Welcome to our resource for MG Car Information.
MG MGF Technical - 0-60s
|Greetings all. I was down at Silverstone on Sunday for Trax2001, popped down there with my Brother. They were running a 0-60 sprint thing, I've wanted to know what mine would do 0-60 in, so I took part. 3 runs, first was 8.89 - second was 8.29 and third 8.6 secs.|
8.2 was obviously the best, not too bad considering the book for the 1.8i is 8.5.
However, I found why the VVC is quicker 0-60 than the MPI, with the MPI you need to change into 3rd to get to 60, with the VVC you don't, you can just red line it in 2nd and you'll get 62mph! Doesn't sound much, but a gear change = a good half a second or so.
Anyway, just wondering if anyone else has had their 0-60 time recorded and what they got.
The first run was the worst, but its the first time I had done something like this - revs to 6,000 and dropped the clutch! - Boy are those AP clutches good, took off straight away, no wheel spin, no clutch slippage! Second and third runs were a little more conservative (for the clutch!), 4,000 and smoother when engaging the clutch.
Still, all good fun. Fastest I saw was a Escort Cossie do it in 3.88 and then an Evo in 3.72.
Shame MG weren't there, perhaps next year :)
|>>>>with the VVC you don't, you can just red line it in 2nd and you'll get 62mph|
Yeah, sometimes I think Rover dould have saved a lot of money and made a much cooler-sounding car if they hadn't provided us with 4th and 5th! ;)
|Long live the VVC engine. Highly underated engine IMO. |
Anybody know if you can raise the rev limiter on the VVC or if it is possible?
|Now I know why my huge great big heavy old BMW bike makes 0-60 in 4 secs - it makes 65+ in first gear!|
|>> Anybody know if you can raise the rev limiter on the VVC or if it is possible? <<|
More to the point, is it wise? - Probably not wise IMO, without engine work. I'm no mechanic, but I believe you need to do something to the tappets(?) and something to the bottom end of the engine to enable it to take the extra stress.
|I'd always thought that the rev limiter was set well below the engines actual limit by the manufactuers and that there was always room for a little fiddling.|
The VVC felt fan-bloody-tastic this morning. You definetly get good car and bad car days with the VVC. Some days the thing wont shift anything short of 3500rpm and other days the thing flies all the way to 7000rpm before you can change gears in a lardy golf.
|>> Some days the thing wont shift anything short of 3500rpm and other days the thing flies all the way to 7000rpm before you can change gears in a lardy golf|
Same with mine - somedays feels superb, othertimes feels as if it just can't be bothered ...
in the 2001 mpi 1.8 1st will pull around 39 and 2nd 69. whats this about 3rd to get 60?
|I am with Steven on this one, mine used to easily clear 60 in second, more than enough to take into account speedo inaccuracy|
|>>The VVC felt fan-bloody-tastic this morning. You definetly get good car and bad car days with the VVC. Some days the thing wont shift anything short of 3500rpm and other days the thing flies all the way to 7000rpm before you can change gears in a lardy golf. <<|
Paul, the weather isn't humid there today by any chance?
Can make a difference to how engines perform.
|Well, I can only go by what the graph said, you could see a change at about 55 mph which was going from 2nd to 3rd. Even the sales stats says that the max speed in 2nd is 62mph and that's on the VVC with the higher rpm limit.|
I would guess Steven and Matt, that its speedo inacurracies that caused it to look like its more than 60, from the day at Bruntingthorpe, mk1 cable driven speedos did seem to be slightly more accurate than mk2 electric driven.
someone may enlighten me.
