http://www.nichecycle.com/ncs/mikuni/accessories/3234-1-ultimate-flow-optimizer-ufo-vm30-vm34-150063.html
Anybody ever try these? I think I looked them up a long time ago, but since forgot until today.
Thoughts?
I'm sure compared to most in this group I'm a pretty novice mechanic, but even by my amateur eye the bottom of a round carb slide just seems like it would better like this.
Maybe that's the selling point though....
Sorry I've got no experience...
Tony Doukas swears by these for his ahrma race bikes. Why race bikes? Because ahrma won't let you use flat slides.
I now remember wanting them, but don't want to pull the triggering they're not worth anything. Rebuilt my engine 4 years ago, and finally getting around to getting it running. Bored over with Pro-X pistons, TDR reeds, DGs, UNI filters and RZ intakes with VM 28s and Dave F Mod.
I was searching for bigger pilots and stumbled across these. They say that I could end up with half the size required without, so again, a conundrum on what to try...
They work great, I have them on my H2 with VM30's.
I remember a magazine (Motocross Action???) doing a dyno and track test on them when they were new. To make a long story short they work well.
15 years ago I put one in my Enfield single. The NA Royal Enfield parts catalog had it and I think they called it The Turbinator.
Curiosity got the better of me last night and I checked out the Niche cycle link. Almost bought the UFOs for my RZ350 and/or some VM30s I'm prepping, but couldn't quite commit. Decent site with generally good prices and free shipping at $100. I had to add some fuel line to make the freight! If one goes for the idea of the UFOs, they offer these:
http://www.nichecycle.com/ncs/categories/carburetor/accessories/vm34-110-ufokit-mikuni-vm32-vm34-slide-idle-left-ufo-kit-by-mikuni.html (http://www.nichecycle.com/ncs/categories/carburetor/accessories/vm34-110-ufokit-mikuni-vm32-vm34-slide-idle-left-ufo-kit-by-mikuni.html)
Maybe...
they are expensive. i know i could machine one pretty easily, but meh.
heres the direct link to the maker:
http://thunderproducts.com/product/ufo-ultimate-flow-optimizer/
ive been considering them for the 34s on the lc hybrid, theres a nagging 5800 rpm snag that is definitely flow related , and ive considered this to resolve the issue. its minor but it bugs me. :twocents:
I bought the Thunder Products UFO's for my H2. Though they were advertised to fit VM30's they were too big. I spent hours carefully grinding them to fit my slides. They work great but it was disappointing to spend so much time grinding expensive pieces of plastic.
This guy Bob sells aluminum inserts in the UK. I bought a set for VM34's and they fit nicely. If you have RD's, maybe he will sell you two. If you have more than one RD, maybe you can buy two sets (of three) then you have enough for three RD's.
Be careful about ordering the inserts to that they fit your carb slides - they can be left side or right side.
Here's the link: https://www.boblesbits.com/
So, if you buy just the disc you have to drill and tap a hole in the bottom of your slide to mount it and blend it to match properly ? :umm:
I think so. Kinda makes their machined slides appealing, but they specify left side idle, and my 30s are a left and a right. I wonder if something could successfully be done with dirko or hylomar; something that would adhere to the slide but do no damage if it came adrift?
i think i'll just machine my own.
actually, the uk place looks pretty good. 6.50 for shipping worldwide? excellent. thats like 90 bucks shipped for 3 , and actual metal. :metal:
I messaged boblesbits about their product, to see if they are compatible with plated brass slides and left/right idle screws.
I see they give a price break on multiple items; would anyone be interested in a group buy?
so did i. im running 3.0 slides on the carbs, so, should be intereting to say the least to see what he says. sent off a stack of pics to him this morning.
I ordered the niche ones with the slide included for my 34mm carbs. I didn't want to grind away on my slides incase there is a problem I can just put my slides back in. My carbs work pretty well now so I hope I'm not disappointed. I also hope the needle circuit doesn't go out of whack too. Ordered smaller pilots like they suggest. It will be an experiment to see if there will be more power. My bike runs real well as is but I'm willing to play around. I'll report back. :patriot:
Quote from: 85RZwade on June 03, 2020, 04:14:22 PM
I think so. Kinda makes their machined slides appealing, but they specify left side idle, and my 30s are a left and a right. I wonder if something could successfully be done with dirko or hylomar; something that would adhere to the slide but do no damage if it came adrift?
sombody did this to a triple, might have been jim hobbs? said it worked well. I'll never feel comfortable with an epoxy in the intake tract of anything on a street bike ( i know its been done but thats just me), but supposedly worked really well as well.
