UK-POLOS.NET - THE VW Polo Forum

Mk2 - All uk spec mk2s had carburettors. Some euro mk2 GTs had fuel injection. All Mk2 G40s have fuel injection, essentially same as mk3 G40

mk3 All fuel injection in one form or another; 5 petrol engines
1043 cc single point injection, 45bhp code: AAU
1272 cc single point injection, 55bhp code: AAV
1272 cc multi point injection, 55bhp code: NZ
1272 cc multi point injection, 75bhp code: 3F
1272 cc multi point injection, supercharged, 113bhp code: PY

And then theres mine:

1390 cc multipoint injection, 80bhp (estimated with standard everything)

Ive got pretty much all the gear ratio data myself tahrey, thats why I can talk to you about all this in such detail! All the mk2 stuff is in the haynes manual which covers all the mk3 45 and 55hp injection engine gearboxes as well and mark hunter posted a big excel spreadsheet with all the mk3 1.3 Litre 5 speed boxes.

Unfortunatelly the transmission casing is too small to fit an extra gear in. As I said before Mark hunter did that gear ratio spreadsheet; this was beacuse he was going to put the 8P 5th in his G40 box which would give him a mega High 5th instead of the standard G40 5th (he couldnt add it to the current one to make it 6). Its quite a difficult task stripping down a gearbox and its not something I fancy doing myself. I will see how my GT gearbox works with this 1400. I get the feeling that it will be ok in town but get shocking fuel economy on the motorway, especially when I fit one of alan lawerences chips to it. Apparently, theres a big kick at 4000rpm which would be at 73mph on a GT box (cruising speed) This would be bad as fuelling would increase dramatically I should imagine. With an 8P box I wont reach 4000 rpm untill about 84mph Which is much better from an economy point of view.

Have you got a 5 speed box then? A 1.0 5 speed box has the same ratios as a GT but with a higher final drive. (some versions have slightly different 4th and 5ths but all other gears are the same) Same goes for the 4 speeds, same ratios on 1.0/1.3, but different final drives. If you want all the data ive got i can email it you. You seem to like talkinga bout gearboxes!

Gareth_GT_Hatch wrote: 1390 cc multipoint injection, 80bhp (estimated with standard everything)

Hehe... what's that.. a rebore, a swap, or some rare euro edition?

Ive got pretty much all the gear ratio data myself tahrey, thats why I can talk to you about all this in such detail! All the mk2 stuff is in the haynes manual which covers all the mk3 45 and 55hp injection engine gearboxes as well

Sunuva.....

and mark hunter posted a big excel spreadsheet with all the mk3 1.3 Litre 5 speed boxes.

....biotch.

Well I can track down a Mk2 haynes easy enough, but where's that other excel sheet? If I'd known I could have clawed back a few precious hours not having to research and make my own

Unfortunatelly the transmission casing is too small to fit an extra gear in.

I'll MAKE it fit
(the 5 sp seems to be a 4sp with different mounting holes and an extended oil cover-plate after all.. why not just extend it even further? )

Mark hunter did that gear ratio spreadsheet; this was beacuse he was going to put the 8P 5th in his G40 box which would give him a mega high 5th instead of the standard (he couldnt add it to the current one to make it 6).

Yow, seeing as it looks like the G40 already has the highest 5th gear of the lot (including diesels) (22.5/k - GT box with a very different final), that would be quite excessively high and something of a jump from 4th!
(looks like 4th there more or less = mine at 17.5 ish... his new 5th would be about 26/k... or similar to/bigger than the gap between 2nd and 3rd).

Be very, very relaxed though, and i've no doubt the engine could handle it. (that's 80 at a touch over 3000rpm... be just seeing the torque peak at 90!)

I get the feeling that it will be ok in town but get shocking fuel economy on the motorway, especially when I fit one of alan lawerences chips to it. Apparently, theres a big kick at 4000rpm which would be at 73mph on a GT box (cruising speed)

You'll just have to stay legal then!
If prices keep on the up and up we'll all be having to stick to 60 anyway. (right now i'm sticking to 60 KMH on the way home to balance out what is often a furious dash to work... see if i can beat 40mpg average between 4-5 thousand all the way there, and no more than 2000 all the way back)

With an 8P box I wont reach 4000 rpm untill about 84mph Which is much better from an economy point of view.

