ed_crouch
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| posted on 27/2/04 at 12:52 PM |
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Locost wheelspin
What are locosts like for wheelspin?? I mention this because they have half of naff all weight over the rear wheels, and hence surely have little or
no grip on the rear??
Ed.
I-iii-iii-iii-ts ME!
Hurrah.
www.wings-and-wheels.net
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theconrodkid
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| posted on 27/2/04 at 01:15 PM |
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erm not a lot of fun in the wet
who cares who wins
pass the pork pies
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Jon Ison
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| posted on 27/2/04 at 01:22 PM |
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wheel spin is directly proportional to how heavy your right foot is at any given time, in other words, yup the wheels can be made to spin, thats 1/2
the fun, your driving somthing that needs driving and driver input rather than point and go...
seat of the pants tells the driver everything he needs to know.
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ned
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| posted on 27/2/04 at 01:24 PM |
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on an irs car you'll also get a bit of torque reaction on the dif, meaning the rear right should go before the rear left does! hicost's
car had a lot of wheelspin on 0-80 (private road obviously officer) when he took me for a ride. stevem's live axle car also wheelspun at
brooklands (live axle 1600xflow on loose concrete)
Ned.
Ned.
beware, I've got yellow skin
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locoboy
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| posted on 27/2/04 at 02:41 PM |
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kind of opposite to wheelspin is engine braking - making you lock up the rear wheels.
i came round a slight bend to a roundabout (know the road well) and was pasting it in 3rd, then braked and then hooked 2nd whilst still going a little
to fast, foot off clutch and facing the wrong way!
It just locked up the rear wheels as if doing a handbrake turn, that was a dry road too, anyone else experienced this magnitude of angine braking?
I know my dad had a jeep cherokee 2.5TD that was a bastard for doing that, again on dry roads too.
ATB
Locoboy
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ned
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| posted on 27/2/04 at 02:47 PM |
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I did something similar once in my old triumh toledo in the dark on a damp road at a t junction. i hoofed it round and ended up facing completely the
wrong way out of the juction as opposed to turning into it!
I also managed ot drag the rear quarter panel of a saxo i once owned through a hedge from simlar circumstances.
Ned.
beware, I've got yellow skin
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Bob C
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| posted on 27/2/04 at 03:14 PM |
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I'm looking forward to seeing how a IRS BEC with LSD behaves... I expect the BEC to be rear heavy & not a lot of weight transfer due to
acceleration with low CofG and I'm going for quite a high geared diff. My last project was rover V8 in a mazda mx5 - this now has a 4.6 in -
& I was concerned that wheelspin & general tail happy lunacy might be a problem - but no, paradoxically it's much better behaved than it
was as a 1.6, traction is phenomenal. Obviously you can lose it if you try hard enough but I generally try not to do that on the queens highway (not
too often anyway...) That has IRS and LSD & the chassis is a bit better than stock 'cos I put an extra wee triangulated subframe to close
the bottom of the transmission tunnel.
Bob C
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blueshift
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| posted on 27/2/04 at 03:23 PM |
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I know that live axles get torque reaction and one wheel going before the other.. there are trailing arm mods in my suspension book to correct it and
give you better straight-line traction than an LSD.
I didn't know IRS suffered from it as well.. Are you sure? I can't quite see how that would work.. have to think about it.
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mackie
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| posted on 27/2/04 at 04:02 PM |
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I went to Silverstone to drive an Elise round and it was very very wet indeed. They couldn't stress enough about taking your time with
downshifting under braking. It helps a bit that they are mid engined but only up to a point since there's more mass that wants to come swinging
round.
Really nice car though Only had it sideways once 
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GO
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| posted on 27/2/04 at 04:16 PM |
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Heel and toe, Heel and toe, Heel and toe, Heel and toe, Heel and toe, Heel and toe, Heel and toe...
lets sing along together,
Heel and toe, Heel and toe, ...
love it.
once you've practised it enough and got it right, you can use it to prevent the driven wheels locking up under engine braking. The idea is to
pick the revs up to match the new gear youre selecting, thus preventing the huge engine braking effect.
I find myself doing almost every gear change now! Bit of a waste of effort most of the time but practise makes perfect and I always make sure of it
when, whats the word, "hacking" it along the lanes, oh and empty roundabouts.
