I think it may be a good idea to run v stacks after or inside my pod filters. From what I have read the filters cause air turbulance. An internal or post v-stack may be beneficial to smoothing out the air flow.
Any recommendations on pre fab solutions or home made ones? Not interested in The Beast.
[popcorn]
I just realized I will only be able to do a test with a stack post filter because the ones I've got have an angled neck (ru-1750). I'm afraid if I put a stack up in the main filter area it will actually restrict flow, unless its really short.
velocity stacks are definitely necessary.
the biggest thing to keep in mind though is intake runner length is a key aspect of determining rpm range for the powerband. shorter means powerband in higher rpms, longer means powerband in lower rpms. and the stock intake setup past the carbs is essentially a velocity stack, but is also quite short. so you'd want to use a stack of equal or shorter length than the stock setup.
I don't know who or where to get the stacks/filters from though, sorry
So you're saying that everyone who is using pods is or should be using stacks?
Strange there's not much about stacks in the search..
you need a really big filter and a stack which fits inside uninterupted. the wasp system is about the best example of pods done properly.
I will likely be doing this improperly. I found a site with alum stacks. I'm thinking of mounting a short stack juuust inside the intake on the TB, hold it in place with rtv and mount the pods over that. Placing the stack inside the TB inlet will only reduce the I'd fractionally. I'm just worried that vibration would eventually knock em loose.
yep, you're doing it wrong.
http://www.waspworks.com/index.php?main_page=product_info&cPath=1&products_id=13&zenid=ngt99hma535381jdolevbv6la6 (http://www.waspworks.com/index.php?main_page=product_info&cPath=1&products_id=13&zenid=ngt99hma535381jdolevbv6la6)
<-- should buy a lathe and produce a kit for the carby's
if you actually look at the carbs, the inlet to the carbs is actually bell shaped, essentially a velocity stack. problem is, there's air jets encorporated into the middle of these bells, and mounting a filter directly to the carbs produces some inconsistent turbulence, not to mention fitment which doesnt allow large enough filters. putting a stack on the carbs enlarges the velocity stack, and smooths out the airflow making it more direct reducing turbulence into the carb allowing for a more consistent mixture of the fuel into the air, and also extends the mounting point away from the carbs allowing room for larger filters. from what I can gather, a stack with a slight curve would be ideal so properly sized filters like the above mentioned wasp system uses could be utilized. I think I just might have to look into this more myself, as I am power hungry, and am frequently known for making quality custom parts for all sorts of things, testing, improving, then offering a limited supply of replicas for sale.
don't hold your breath though waiting on me to do it, I'm unreliable time-wise, and prefer to simply wait til everything is done to announce it publicly
Big filter volume and velocity stacks! [thumbsup]
Small filter volume and right angle inlet [thumbsdown].
Worst dyno runs on a modified '95 M900 were with those RU 1750s. Yet they still flow enough to make 100hp on MBP motors.
I enquired with TPO re a kit for carbs, but injection is the present and future.
It would be good to run FCRs with the blue velocity stacks in a large 2 into 1 barrel filter. An airbox of correct design even better. Kaenma have done work with special airboxes.
There's room for two huge pods on the ie bikes. The carb models restrict the space available.
I emailed them. We'll see. Maybe a short extension off the carbs so those big ol filters could fit?
The carbs are so close to each other and so high and forward under the tank, it only allows smaller pods. Unless you run split FCRs on short manifolds! [evil]
That will have to wait til funds have built up. Yeah those wasps are pretty friggin huge.
I wonder what would happen if I cut off the 1750 elbow where it meets the filter and glue in the stock airbox rubber stacks in their place? Enough room side to side?
Or comparitively, I wonder how well(with proper jetting) a filtered v stack would perform? Like a regular stack but with one of those pancake lookin filters on top.
Quote from: memper on October 30, 2012, 12:33:40 PM
Maybe a short extension off the carbs so those big ol filters could fit?
this is what I'll be aiming for
Quote from: motoxmann on October 30, 2012, 03:21:05 PM
this is what I'll be aiming for
Alum would be nice but you could prolly find silicone 20 degree intake bends that would do the job.
V stacks from Velocity of Sound are on the way. I am going to perform two experiments.
1) stacks with glued in k&n filter (cut from my old flat filter)
2) stacks inserted into the 1750s (elbows cut off and glued in at base of filter)
I have the feeling that the stacks inside the filters will be best but I'm hoping #1 works too because it will look cooler... ;D
Too bad it's getting cold. It may have to wait til the spring unless we (northeasterners usa)get a tiny heat wave...doing jet changes in these temps will likely throw off results.
um, #1 sounds like a horrible idea, if I'm picturing it correctly. are you saying you'll cut a circle from a K&N flat filter, and glue the pieces in/on to the bell opening of the stack? EEK! if thats the case, thats pretty much asking for the filter to get sucked into the intake, and be extremely restrictive even if it doesnt.
the amount of airflow possible is solely based on the surface area of the air filter (when comparing identical filter composition). so if you use only small pieces of the original filter, you're reducing the amount of possible airflow by however much filter element surface area you're discarding.
Good point. I will still try it but I will make sure to construct it so no filter pieces will be sucked in. I'm curious. It must be done. I've read on other bike forums of people doing it on CV carbs and having relative success. Dialing in is challenging though, i read. But I like bike related challenges, even to find that my efforts were unsuccessful.
Otherwise I may get a set of those pancake filters and see how that goes. Im also looking at heat welded polyester filter bags from Mcmastercarr. http://www.mcmaster.com/#standard-filter-bags/=jzq553 (http://www.mcmaster.com/#standard-filter-bags/=jzq553)
I could cut them up and make booties of my own. Just not sure of which micron rating. Maybe 25...
MY 2001 F.I. M 750 has a nylon hoddie cloth cut out which is steel zip tied around the end of the trumpet ... WORKS GREAT
Good to know Chuck! Thanks.