maritain Posted June 28, 2001 Share Posted June 28, 2001 i love coming up with these questions for the tech experts to answer! cool.gif idea.gifnow that the MGF comes also with tiptronic, is it possible to have a 7 with a VVC engine and a tiptronic gear box question.gif Link to comment Share on other sites More sharing options...
James Arnold Posted June 28, 2001 Share Posted June 28, 2001 Once you get the engine in transversely, fitting the tiptronic bit should easy. Link to comment Share on other sites More sharing options...
Barry Posted June 28, 2001 Share Posted June 28, 2001 Sure, if you put it all in the boot. Link to comment Share on other sites More sharing options...
maritain Posted June 28, 2001 Author Share Posted June 28, 2001 damn very good point barry. that was a small technicality i overlooked drive a seven , experience heaven Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 28, 2001 Share Posted June 28, 2001 The steptronic (or whatever marketing-led name it goes by) is a travesty and an abomination. The gearbox is a CVT (continuously variable transmission) which has gear ratios artificially imposed on it. Let's examine that concept a bit closer... CONTINUOUSLY VARIABLE and DISCRETE are opposites. CONTINUOUS VARIABILITY offers efficiency and power advantages. DISCRETE GEARING offers you the *traditional sound of an accelerating car*. The CVT bit of the transmission is a clever idea, but suffers from excessive transmission losses. Imposing gear ratios on it *because people don't like the constant droning noise of a CVT* is plainly crass. You get all the transmission losses and you get the inefficiency of running the engine at other than optimum revs. Baby/bathwater. I wonder how many they have sold... Link to comment Share on other sites More sharing options...
PACR Posted June 28, 2001 Share Posted June 28, 2001 Are any of the ECU manufacturers developing paddle shift kits? As far as I can see it's not the remote shifting of the 'stick' (or whatever is used to interface with the gearbox) that's a problem (mechanically quite simple) - it's the control of the engine and clutch. Now that a few manufacturers are using and hopefully perfecting these systems an aftermarket application has to be a money spinner if the OEMs hard work can be poached! I agree with Peter about the MGF Steptronic - anyone with a bit of engineering appreciation is sure to find the idea hateful - however it's not really an engineering issue - just a marketing one (judging by the MGF drivers I know. Try asking one what VVC does.. (or even better refer to their car as a WC...)). Piers Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 28, 2001 Share Posted June 28, 2001 I would like to have seen the use of a CVT mapped against the engine characteristics so that the accelerator pedal could become a power demand control. Push down more on the accelerator, and the computer decides whether to step the ratio down (lower gear) or open up the butterfly a bit more. Full throttle would have the engine operating at constant maximum power rpm. Cruising would pick the best economy. Link to comment Share on other sites More sharing options...
James Arnold Posted June 28, 2001 Share Posted June 28, 2001 Many years ago I used to have use of my Grandmother's Volvo 340, complete with rubber band gear box (CVT). Personally I felt that the gear box was ideally suited to this sort of car and not much else. even my Grandmother was disappointed with it! Can anybody enlighten me what happened to the other continuous variable transmission idea. I can't remember all the details - based on a toroid shape (at least I think thats the word, like a ring donut...) I think it might have been called the torotrack. Leyland had a few trial busses using it years ago (70s). It always seemed a more elegant solution to the belt drive principal. James Link to comment Share on other sites More sharing options...
FH Posted June 28, 2001 Share Posted June 28, 2001 I hate all step/switch/select/tip -tronic gearboxes and I've driven thousands of miles in them mad.gif The worst characteristic IMHO, is a propensity for the engine management system to "decide to change up" - just when I'd be considering a lower gear e.g. on the approach to a bend. Unless you are unfortunate enough to have a disability which precludes normal driving, and if you have two feet, then use them teeth.gif FH Link to comment Share on other sites More sharing options...