The aluminum ones that bolt in seem like a better solution to me.
the full slide is a good idea as well.
we'll see as i think we will all have a few versions to compare here soon. :cheerleader:
Quote from: m in sc on June 04, 2020, 08:02:48 AM
Quote from: 85RZwade on June 03, 2020, 04:14:22 PM
I think so. Kinda makes their machined slides appealing, but they specify left side idle, and my 30s are a left and a right. I wonder if something could successfully be done with dirko or hylomar; something that would adhere to the slide but do no damage if it came adrift?
sombody did this to a triple, might have been jim hobbs? said it worked well. I'll never feel comfortable with an epoxy in the intake tract of anything on a street bike ( i know its been done but thats just me), but supposedly worked really well as well.
The aluminum ones that bolt in seem like a better solution to me.
the full slide is a good idea as well.
we'll see as i think we will all have a few versions to compare here soon. :cheerleader:
I look forward to your report Mark!
Two sets, three bikes. About $70 a bike shipped from the UK... Hard to beat that. I wonder how these would work in my 400?
we're talking back and forth, im going to take some dimensions
Got some on my VM28's. A tad too small, but fills in most of the volume. Drilled a hole in the slide, mounted with a wood style screw from the upper side and did a little material removal.
Don't have good experience with or without to compare. Was running plain 2.0's and was too rich right at throttle opening. 2.5's with UFO's are working great, really great.
Had to adjust the slides up for idle, (RD400).
Certainly something to try, IMO.
I think the aluminum ones are def the ticket. if they don't work or i want to try, just cinched the deal on a new 3d printer for work, not some bullshit hobby one either.
However, Bob in the UK seems to really be on top of it, he sent me some print dimensions to compare, i think he def took the thunder products concept to the next level by dialing in some give-a-shit.
Glad this has inspired you guys.
At the moment I am going to back off on the purchase and make sure I have the appropriate pilots to get mine running without. I've gone too long without riding on two wheels.
Quote from: m in sc on June 04, 2020, 08:02:48 AM
Quote from: 85RZwade on June 03, 2020, 04:14:22 PM
I think so. Kinda makes their machined slides appealing, but they specify left side idle, and my 30s are a left and a right. I wonder if something could successfully be done with dirko or hylomar; something that would adhere to the slide but do no damage if it came adrift?
sombody did this to a triple, might have been jim hobbs? said it worked well. I'll never feel comfortable with an epoxy in the intake tract of anything on a street bike ( i know its been done but thats just me), but supposedly worked really well as well.
The aluminum ones that bolt in seem like a better solution to me.
the full slide is a good idea as well.
we'll see as i think we will all have a few versions to compare here soon. :cheerleader:
I did these in Jim Cannons H2 with his 30mm small body snowmobile carbs, mild port, re-milled heads and decks to get a real chamber design and with a few pilots changes worked great! Piston port motor now snaps like a RD reed engine.
I used some in Scott Turner's CB350 racebike and didn't work all that well, was too inconsistent at high rpm throttle snap off and roll on.
I haven't played with with them since...I do cut the slides to 3.0 with them in.
Been using TM34's on my yellow screamer for years and still have the VM34's and a set of ufo's out of Scott's bike if I want to try on them on my RD400...
Chuck
my reasoning is im definitley getting a hiccup rpm related at around 5800. shocker, i know, right? :wave:. i absolutely can not tune it out ignition or jetting wise. since the vms i have work so well everywhere else above and below, i figure i'll give this a try before moving back over to flatslides and kinda starting over. its more of a science experiment for me, but i think the more laminar flow under the slide will help. the 3.0 cutout probably isnt doing me any favors either :dawg: :busey:
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/vm34-large-bellmouth-18/vm34-slide-rh.jpg)
:whistle:
:thumbs:
My UFO's have "3.0" molded into them but I'm using with the stock 2.5's.
i just refuse to pay that for 2 pieces of abs plastic that may or may not fit my particular slide.
