Pooder

Going round a long sweeping rt hander the other day I was accelerating hard in 3rd hit the rev limiter (7000) changed into 4th and the car snaked I thought for a moment I had blown a tyre. It was a pretty scary moment-once in 4th WOT the car recovered
Anyone else had a similar experience
Steve

chrisp

lift off oversteer, a very common trait

Dave T-S

If power on, more likely the front Suretrac diff tightening up - what it's designed to do - but treat it with care! (particularly in the wet).

[Edited by Dave T-S - 7/20/2002 9:08:57 PM]

Pooder

Thanks for your replies----Dave this happened as I pushed the clutch to change gear the car sort of performed two s manoevers.
I have now got used to the initial understeer being controled by more power to bring the nose into line but this was wierd.Never experienced it on any other car
Steve

Dave T-S

I recognise the motion you described further, probably a combination of Chris's answer and mine - by dipping the clutch to change gear you will lose the grip of the front diff, as well as induce lift off oversteer. This is probably the situation an STi7 hates the most - definitely don't try this in the wet!!

What tyre pressures are you running? I find the rear recommended 28 psi a bit soft and are running 32 psi all round.


[Edited by Dave T-S - 7/21/2002 8:27:20 AM]

mutant_matt

I get a very small and controlable version of this at the moment due to the fact that I'm still running mine in and am forced to change gear sometimes when going quickly round say a large roundabout.

You know not to change gear or lift of mid bend right? This is what happens when you do. Try and plan to be in the correct gear to get you all the way round the corner. If you find you've run out of revs, just stop accelerating (stay at the redline) until you've finished the bend and then change gear.

Matt

Big Goon

lol @ matt

Still running in ???

2700 under my belt now

Gotta say, long as you keep your foot planted it goes round corners like a boomerang, awesome handling

T5NYW

iTrader: (4)

Yep also happen to me due to 4500rpm - 7500 rpm pulling range needing to change on bend or hit limiter what's required is more low/mid range Torque The Suretrac diff's really like pulling round twisties

PPP hopefully will help as more usable torque IMHO

Tony

chiark

Don't change gear in mid bend unless you absolutlely have to, and if you have to be smooth with the power feeding off and on.

You're upsetting the weight balance of the car, and as has been said I wonder if the diffs are playing tricks too?

Pooder

Chiark
It felt like the diffs were playing tricks-I take the point raised here about not changing gear mid bend but this is a very long right hander and with the close ratios it is a pity it behaves like this-my MY98 would not have done this just a bit of power off oversteer. Just be careful everyone I want to explore this behaviour further on the track
Steve

X SOOOBY

6 gears and now we are told you shouldn`t change gear mid bend in a sti 7 if that is the case it should say it in the handbook

when i test drove a sti7 it was in the pouring rain i came to this point on a duel carriageway where you could do a safe u turn gave it plenty of welly and woahhh i am going sideways for 25 yards trying to correct it

i didn`t know why it did this but now i know about these suretrack diffs so i understand

so obviously this is not a point and squert car it needs better driver involment

mutant_matt

You should aim to never change gear mid bend, regardless of what car you are driving. It doesn't say so in the manual, presumably because the manual in the main, tells you about the car and not how to drive. Afterall, you wouldn't expect the manual to tell you to only brake in a straight line would you!

As has been said before, the new STi is more of a drivers car than the old shape and requires more driving ability to be safe. The flip side of this is that it is more involving which is what most of us want, that's what it's all about.

Matt

Phil Harrison

Pooder...

Is the "sweeping right hander" in our neck of the woods?? No doubt you've ordered your PPP, so you'll be able to take the whole thing in 4th..... or maybe have to change up to 5th in mid bend!

Phil

Deep Singh

Personally I think that the STi7 offers less wet weather grip than the classic.I d'ont think its fair to dress it up as 'driver invovement needed'.I buy these cars because they are 4wd and expect them to grip.If I wanted tail out action in the wet I would have bought a 911.A little disappointed.....

DJB

Deep

I agree.

