390 lbs/ft torque from a vf34?
31 January 2010, 01:12 PM
#33
Hi guys got back from [the racing line] after haveing the car mapped the results were 350hp/390lbs
just wondering if anyone else has seen a vf34 give that much torque as i only see around 350/350
mods
gems ecu
fmic
inducion k&n
full H&S exhaust
gt spec headers/uppipe
740 inj
forge actuator
forged 2.0l built be ZEN
will post printout up [membership]
just wondering if anyone else has seen a vf34 give that much torque as i only see around 350/350
mods
gems ecu
fmic
inducion k&n
full H&S exhaust
gt spec headers/uppipe
740 inj
forge actuator
forged 2.0l built be ZEN
will post printout up [membership]
Trev
31 January 2010, 02:12 PM
#34
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hi bud the stock actuator had a weak spring and was loseing boost, iv got the rolling road printout before the actuator was fitted
so £100 well spent in me eyes
so £100 well spent in me eyes
31 January 2010, 05:52 PM
#39
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Mind, it's to be expected if the old one's spring was weak...
31 January 2010, 08:23 PM
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yes mate very happy put its not just the 7bhp more at top end its the 70lbs more torque at 4000rpm
,just start saving for a 6 speed now
,just start saving for a 6 speed now
Last edited by pooeater; 31 January 2010 at 08:27 PM.
31 January 2010, 09:14 PM
#48
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Its common on vf's pushed hard for the egbp to force the wastegate open even with good boost control. Which where the tougher spring helps.
But its a sign there isn't much power left in the turbo.
But its a sign there isn't much power left in the turbo.
31 January 2010, 10:12 PM
#49
pooeater, so that weak spring initially prevented you from getting that extra 70lb ft at 4k rpm!? Once again, are you sure that's not actually 70Nm, therefore 52lb ft?
Also, as said, that 413Nm = 304lb ft (at the flywheel?)... If so, then what does this other quoted "390lb ft" figure relate to?!
Or is it 304lb ft at the wheels; 390lb ft at the fly? (That'd be a tranny loss of 22%, so it would be spot on)?
Getting confusing... (at least we got the bhp sorted!) lol
Also, as said, that 413Nm = 304lb ft (at the flywheel?)... If so, then what does this other quoted "390lb ft" figure relate to?!
Or is it 304lb ft at the wheels; 390lb ft at the fly? (That'd be a tranny loss of 22%, so it would be spot on)?
Getting confusing... (at least we got the bhp sorted!) lol
Last edited by joz8968; 31 January 2010 at 10:24 PM.
31 January 2010, 10:26 PM
#50
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Joz - I'm certainly no expert, but the graphs that you posted would suggest that the adjustment for transmission loss etc is 27% (diff between 275 and 350bhp).
Is that right?
Is that right?
31 January 2010, 10:40 PM
#51
No, you don't do the calc as...
350.9 / 275.9 x 100
...This is just expressing the difference, in percent, between wheel and flyweel bhp. It's not actually working out how much percentage of the flywheel bhp which needs to be subtracted from itself, so as to end up with the wheel bhp (this is NOT the same as the difference between the two figures i.e. we want to find the initial loss; not the end difference).
The actual equation is...
350.9 - x% = 275.9
i.e. 350.9 - (x x 350.9 / 100) = 275.9
...So x = c.21.3% ...because you are subtracting (i.e. tranny losses) from the higher flywheel figure. The higher flyweel bhp is made 'first', then tranny losses applied 'after'.
350.9 / 275.9 x 100
...This is just expressing the difference, in percent, between wheel and flyweel bhp. It's not actually working out how much percentage of the flywheel bhp which needs to be subtracted from itself, so as to end up with the wheel bhp (this is NOT the same as the difference between the two figures i.e. we want to find the initial loss; not the end difference).
The actual equation is...
350.9 - x% = 275.9
i.e. 350.9 - (x x 350.9 / 100) = 275.9
...So x = c.21.3% ...because you are subtracting (i.e. tranny losses) from the higher flywheel figure. The higher flyweel bhp is made 'first', then tranny losses applied 'after'.
Last edited by joz8968; 31 January 2010 at 11:47 PM.
31 January 2010, 10:55 PM
#52
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pooeater, so that weak spring initially prevented you from getting that extra 70lb ft at 4k rpm!? Once again, are you sure that's not actually 70Nm, therefore 52lb ft?
Also, as said, that 413Nm = 304lb ft (at the flywheel?)... If so, then what does this other quoted "390lb ft" figure relate to?!
Or is it 304lb ft at the wheels; 390lb ft at the fly? (That'd be a tranny loss of 22%, so it would be spot on)?
Getting confusing... (at least we got the bhp sorted!) lol
Also, as said, that 413Nm = 304lb ft (at the flywheel?)... If so, then what does this other quoted "390lb ft" figure relate to?!
Or is it 304lb ft at the wheels; 390lb ft at the fly? (That'd be a tranny loss of 22%, so it would be spot on)?
Getting confusing... (at least we got the bhp sorted!) lol
Thats 390lbft at the fly.... yes the weak spring stopped him from getting over 1.4bar
31 January 2010, 10:57 PM
#53
31 January 2010, 11:29 PM
#55
I had a VF34 on my 2.5 conversion, it ran 336bhp/379lbsft at abt 1.4bar-spool-up was from around 3k.
Pooeater is running 1.8bar on his 2ltr and it isn't surprising he's getting that big punch of torque at 4k. I wouldn't have thought the stock actuater would have allowed that amount of boost, usually VF34 are around the 1.3/1.4 bar.
Pooeater is running 1.8bar on his 2ltr and it isn't surprising he's getting that big punch of torque at 4k. I wouldn't have thought the stock actuater would have allowed that amount of boost, usually VF34 are around the 1.3/1.4 bar.
Last edited by trevsjwood; 01 February 2010 at 04:36 AM.
01 February 2010, 03:31 AM
#56
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Also, as said, that 413Nm = 304lb ft (at the flywheel?)... If so, then what does this other quoted "390lb ft" figure relate to?!
495lbft vs 460lbft of torque !!