The making UFO's is not such as easy task as one thinks; the fitment and subsequent jetting will probably create frustration to many users. Its a path not to be taken lightly.
Its much easier to buy and further develop your knowledge and fully understand the amount of the time it will take to get them to work effectively with your engine.
oh, im aware of whats involved, thats its not a bolt in and go, for sure. I enjoy the tuning. :toot:
Niche order arrived. Here is the UFO and a machined 2.5 slide for 34mm carb. Slight problem with order though, whoever packed it put only 1 UFO in there and a template for drilling which they must of mistaken for a UFO. The missing one is on it's way. They definitely have scalloped shapes to them. The 2.5 cutaway has been altered to fit like a glove. Will follow up with the way it runs when I get the other one.
(https://i.ibb.co/mtx76TX/20200608-143612.jpg) (https://ibb.co/S0LpRyd)
(https://i.ibb.co/PZ38CBg/20200608-144855.jpg) (https://ibb.co/Lzbfp41)
(https://i.ibb.co/J3xmsZq/20200608-143626.jpg) (https://ibb.co/2Z8WkJS)
You're gonna like it. Midrange power improves.
i cant say by the pics i'm super impressed with the fit, but def going to be better. :twocents:
Quote from: m in sc on June 08, 2020, 03:17:28 PM
i cant say by the pics i'm super impressed with the fit, but def going to be better. :twocents:
The 2 pics I took outside I noticed it was not quite fully seated. Has anyone ever used a "drag strip" app on their phone to get acceleration numbers, ie 0-60, 1/4 mile, etc. so I can get before and after performance results?
The side cutouts appear to be symmetrical, like they'd work in a left or right side idle carburetor, right?
They won't fit either side on a triple and I don't think they will fit either side on an RD.
^ this is why Bob in the uk seems like a better option that thunder products tot he general public, to me. he's willing to work with what you actually have. (and actually specializes in triples). that's why i reached out.
You must have emailed with your work title, or Site Administrator, 'cause he still hasn't responded to me.
no, personal e-mail. he doesn't know who i am from anywhere else. (not like i have any sway anyway, lol) he said he was in the middle of a big project though. I didn't hear from him for 2 or 3 days though.
Quote from: 1976RD400C on June 08, 2020, 03:07:11 PM
Niche order arrived. Here is the UFO and a machined 2.5 slide for 34mm carb. Slight problem with order though, whoever packed it put only 1 UFO in there and a template for drilling which they must of mistaken for a UFO. The missing one is on it's way. They definitely have scalloped shapes to them. The 2.5 cutaway has been altered to fit like a glove. Will follow up with the way it runs when I get the other one.
Been curious about these for long time, looking forward to hearing your results.
Quote from: RDFL on June 08, 2020, 11:20:13 PM
Quote from: 1976RD400C on June 08, 2020, 03:07:11 PM
Niche order arrived. Here is the UFO and a machined 2.5 slide for 34mm carb. Slight problem with order though, whoever packed it put only 1 UFO in there and a template for drilling which they must of mistaken for a UFO. The missing one is on it's way. They definitely have scalloped shapes to them. The 2.5 cutaway has been altered to fit like a glove. Will follow up with the way it runs when I get the other one.
Been curious about these for long time, looking forward to hearing your results.
Me too! :nana:
I've got hard data. :toot: I tried to use a cell phone app to record drag race data but it was all over the place and I had problems with having to take my glove off to touch the screen to start it and it would trip on just from the vibrations from my bike. So I took my Qstarz GPS data recorder, that I never really used for much, and wow. It records time, speed, where you are, and G forces. The software graphs it and you get a great readout on what's happening. I did a drag race that was about 985 feet. Here's the screen shot at the end. The little lines coming off are the G forces from the bend in the road. I marked the shift points. Then there is a video of it in action recording speed, distance, and G forces. I'm kind of impressed with the G forces at launch. ;D And then finally, Go Pro on board. Now I got data I before UFO's. I'm ready to install them and give it another run. With the software I can lay one graph over the other and see what they do. :pop: This was so much fun and I'm happy the way it turned out for a first try.