As well as just improving it generally by spinning the engine slower and keeping you closer to "torque" than "power" at high speed (assuming yours has more of an 8v characteristic than a 16v)...
something i reckon many people don't consider is the intertia and friction generated by the engine itself... but you've got at least (three?) four reasonably large bits of metal having to fly one direction then the other fifty or more times per second.. the more often they have to change direction, the more energy the engine saps for the same road speed (plus there's the thing of there being a maximum amount of fuel it can use per sec governed by the rpm anyway). And you've surely felt the engine braking effect downhill.
(i found last night, experimenting, that on one part of the route home, i can be engine-off in neutral and maintain a constant 35-40 speed for something more than a half mile, whereas in 4th i'd need slight throttle to prevent it gradually slowing... every little helps!*)

Have you got a 5 speed box then?

Nope. I was in possession of a damaged one for a short while, but that had to go back, and I only just got the damn refund off it - 3 and a half weeks and countless phonecalls later. Measuring time from the point when their courier picked it up, NOT from when the garage FINALLY received it and noted that it was knackered (more like 6 weeks overall).

Don't suppose in that excel sheet there's any data on an "SET" code gearbox is there? It's the closest thing to a type code I could find on it... it was supposedly an 8P when they sent it!
(mind you, I can't find *anything* on my current one, but that may be for lack of line-of-sight)

A 1.0 5 speed box has the same ratios as a GT but with a higher final drive. (some versions have slightly different 4th and 5ths but all other gears are the same).

Yup... some are exact GT by the look of it, others (hopefully "most") are GT with a diff that gives them slightly higher revs, so 5th is almost identical to my 4th. Which aint so bad I guess, but I'd feel cheated to get a non-sporty "5 speed" car that revved so high in top.
And then there's the 1-Litre only ones that have dropped upper ratios to make 5th similar to my top without changing the diff - or even lower (like mk2 4th) with the tweaked one. It's a little disappointing when you suddenly realise that maybe Gran Turismo 2 got it right.
(which means i'm going to have to borrow a Cinq Sporting at some point and see if it really does hit the rev limiter at 95mph downhill in 5th)

Same goes for the 4 speeds, same ratios on 1.0/1.3, but different final drives.

mmmm.... depends.... unless my speedo is VERY whacked, i think i've got the same as a 1.3 CL 4-sp haynes says I could have that, or one with a "lower" diff... 17.5m/k or 16.8... it seems more like 17.5...

If you want all the data ive got i can email it you. You seem to like talkinga bout gearboxes!

Eh, mostly because it's a sticky point

First time noticing, driving mums punto, not being too happy that it was turning a noisy 4500 at my chosen cruising speed of 85.... then seeing that turn to a touch under 4000 when the box went PHUT and a make-do replacement was put on. Much nicer (oddly, how i remember it, that one was almost a dead-straight ringer for the 8P!)

Then introduced to GT2 on the playstation.. finding that several of the cars I liked had plain awful gearing, saving up for the custom gearboxes and playing with them to get a better experience (i kick ass on the test track and mountain-style races ).. though it's something I've only got really proficient with in the last few months, coming back to the game with an offical english version instead of a japanese pirate disc, and knowing somewhat more about power/torque curves (damn you, GT3) than I *thought* I knew, and ratios, final drives, a little bit of LSD and clutch..
(which is how i get on to the idea of choosing the best 4th and 5th ratios as well ... i could put Mark H's extended G40 box on mine quite happily for mega mpg in top (crusing 90kmh at 2000rpm) but still with max speed in 4th - though starting off in 1st would be a little more strained. I'd never get much past 70mph without a hill in that config though! 72mph would be at my torque peak... where the 1043 would be putting out just enough power to reach 73mph, maybe 75 with a de-cat, and the figures simply can't get any better power-per-bhp at any other rpms)
(full-throttle running at max torque is about an engine's most efficient point from what i think i know - least restriction and turbulence on air intake, best possibility of lean-burn, and making most power per "bang" even though there's not so many bangs per second.. possibly more efficient to be full-throttle in 4th than half throttle in 3rd, if the resultant acceleration / uphill speed is the same)

Lastly I ended up buying a 4 speed Polo, with a crap stereo First desire was to get a 5 speed so i could hear music at 70mph, now it's to hear the music better and use less fuel (and oil..). Finding out about the wide/close variants was a bit of an eye opener (especially when I got the *proper* numbers, rather than somewhat rough north american equivalents)... I could quite easily have made a complete t1t of myself and ended up with one of those close, low 1-litre 5 speeds that would have offered as much noise at 65mph as was previously got at 70...

