Ive fitted an ST170 engine on ZZ6R bike carbs with a pipercross 90mm depth dome filter
When under load and full bore fuel mist comes out of the filters
With it being a front engine car and the filters sticking out in the air this fuel mist sprays back on onto my visor
Anyone got any ideas
deeper filters 150mm?
longer intake tubes?
longer trumpets?
on the road you don't notice as its not often I give it that much as it wheel spins with it only being light (500kgs)
But I have fitted an LSD so now can give it more throttle and be under load, not spinning the wheels
That's it
Here is mine with no filters on rolling road about 12 seconds in mist http://youtu.be/Ppjy8rGHvZk
Any ideas on how long or short to make the intakes
plus 1\4"
plus 1\2"
plus 1"
Where would I start??????
quote:Originally posted by britishtrident
The only real cure is an airbox.
Is that curing it or hiding it? Are you going to end up with a puddle of petrol waiting for the next backfire for fun and chuckles?
I think the idea of the airbox is to reflect the pulses at the resonant frequencies so i guess thats a cure if you get the frequency right and hiding
it if you get it wrong
Cheers!
PS can the OP lengthen the inlet tracts? Although it may seem counter intuitive by lowering the resonant frequency the pulse strength is also lowered
and the added inertia of the gas may overcome the pulse - Whell something like that !
[Edited on 5-2-14 by v8kid]
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quote:Originally posted by pickmaster
I don't think an air box is an option
I won't be able to see where I'm going with that in the way
Then the only way to work around this would be longer trumpets to try and contain the stand-off, but that may require the carbs to be rejetted, and
you may sacrifice some top end for more mid range (which is often a good thing).
That's a neat solution
But I'd like to spend a bit more time trying to cure the problem rather than contain it
I'm going to experiment with intake lengths and see how I get on
If not maybe a mesh baffle inside a larger filter
I'll try 3" longer then shorten 1/2" at a time see what happens
quote:Originally posted by pickmaster
That's a neat solution
But I'd like to spend a bit more time trying to cure the problem rather than contain it
You can't "cure" it, it's an inevitable part of engine operation. . Containing the stand-off is the only solution, whether it
be in longer trumpets or within a plenum or air box.
I've been on the phone to pipercross today and they have said there is a carbon element in the filter to stop this
But I've been using K&N filter oil and they think its worth trying there's first as the two oils are for different materials
Watch this space!!!!
I've cleaned and recoiled filters with pipercross filter oil and been out this afternoon when it was dry
Still the same oil and fuel coming out at 4000 rpm and full throttle
Next time I get half an hour I'm going to extend the inlets an inch
See what happens
quote:Originally posted by pickmaster
I've cleaned and recoiled filters with pipercross filter oil and been out this afternoon when it was dry
Still the same oil and fuel coming out at 4000 rpm and full throttle
Next time I get half an hour I'm going to extend the inlets an inch
See what happens
As others have aready said you can't stop it from happening only contain it so it gets sucked back in and not blown away in the slipstream
Although the. net flow into a cylinder is inward airflow into a single inlet tract pulses in both directions.
You can't rewrite the laws of physics the length of the inlet tract. has a major affect on power delivery and mixture.
[Edited on 9/2/14 by britishtrident]
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