) The set-up with no diff is very predictable so inspires confidence
to get the back end out. HTH?
I'm converting my roadgoing bookbuilt chassis to use purely for autotesting. One of the tweeks I'm considering is welding/ locking/spooling
the diff to get more traction without the expense of a LSD. Does anyone have any experience of driving a car with a locked diff, particularly in
autotesting or similar?
Richard
My race car has no differential so is a locked diff. It's an enhanced driving style you will have to learn in effect you need to induce
oversteer and then control it to get round corners. It will feel like you have loads of understeer but that is because the back really pushes through
the front of the car. (not sure that makes sense as it is poorly articulated! ) The set-up with no diff is very predictable so inspires confidence
to get the back end out.
HTH?
quote:
Originally posted by carpmart
My race car has no differential so is a locked diff. It's an enhanced driving style you will have to learn in effect you need to induce oversteer and then control it to get round corners. It will feel like you have loads of understeer but that is because the back really pushes through the front of the car. (not sure that makes sense as it is poorly articulated!
HTH?
I don't think locking the diff actually reduce front grip, it just feels like it does!
I used to race an F2 BRISA Stockcar a gazzillion years ago with a welded diff. I wouldn't think it would be useful in Autotesting as it is less
agile / nimble then a stock diff.
Is it something common they do in Autotesting or are you looking at it as an inovation?
.............. Neil
quote:
Originally posted by Nash
Is it something common they do in Autotesting or are you looking at it as an inovation?
.............. Neil
They're fine in the dry but absolutely useless in the wet and downright dangerous on a wet road.
I would have thought in autotest more time is to be saved in the twisty bits (the whole course?) than 'long fast sections' (do they
exist?) where you wouldn't want to be giving yourself extra understeer. But then if you have the torque to wheel-spin on demand, maybe a welded
diff's a good thing?
Best answer is to just ask this guy what he's using and go for that...
http://www.youtube.com/watch?v=3Rhz19ZrpZg
Autotesting needs tight turning and agility. The exact opposite of what a 'spooled' or locked diff will give you. You need to be able to
turn in easily and quickly, and get drive out of the turns. The locked diff WILL give you attrocious turn in push, and violent power reactions,
especially on the tarmac most of these events are held on.
Innovative? No, not really. It's been done and found severely wanting.
What you need is a very good lsd, set up to your style. Viscous don't do the job for this either.
Cheers,
Nev.
That sounds very sensible advice and from someone who's been there.
Come to think of it that also applies to my other project at the moment. I've stripped my bike engined single seat hillclimber for a winter
overhaul. I discovered it runs an open (fiesta)diff, whereas I was led to believe it was LSD. Your comments about viscous LSDs answers a thought I had
about fitting an Escort RS turbo viscous LSD. The car already tends to understeer and from what you say a viscous diff would probably make the
situation even worse.
Thanks Nev
Richard
[Edited on 27/1/11 by sevaun]
This is worth looking at.
http://www.phantomgrip.com/
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
I have had a play with a pinto Indy with welded diff and it was terrible.
So much understeer (certainly what it felt like from the rear)
I can kick the back end out in my LSD indy and do nut, figure of eight do nut etc, but not a chance with the welded diff, just felt totally
unconnected and horrible.
Would think in the wet or grass would be even worse.
get a 3.62 sierra lsd for less than £300?
quote:
Originally posted by Doctor Derek Doctors
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
All sounds a bit like snake oil to me. No pics of the internals or any real engineering info.
Not having a list of fitments or prices doesn't really help either. A shame as it coul;d be a decent bit of kit.
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
To make use of a welded diff you;d have to be pretty much constantly sideways, opposite lock to opposite lock. You might get that on an Autosolo, but defo not at an Autotest.
terrible idea IMO. ok for drifiting and drag racing i guess, but anything involving corners (without both wheels smoking) it will be pretty hopeless
quote:
Originally posted by daviep
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
Looks like a housing with some strong springs to exert pressure between the planet gears, not going to be very healthy for the thrust washers behind the planet gears.
quote:
Originally posted by Uphill Racer
quote:
Originally posted by daviep
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
Looks like a housing with some strong springs to exert pressure between the planet gears, not going to be very healthy for the thrust washers behind the planet gears.
The springs need only be 'strong' enough to try to provide a rotational force against the spider gears. I love its simplicity and the testimonials look good.
quote:
Originally posted by blakep82
quote:
Originally posted by Uphill Racer
quote:
Originally posted by daviep
quote:
Originally posted by Uphill Racer
This is worth looking at.
http://www.phantomgrip.com/
Looks like a housing with some strong springs to exert pressure between the planet gears, not going to be very healthy for the thrust washers behind the planet gears.
The springs need only be 'strong' enough to try to provide a rotational force against the spider gears. I love its simplicity and the testimonials look good.
i'm sure if i wanted to sell people something that doesn't work, i could write a few good testimonials
well, looking at it, it appears to be a small box containing springs, which pushes against the side gears in an open diff giving some resistance.
have a look at this, its an exploded diagram of a plate type LSD
_gif.jpg)
it also features a plate inside with springs acting on the side gears, but the side gears are forced onto clutch plates which locks the gear against
the diff case.
without those clutch plates, what does it lock the gears onto? onto a thrust washer basically, or an oiled up shim. and if it was that easy, why do
tran-x, quaife and others bother with the plates?
i produced a small magnet which is glued on the side of an axle, pulling the gears out (rather than pushing them like on normal LSD set ups)
here's some testimonials
dave, oxford
i was sceptical on how a system half the price of normal LSDs could work, but i stuck the magnets to the side of sierra diff as shown in the
instructions. all i can say is WOW my cars handling has been completely transformed! on hard acceleration, my car used to just spin the right hand
wheel, but now i can drift my car round roundabouts! its amazing.
keving, doncaster
i fitted this to my skyline in minutes. i couldn't beleive how easy the instructions were to follow. the device was fitted in minutes, without
all the expensive set up normally needed for the usual LSDs. best £200 i've ever spent!
you get the idea... testimonials mean nothing really