If I ever get it sorted, I'll probably go right off the subject, but for now... i'd like to just keep the data available out there, because it was a complete pain in the arse finding somewhere to get the information from. In the end it came down to stumbling across a short-lived russian site where someone had pirated an ETKA disc and turned it into a clever webpage system... and working out the numbers myself from the confusing diagrams and the stated geartooth counts. (1st is 38 by 11, factfans). Then crossreferencing with other stuff I already had (e.g. rolling-road measured speeds-per-rpm from http://www.badcompany.demon.co.uk/polo).
Hopefully anyone else trying to dig the info up won't have to jump through as many hoops - Google should have spidered to my page by now




My sincere apologies to your eyes. I hope you have a high refresh rate or an LCD monitor.



* dont y'all come out of the woodwork now and tell me how i wont be able to control the car, the brakes wont work, the steering will go heavy or lock, my lights and speedo will cease functioning etc. I had enough of that crap when i noted such fuel saving tips on a uni message board not long after i got the car (i had a period where my 'current' tank of petrol was going to be the last until the next loan cheque came in - went right down to emptying the spare can, til i had enough spare money to get home with). I'll say the same as i did then...
1. The mk2 polo didn't have any brake assistance at all. therefore losing the servo only puts my car back one single model year. Its easy to stop. I'll use the handbrake if neccessary... which it wont be.
2. No power steering anyway, fool, and i leave the key in - no steering lock.
3. Oddly, the only things that stop working on a polo when you put the key off is - head/fog/indicator/reversing lights, horn (yes!), minor accessories like fan, wipers, fuel/temp guage... and engine. Side/tail lights, brake lights, speedo, and strangely radio still work. And I can use the "parking light" function to have an american-style indicator. Anyway, as soon as it drops 0rpm, i can go into neutral and put ignition back on. No fuel use... but all accessories are live again.
4. you're an idiot and your mother's ugly.
5. biscuits should only be dunked for 5 seconds max
6. yeah, cities of gold, ulysses, transformers and castle in the sky were great werent they i have them all on CDR if you want to reminisce. meet me in the biology block foyer.
7. the girls end up with the bad guys because the nice guys are too afraid to make a move

....and your point is ?

Do you want that excel file or not? Ive added loads of stuff to it; the two 4 speed boxes available (yes there were only 2) and the however many 5 speeds there were. plus speeds with certain tyres.

There is no way you could do anything with that super high G40 5th. It jst wouldnt pull at all, even at full throttle. Marks only doing it to his because hes turbocharged a mk2 polo that used to be supercharged, itll have about 200hp and that higher gear is just for motorway miles. Itll prob have about 3 or 4 times the max torque if a 1.0 and obviosly 4 times the max power.

Fuelling doesnt work like you describe. If ur throttle is fully open then fuel consumption is at maximum as the mixture is fully richened. And under full load its even worse. Just becuase ur engine is revving highly doesnt mean its using alot of fuel. One mistake I made when I first started driving was changing up way too early. You require more throttle in top gear than you do in the one below it below a certain speed. Very light throttle at reasonable revs is when economy is best. This is almost always at 56 mph in top gear. (american speed limit (55))

The 1390 cc GT is something im working on at the mo using a 1.4litre mk4 polo bottom end and GT rest of car.

And there I was worried that Water-cooled VW owners were all of the 'Max Power' school of thought

hardhitter wrote:....and your point is ?

um.
where?

Gareth_GT_Hatch wrote: Do you want that excel file or not?
Ive added loads of stuff to it; the two 4 speed boxes available (yes there were only 2)

Please!
Attach in a PM (can you do that here?) or email to.. how can i do this..
mark
.. penrice
(a) blue =-
yonder , co , uk

but without all the spacey bits

(which 4 speeds were those you had? cuz my info suggests at least 6, not counting the 3+E novelties)

There is no way you could do anything with that super high G40 5th. It jst wouldnt pull at all, even at full throttle.

I know, I know... the 8P is about the highest practical ratio I could put on it. Even the regular G40 box would be a strain. Just a little pipe dream.