Violet Elizabeth Posted June 28, 2001 Share Posted June 28, 2001 ...unless of course you happen to be in an F1 car, but hey, what do thoese guys know, eh ? Can't get them started most of the time !!! Link to comment Share on other sites More sharing options...
rynicolson Posted June 28, 2001 Share Posted June 28, 2001 Peter and others who may be interested... these concepts are something I've discussed many times with my over qualified brother who until recently worked as senior engineer (tribology) at Torotrak in Leyland. They have a number of development "auto" boxes... as a business funded by the GM's, Toyota's (until recently) their interest is in a mass production solution... I have seen some of their IVT's (infinitely variable automatic transmissions) in test conditions, and they are much simpler solutions to many of the CVT.... It would take a few pages for me to explain the difference, go to www.torotrak.com to find out more. Most of the test installations I saw were on Mondeos, Explorers and tractors. I would be happy to expand if anyone feels trainspotting is exciting.... regards Tricks Y57 CDS "Mutley" Link to comment Share on other sites More sharing options...
Barry Posted June 28, 2001 Share Posted June 28, 2001 Peter, as you brought up CVT, check this out:id=red> http://www.ritzsite.demon.nl/DAF/DAF_cars_p17.htm Edited by - barry on 28 Jun 2001 20:37:51 Link to comment Share on other sites More sharing options...
EFA Posted June 28, 2001 Share Posted June 28, 2001 I drove a 911 Tip for a weekend a couple of years ago. Have to say it is absolutely the most dissapointing drive of my life. Arnie Webb The Car in Front is Full of Lard....wink.gif See Fat Arnies LardMobile here See the Le Mans Trip Website here Link to comment Share on other sites More sharing options...
Marius Posted June 29, 2001 Share Posted June 29, 2001 Picked up my BMW with this Select-Tiptronic-shifting-**** in it, glad I didn´t have to pay for it as an extra, not worth the money. Richards 360 Modena behaved fine with the pedal-shifts behind the wheel, felt and sounded quite fast (from the passenger-side..). The new M3 has a similiar new system now, which is able to shift within 0.8 seconds or so. Mike from UAE, do you read this? What´s your sequential-box like after a few hundred miles now ? Cheers, Marius Link to comment Share on other sites More sharing options...
Tony Martyr Posted June 29, 2001 Share Posted June 29, 2001 I drive an Alfa 156 with a two pedal sequential box which is as near as you can get to an after market modification as it is a system bolted onto the original Alfa 5 speed box. I have driven 17000 miles but still have mixed feelings. It is not good with roundabouts because it can't anticipate the quick changes you need. It changes down automatically according to a map that takes a lot of learning. I change up. I have visited the Alfa test facility in Italy intending to ask about the engine/drive map but I got so involved in the clever strategies you can play with a twin spark engines that I forgot all about gear boxes. Oh and the test engineers all wore smart 'anti-phase' ear protectors which I would like in the 7. Link to comment Share on other sites More sharing options...
Super_Rich_Bernie Posted June 29, 2001 Share Posted June 29, 2001 The conventional clutch and manual box must have endured coming up to 100 years of use. I reckon its about time modern technology came up with something more elegant than making the driver co-ordinate left and right foot movement, and taking a hand off the wheel to manually engage gears with each other. I have tried Tiptronic & Auto (but not paddle shifts a la Alfa) and would not pay extra for either. I suggest: - Gear selection must not require reaching for a lever many inches from the wheel. - It should be possible to select the next gear you want before engaging it. That way you can keep hands firmly on the wheel and mind on the road when braking for the next corner. - Gear engagement should be a single pedal push. No fancy heel and toe footwork needed. Shouldn't be too hard. Anyone driven a pre-war Riley, ERA or London Bus ? cheers Jonathan Link to comment Share on other sites More sharing options...
Jude Posted June 29, 2001 Share Posted June 29, 2001 As someone who has a disability and cannot use his legs, I have used Tiptronic gearboxes for a number of years, but to be honest if I had full use of my legs I wouldnt bother with this option. If its left in drive mode, and you put your foot down, it just seems to change up and down gears on its own accord. If you use it manually then you seem to get that bit of lag changing gear which is quite noticeable. I suppose I could convert a manual gearbox to semi automatic, but usually the cost of this conversion can be in the region of £3500 GBP. What you do get is a gear change as quick as a Touring Car but also something that can be unreliable for everyday use. Hopefully my converted Blackbird will make its debut on Le Sept...details to follow soon. Link to comment Share on other sites More sharing options...
