My bike only requires a quick flick of the wrist forward to cut throttle a bit before stepping on the shifter to select the next highest gear (GP shift pattern). No clutch required. To downshift, I hold in the clutch and lift the shift lever with my toe.
You must not be talking at WOT. I've never driven an autobox that wouldn't slam into gear at WOT. Hell, I used to have a 1986 Pontiac 6000. 2.8L V6, FWD boat. The roads on Vancouver Island get really slick for some reason in the rain, and it's spin the tires during a 1-2 shift in the rain (WOT obviously). Most manual drivers only shift like their ass is on fire if they're trying to go real fast for some reason, so compare apples to apples. In that situation, any auto I've ever seen shifts instantly and TBH rather violently.
Maybe it has to do with the tech in the transmission, or the transmission it's self. My car will only shift quickly if lift off the throttle while it shifts. Not changing the throttle's position will result in the RPM shooting up about an extra 100 - 200 RPM, then it slowly goes down. Estimated time to complete a shift under normal driving conditions would be about 3/4 or a second or a tad longer.
There are times where I try to accelerate into an on-ramp and it'll take just over a full second to shift.
I'd like to pick up on this point. I've been driving manual for years but my wife doesn't. On the rare occasions when I need to drive her van, I leave her stranded with a car she can't drive. So I'm thinking about getting something with a tiptronic/steptronic for my next car, probably either a Mini or a VW Rabbit.
Has anyone used one of the above trannys? Of course the downside of my wife being able to drive my car is that she might like it and leave me with the van.
Little tip when you get a auto with a tiptronic stick...
When you buy it and they start preparing it for you, tell them to turn the stick around.
I have no clue why, but every single tiptronic auto box I've driven has the damn stick in it backwards... Push forward on the stick = down, pull backwards on the stick = up... How hard can it be?
Also, make sure you buy one that doesn't insist on shifting down for you (like fiats) even when you have it set to manual. Brake and shift from 4th to 3rd right after the car has decided it would do that for you makes for really sore ribs and neckpains.
Only auto I've ever been able to get the tires to spin was a supercharged Bonneville, round 2002 or something.
A GM 2.8L V6 spinning the tires, that's a funny one. They must make them quite different for Canadia. I don't think I've ever driven a vehicle with such a gutless motor in it. The Pontiac Grand Prix with the 3.4L ran great, but still it would never have spun the tires.
Automatic experience in no certain order....
1988 Cavalier 2.0
1992 Corsica 3.1
1989 Grand Prix 3.4 (I think)
1983 Escort 1.6
19xx Celebrity 2.8
198x S10 Blazer 2.8 (incredible joke that was)
1979 Fairmont 200cu in straight 6 (can't be bothered to calculate it out in liters)
1990 Taurus 3.0
1996 Altima 2.4
2006 Tribute 3.0
1970 Mercury Montego 302cu in. Ok, I'll admit this one could spin the tires. Could light them up in all 3 gears and snap your head back like you wouldn't believe.
198x S10 pickup truck 4 cyl.
2007/8 Suzuki SX4 (recently obviously and I'm an adult now and it's not my car. I certainly didn't test it out.)
Hehe. The 3.8L V6 (rated at 170HP, IIRC) in my 1994 Pontiac Bonneville would spin up the wheels just a little bit from a stop if you really stomped on the gas. 4-speed auto in that land yacht.
One of two other autos I've driven was my mom's 1995 BMW 325i convertible coupe. It felt totally gutless compared to my dad's 1994 BMW 325is coupe with the usual 5-speed manual, and often could not decide between two gears when accelerating. The other was a large American cargo van and it felt much the same as the auto in the Bonneville (large American car).
I'm able to get my '92 Buick Regal to spin the tires with a 3.8 liter V6. It's actually quite easy. Not sure of hp rating. Even tried a neutral drop once... Think it was at 2,000 RPM when I dropped it. Nothing broke, but I'll never do it again... Shook so much the damn ash tray flew back at me...