(did a bit of figuring with that last night - with the best-estimate power curve - what power it would be putting out at a particular speed (about 29hp at 2800) vs how much would be needed to keep going against still air. The best it would do is hold the speed steady between about 40 and 75 on the flat - regardless of the actual point you shifted up at, it wouldn't change afterwards... absolutely no acceleration or hill climbing). The gearing being so high that the power output was rising pretty much in synch with the requirement, just with maybe 1% excess, so you could get a 10 minute 50-70mph time if there wasnt a sudden gust. (the rising torque meaning the power output was rising exponentially, just like the force of the wind friction.
Now if it was 24mph/1000...that would almost be workable...
I was thinking of those extreme ratios more in terms of a CVT box range though - e.g. Audi's advanced Multitronic box which actually DOES have a slight advantage over manual for speed and economy - by about 1% - for the first time ever... it also has a massive 6.1x ratio range.. or in other words from that super high G40 ratio down to about the lowest 1st gear over all the boxes in my spreadsheet)

Marks only doing to his turbocharged mk2 polo, itll have about 200hp

sweet

Fuelling doesnt work like you describe.

Educate me dude, i'm like a big black hole for your knowledge... well, everyone's knowledge. I'm having a bit of trouble at the moment because, as usual, each new bit half contradicts various points of the old. Please I hope you don't mind if i ask some questions

If ur throttle is fully open then fuel consumption is at maximum as the mixture is fully richened.

?? i thought if it was an electronic/lambda controlled ignition, the fuel richness stayed relatively constant for the best combustion and least damage to the cat?

And under full load its even worse.

Why's that then?

Just becuase ur engine is revving highly doesnt mean its using alot of fuel.

Suppose so... but it's still needing the extra power to keep itself spinning that quick. And a nearly-closed butterfly valve offers a lot more resistance to the air flow than a nearly full-open one.

(that last nugget, true or otherwise, comes from a japanese based (but eng language) motor technology site i found - apparently mercedes made a 20% more efficient engine by doing away with the throttle valve completely and just varying the actual inlet valve movement)

One mistake I made when I first started driving was changing up way too early.

I'm wary of that one... if only because of the much reduced torque (=less efficient?), increased engine vibration etc.

You require more throttle in top gear than you do in the one below it below a certain speed.

25mph? considering that my top gear is pretty low.
(actually, probably make that 50mph, as 3rd's max power curve isn't beaten by 4th until at least 75mph.. but would you want to drive at 70 in 3rd?)

Very light throttle at reasonable revs is when economy is best.

I suppose so.. but what's your reasonable revs? I remember someone on here quoting 1400rpm round town in 5th, but as i'm in "edit" rather than "new post" mode, i can't check who. You or someone else? I'm happy doing 35mph home at 4am... the car seems *very* quiet and settled with that, and the engine's running at about 2000rpm, which still seems to have ample power available for all but the hardest gradients (the ones which you might choose to engine-brake down in 2nd).
Plus I don't get in anyone's way while i'm doing it, which I would in the daytime... on a mix of 60, 40, 30 roads.

If it were 3rd rather than 4th, it would be doing a touch over 2800 - or in other words, smack on peak torque and what it might be doing at 50 in 4th (or 56 in 5th...)... would it be better instead to use 3rd, if indeed the top torque is the top efficiency?
(that point of torque = best use of available fuel is a thing my dad fed to me... though he also thinks i change up too soon and that turning the motor off at the lights wastes fuel somehow)

This is almost always at 56 mph in top gear. (american speed limit (55))

It's not anything to do with the american speed limit so far as i know - which is as high as 75 in some states nowadays - particularly as so few "economy" euro cars are sold in the states... it's the old European fuel consumption test stuff which was phased out in the mid 90s. Cars would be rated for economy round town, at a steady 90kmh and a steady 120kmh round the test track. Or in english - 56 and 75mph. So it was prudent for manufacturers to try and optimise the economy at those speeds, or ones close to it, even if it was a real drinker at all other speeds
(which also meant that the majority of cars sold would be reasonably efficient when cruising at the speed limits of almost all european states - between 80 and 100kmh on main single carriageway routes (uk being 96k), and 90 - 110 - 130 kmh on motorways (uk 112))

However with thoughts of wind resistance, engine friction, acceleration needed to reach a particular speed, I'm not throwing out the possibility that an even lower constant speed could be more thrifty, especially as I doubt VW had to do much tinkering to make the 1-litre seem the most efficient. Taking the torque thing again, 56mph is *only just* within my 'extended' range (ie, i've seen figures which quote a single peak at 2800, others which give a wider band around 3000.. for the same engine) at 3200rpm in 4th, which sounds a fairly high figure when written like that... Perhaps the car will be very efficient at 56mph and i won't be able to improve on it. Perhaps I will, which is why I'm experimenting!

