Gear box Ratios

[Rnash2002]

Ok does anyone know of a site or if they know the gearbox ratios in a m59 box and a box on a c70 t5 me7,or is the c70 a m56 box?

Reason i ask is when i timed a 60 to 100 mph run in the c70 it was quicker than my 850 t5 with the k24 but was way lower bhp and lbft figures when on the dyno.

[Wobbly Dave]

Our cars are both running M56 boxes. I believe the ratios remain unchanged.

[Rnash2002]

Our cars are both running M56 boxes. I believe the ratios remain unchanged.

Cheers Dave,that takes that out of the equation then,any chance you could time a 60 to 100 mph? lol

[smithy]

we will see how fast the car is on the strip mate

[Wobbly Dave]

Hi, I have been looking over my old chits from the quarter miles & looking over my old vid from May last year. About 10 seconds in 4th (I think this is 4th?)

Sadly I don't seem able to upload this video directly.

Here is the 4th gear vid...

[ame]http://www.youtube.com/watch?v=UvedfROlge4[/ame]

[Wobbly Dave]

3rd Gear

[ame]http://www.youtube.com/watch?v=xyZX5HVnOLA[/ame]

[jardon]

There are different final drives in M56 boxes depending on car and year but I don't know what those ratios are. Was there an M56L and M56H or am I making it up?

[Rnash2002]

3rd Gear

http://www.youtube.com/watch?v=xyZX5HVnOLA

I take it you have your limiter raised? as it didnt sound like you changed gear?

[Wobbly Dave]

The car will run upto approx 72 in second, ~ 110 in 3rd, about 140 in 4th & off the clock in 5th. My red line is about 7200. It has been raised on this map.

I am able to stay in 3rd on the drag & complete doing a top speed measured at 103 & I was almost out of revs.

That applies to the slightly older box (which came off an S70 I believe) which has the ATB in it & the original gearbox.

I will get confirmation in the next few days about the ratios - as the new box is currently back in the workshop being investigated.

[Rnash2002]

Ok so when these were taken you were running 300bhp?

Ive done the same runs today in mine as she is and put my foot down from 60 like you have heres mine and your times.

Mine


60 to 100 3rd and 4th gear = 7.03 (Have to change as limiter still stock)
60 to 100 4th = 8.15

Dave

60 to 100 3rd = 6.97
60 to 100 4th = 9.68

Now i just cant see mine making 256 bhp and 300 lbft to be beating yours in the 4th gear run and very close in the 3rd to 4th also take a few tenths to change gear aswell lol.

[T5frankie]

Ok so when these were taken you were running 300bhp?

Ive done the same runs today in mine as she is and put my foot down from 60 like you have heres mine and your times.

Mine


60 to 100 3rd and 4th gear = 7.03 (Have to change as limiter still stock)
60 to 100 4th = 8.15

Dave

60 to 100 3rd = 6.97
60 to 100 4th = 9.68

Now i just cant see mine making 256 bhp and 300 lbft to be beating yours in the 4th gear run and very close in the 3rd to 4th also take a few tenths to change gear aswell lol.

remember dave's has a 19t so in fourth wont come on boost till much after your 16t so thats why his time is slower in fourth but not third

[Rnash2002]

remember dave's has a 19t so in fourth wont come on boost till much after your 16t so thats why his time is slower in fourth but not third

Yes but i have to change from 3rd to 4th and that would lose me somtime.
Im just struggling to see why mine only made 256bhp when its as quick as a 300bhp c70 and also slighlty quicker than my 850 was with the k24 on it.
Dont get my wrong im not complaing at all as she feels good on the road.

[T5frankie]

Yes but i have to change from 3rd to 4th and that would lose me somtime.
Im just struggling to see why mine only made 256bhp when its as quick as a 300bhp c70 and also slighlty quicker than my 850 was with the k24 on it.
Dont get my wrong im not complaing at all as she feels good on the road.

but he is about 700 rpms off boost in 4th that takes more than a few tenths, remember my car only made 262bhp with the 18t at 22psi at 4000rpm that too felt rapid on the road but not on the track, you going to york?

[Wobbly Dave]

According to my map my boost starts around 3K but will not be fully in till 3500 - 4000. I am only running 0.9 bar at WOT. The 300 figure is explained by the long torque curve that remain high right the way through till about 5500. Peak figures are not always the best explaination. It is the area under the torque curve that gives the game away.

http://www.vpcuk.org/forums/attachme...9&d=1288918938

[Rnash2002]

but he is about 700 rpms off boost in 4th that takes more than a few tenths, remember my car only made 262bhp with the 18t at 22psi at 4000rpm that too felt rapid on the road but not on the track, you going to york?

I see where you comming from but im also going on my 850 with the k24,now that wouldnt be on boost as quick as the 16t.
Yes i will be at york,if i can i might try and get down sooner as im itching to see what she runs like.

According to my map my boost starts around 3K but will not be fully in till 3500 - 4000. I am only running 0.9 bar at WOT. The 300 figure is explained by the long torque curve that remain high right the way through till about 5500. Peak figures are not always the best explaination. It is the area under the torque curve that gives the game away.

http://www.vpcuk.org/forums/attachme...9&d=1288918938

I do see and understand this but i thought it was the lbft's that pull the car along so the higher they are the quick it should pull you along?

[T5frankie]

I see where you comming from but im also going on my 850 with the k24,now that wouldnt be on boost as quick as the 16t.
Yes i will be at york,if i can i might try and get down sooner as im itching to see what she runs like.



I do see and understand this but i thought it was the lbft's that pull the car along so the higher they are the quick it should pull you along?

thats what made my car so quick on the road cos it had 335lbs ft torque (455nms) made all its power at 4k. i think daves car has high bhp but quite low torque compared to some thats why his car only gets moving after 1/8th mile my car is the other way round quite high torque but relatively low bhp thats why my car is crap on the second half of the quarter

[Wobbly Dave]

I see where you comming from but im also going on my 850 with the k24,now that wouldnt be on boost as quick as the 16t.
Yes i will be at york,if i can i might try and get down sooner as im itching to see what she runs like.



I do see and understand this but i thought it was the lbft's that pull the car along so the higher they are the quick it should pull you along?

torque give you the acceleration. Power gives the speed. So if the torque remains high the acceleration should not disipate as fast even though this is balanced against the drag (moving the air out of the way) + friction from the tyres + overcoming the inertia.

I am no physicist but I know that the car moves well. We shall see at York no doubt.

[Wobbly Dave]

thats what made my car so quick on the road cos it had 335lbs ft torque (455nms) made all its power at 4k. i think daves car has high bhp but quite low torque compared to some thats why his car only gets moving after 1/8th mile my car is the other way round quite high torque but relatively low bhp thats why my car is crap on the second half of the quarter

I dare say I am not making the same volume of airflow through the induction system in 2nd as the 16T - boost will be lower hence I am not making much headway on the drag strip until 3rd - hence the high speed finishes (103) but relatively slow times 14.7 so far this season. Best 60 ft was 2.4 seconds.

[T5frankie]

I dare say I am not making the same volume of airflow through the induction system in 2nd as the 16T - boost will be lower hence I am not making much headway on the drag strip until 3rd - hence the high speed finishes (103) but relatively slow times 14.7 so far this season. Best 60 ft was 2.4 seconds.

whats your best 1/8th mile dave?

[Wobbly Dave]

been looking for my old slips - what I can find - which is not a lot is about 9 seconds for the 1/8th mile.