, I had driven fwd for years and it took a while to get used to the difference. Coupled with hard and relatively old tyres it taught me to really respect the car and understand the feedback I got from the chassis. Once I got used to it and had new rubber on it was a revelation, hence why I have the same car several years later.
Title: Re: Under steer ?
Post by: steve b on August 2, 2014, 08:03
Quote from: "maybeturbo"Oh yeah, completely agree, total pot luck.

I always found the pre face lift under steered a bit if you weren't forcing grip to the front by lifting off

Lifting off ?  You mean trail braking surely?

As said it only takes a bit of geometry adjustment and a tyre change to banish all understeer.  Unless specifically provoked or appalling driving.
Title: Re: Under steer ?
Post by: GT4thomas on August 2, 2014, 08:57
I'm thinking the tyres are gone on the front. Just really really old.

Once/if I get the car sorted tyres and alignment will be the next job.
Title: Re: Under steer ?
Post by: maybeturbo on August 2, 2014, 09:31
In road driving I meant, not track. Lifting off to encourage better cornering, on say approaching a roundabout. But yeah, trail braking into corners would be similar on track driving.

What is the weight split of these cars?
Title: Re: Under steer ?
Post by: AndyM on August 2, 2014, 09:35
Pretty much 50/50 I believe (if the spare wheel is retained and based on average cabin weight).
Title: Re: Under steer ?
Post by: Wabbitkilla on August 2, 2014, 09:36
Well yes I would just call that proper driving of a rwd car, get your speed down and correct for entering the turn and then smoothly apply the power through the second half of the turn. Depends on conditions and it's hard to describe the formula in writing, it's more about what you feel from the car than specifying rules. But it's hugely different from fwd or awd.
Title: Re: Under steer ?
Post by: Joesson on August 2, 2014, 09:47
My 2 is silver (not red!) So what driving style should I be using?
Title: Re: Under steer ?
Post by: maybeturbo on August 2, 2014, 09:49
For sure. I hate when people exactly describe how and what to do to drive a car properly,   it is 100% about a feel for the car and grip, balance etc. That's why you get great drivers with such different approaches and styles, everybody's different.  
I like a car that's not too stiff and quite loose, find most coil overs even on softest settings to be too stiff on the road and end up upsetting the car more than aiding grip. Good dampers and springs, bushes and some adjustable shiny bits is ideal for me.
Title: Re: Under steer ?
Post by: Wabbitkilla on August 2, 2014, 09:52
Quote from: "Joesson"My 2 is silver (not red!) So what driving style should I be using?
Rwd   s:roll: :roll: s:roll:   dyac!

Corrected   s:wink: :wink: s:wink:
Title: Re: Under steer ?
Post by: Wabbitkilla on August 2, 2014, 09:56
Quote from: "maybeturbo"For sure. I hate when people exactly describe how and what to do to drive a car properly,   it is 100% about a feel for the car and grip, balance etc. That's why you get great drivers with such different approaches and styles, everybody's different.  
I like a car that's not too stiff and quite loose, find most coil overs even on softest settings to be too stiff on the road and end up upsetting the car more than aiding grip. Good dampers and springs, bushes and some adjustable shiny bits is ideal for me.

Absolutely, though I disagree about coilovers and bracing, though I have my coilovers set to the way I like them and the breastplate adds stiffness while still allowing a bit of compliance. The car handles great and suits my driving style well, combination of stiffness, suspension, and tyre makes a big difference.
Title: Re: Under steer ?
Post by: maybeturbo on August 2, 2014, 10:04
My point exactly. Everyone's style and feel is different. Eg, two teammates of an f1 team with identical cars and nothing between lap times will often have totally different set ups. I guess truly great drivers are able to make the most of anything.
For me a car that's too stiff I usually end up spinning out, a bit of flex gives you a fraction more warning of what's about to happen, like a lamppost in your lap, maybe I have slow reactions?!
Title: Re: Under steer ?
Post by: maybeturbo on August 2, 2014, 10:06
Having said that I havnt driven a mk3 with any bracing, only heard/read great things.
Title: Re: Under steer ?
Post by: FGrob on August 2, 2014, 11:04
Coilovers (coil spring over shock) - also sometimes called a Macpherson strut, which is not the same as a shock and spring (meaning they are not mounted together) I'm sure my 3 came with coil overs as new from the factory - none adjustable of course.