FH Posted June 29, 2001 Share Posted June 29, 2001 Look forward to seeing you there Geoff smile.gif FH Link to comment Share on other sites More sharing options...
rynicolson Posted June 30, 2001 Share Posted June 30, 2001 Jonathan... got to come back on this one... brothers lagonda('36) is brake, clutch, power... I had great fun driving this for the first time through the McDonalds drive through, anyway last week drove my new toy...Lotus 61 with hewland box... couldn't find clutch peddle, got in it... eventuallt, much worse than a 7, drove to end of the garage 'pound' in second... couldn't find reverse (is there one?!?) manually turned round, into third in return trip (150 yds)... is this a potential guiness record? anyway, the point of this drabble, I've driven a 911, Alfa and BMW all with so called "quick" shifts... you can't beat the traditional method of gear change... having said that the F1 boys have it sewn uo so don't write it off... though I'll go for ferrari or Williams b4 McLaren, well, if they can't get their starts right what hope is there... Geoff probably had it right, sequential bike box.......... Link to comment Share on other sites More sharing options...
Mike Biddle Posted July 1, 2001 Share Posted July 1, 2001 Marius, yes I do still browse the forum on a regular basis but a new business is soaking up a lot of my time right now, and of course it's too hot to seven right now so my attention is wandering a bit. The sequential box is fine, still noisy but I'm used to it now, and I would say it's worth suffering the noise. On the subject of quick shifts, I could fit a "flat shift" system, my ECU supports it, but I don't think the small improvement in upshift time is worth it. Link to comment Share on other sites More sharing options...
Paul Drawmer Posted July 3, 2001 Share Posted July 3, 2001 I 'think' only Alfa, Ferrari and BMW use sequential change on a hydro/electric/manual gearbox and clutch. All those that don't have a torque converter, which is the unsatisfying bit. I have been driven in the BMW with what they call SMG2. It's brilliant, it has all the advantages of a lightning quick up and down change with electronically controlled engine speed matching, or could be used as a full auto if you really wanted. BTW Not 0.8sec changes, 0.008sec! (only available in the most manic mode, together with launch control hehehehehe) I wouldn't touch any system with a torque converter, no Sir. I wouldn't touch a CVT either (even with trick rations imposed on it). Link to comment Share on other sites More sharing options...
Peter Carmichael Posted July 4, 2001 Share Posted July 4, 2001 Excuse my disbelief, but I have not read anything about this BMW system apart from what has been written here. Considering that Ferrari possesses the fastest gearshift in F1 at 0.04 seconds, I have a problem believing that BMW have a system doing it in 0.008 seconds. Especially with a BMW traction engine flywheel. 0.8s sounds much much much more likely. In my seven with a 5.5 inch clutch and 2.5 kg flywheel the fastest gearchanges I have seen in the datalogs have been of the order of 0.2s. Link to comment Share on other sites More sharing options...
Paul Drawmer Posted July 4, 2001 Share Posted July 4, 2001 err egg on face.. Can't count my zeros.. 0.08 secs (For some reason BMW count it as 80 millliseconds) Oh how wild claims get exaggerated!! Edited by - Paul Drawmer on 4 Jul 2001 12:28:08 Link to comment Share on other sites More sharing options...
Paul Ranson Posted July 4, 2001 Share Posted July 4, 2001 In my seven with a 5.5 inch clutch and 2.5 kg flywheel the fastest gearchanges I have seen in the datalogs have been of the order of 0.2s. What's the sampling rate? With my Pi sampling at 20Hz and a Hewland sequential/7.5 inch clutch/fat bastard Swindon flywheel I seem to usually record between 0.15 and 0.2, must try harder.... Paul Link to comment Share on other sites More sharing options...
John Fossey Posted July 4, 2001 Share Posted July 4, 2001 Perhaps they should go back to the push button gearbox fitted to some older US Chryslers - very retro, and therefore completely up to date Link to comment Share on other sites More sharing options...
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