What about gas mileage? Is it possible to take a standard car out of gear while going down hills without hurting it? In theory, I can't find anything wrong with it, but I've never practiced it...
Out of a desperate attempt to save gas in my guzzling motor, I've been taking it out of gear, and for the ones I know are long and shallow enough, I even turn it off. Screws up my gauges though and at times have to go miles on end with no speedometer. the Tach always works find after a few seconds... Strange...
I can get wheelspin in my S40 auto too (2.5 V5 turbo petrol, 226bhp).
By standard do you mean manual (stick)? If so you can take it out of gear and coast in neutral so you're only idling the engine.
Do you leave the ignition key in a position that means the power steering / power brakes are still functioning? I heard of a story a while ago where someone had turned their ignition to the full off position and not only did the power steering stop working but the steering lock actually came on so he couldn't turn his car and he actually had a crash.
In my car (and probably in a lot of modern cars) they can bring the fuel usage down to virtually nothing when you're not using the throttle pedal. I can show instantaneous fuel mileage with my onboard computer and when I lift off the throttle going down a hill my fuel usage goes from say 35 mpg to 99.9 mpg.
On my car if you knock the ignition back so the engine goes off, the steering lock stays off, but the power steering and assisted brakes start to go - the steering gets heavyish, but the brakes get very very hard very quick...
My car loses servo'd brakes after 2-3 goes on the pedal once the car is off. Nigh-on impossible to stop it without the servo assistance, the pedal feels like it has a rock underneath it. Power steering goes almost instantly, but it's still very drivable without it.
I don't get why you'd put the car into neutral while going downhill though. In fact, you're probably using more fuel when ticking over in neutral, rather than leaving the car in gear going downhill. When you're going downhill, with your foot off the throttle, it's using the car's momentum to keep the engine running. It sounds completely different, as it isn't combusting to keep the engine running. It's also a bit easier on the brakes, as the engine is doing some of the braking. Try it yourself, my fuel usage-ometer goes to 0.0 l/100km when going down a significant hill with the throttle off, compared to 0.8l/100km with the clutch in (and 0.6l/100km when idling at rest for some reason)
Assuming you're using fuel injection of course, as most carbs still use fuel in this case. Although my bike (carb'd 250cc 2-stroke) cuts fuel when I'm not on the throttle as far as I know. If you go downhill in-gear with the engine off, it sounds exactly the same as going with the engine on
my cousin used to do that in his mazda... he'd start rolling down the hill, put on the clutch and turn off the engine (but putting it back into the on position)... when he hits the bottom of the hill, he uses engine braking to start the engine again. whether or not that actually saves gas is anyone's guess.
I'd suggest refraining from doing too much engine braking at high revs. Brake pads are a hell of a lot cheaper than crankshafts.
Unless your bike has a separate tank for fuel and oil and a valve that cuts off fuel from the mix, I doubt it. If you cut off the entire fuel and oil mix, you'd seize the piston very quickly.
Definitely not, it's not recommended to bump/push start a car at all, as it leads to petrol getting into the exhaust system, which eats the cat. Whether the short time required to bump start going downhill makes any difference, I don't know
I wouldn't use high revs, I meant normal road use. If it was track or competition use, petrol efficiency doesn't matter I've been running this bike for 3 years now, engine is still using the original parts from 17 years ago. When it's out, it gets a fair thrashing (full throttle up through the gears to 6th, rev limiter was removed before I got the bike), hasn't needed anything done yet, apart from an unknown cooling problem. After climbing for too long, it just blows steam from the rad cap (into my face unfortunately ) and needs to be refilled. But that's a side issue, it's been like that since the day I bought it.
