Velocity stacks

[Rev. Steve]

Is there any benefit to swapping these round or has someone just put the airbox back together wrong?

[mik_str]

can't comment on swapping them around but you can get a small but noticeable boost in lows and mids by running two long ones

[tony.mon]

The arrows on the tabs line up when you have them installed correctly.
There is a disadvantage from swapping front to back, as the longer ones, if fitted in the wrong location, sit too close to the filter plate and decrease power.
Two longs works well to gain a little mid at the expense of top end power, it's a trade-off, not free extra power.

[Rev. Steve]

I figured the arrows had to match up and they even put R and F on them and still got it wrong, kinda worried now what else I'll find.

[rollingthunderx2]

I have moulds for Moriwaki spec velocity stacks in carbon fibre, the moulds were made directly from an alloy Mori stack, and the radius was transferred to a longer stack.
I can make short, standard long, or longer stacks.
Longer stacks make 5hp more in the midrange.
The carbon fibre Moriwaki copy velocity stacks are bonded into standard inlet stacks, to save production costs.

[YETI]

??? I thought Moriwaki only claimed 4bhp gain with their stacks when used in conjunction with some of their other products ..... you must have made a big improvement on the originals somehow?????
Regards
Yeti .

[rollingthunderx2]

It is what Moriwaki quoted in their literature, according to the guy I got the alloy stack from, so, no Im not bothered whether 4 or 5 hp, it is a small increase that doesnt cost a fortune, which used with a better exhaust will improve HP, a little here and there, whether you think its 4 or 5 is irrelevant, they are Moriwaki copies that are, A, not unobtaium, B, affordable, as far as I can see that shouldnt be an issue.
You can please some of the people some of the time, but not all the people all the time.LOL.

[YETI]

So what evidence do you have that those stacks improve the bhp at all on a standard engine or a set up with let's say ?? A : set of race cans ? Or B : a slightly fettled with engine
Or are you just quoting a number ( 4 or 5 or something around there , kind of .... possibly cos a mate said they read it somewhere ) without any factual proof.
So are the Moriwaki stacks ( which are of unequal length ) the same length as the standard Honda stacks that you are grafting your crap to ?
You'll gain naff all from your stacks except tuning issues .
People will try to flog a dead horse if it fills their pocket .

[tony.mon]

So what evidence do you have that those stacks improve the bhp at all on a standard engine or a set up with let's say ?? A : set of race cans ? Or B : a slightly fettled with engine
Or are you just quoting a number ( 4 or 5 or something around there , kind of .... possibly cos a mate said they read it somewhere ) without any factual proof.
So are the Moriwaki stacks ( which are of unequal length ) the same length as the standard Honda stacks that you are grafting your crap to ?
You'll gain naff all from your stacks except tuning issues .
People will try to flog a dead horse if it fills their pocket .

How to make friends and inluence people! I thought I was blunt.

[Roger Ditchfield]

As the Moriwaki Importer for over thirty years I am certain that they never made a claim of a 4bhp to 5bhp power increase for their velocity stacks alone because it is an impossible claim. Moriwaki do not even make that claim for their special carbs fitted with their velocity stacks. The only claim of that proportion is for there Street Zero exhaust system. I hope this brings some clarification.

[fabiostar]

stacks and more stacks .

i pickled my head a year or so a go with stacks and only used my elbow dyno

back to back on the same day on the same road i tried
2 honda shorts
2 honda longs
mori stacks
and the 3 d printed Jessie stacks from Aus..

outa all of them you need a dam fine well tuned elbow dyno to detect the difference but difference there was..

we are talking small increases up or down but the honda ones cant say i noticed much, the biggest difference was between the printed stacks and the mori ones..

the 3 d printed ones did increase the midrange enough to feel, the best outa all of them at those revs but flattened out a little high up.

the mori alloy ones did increase the way the engine pulled harder from midrange onwards

as i say just what my elbow dyno was able to feel..

all done on dori here so not a standard bike.

[MK_WF]

Only properly shaved tonsils are capable of measuring those subtle differences.

But I have a very affordable way to skin that cat a different way:
There's several apps that record acceleration and rpm and calculate a performance curve from that (plus user entered values for weight and drag/rolling resistance).

In this case it doesn't even matter if it's showing the right values.
You simply do a baseline in stock configuration and then compare your modifications to that baseline. The measured difference is reliable.

In the past I used this one, which is determining rpm from the recorded engine sound.
https://play.google.com/store/apps/deta ... epowerdyno

Basically you press start on your smartphone app, stuff it into your backpack, do a WOT acceleration in one gear on a flat straight road and proceed that data afterwards.

Yes, it's not as accurate as a dyno and it takes quite some time for multiple measurements, but at the end it's MUCH cheaper than a dyno day.

[fixxlevy]

I have moulds for Moriwaki spec velocity stacks in carbon fibre, the moulds were made directly from an alloy Mori stack, and the radius was transferred to a longer stack.
I can make short, standard long, or longer stacks.
Longer stacks make 5hp more in the midrange.
The carbon fibre Moriwaki copy velocity stacks are bonded into standard inlet stacks, to save production costs.

Could be interested in this?

[tony.mon]

Ask to see the Dyno evidence before you believe the claims...

[rollingthunderx2]

well it seems the Mori stacks are the best.
Cant remember the stats I read.
TBH theres no need to get flakey and obnoxious about it.
These people would be better trolling over "coolants"
on another forum....