As for setting - it's really down to the individual and driving skill, one mans track / road beast is another mans ring stinger, plus it also depends how much cash you want to throw at it, this discussion is no different to anything that was said 8 years ago and probably in another 8 years to come - people only hear what they want and always think they know best.
Title: Re: Under steer ?
Post by: maybeturbo on August 2, 2014, 12:13
There's always one, that's forums..... alright, what i was getting at was that any aftermarket coil over I've used,  I have found comes with springs too hard for road use and the damping rates are too stiff even at the soft end as most aftermarket coilovers are aimed at track use no potholes and speed bumps and drain covers etc to upset the car.
Sorry for not making my opinion clearer.
Title: Re: Under steer ?
Post by: Wabbitkilla on August 2, 2014, 13:30
One of the best advantages pf sport coilovers is the rebound damping which you don't get in standard type dampers.
Title: Re: Under steer ?
Post by: Bernie on August 2, 2014, 14:56
I have Robs 2 with the set up below and run it at a softer setting and yes it's a firm ride but it's perfect for my driving style and not at all uncomfortable very planted and corners on rails


Been mentioned in another post but well worth reading Porsche high performance driving handbook by Vic Elford some great tips and insight into RWD techniques

Suspension

Tein MonoFlex Coilovers plus EDFC controller. (30mm drop)
Megan racing rear adjustable Tie bars C/W pillow ball ends (Camber, Toe and caster)
Standard front and rear Anti roll bars – nylon coated
Super Pro up-rated anti roll bar mountings
Twos R Us Heavy Duty front and rear Drop links

Chassis

Standard 04 front and rear bracing
TTE centre cross brace
Cusco Front Top tower brace
C-One Rear Top tower brace


Back to the OP second the previous opinions good rubber at correct pressures and4 wheel alignment are a good start point
Title: Re: Under steer ?
Post by: james_gt3rs on August 6, 2014, 13:47
The MR2's weight distribution definitely isn't 50/50, remember it's almost a rear engined car! It's somewhere between 45/55 and 40/60. And given that it's also light this means that it will understeer if you don't trail brake. Once that clicks though it's got a super front end, and really adjustable!
Title: Re: Under steer ?
Post by: lamcote on August 6, 2014, 15:22
At the risk of starting another argument, a car with more of its weight at the back will naturally tend to oversteer not understeer. Obviously this basic natural balance will be affected by tyre sizes, wheel geometry settings and driver inputs but for any given tyre, more static vehicle weight equals less cornering capability. ie a car with a rearward weight balance will tend towards oversteer and one with a heavier nose will naturally understeer.
Title: Re: Under steer ?
Post by: maybeturbo on August 6, 2014, 21:53
True, but like a lot of cars it's safer to make it have a tendency to understeer than oversteer and end up side on into a lamppost.
Title: Re: Under steer ?
Post by: Alex Knight on August 7, 2014, 09:39
Quote from: "maybeturbo"True, but like a lot of cars it's safer to make it have a tendency to understeer than oversteer and end up side on into a lamppost.

This may be true for mainstream econo-boxes that most people drive, however sports cars don't tend to have this characteristic engineered into them.

And you can still understeer into a lamppost...
Title: Re: Under steer ?
Post by: maybeturbo on August 8, 2014, 18:44
Oh, come on! It's hardly a dedicated sports car. Like most cars, it's handling is well on the safe side.  it's a usual toyota parts bin special, like most toyotas. Don't get me wrong, I think it's a great car, but as always toyota were more concerned with the profit than the product. It's got yaris brakes hasn't it? And wheel bearings? And an avensis engine! Good diff though, they got that bit very right. It's not unusual, toyota have always made cars that way, they are the sneakiness manufacturer by far. I kind of like that about them, and it allows you to make Frankenstein engines and stuff, which is cool.
Title: Re: Under steer ?
Post by: FGrob on August 9, 2014, 10:47
Quote from: "maybeturbo"Oh, come on! It's hardly a dedicated sports car.
Hmmmm - so what do you call a dedicated sports car

Do you own a MR2 yet??? - If so why ??? - if it's not a dedicated sports car.
Title: Re: Under steer ?
Post by: MartinC on August 9, 2014, 10:52
 m http://www.oxforddictionaries.com/defin ... sports-car (http://www.oxforddictionaries.com/definition/english/sports-car) m

I think this definition sums up an MR2 quite well.
Title: Re: Under steer ?
Post by: maybeturbo on August 9, 2014, 20:30
I've owned 4 propper on the road mr2's, had a few sheds too. don't be so sensitive. I'm a big toyota fan. I'm looking for an mr2 now and will buy one and turbo it. I've owned a supra tt uk manual 6spd 440hp, a mk2 turbo, couple of mk1's, and some less inspiring models. I've still got an ae86 corolla, I'm a BIG toyota fan, but let's be honest, the mk3 is pretty compromised in standard form, it's a great start but needed to be lower, sleeker, about 50hp more than it had etc. just the fact that it had an engine with an 'fe' head shows they dropped the ball, do you know what that means? I'm a big fan, but a realist.   s:D :D s:D
Title: Re: Under steer ?
Post by: Alex Knight on August 10, 2014, 15:25
Engine aside, the chassis is fantastic.

