Now dare I ask effect of trumpet length?
... probably been asked a trillion times before but what is effect of inlet manifold length?
I seem to recall that shorter lengths are will be more effective at high rpm and longer ones at lower rpm.
no doubt cam timing has an effect too.
so a simple summary anyone?
AFAIK its best to have the butterflies as close to the inlet port as possible for the best throttle response
for throttle response: as close as possible.
for more torque at lower rpm: longer is better (usually)
i think saab came up with the idea of a variable volume design which gave best of both worlds.
bmw have a system where the valve lift is varaiable - wont get much closer than that!
[Edited on 3/4/09 by dinosaurjuice]
Is that why my laguna is so slow and the throttle responce is awful but have plenty of torque at low rpm?
The manifold runs from the back of the engine to the front.
Have a look at the FAQ section on the Jenvey site here:
http://www.jenvey.co.uk/
It answers most of the questions people have about induction systems.
Longer inlets resonate at lower frequencies so contribute to better cylinder filling at lower RPM but may restrict airflow a bit at high RPM.
Shorter inlets resonate at higher frequency as there's less volume of air in there. This gives better filling at higher RPM so better torque and
power up the RPM band.
Resonance in a system of a cavity (cylinder) and neck (inlet tract) can give a cylinder volumetric efficiency of over 100%. That is the air and fuel
are rushing towards the cylinder at the moment the valve opens and just piles in to the cylinder. When the cylinder is full, the momentum of the air
in the column squeezes just a bit more in, giving you just over 100% filling. The inlet valve closes and you've got a peak in your torque curve.
cheers, 's how I understood it.
Now dare I ask effect of trumpet length?
quote:
Originally posted by l0rd
Is that why my laguna is so slow and the throttle responce is awful but have plenty of torque at low rpm?
The manifold runs from the back of the engine to the front.
quote:
Originally posted by l0rd
Is that why my laguna is so slow and the throttle responce is awful but have plenty of torque at low rpm?
The manifold runs from the back of the engine to the front.
quote:
Originally posted by 02GF74
cheers, 's how I understood it.
Now dare I ask effect of trumpet length?
So is there a best length for both tourqe and responce ???
also what would happen if you had say a throttle body nearer to cylinder no 1 ???
quote:
Originally posted by dinosaurjuice
theres a few other factors, but yeah thats why.
quote:
Originally posted by yellow melos
So is there a best length for both tourqe and responce ???
also what would happen if you had say a throttle body nearer to cylinder no 1 ???
quote:
Originally posted by yellow melos
So is there a best length for both tourqe and responce ???
also what would happen if you had say a throttle body nearer to cylinder no 1 ???
I refer to my posts of a few post ago! There's not much point in asking questions if you don't look at the answers!
Look i have had an hour less sleep this week due to the stupid clocks going forward.... give me a chance. 