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mackie
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| posted on 27/2/04 at 04:49 PM |
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I can't physically do it in my current car, hopefully the Puma is better 
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locoboy
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| posted on 27/2/04 at 05:30 PM |
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right can someone explain this heel and toe thingy to me, i have heard it plenty of times but not sure about it really 
ATB
Locoboy
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andyps
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| posted on 27/2/04 at 06:51 PM |
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Heel and toe is a bit of an exaggeration - basically you use your toes on the brake to be slowing the car down, and the heel to "blip" the
throttle to get the revs up to the right level for the lower gear being selected. Hence, when you release the clutch there is no engine braking
because the engine is at the right speed. Exaggeration because it is typically ball of the foot on the brake and side on the throttle.
Ideally combined with double de-clutching for the smoothest gearchange and least wear on components. That means releasing the clutch when in neutral
during the change, blipping the throttle then, then down with the clutch again and into the lower gear. This makes sure the gearbox shafts are
spinning at the right pace as well as the engine.
Probably clear as mud that I should think!!
[Edited on 27/2/04 by andyps]
Andy
An expert is someone who knows more and more about less and less
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Mark Allanson
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| posted on 27/2/04 at 07:21 PM |
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andyps, really good explanation, but I have never driven a car where I could use my heel. I usually brake with most of my right foot and the trottle
pedal is sufficiently close to the brake to blip the throttle with the outside of my foot. Italian cars seem best set up for this. I copied the pedal
spacing of a X19 with my sierra pedals, to make sure it was as intuitive as the marvelous if decaying X19
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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JoelP
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| posted on 27/2/04 at 07:35 PM |
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i worked it out myself, unfortunately the wrong way round though! so i brake with my heel and tap the throttle with my toes. i actually set the pedals
up like this on the locost so i best not try doing it the proper way!
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blueshift
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| posted on 29/2/04 at 03:11 AM |
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I brake with the heel and blip with the toes too, on my primera.. other way round didn't seem to work for me.
then again, I'm not very good at it anyway.. but I am ok at just blipping without braking, makes for smoother shift-downs and less bothering my
clutch (which is on the way out anyway)
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craig1410
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| posted on 29/2/04 at 08:15 PM |
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Guys,
I'm building my pedal box at present and would appreciate any advice on the best placement of pedals. I have size 10 feet (quite narrow too) so
hopefully some of you out there will be similar.
What is the best spacing between pedal centre's and how do I set my throttle pedal up best for heel and toe? I'm hoping to just use the
Sierra pedals with various mods to straighten them out. On that subject, I was following your recommendations (Mark A) on Sierra pedal mods but it
appears that my Sierra master cylinder is of a different design to the one you are using and I can't get all the holes to line up between the
pedal box and the master cylinder mounts. My master cylinder is the one with the Ford logo on it and three outlets. It also has the numbers 22 on the
side. I think it is a bendix type going by brakepart's website.
Should I try to get a different m/cyl or do you have any other suggestions?
Cheers,
Craig.
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Mark Allanson
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| posted on 29/2/04 at 09:43 PM |
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It seems that I heel & toe differently to anyone else, so pedal spacing must be to personal preference. I brake with the ball part of my foot at
the base of the big toe, and rock my foot to the right to blip the throttle with my little toe. I cannot image braking with my heel and dabbing the
throttle with my toes, my shoe laces would get tangled in the steering column!
Sorry to hear about your master cylinder, if you took your pedal box to the scrappies (show the rottweiller on the way in!), and match up a master
cylinder from a sierra, I think that most have the same cylinder as mine (89 2.0i). The setup I have used does save a hell of a lot of f@cking about,
and special expensive M/C's
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
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craig1410
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| posted on 29/2/04 at 10:08 PM |
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Mark,
Thanks for that and for what it's worth I think your heel and toe technique is "normal". I have watched Tony Pond on the "TT
Challenge" video and also footage of F1 drivers and Colin McRae and they all seem to brake with the ball of their foot and sort of clumsily dab
the throttle with the side of the foot and perhaps the side of the heel. I can't see how it can be done with the heel on the brake and toe on
the throttle unless you have double jointed ankles! I can't make my toe come up far enough!