(it's another reason why i was after a 5-speed fitting; with the 8P, 56mph would be at 2650rpm, still quite torquey and with enough power to keep going - and I could possibly go up to 60mph at 2800.. With the (rare?) variant on that with the lower geared differential, it'd be more like 2700-2750.. near perfect. Heck, even with the GT box, it wouldn't be far past 3000 - better than 3200, if only a little)

Last Q - why neccessarily would a slightly wider throttle opening at a lower engine speed use more fuel than a narrower setting in a higher gear? don't forget that the engine is spinning faster - more vacuum pressure on that smaller opening, that can draw more air (and fuel), more combustions per second and particularly per wheel rotation... etc. Plus in both cases the engine is putting out about the same power to the wheels, but more likely than not absorbing more for itself.
Not one to ever trust HM Govt on such matters, but my mind goes back to their statement that a constant 30mph in 2nd uses almost twice the fuel that the same period of travel in 4th would.

What I'd *really* like to see is a set of rolling road printouts showing the engine output curves at different throttle settings - are the max torque and power points at the same rpms with the throttle 1/3, 1/2, 3/4 open as they are at full throttle? I really doubt they are, seeing as something as minor as a de-restricted intake and a wider exhaust can alter where they are by a few hundred rpms, or a chip that controls the amount of fuel put in by the injectors - and the throttle valve has FAR more control than those over both aspects. I'm thinking both peaks drop to lower in the rev range, but i can't say anything about it without some kind of proof or data. If anyone else can actually provide on this subject......... i'd be very, very grateful.

And what effect might the idle speed adjuster (electronically/vacuum controlled on the Mk3?) have at the lower speeds?

(mmm, a good discussion, gets the ol' brain wheels lubricated again)

The 1390 cc GT is something im working on at the mo using a 1.4litre mk4 polo bottom end and GT rest of car.

That sounds like it could be very cool if it works. (Well, obviously, it IS working? )
What if you were to super/turbocharge that sucker?


Anyway chuck us that excel file and i'll have a gander, see what's what.



EDIT - last thing i thought of/remembered.....
I've tried before holding the throttle steady (at, say, enough for 2000-2400rpm in neutral?) and just shifted the gears to see what happened, purely out of curiosity. In all gears including 4th, after i acheived a steady speed in one, clutch down, move stick, clutch up - without ANY movement on the throttle (basically I bridged my foot across to it over the wheel arch)... the car started moving faster. It was kind of gradual, as the opening was pretty small, but it did so, up to the low 30s in top. So same throttle opening meant higher speed in the next gear, though the engine started to spin a *little* slower. Hmmm......

Bloody hell ur posts r getting longer and longer! Ask one question at a time please.

It was me that said 1400rpm in 5th but that was in a mk2 which is very light and had deecent low down torque so it could cope.

Reasonable revs depends on engine. A 1.3litre single point injection polo uses alot more fuel at the same revs by comparison to a GT. Reasnonable revs for a GT is between about 2000 and 3500 where as on a CL it would be between 1500 and 3000 or so. Thats one of the reasons the CL has such long gears, it is less efficient than a GT at higher revs. it also has more torque low down than a GT

As for 4 speed boxes, there were only 2 used after 1987 apparently which are the only two ive put on this thing. All the 4 speed "Formel E" gearboxes were phased out at this point which are probably the ones you are referring to. (there were a total of 6 others before this date just for your information - these were not used on later models)

Why dont u just pm me with ur email address, that stuff you wrote doesnt make any sense.

(did a bit of figuring with that last night - with the best-estimate power curve - what power it would be putting out at a particular speed (about 29hp at 2800) vs how much would be needed to keep going against still air. The best it would do is hold the speed steady between about 40 and 75 on the flat - regardless of the actual point you shifted up at, it wouldn't change afterwards... absolutely no acceleration or hill climbing). The gearing being so high that the power output was rising pretty much in synch with the requirement, just with maybe 1% excess, so you could get a 10 minute 50-70mph time if there wasnt a sudden gust. (the rising torque meaning the power output was rising exponentially, just like the force of the wind friction.
Now if it was 24mph/1000...that would almost be workable...

Ur confusing everyone with all your numbers (including me) - please stop it!