If that doesn't make it a proper sports car, I don't know what does.
Title: Re: Under steer ?
Post by: Wabbitkilla on August 10, 2014, 15:42
Beats me why you're here if you have such a low opinion of the car, you always seem to be looking for something to slate it. There are many sportscars with "humble" engines. Many of them made by Lotus, in the past the Coventry Climax was staple for British sportscars and that came from the most humble origins.

The 1zz has great character, and can be improved in straightforward ways. There's not many engines you can strap a turbo onto and add 100bhp without needing to rebuild with uprated parts.

The roadster concept is typically a car that is sporty and easy to live with. The MR2 fulfills that superbly in standard form. You can easily shift its focus to more strongly sportscar by sacrificing on some of the compromises that make it easy to live with. It's personal preference which sacrifices you ate comfortable making. Be assured though it is a sportscar, the whole mid engine rwd setup with decent chassis proves it.
Title: Re: Under steer ?
Post by: maybeturbo on August 10, 2014, 18:43
Wow! What has got you guys so worked up over what I've said? It's all true! I'm not knocking the car, just having a chat about what it could/should have been. Take the mk1 mr2, 4age engine, suited to the car etc and really built, I think they can handle about 9k standard, and they take boost better than a these motors, and there was an f.i version, 4agze, when toyota could really build engines, I think they can go 300hp plus on a standard block, ceramic, forged pistons standard. Then there's the mk2, yes the 3sge was ok, but the 3sgte was awesome, he'll of a combination. If toyota were doing it propperly like they used to the mk3 would have had the 2zz, and if they were really doing it propperly the 2zz wouldn't be getting switched out for honda equivalents! Hondas a great example, when they built the s2000 they didn't adapt the civics engine, they started from scratch and made a masterpiece with serious race stuff in it and amazingly reliable.
Let the abuse of me commence!!!! Lol.
Sorry if I've offended anyone but it's an open forum and right or wrong these are my opinions and I'll stick with 'em, thanks.

Chassis is fantastic, as is the diff and a great job on the stock suspension, great round bends and on bumps, not an easy task.
Biggest let downs are flimsy trim and lack of power.
Title: Re: Under steer ?
Post by: tomaky on August 10, 2014, 18:55
By any chance is your car a pre fl? The FL does have better trim generally and alot can be put on your pre (if you have a pre).
Title: Re: Under steer ?
Post by: FGrob on August 10, 2014, 19:40
Quote from: "tomaky"By any chance is your car a pre fl? The FL does have better trim generally and alot can be put on your pre (if you have a pre).
I think you will find he's only got a manifold - unless he's brought one over the weekend to replace his AE86 or Yaris - I'm not sure which.
Title: Re: Under steer ?
Post by: Alex Knight on August 10, 2014, 21:47
Quote from: "maybeturbo"Chassis is fantastic, as is the diff and a great job on the stock suspension, great round bends and on bumps, not an easy task.
Biggest let downs are flimsy trim and lack of power.

Exactly why I fitted a 2ZZ. Completes the car for me.
Title: Re: Under steer ?
Post by: tomaky on August 10, 2014, 21:52
I think you may be right with the 2zz i think 90% the mr2 1zz na population including myself would atleast like to try a 2zz that being said through the corners sometimes more power might not be so good, when going really pushing it through twisties i often think i dont need anymore power.
Title: Re: Under steer ?
Post by: loadswine on August 10, 2014, 23:39
You are probably right Tom. I have had various turbos over the years, but on twisty roads that extra power doesn't make a vast difference to progress made. That is all in the chassis and balance. I actually like a fairly standard car and the v6 conversions most, as they allow you to enjoy more of the car more of the time. Turbos are fun too, but often mean quite high speeds to feel their benefit. Of course its a sports car! Moreso than its previous incarnation. Imho.
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 09:31
If you'll notice, my username is now backwards, used to be 'maybeturbo' but it would seem that my membership level was changed to not allow me to post or read messages etc, please don't tell me that somebody was that pathetic after sharing my opinions?
And 'fgrob' why would I lie about what vehicles I've had or have? Like I've said a few times I'm a big Toyota fan, I've only owned two other cars, both s-body Nissan.  If you want to pop round and check them out feel free mate.
I'm really surprised at how petty some people have been on here.
Back to the topic, yeah, the mk2 did get away from the spirit of the mr2 a bit but the turbo was a beast. The NA was a bit 'meh'
I'm sure the V6 are great and that 3.5 they have in the states is a bit of a monster motor! But I like the idea of keeping fuel economy too with a turbo.