Doesn't the limiter at the 1.8i cut in at 60 mph (6500 revs)?
|The rev limiter cuts in a little after the red line- which on a 1.8i is 6750- rev limiter (I'm guessing here) @ say 6800 rpm.|
The rev limiter probably *could* be altered if you so wished- just re-programme the MEMS with Testbook. As to whether you'd want to is another question. I think that Paul is right- there is a fair margin for safety in the setting of the rev limiter- it will be conservative (and rightly so) for a production road car engine. But as the standard 1.8i and VVC develop peak power well before the rev limiter (between 500-1000 rpm earlier) then in fact there is little to be gained by doing this. Modified engines are of course a different kettle of fish...
|Sorry jumping back in the conversation a bit late (had some of that horrible work stuff to do).|
Gareth, Nieuwegein - Yes you're absolutely right but I tend to find that the car performs better in the winter time. I imagine the K&N is then being fed with much cooler air than during the summer time.
In fact I remember once the car was literally flying when we had a bit of freezing fog (OK it wasn't quite freezing but quite cold).
Oh and by the way I hit 60mph in first gear the other day and managed 0-60 in 2seconds..........OK,OK.....getting my coat
|Steve, mine was a Mk1 though. I can clearly rememember driving the car and being able to get it nearly to 70 on the clock, we will never know now, unless the new owner turns up. mind you the car is still lost in the bowels of MG finance. the garage i took it back too over a month ago, kindly forgot to tell MG finance that they had it, so i got a bill for settlement, cheers. anyway thats not the point. the point is that car was great and the quickest in the world ever. obviously i don't miss it|
|Well, I can only say what I could do in mine!! I didn't redline it but got damn close to doing so. The MG website does say max speed in 2nd gear for the VVC is 62mph.|
the VVC has a shorter final ratio, so it could be possible that at the rev limiter, it's slower than the Mpi, although it revs faster ... I don't know, but it could be calculated. I don't remember where I saw the rpm/mph graphs for every gear ratio... Don't forget that tyres could introduce an error.
BTW, you have had you gearbox changed, IIRC. Have you also had the differential changed ?
|>> Have you also had the differential changed <<|
Not as far as I know, the gearbox was just swapped.
BTW, I've always wondered, what is the "final Drive ratio" ??
|I have to say that in 1st I can get up to 42-3mph, 2nd 69-70 mph. Steve I would have thought that your car was quicker than that.|
I raced one of my mates that has a golf gti 16v which does 0-60 in about 7.9, I can keep up with it.
|The final drive ratio is the ratio of the differential.|
If you have your engine revving at, say, 4000 rpm, the gearbox first reduces its rotational speed (more or less depending on the gear engaged ; in fact, higher gears generally increase the rotational speed), and then this speed is again reduced by the differential : the final speed is the rotational speed of the wheels.
The final ratio for the MPi is 3.938:1 and 4.2:1 for the VVC.
I asked about your differential because if it was swapped, it could have been changed for a VVC one ... maybe not a bad thing : should pull harder, but increase revs.
|Ashley, i would say that Steve's car might well be quicker than he managed, when you consider that figures for cars are based on many many goes, theres no way that a golf will get 7.9 every time. as steve showed, he managed nearly a second between his best and worse (if you consider just over half a second nearly a second that is!)|
and lets not forget that the fact is 0-60 is a pretty meaningless figure. I saw one american magazine that interesingly quoted something like 10-60 rolling start in second.
|>> I saw one american magazine that interesingly quoted something like 10-60 rolling start in <<|
Wouldn't that be roughly like the 50-70 in forth test, mainly testing torque rather than power?
The 0-60 times are only meaningful when you want to get away from the lights first! As mostly you only get up to around 60 legally anyway ;)
But yeah, I pay more attention to the overtaking speed bands than the 0-60, 0-60 is easy to "fix" i.e. difference between MPi and VVC.
|Having owned both a 1.8 MPI and a VVC, and not being shy to rev the beasts to the limiter, I can state with certainty that you can go above 60 mph (indicated 105-107km/h, that's about 64-65mph) in both cars without changing into third. The top speed in second gear is almost exactly the same for both cars: longer gear ratios in the MPI compensate for the lower revs before cutoff.|
The main reason for the difference in 0-60 time is that the MPI loses a fair amount of its torque at 6,000 rpm so takes a longer time to rev to the limiter at 6800.