?? i thought if it was an electronic/lambda controlled ignition, the fuel richness stayed relatively constant for the best combustion and least damage to the cat?

The ecu ignores the lambda proba at full throttle and therefore also ignores it a full load at full throttle which is why fuel consumption is higest here. For max power and torque you need as much fuel as possible.

something about mercs I cant be bothered cutting and pasting

Quite alot of new cars have variable intake manifolds, I think the 1.4 16V polo has one but im not sure. Actually I think its the 1.6 100bhp polo saloon/estate that has this.

This is in completely the worng order I know.

25mph? considering that my top gear is pretty low.
(actually, probably make that 50mph, as 3rd's max power curve isn't beaten by 4th until at least 75mph.. but would you want to drive at 70 in 3rd?)

Its not based on power curves, its based on percentage of open throttle. There is a point where the amount of throttle openness required is the same in one gear and the next. This is probably at about 30mph between 3rd and 4th on a 4 speed, about 35 on a GT between 4th and 5th and 40 on a CL. all on the flat of course. Ive gone to the trouble of drawing a pic on the back of an envelope, just to illustrate a point:


Hopefully that clears things up.

Last Q - why neccessarily would a slightly wider throttle opening at a lower engine speed use more fuel than a narrower setting in a higher gear? don't forget that the engine is spinning faster - more vacuum pressure on that smaller opening, that can draw more air (and fuel), more combustions per second and particularly per wheel rotation... etc. Plus in both cases the engine is putting out about the same power to the wheels, but more likely than not absorbing more for itself.

I think you might be contradicting yourself there but Im not sure. The car doesnt measure the speed its travelling it just measures throttle position, and the more open the throttle is, the more fuel it injects to maintain the correct air/fuel ratio. Forget about air flow resistance, thats how the throttle is controlled in the first place. Say ur doing 50mph at about 3500rpm in 3rd. U probably need about 50% throttle. That means it injecting 50% of the fuel as well. Lets say you are doing the same speed in 4th. Now ur doing 3000rpm and using only 30% throttle and thus alot less fuel is being injected. These figures are obviosly guesses but they are in the right areas.

I probably havent answered all your questions there and no doubt you will have several more when I check back tomorrow, but thats it for now.

I'm going to sit and think about this for a moment, give you a rest

plus i got computers to fix, and a "new" fitted door to look at whilst drawing air in thru teeth and going..... oooh, thats not a very good match, you'll have to do it over just to psyche the culprit


EDIT.... mm, just cruised round the block as they parked too far up, and i didnt fancy trying a 3-point turn with the old door in the back... there's a Formel E for sale two corners away, £250.... worth it?

Righto, haven't read all of this because posts are starting to get insane However, something I must point out as a matter of urgency, ie life and death..

2. No power steering anyway, fool, and i leave the key in - no steering lock.

You leave the key in but not set to 'accessory', 'ignition' or 'starter' position, steering lock still works. Please, please don't try to turn a corner with the engine turned off and the key not at least set to 'ignition', because you will kill yourself. The thing to do is, on the straight, turn the engine off, leave it half a second or so, then turn the key back to ignition, assuming it's not in gear the engine won't fire up again, you'll get your brake servo and electronics back again and your steering won't lock up suddenly. Or, if you're lazy like me, just leave the engine running and kick it out of gear to coast down, it's not like it uses much fuel just idling anyway

Oh, and that formel E.. personally I wouldn't touch one with a bargepole. Consider the fact that the standard 4 speed is wide enough to cruise happily enough up to about 75, and will run up to about 90.. then widen that until the top gear is similar to that of the 4+e boxes. It's just a nasty thought However, I haven't actually driven one so it may be worth taking a test drive.. see exactly what it's like

Well... it's a 1.3, so it should be good for 90 or a little more in top
1.1s, now, you wouldn't want to go near them.

(hmmm, £250, is that a good deal for a 1.3 engine and some other spares? like the new clutch and brakes the ad in the window mentions... cuz i'm wondering whether i've knackered the anti roll bar rather than the shocks now on mine)

As a matter for the record, I don't know how it works on mk2s, but certainly on my own car the steering lock never, ever, ever activates until the key is removed. It's a safety feature.... guess maybe it was put in after a few people tried coasting mk2s and topped themselves. Plus it means you don't forget the key in the ignition if you make a habit of locking the steering when you park - enough times i've tried it, found the wheel won't click... and, oh, i forgot the key, doh.

