Intake manifold length

[Aussie Ninja]

Just after opinions on weather this would be benificial or not. I have discovered that the intake manifolds on a '00 zx6r are 7mm shorter than my '98. I was thinking about throwing a set on to see if it made an improvement to my engines delivery. In theory I'm guessing that it would improve top end but I don't want to do that at the expense of the mid range.

[Smitty]

Just after opinions on weather this would be benificial or not. I have discovered that the intake manifolds on a '00 zx6r are 7mm shorter than my '98. I was thinking about throwing a set on to see if it made an improvement to my engines delivery. In theory I'm guessing that it would improve top end but I don't want to do that at the expense of the mid range.

the theory is
the longer the intake path ..the better than low and mid range
response, the shorter the path the better the top end
and
generally not much change in total engine output



hth

[Smitty]

Just after opinions on weather this would be benificial or not. I have discovered that the intake manifolds on a '00 zx6r are 7mm shorter than my '98. I was thinking about throwing a set on to see if it made an improvement to my engines delivery. In theory I'm guessing that it would improve top end but I don't want to do that at the expense of the mid range.

the theory is
the longer the intake path ..the better the low and mid range
response, the shorter the path the better the top end
and
generally not much change in total engine output



hth

[Aussie Ninja]

generally not much change in total engine output

That's the key phrase I was looking for. I was considering the possibility that the kwaka engineers realised they screwed up and shortened the length to get more power. If its going to move my peak up the range but not increase it, then there isn't much point is there.

[Smitty]

If its going to move my peak up the range but not increase it, then there isn't much point is there.

what tends to happen (specially in racing)
is that this change is accompanied by a camshaft change
to take account of the shorter inlet tract (and maybe other changes
like mods to cyl heads)
so you do get an increase in max power..higher up the rev range

for the street, without the other changes I mentioned
max output will barely change if at all
it will be just higher up the rev range

hth