I agree with Paul that the VVC feels like it could easily rev higher than 7150: when the rev limiter cuts in in first gear it's as if you hit the brakes by mistake! Also, the fact that despite the variable valve timing the max rpm is only raised by 350rpm indicates that the VVC's rev limiter is set "conservatively". I reckon one could easily get 170 bhp or more out of a trophy 160 just by raising the limiter to, say, 7,500. HP = torque x rpm (plus a conversion factor), and there still seems to be lots of torque on a VVC at 7150. Look at Honda's old V-TECs in comparison to the standadr engines. And the V-TEC is more basic than MGR's VVC.
I suppose Rover were playing it safe at first when they launched the VVC engine because this was a new technology to them and they did not know how it would withstand wear and tear on the long term. I just wonder why they weren't more daring with the 160. Lotus get 177 bhp or 190 out of the 1.8 K-series partly by raising the max rpm.
|Anthony, the rev limiter operates after the max power load. So, pushing forward the rev limiter wouldn't produce any extra bhp without making other changes (mainly to the cams profile).|
That doesn't mean that the VVC wouldn't benefit from higher revs in 0-60 times ...
I tried to do a 0-60 last night, how the hell to you do it without your spinning the wheels, tried 4000, 6000, they spin and smoke..looks cool, but not what I was after...
|<<I tried to do a 0-60 last night, how the hell to you do it without your spinning the wheels>>|
Have not managed to spin my wheels since I got the SO3s fitted.
|I still have the crappy NCT 3 on the car|
BALANCE!!! It's a fine art, Medium right foot - Feel the force flow through you, find the limits of traction against power, close your eyes, be at one with the car and success will be yours.....ok, i'm off now!
|Regarding the earlier comment about cars feeling faster on some days than others - it's usually related to air temperature and moisture content. Cue a physics lesson...|
The lower the air temperature the denser the air will be, thus more oxygen is drawn in per breath of the engine. with more moisture in the air, the fuel/air mixture may be compressed further before igniting as the water dampens the charge slightly, therefore giving a more explosive detonation in the cylinder.
The K&N Cone air filter works by doing some of the above - The cool air pipe provides the cooler air, so more 02, and the expanding cone shape of the filter itself also serves to actually slow down the velocity of the incoming air - slower air is also denser air, increasing the above effect.
Some people install "water injection" systems in highly modified turbo/supercharger engines as a means of dampening down the fuel/air charge.
Raising the rev limit should always in theory produce more power - more revs=more bangs per second = more power, but ultimately friction, fuel and oxygen starvation catch up with you. Of course the manufacturers are always conservative to provide long-term reliability (ha!). Hence for example the BMW F1 engine being the most powerful unit in F1 at approx 860bhp in qualifying trim, revving to 18,500rpm, but in race trim they knock this back to try to get to the end of the race (190 miles)...
|re "but in race trim they knock this back to try to get to the end of the race (190 miles)... "|
Great theory but did not seem to work at the Belgian Grand Prix.....
|Gear speeds are 8.6mph per 1000rpm in second for the VVC and 9.2 for the 1.6 and 1.8. Maximums for max permitted revs shows the two results to be very close and both are over 60 as said.|
Engine cut out speeds on the VVC can vary below that which is quoted as the maximum and often this is due to the alignement of the two VVC solenoids being too close to each other. These are the two black items each with an electrical plug coming out of the side oif the VVC extension housing on top of the cylinder head. I made the mistake when I fitted a modded head initially to a VVC engine of lining these up, as is the natural thing to do, but then found the engine rev limited to around 6700, and a little flat, Spacing the two significantly apart when viewed on a clock face then the limit came back to normal and the power rose significantly. I wonder how many engines are being restricted from this which prevents proper VVC operation?
This thread was discussed between 03/09/2001 and 05/09/2001
MG MGF Technical index
This thread is from the archive. The Live MG MGF Technical BBS is active now.