As for the m/cyl, I have got two now from randomly selected 1989-1990 sierra's and both were the same type as described. At least I now know
what to look for next time. In the meantime I will look into simple welding a thick plate onto the front of the pedal box to mount both the brake and
Rover SD1 clutch master cyls onto. This may well be a good route anyway as I'm not using the cable clutch mechanism and will need a plate for
the clutch m/cyl anyway.
Cheers,
Craig.
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andyps
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| posted on 29/2/04 at 10:35 PM |
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I had a go at heel and toeing using the heel on the brake and toe on the accelerator today - I reckon you must need strange jointing in ankles for
that to work
I'm going to stick with toe/ball of foot on brake, heel on accelerator thanks!
Andy
An expert is someone who knows more and more about less and less
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Simon
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| posted on 29/2/04 at 10:56 PM |
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Craig,
I don't know if you saw my reply to "fully welded seat belt mounting" but, I've popped a few more pics in the archive,
including my pdeal box.
I've reordered the spacing of the washers and spacer, which now go:
1. Spring clip
2. Washer
3. Clutch pedal
4. Spring
5. Frame of box
6. Large Bush
7. Brake pedal
8. Large Bush
9. Spring Clip
10. Small bush
11. Outer frame of box
Throttle pedal separate
Gap betweeen pedal rubbers and footwell walls
Inner wall to clutch pedal - 35mm
Clutch pedal to Brake - 71mm
Brake pedal to throttle pedal - 71mm
Throttle to outer wall 11mm
HTH
ATB
Simon
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craig1410
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| posted on 1/3/04 at 01:04 AM |
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Simon,
Thanks for that, I'll take another look at it tomorrow night and see if I can apply any of that to my car. Obviously you have gone for the
reverse assembly whereas I think I have enough room for the traditional assembly so I'm not sure what differences this will produce.
Do you find the spacing to be "comfortable" and are the dimensions from centre to centre or between closest points?
I'm not long in from the garage and I've decided to just weld the pedal box onto a 4mm thick piece of steel plate which will be bolted or
welded onto the top inside vertex of the tube just above my steering column lower support bush. I'll also support the sierra pedal box at the
upper slotted mount using some sort of bracket.
I've measured my "ideal" pedal rubber centre point to be 7" off the floor and this translates into 18" from floor to
centre of pedal pivot. This also takes account of the required slope of the master cylinder which I worked out to be 12 degrees upwards (from mounting
face to the end of the m/cyl)
Sorry if this has taken the thread off topic a bit...
Cheers,
Craig.
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locoboy
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| posted on 1/3/04 at 09:08 AM |
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just a quicky,
Simon, where did you get the clutch master cylinder from and can you give me an idea on price please.
Many thanks
ATB
Locoboy
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Simon
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| posted on 1/3/04 at 08:17 PM |
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Craig,
The distances I quoted were for the spaces between pedal rubbers or pedal rubber to inside footwell walll. As for comfort, seems to be ok. If anything
pedals could do with being a little higher, but I don't won't to lose any "leverage" by shortening them.
Colin,
Got clutch m/c from Raldes - Part no RD3620 (0.70" bore) - £28.50 +del/VAT.
FYI
RD3619 = 0.625" Bore
RD3621 = 0.750"
RD3632 = 0.813"
All intregal reservoir
Non intergal also available.
I'm not sure I've got he right one though (need to investigate clutch before I comment further!)
ATB
Simon
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craig1410
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| posted on 2/3/04 at 12:21 AM |
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Simon,
Thanks for the dimensions and other information, it should come in handy in the next few days.
Here is a picture of what I am trying to build. There are another 6 or 7 pictures on my website from different angles. Check out my March Diary for
details. The plate at the back is 4mm thick mild steel inclined at 12 degrees from the vertical (to suit the master cylinder reservior) and I am using
self tappers to secure the Sierra pedal box to it while I evaluate the positioning. Once I am happy with the positioning I can weld the sierra pedal
box to the 4mm plate which will itself be held in place by bolting it to a couple of 5mm thick brackets. I will then build a bracket to secure the
upper mount which is important to prevent the pedal box from twisting under load.
Finally I will drill a large (41mm) hole for the brake master cylinder and another for the clutch m/cyl.
Comments very welcome!
Cheers,
Craig.
[Edited on 2/3/2004 by craig1410]
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