I find the STi7 scary in the wet and it does seems to be very prone to understeer with minimal provocation. I strongly suspect that its the tyres. Once I've changed to new Goodyear F1s (I'll wait 'til the present Bridgestones wear out first) I'll then make a proper judgement.

D.

Steve Whitehorn

iTrader: (13)

I have a WRX and as a rule never change gear in mid bend. However there is a very fast sweeping righthander on my way home from work and I often change up from 4th to 5th. The revs are very high in fourth and I am very gentle and quick with the clutch. It is difficult to explain but I almost 'slip' the car into 5th whilst keeping the revs high so not to induce any engine braking. I found this works. Sounds a bit strange I know

Cheers
Steve

Dave T-S

The first time I drove an STi7 I said people would be putting these cars backwards through hedges before long - note this is NOT a criticism of Steve.

It is totally different car to earlier Imprezas, mainly due to the front diff, and can bite back if not driven with respect.

Me? I like the handling - and I enjoy driving it in the wet...

[Edited by Dave T-S - 7/22/2002 8:08:37 PM]

wilf

"More driver involvement" pish. I suppose that makes the plastic pig top of your list of all time great drivers cars then?

Just to add. I agree with Deep Singh. Most people must buy scoobs/EVOs cos they want a car that will handle predictably and can be driven flat out almost anywhere. And yes before you say it I have already done the RWD thing.

If I wanted unpredictable I would have bought a TVR or Z MCoupe.

[Edited by wilf - 7/23/2002 8:20:23 AM]

Pooder

Phil
Yes it is the M23 exit onto the M25 understand you know Graham I let him drive mine last week he was well impressed
Steve

JGRIFF

Deep, sorry to disapoint you fella, but lateral grip has nothing to do with the number of driven wheels, loss of grip is caused by a change, and the degree of change in the transient state. This is how you get lift off oversteer or power on understeer, the "resultant" force is greater than the mechanical grip of the tyres on the road surface. 4WD has two advantages, 1. It masks the change of power by distributing the change to all four wheels, not two as in a FWD or RWD, (or even one in the case of a bike), and 2. Having gone through a corner it will optimise the available propulsive grip to allow the fastest acceleration for the given road surface (hence why WRC cars have 4WD - and are so bloody quick on the loose)
People talk about "wet" and "dry" weather handling, this is a misnomer, what they are actually talking about is the differences in wet and dry grip. Wet surfaces lower the co-efficient of friction the change from "grip" to "no grip" happens at much lower force levels, it is for this reason that the choice of tyre has far more impact on grip than the difference between 2 or 4 driven wheels (just look at the difference that wet or dry tyres make to a Grand Prix car at a wet GP race) As for the Suretrac diff, well that proportions the power across the axle to mask the transient change and optomise the grip.

Never forget that a skid i.e. loss of grip is caused by coarse steering, acceleration, or braking, or in other words the three situations were you alter the forces acting on the car, so that the "resultant" force is greater than the mechanical grip of the tyres on the road.

[Edited by JGRIFF - 7/25/2002 7:33:53 AM]

Phil Harrison

Thanks Pooder. He only gets to drive my Daihatsu Fourtrak, so he would be well impressed!!

Phil

Deep Singh

Jgriff,many thanks for your fascinating lecture on Physics.Thats all just theory and the proof of the pudding as they say... I had a STi 4Type R with 16inch Goodyear F1s.I know have a STi 7 with 18inch Toyos and Leda.I know that my car loses traction much easier than my Sti4(especially in the wet),on the same roundabouts in similar conditions.My driving style has not suddenly undergone a Jekyll and Hyde transformation overnight.Also my STi4 actually had at least 15% more power to contend with(Link etc).
No offence matey but your O level Physics talk does'nt really amount to zip.This is my fourth Scoob and my eleventh car.I think I know when my
car does'nt grip as well in the wet as the last one.Forget the pub talk and drive the car!!!
ps I'm going to change to Goodyears soon but I have a feeling this will not make that much difference.