Can an admin please reinstate my original account 'maybeturbo' I would like to access a private message I received.
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 09:34
Seems a bit harsh that the account has been locked. I would have thought you are at least owed an explanation.
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 09:39
Tell me about it. Toys and prams etc........
Title: Re: Under steer ?
Post by: AndyM on August 11, 2014, 10:13
[MOD]maybeturbo, your account hasn't been locked/banned. We're having a bit of technical issue with the user groups at the moment which is causing some access issues for newer users, apologies for the hassle. The admin's are looking into it and will resolve it as soon as they can at which point this duplicate account will be removed and your original account will be fine to use.
Title: Re: Under steer ?
Post by: tomaky on August 11, 2014, 10:21
All is well afterall  s:) :) s:)
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 10:26
Ok.  Many thanks.
Title: Re: Under steer ?
Post by: FGrob on August 11, 2014, 10:27
Quote from: "Obrutebyam"And 'fgrob' why would I lie about what vehicles I've had or have? Like I've said a few times I'm a big Toyota fan, I've only owned two other cars, both s-body Nissan.
No one stated you were telling lies just you had not purchased an MR2 yet, which then raises the issue of why make negative comments if you have not owned one yet.

I assume the above means most of your cars owned were Toyota with only two others being Nissan's.???
Title: Re: Under steer ?
Post by: tomaky on August 11, 2014, 10:35
Hence the term "Dont knock until you have tried it"
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 10:40
Quote from: "FGrob"
Quote from: "tomaky"By any chance is your car a pre fl? The FL does have better trim generally and alot can be put on your pre (if you have a pre).
I think you will find he's only got a manifold - unless he's brought one over the weekend to replace his AE86 or Yaris - I'm not sure which.


That's a dig mate, no way round it.
Title: Re: Under steer ?
Post by: Anonymous on August 11, 2014, 10:44
And yeah, that's what I mean. A Nissan s14 with about 29th,  lovely and a ps13 with about 340hp which is basically suicide on wheels!   s:shock: :shock: s:shock:  

But of mk3 mr2's I've had both types and prefer the earlier car with 5 spd.  That's what I'm currently shopping for.
Title: Re: Under steer ?
Post by: nathanMR2 on August 11, 2014, 11:08
MOD - I have reinstated account Maybeturbo. I did PM you this morning as i anticipated you might be having problems. I've deleted your account Obrutebyam but retained your posts.

We are still looking into the technical issue but your original account should be ok going forward
Title: Re: Under steer ?
Post by: FGrob on August 11, 2014, 11:52
Quote from: "Obrutebyam"And yeah, that's what I mean. A Nissan s14 with about 29th,  lovely and a ps13 with about 340hp which is basically suicide on wheels!   s:shock: :shock: s:shock:  

But of mk3 mr2's I've had both types and prefer the earlier car with 5 spd.  That's what I'm currently shopping for.
Might be worth you doing an introduction in the newbie section - you can then go through all the cars you have owned which will clear up any confusion you have given.
Title: Re: Under steer ?
Post by: maybeturbo on August 11, 2014, 12:40
Fgrob,  you seem to have some issues, it'd no good for you keeping it all inside. I'm a good listener if you ever want to get it out, come on, share with us- why are you so angry?
Title: Re: Under steer ?
Post by: FGrob on August 11, 2014, 12:57
Jesus Man - just do an introduction then people will trust you more (I'm not just talking about me either) Over the past 8 years there have been many different members join this forum with certain comments which just make you wonder if they are for real.

There are more important matters to be angry with than a car forum.
Title: Re: Under steer ?
Post by: nathanMR2 on August 11, 2014, 13:04
MOD - come on guys simmer down and lets get the thread back on topic please. I've already had a traumatic day without having to deal with hand bags.

Maybeturbo - you must understand you are on a dedicated MR2 Roadster forum so people around here are understandably precious about the car. Slate the it and your going to find people are going to get on the defensive with you.
Title: Re: Under steer ?
Post by: maybeturbo on August 11, 2014, 13:14
Really wasn't slating the 2. I like it a lot.  Just joining in a discussion and getting sniped for innocent comments made about the car/manufacturer. I even said at one point "sorry if I've offended anyone" can't believe the hostility from some.
Title: Re: Under steer ?
Post by: nathanMR2 on August 11, 2014, 14:14
MOD - chat moved over to chit chat under the heading BarryBoys