I engine brake in my car too, but at sensible revs, usually in 3rd or even 4th. For a 1 litre it has surprisingly good engine braking power
It uses pre-mix. I have no idea what way it works, but even holding the kill switch down while going downhill makes no difference, it just keeps making the same noise (so I presume the engine is burning or not burning the same). If it's doing a good bit of engine braking it seems to use fuel though, as it puts it under load. I haven't really looked into this on the bike, it's just my own experiences. It's all off-road stuff anyway, so fuel efficiency makes no odds
The one I drove was the supercharged 3.8L. Yeah, it was a rocket. I barely touched the throttle and the tires started screaming, hit 2nd, tires screamed, hit 3rd and got a chirp. I can't remember the HP rating, something like 260 or so? That thing moved. Just had to make sure you could slow down before a bend because it also felt like a land yacht.
If you shut your car off for going down hills, you certainly will lose all power steering and brakes. They are hydraulic, thus you lose it without the motor running. If you don't turn the key back to on, the steering wheel will lock.
You save fuel going downhill by lifting off the throttle. You don't save much, but that is the idea of the hypermilling sensationalizing when fuel prices rose up. All that hypermilling BS could have just been summarized up as "don't drive like a moron". I checked it out back then and after reading about it, I thought, "OK, I just drive normally then and I'm doing this stupid hypermilling stuff...."
Put the car in neutral on one hill then just lift off the throttle on the next and see if there's any difference in your speed. I'd bet you see very little difference. You'd have to have quite a hill for there to be a difference between coasting out of gear and coasting just off the throttle.
Yeah, dropping in to neutral when going downhill in a car with so called modern fuel injection is pointless. The injection system recognizes when you lift the throttle and so when engine braking, it doesn't inject any fuel to the engine. In a way you could say that it shuts down, but if you let the revs go to idle speed it starts to inject fuel again.
Carbs usually are different, they will keep fueling even when the throttle is closed, dunno about bikes, but never heard of a car with a carb cutting the fueling while engine braking.
This usually means that your headgasket is gone. If you have an aluminium cylinder head I would be very concerned about ruining it (twisting, cracking, you name it) and would sort the problem out immediately. Or even the block could get ruined.
Even if it's just cast iron head, overheating is never good, some engines take more abuse than others.
The chamber(?) for the impeller shaft is made from magnesium on these bikes to save weight, and I'm almost sure that's the problem (magnesium + water = corrosion). It was very corroded when we got it, so we patched it up with areldite. Either there's a leak there, or it's made the chamber too small for water to flow freely. It could also be the impeller head itself, as it's slightly chewed on a couple of the turbines. I'm not that worried about it though, it only overheats after an hour of hard driving almost vertical, and I can feel it when it's getting too hot. There's no respone in the low revs when it gets too hot, and it's very noticeable. A 10 min break after 30 mins riding sorts it out Even after letting it overheat, it doesn't seize, but I'd imagine it would fairly quickly if I didn't kill it after the rad overheating.
The block, head and gasket are all perfect, the engine itself is surprisingly mint even after 17 years. Had a few plug changes, 2 over the course of 3 years I think, nothing worrying. Starts second kick every time, no matter how hot or cold it is
But that's off-topic, and has nothing to do with downhill procedures or slushboxes
Engine braking won't damage or wear the crank shaft any more than normal use unless you let the revs go past redline.
Putting the car in neutral on a downhill is not an advisable practice and is frowned appon by most professional driving instructors. If a driving instructor ever tells you to do it, that instructor is not a professional, and I personaly would call the test off right then and there.
Putting the car in neutral delays the option of accelerating away from trouble. If you ever need to accelerate out of a situation on a down hill you'd have to take the time to put the car back in gear and then accelerate away.
Shutting the engine off is even less advisable since it adds an additional step before you can accelerate.
I have witnessed people getting rear ended by an out of control object, car or other, because they put the car in neutral and didn't have the time to put it back in gear and pull away before the object hit them. It sounds unlikely, but it has happened.
As for a carbureted bike cutting fuel, it isn't realy, but it is reducing it.
Most bikes use a slide barrel carburetor, they have a tappered variable main jet fixed to center of the slide barrel, as you open and close the throttle, the jet changes size increasing or decreasing fuel.
If the engine is running fast and you lower the throttle the engine gets less fuel than it needs for optimum combustion and will sometimes sound as if it isn't combusting at all.