JGRIFF

Deep, thank you for your polite response, tyres will make the biggest difference. You mention the change to Leda suspension I'm guessing but I assume that your spring rates, bounce, and rebound rates have all gone up ie stiffer. This will have a negative effect on your ability to find traction. But the other big thing is vehicle weight, and I would think that not only did your 4 have more power, but probably weighed less as well, so you are the living example of what I said. I've got Toyo's on mine and I'm quite happy!.

[Edited by JGRIFF - 7/25/2002 8:32:38 PM]

Dave T-S

Deep
Junk the Leda, put the standard STi suspension back on and it will probably be better. And, yes, I have driven on both setups.

Don't have ANY problems with grip in the wet with our STi7's even with crappy old RE040 tyres on

Dave T-S

PS - I think you might find JGriff can deliver driving wise in practice as well as in theory

Deep Singh

JGriff sorry if I sounded impolite.I've had a few beers! I thought the Ledas would compensate for any increase in unsprung weight?
DTS;I wish you had'nt said that,now I'm really confused.I thought the Ledas would have helped not hindered.Also the other guys complaining about the STi's grip are running standard suspension.

jeremy

Deep and others,

Why doesn't someone try replacing the sure-trac with some other more progressive LSD or take if off altogether- after all I never heard any Scooby Driver complain that they needed a LSD? (not the drug by the way)

scoobycar60

I am no expert on whats going on with respect to suspension lsd's etc but I have noted that
1. My new STI feels far more responsive to steering inputs if pushed hard e.g fast right...hard left...hard right again and with almost none of my old MY01 WRX's tendancy to plough on with loads of understeer (easy as it is to control)

2. The point where the power transfer occurs with the front slippers scared me to death the first few times it occured, it really is a spooky feeling but the car is lightenly quick round corners by virtue of this.

Now I of course would never push the car this hard but I "imagine" if I had taken the car to the limit I may have noticed the following

The car can be driven closer to the ultimate limit of the cars tyres adhesion to the road than a standard WRX.
When it does finally let go it is more dramatic than the understeer of the WRX... mine I "imagine" would end up slightly oversteering on the limit although it may feel more like a drift, by this time the tyres I "imagine" are making interesting noises as the grip varies from the front to the back.



Ohh! In the wet I never really try hard, IMHO the drainage on our roads is so bad how the car handles is a lottery depending on how much and where there is standing water on the road, dry patches and oily bits etc.I do suspect you would be more lkely put an STI backwards through a hedge if you went mad in it, loose grip on all 4 wheels and IMHO all scoobies handle like bambi on ice.



[Edited by scoobycar60 - 7/25/2002 11:51:55 PM]

ProperCharlie

As I have never driven an old scoob I can't really comment on this... but I will anyway!

The main characteristic that I've noticed is that when pushing on through quite tight corners I may have to start taking lock off a bit quicker than I might have expected (the front bites in, you are suddenly round the corner). I don't see this as a problem in any way. I like the fact that the car changes its attitude depending on how much power you are putting down - it feels very taught and lets you know what's going on.

As a matter of interest, can anyone tell me roughly how much more the new STi weighs than the old cars?

Cheers,

Charlie.

Dave T-S

Deep
As you may recall we had two MY01 WRX's with Leda on, and did about 15000 miles with them.

When I first drove the STi7 I felt the Leda was superior, and the STi suspension was too soft, with too much body roll. Very early on I decided the other way, the STi suspension is more supple than the Leda and a better all round setup for the road. 7000 miles down the road I am still convinced this is the case. The new Prodrive springs for the STi should make it just about right. If the spring rates of the Leda are the same as the WRX, which I believe they are, then it probably makes the back end a little too softly sprung; and possibly the front too (as you know the STi is about 90kg heavier than the WRX). The instinct would be to probably stiffen the back end up a bit (or both ends) and this will make the car a lot more on tiptoes. Are you running the Leda at 7 clicks or higher either end?

Scoobycar60
I agree. Tuck the STi into a fast corner you know in a neutral to oversteer state, apply throttle, front end tightens, and car fired out of bend like an arrow. VERY satisfying But do it carefully in the wet