(https://i.ibb.co/TbF6Yy4/gps-graph.png) (https://ibb.co/z70pQdX)
https://youtu.be/WXS5oY9NISk
https://youtu.be/SEjrI7xOqKQ
UFO report: The missing niche ufo arrived and I installed them. Switched from 50 pilot to 30. Left the air screws at 1 3/4 turns. Left the needles where they were and didn't do anything to the main jet. Got all cleaned up and ready to go..... Bike won't start. Push start all by myself and it idles but refuses to take ANY throttle. It was so bad I said go 2 grooves richer on needle. Now I got gas all over me but hoping for the best. It takes throttle but I can tell it is still leaner than it was before I installed The UFO's. OK lets keep going and see what happens. Go putt putt till it warms up. Pull away from the stop sign, and notice, yes, something is going on. Catch 2nd gear and for sure at 1/2 throttle is really pulling nice. It makes the power feel more like an electric motor with instant torque, very quick response. Went for 20 mile loop and yes they seem to smooth things out, quicker response. The pilot circuit is too lean. The motor is chucking all over the place when it is off throttle. Idle is higher now too, but they are different slides in there. Anyway, the pilot has be richer and maybe one more notch on the needle and try again. Summery: Don't make the pilot jet 1/2 the size it was, needle needs to go probably 3 notches richer, you will feel the throttle response gets better, probably more power but must test some more. A little more fine tuning and I think I will be happy with them. One thing for sure is 34mm carbs on a ported motor make excellent power at 1/2 throttle and when you open them up, it's like kicking in the 4 barrels on a V-8. :twocents:
nice, thanks for info
the aluminum ones from the uk i had made are done and shipping monday. will report.
also have a set of brand new tms on the way as well as plan b. :toot:
Mark, for what carbs did you order the CSIs? I'm still wondering if I can get a pair to suit my VM30 2.5 brass slides right/left idle. The UFOs appear to be symmetrical and sold individually, the CSIs left idle only and sold in sets of 3. Also interested in your tuning results when you get that far!
vm34s with a 3.0 cutout
I got a chance to tinker some more with the jetting after installing the UFOs with the store bought slides from Niche. This is the jet changes done. 34mm vm carbs.
Had 2.5 slides, new slides with UFO are cut to a 3.0 or maybe even 3.5 The UFO has 3.5 on the disc.
Went from 50 pilot to 30. Kept air screw at 1.75 turns out. Wouldn't start or run without jet change.
Raised needle clip from position 2 to position 4 (richer). Still too lean and pilot circuit lean.
Changed needle jet from P-2 to P-4. Kept clip on position 4. Turn air screw in to 1 turn out (richer).
Never did anything with the main jet (300)
Runs real good now. Pilot should go to 40 though.
I notice it really runs well from 0-1/2 throttle, real crisp and great throttle response. 0-1/4 throttle is sweet, real crisp, pulls hard.
Seems to run better now at low RPM 3500-4000 and putting it under load.
I never had a flat spot before but there is no sign of one now, at any RPM, throttle position, or load on the motor what so ever.
As for wide open, I'm not sure how the UFO does much because with the 3.0 slide the leading edge of the UFO is pulled way up in the slide chamber at WFO and just the very bit of the trailing edge is anywhere near the venturi area.
Another thing I noticed is the idle stop screw only needs to be turned 1/4 of a turn from touching the slide to get it to idle down low (maybe richer pilot jet will change that).
Also noticed my cylinder head temperature gauges read about 20 degrees higher now. When I opened it up temp went up to 350, it never went that high road riding before.
I'm happy, it seems to carburate perfect. I haven't had a chance to do a GPS log of a drag race to compare power. Going through the twisties and exiting turns the carbs are working perfect at any RPM. You do notice the crisp throttle response, and it makes easier to ride. Normal riding when you are at 0-1/2 throttle is where you notice they are working nice and it improves the way it runs. I'm still going to tinker with the needle clip and install the 40 pilots.