I was going to argue that having the engine idle would use as much energy out of that fuel, as the fuel you would need to either maintain speed or regain it after engine braking effects, but the motor would be spinning a fair bit slower (lack of torque at low crank speeds excepted) so.. it still needs power... but not anywhere near as much. Like 850/2500ths... So a decent second best if there's a risk of the wheel locking.

(come to think of it....... i think the Punto had that particular death-trick as well O_O... didn't coast that more than a couple times, when fuel was low)

Fair enough then, as long as you're sure it's not going to suddenly lock up on you.. personally I'd just turn the ignition on anyway, then at least you've got your electrics back, even if the engine itself isn't running. That's not going to do any harm to your fuel economy, because it won't be using any fuel Personally I just pull it out of gear and let the engine idle, but that's mainly because it has a nasty habit of refusing to start straight away at the most awkward of times..

If the formel e is in decent nick, then yeah, go for it I guess. Apart from anything else, it's a chance to improve your mechanical confidence without worrying about how you're going to get to work

£250 is alot for a 1.3 enigne these days. Assuming ur on about getting an engine for a conversion I couldve had a GT lump for £125 with 52K n it (allegedly). But I went for a 1.4 with 45K on it for £200 and bloddy hell I really wish I hadnt! A G40 would have been much better! But I would have settled for another GT knowing what I know now.

What did your 1.4 engine come from?

Hmmmm maybe not then... i'd get my arse kicked anyway
(then again, its a 1.3 mk2... if i could ever get my gearbox into it, and the wider tyres, it'd be a nice country lane blaster )

Plus, well, you certainly wouldn't know it, but.. the servo dies after a few pushes even with the ignition on, if the engine isn't turning. It feeds off the inlet vacuum if I remember right. Not that I have much problem getting the car to stop even without it

Still thinking on the throttle and fuelling points. I need to go re-read some stuff. On the one hand I can't see why VW would effectively map the ECU so it runs "full choke" when you put your foot down (surely hurting the power, not good in a very low powered machine that might be at full throttle quite a lot) - and my 90mph/5000rpm/fully open motorway economy doesn't suggest it's chowing petrol like there's no tomorrow. Down to 30mpg, yes, when i can get probably 60 at 56mph, but then there's a whole lot extra wind resistance (requiring ~45hp output instead of ~20 to maintain constant speed - lots of wasted energy and wasted fuel) plus the torque is lower there
Then again, I have a dim recollection of reading things that say maximum power air:fuel ratio isn't the same as best economy/combustion/emissions.... like 11:1 compared to 14:1..?

Still... this brings up the idea... mebbe I could figure out what point this switch happens, and put in a stubby, stronger spring so that I can only exceed that throttle opening when really caning it Kind of like the kickdown spring in an auto.

And i'm still not convinced that wider opening in higher gear (ie lower revs) neccessarily = bad. I like the graph (very informative ) - and i'd put money on your lowest points being at maximum torque btw - but what of one showing the function of throttle opening multiplied by rpm..? with a red line showing the point at which the ecu starts ignoring the probe

GroovyCarrot wrote:What did your 1.4 engine come from?

A breakers yard. But before then it was on a mk4 polo. The engine blocks are the same size and the engine mounts are compatible but on the one I bought I fould the inlet manifold didnt fit so now Im using the GT cylinder head (which is better anyway) so I can fit all the GT ancillaries on and run GT injection. Essentially a 1.4 GT with a slightly higher compression ratio. What exactly it will be I do not yet know, somewhere in the region of 10 and 10.5:1.

Servo works off engine yes. You can build up the vacuum in a servo with the engine on but 3 or 4 pushes of the brake and its gone with the engine off and youll have some brakes then that are worse than a mk2!

Formel E's arent as bad as you think, they have more torque than a standard engine (the 1.1s anyway) and will go all day at 90 I would imagine.

That graph is a sketch based on my own driving experience, theres no mathematical function to it. All of it is just guesses. The bottomes off all the curves correspond to the lowest amount of throttle required to maintain car speed without the engine labouring. This isnt very accurate on my graph as theyre all the same when they shouldnt be (they should get progressively higher through the gears)

Do you drive at 90 with full throttle all the time then? 30mpg sounds about right to me. Its because of the high speed that you are getting such "good" economy. 3 gallons an hour, which is another way of looking at it, is not so good.