Yes, every time I turned the car off while moving, I would put it back into the on position after the revs stopped. I've tried a few times and actually kept it going because I didn't leave it off long enough. Usually about 2 seconds is long enough.
When I do that, of course I lose power steering, and have 2 good pumps on the breaks before it's useless.
I only chanced that because it would take about 3 seconds for the car to accelerate away from anything at any time unless I'm controlling the gear. Damn computer doesn't know when to shift to benefit anything...
I thought that when the engine was breaking, it was still spitting fuel into the cylinders... I thought I could use it at 2000 RPM, or I could go to 700 RPM. I suppose it would be worth the loss of speed if no fuel is used in gear.
you can fook the crankshaft with your engine after you over revd it,timing chain jumped=needs engine. Btw my opinion about transes manual,change clutch= max 800$ change an auto trans,5G$ for a new,used installed about 3G and there is a chance it wont work (well these are bmw&benz prices,as i work on these only) just for an example,last week i did a e46 m3 clutch it cost 900$ a month ago an e60 needed trans,new trans 8 grand! O.O
Oh and if you have 2000 bmw 323i in usa,and you need trans contact bmw nort america,they will pay for it,its like a recall. sorry for ot.
You are less likely to damage the crank then you are anything else in the engine. The crank shaft has to endure intense forces for its entire expected life, it is usualy built strong enough to withstand anything you can throw at it.
The main bearings may overheat, but it's likely the valves will crash into the pistons before that happens. At which point everything from the lifters to even maybe the timing chain or belt will need to be replaced. Not to mention it could shatter the piston face, I've seen that a fue times.
If you are engine braking it should use the same amount of fuel as it would at the same RPM. so if you are engine braking or cruising at 3k RPM, it should use the same amount of fuel.
That is assuming the fuel system is static and just adds fuel as it needs to, if the computer is programed to, it may actualy lower or cut fuel, but I've never thaught of testing it.
yeah,the valves will bend or break,or get stuck in the head,but i seen lots of times on benz the rod comes out of the block.but when these happen,its cheaper to put a used engine in it,than rebuild everything.+ saves lots of time too.
If you're going to be stopping or otherwise reducing your speed it's better to stay in gear with no throttle as most modern cars have a DFCO function (deceleration fuel cutoff) which cuts fuel consumption to nil when coasting in gear. Coasting in neutral is more efficient if you're trying to conserve momentum (like when driving on a hilly road) as you're not throwing away the energy you already spent to get up to speed (it's not like the engine braking converts air back into fuel.)
Then there's pulse and glide where you accelerate "hard" so that the engine is operating at the point where its specific fuel consumption is lowest and then coast in neutral (or with engine off for the hard-core hypermilers.) Don't try in traffic unless you want to piss off everyone else around you.
Quite a few hypermiling techniques are inappropriate (if not outright dangerous) in traffic, but can work quite well when used wisely in the proper situations.
Anyway, back on topic. Out of the 4 cars I've owned, all but the first have had manual transmissions. I've also driven a semi so I know how to drive a non-synchronized manual as well. I'd like an automatic like the ones used in trucks, which are pretty much just a conventional non-synchronized manual transmission but with a computer operating the shifter and throttle to change gears without using the clutch.
Although, if you go as low as 700 RPM, it probably is injecting fuel. This can be seen in LFS too. Drive into first, up to about 3000 RPM. Then slowly brake. The green throttle bar in the bottom right should be empty. As you reach idle speed, it'll start to automatically give it some throttle. The slower you go past idle, the more throttle it's going to give to try and keep the car going.
It's much the same in real life, ECUs are programmed to give the car some juice if it's going to stall. This isn't enough to stop you stalling at the traffic lights for example, but it is enough to keep it going when the revs drop too low.
(well these are bmw&benz prices,as i work on these only) just for an example,last week i did a e46 m3 clutch it cost 900$ a month ago an e60 needed trans,new trans 8 grand! O.O