:clap:
good info, very good. :clap:
your head temp may be resolved with the pilot somewhat as well, curious to see. (the pilot does provide fuel through the whole range soemwhat)
I got a chance to play with the jetting again. Installed a 40 pilot. Before UFO's I had a 50. After UFO's I tried a 30, way too lean at 1 3/4 turns on the air screw. Still too lean at 1 turn on screw. Now with the 40, it is too rich with air screw at 1 3/4 turns. Just a crack off idle it is popping away and it developed a slight richness going through 5500 rpm. The only thing I changed was the pilot and it developed the 5500 richness. I can tell the whole midrange is too rich now, just like Mark said a pilot will effect. The rich mid range slows down acceleration. Also the temperature came way down, 30-40 degrees. So, a 35 pilot I think will put it spot on (unless I set air screw with the 40 at maybe 2 1/4 turns ?). Anyway, once the pilot and mid range is leaned some it should be right on the money. Looks like the jet changes for UFO's in 34mm vm carbs, on a stage II large reed motor will be: 50 to 35 on the pilot, 1 size larger needle jet, and 1-2 spot richer position on the needle clip. One odd thing is I can't get it to idle so low that it will stall by turning the idle stop screws way out. Maybe the UFO is not letting the slide to drop all the way down? Maybe it is hitting that shroud that sticks up on the needle jet? I better investigate that. (ya know, the cnc machined slide combo that cost $63 each :whistle:) The bike was running stronger when it was leaner. The UFO's seemed to give it better throttle response. Once I lean the pilot circuit and maybe go from 2 clip positions richer to just 1 it will be just right. Final test coming soon (preview: it's not going to have 8 more hp, but will have a noticeable better throttle response). :vroom:
Things I'm learning:
If you have a deserted rural area where you can play with the throttle position and speed you can really feel these carb jet changes happening and it isn't that hard to get it just right. The pilot circuit does effect the mid range. Too lean a pilot makes it run hotter.
Looking at the chart you see the cutaway change (2.5 to 3.0) leaned it at 25% throttle so the needle jet change corrected that (P2-P4)
(https://i.ibb.co/0BXBsJ7/cutaway.jpg) (https://ibb.co/9wvwZYD)
(https://i.ibb.co/b169cw7/needlejet.jpg) (https://ibb.co/WnHJm8s)
TIMELY AS I JUST GOT MINE.
so, what jet tube are you currently running? p4, or 2?
P-4 and the needle is a 6F9
I use UfOs often , I install many for my customers . They work great and cause a round slide carb to out flow a flat slide up to 13/16 throttle opening . I modify lots ofcarb with venturi dividers , both mods together are wonderful . They require a smaller pilot because the signal to the needle jet is increased and starts pulling much sooner causing a greater over lap during transition of circuits also cuttint he slide arch is necessary usually 1 to 2 mm . The are worth the effort . Check out my web site richstaylordporting.com aor give me a call if you would like to know more
Rich
More pics that wouldnt load
again
one more
The blades look like they could help but what tells you where or how many and how long does what?
How many? Well I started with doing just 2 at half throttle position , the difference was evident ao I went to 2 Two at half throttle ann two at 1/4 . Worked even better noticable better snap and pull through those windows , Then about 10 years ago I tried 6 dividers 1/4 1/2 and 3/4 Waaaay better linear power through out . So I would say that experience told me what worked . How Long you ask they reach to the slide and conform to it with about 1mm clearence . I have alot of them out there . Go to my testimonial page of my web site and read what one guy said how it worked on his 2016 TM 125 with power valve . I told him thai I believed that with m carb a power valve wouldnt be necessaayso he did his own experiment , Check it out . I first did porting and carb as well as my reed conversion on His vintage racers on his 370 Bultaco as wel as hus Rickman Hodaka , both on the same page . I have don 15 carbs for a vintage snowmobile racer plus several port jobs and he won the biggest ice flat track race in the country with his Kohler 440 tripple that made 126 hp and 98 lbs torque . The is also a RD 400 on my site that had earned the #1 plate on east coast using my carbs and porting .
Rich
I'm done jetting and here is what changes I did after installing the Niche slide and UFO assemblies on the VM34s.
Before After
Pilot 50 1 3/4 air screw turns 40 2 1/2 air screw turns it's a touch ricer now, going to 35
Needle jet P2 P4
Needle clip position 2 lean position 3 middle richer than before
0-1/4 throttle is super smooth, crisp and makes more power, acceleration is perfect with the 34s. 0-1/2 throttle same thing runs sweet. Full throttle may be making more power, not sure yet. It seems to pull up hills at low rpm better. It's running cooler with the pilot circuit a touch richer. One problem is I can't get it to idle under 2000rpm even with the idle stop screws backed out. All in all it makes the bike quite a bit easier to ride with the crisp smoothness, throttle response, and power that it is making by just using 1/2 throttle. I like. 8)
I havent had time to play witht hem at all, but i did dig out the carbs and the inserts and mocked 1 up. this is what they look like. to me, way better built but cant speak to fuction.
I need to correct my drawing as the 'bolt' hole for the slide was a hair off (on me) and resubmit to bob for the 34's, but i can make these work.
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/vm34-large-bellmouth-18/ufo-inserts-bobblebitsuk/uk-ufos_2-rotated.jpg)
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/vm34-large-bellmouth-18/ufo-inserts-bobblebitsuk/uk-ufos_1-rotated.jpg)
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/vm34-large-bellmouth-18/ufo-inserts-bobblebitsuk/uk-ufos_3-rotated.jpg)
(http://www.2strokeworld.net/wp-content/uploads/LC-HYBRID/vm34-large-bellmouth-18/ufo-inserts-bobblebitsuk/uk-ufos_4-rotated.jpg)
Looks nice . still count on cutting the slide as wll as the ufo piece 1 to 2 mm or it will be very rich on the bottom and reduce pilot size
Rich
i thought about that. my pj34's ont he lightweight have a (factory) notch in the slide, very small, for the same reason. if that's the case, i'll emulate that on my mill with a 1/16"" endmill if i have to. i'll try it as is at 1st and go from there though. thanks for the info, i was curious about that as well.
Great work guys! I love it when you can make more power burning fuel better.
I've got a 75 400 triple, stock with Jemco pipes. Want to gradually raise port timing and cut heads, have 3 sets to work with. Are my stock 26mm carbs adequate before I take time to put UFO's in or should I start with 28s?
26mm carbs toooo small to make good power. You could give me a call and we could discuss your project further if you like . Check out my web site richstaylordporting.com 702-858-9177
Rich
Here's another pic of the Niche slide showing how steep it is.
(https://i.ibb.co/dQ6RZt7/20200608-144847.jpg) (https://ibb.co/2jPTJS5)
26's on a 400 triple are good. I put down almost 60hp at rear wheel on a non ported 350 triple with 26mm s3 carbs & denco chambers. If you want to add reeds, that's a different story IMHO.
sure 26 is good as on a banshee but not ultimate , it depends on what someone my want to achieve . A tripple Kohler 440 I did all the work on made 126 hp and 98 lbs of torque with 38s and one the bigest snowmobile vintage flat track race in the country . And his 34 twin made 92 hp . Its all about what you want .
yeah, but we're talking about a street ridden S3-400 kawi with the most dismal transfer port layout you can imagine. apples and oranges here methinks.
Your right but still more can be had while maintaining rideability. Cool thing about the venturi dividers in carbs is that you can run bigger carbs since laminar flow is achieved in stages so velocity stays high . Bigger carbs behave small but make more power at the same time . 32mm is not out of the question here .
Rich
Always been skeptical about the venture divider type mods, especially when they are marketed like this.
Power now ! Does have some benefit but not much . It does nothing to create laminat air flow . And what happens after the air passes the slide? It expands again Blah!! I can connect anyone here to my actual customers ( they dont mind ) if you want to hear haw well 6 divider work. Just call me and I will hook you up to some if you like . 702-858-9177
Rich
Here is another carb I just finished and mailed off today . Has intelajet also , a great mod
one at a time
Very pleased with the info coming out of this thread. :clap:Didn't imagine it going this far. Someday after I get mine tuned without, maybe I'll give them a try.
:agree:, some fascinating information here. Obviously there are some gimmicks out there, but there are apparently some things that may look weird, but offer real benefits. Cool stuff.
I mentioned how the UFOs really crisped up the 0-1/2 throttle and the response. 0-1/4 is something else. With the 34mm carbs you get a lot going on with just a little throttle. It makes it so easy and smooth to ride. The first accel I turn to 1/2 throttle and roll it right back to 1/4. The next one is about 1/4 throttle. I really like how it is running. :clap:
https://youtu.be/sDHceoRcW9Q
sounds really good :clap: :cheerleader: