ban99shee Posted October 16, 2011 Report Share Posted October 16, 2011 Recently got a banshee and it's the first owned in almost 20 years. It a 94 and mainly stock, 2nd owner and well cared for. I already and put a ton of money and time into it...the addication has started!! I have spend weeks working on it and only a few day riding it so far!! But it did run perfect! The last 12+ years I've been riding 4-stroke qauds and sleds. Lately i got a bug up my ass and decided I was sick of only going 85mph on my yfz450. And after being on some high powered sleds most of my life..the 450 just seemed like a toy. I'm in wisconsin and there are tons of atvs trails so i decided to build something old school and fast. Right now i have a 4mm stroker(trued, welded+RZ bearing), 421 Serval Cub(no port work), cases were port matched, V-force 3 reeds, T5s, clamp-on K@Ns, dual feed petcock, Modqaud alloy intakes w/connecting tube, 7degrees of timing, 18cc domes, lighten flywheel and etc. Currently I'm running 28mm pwks and realize I'm missing out on top end. Would boring them to 30s be worth it? Or should I just sell them and go bigger. I mostly trail ride but still like having alot of top speed. The trails I ride on are usuallt longer gravel roads and etc anyways....your maily in 5th gear+. And I have a 5 gallon Clark tank and bring extra fuel..so i'm not worried about fuel milage either Plus I was thinking of racing the same bike on the ice this winter and TT next summer. Some of the TT are 1/2 to mile oval. So...what would you guys run for carbs and why? I would like to stay with pwks cause i already have a ton of jets. I know the main jet work in larger carbs...do the needles jets from a 28mm PWK work in a 33-34mm? I also was wondering about getting Shearer small bore in-frame pipes. I think the T5s are cutting out on top end. Im more concerned about mid and high speed. Whats the main difference between CPI and Shearer's on a cub? Thanks for your input! BRRRAAAPPPPP Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted October 16, 2011 Report Share Posted October 16, 2011 33's should suit you fine.....they'll allow a larger fuel dump in the high revs where as the 28s can't gobble enough air.... The problem with going larger than that with most bikes is that you begin to lose your low end pull. Also the shearers allow more over rev than the t5's that you are currently running. The cpi's will also allow more over rev than the t5's. If you jumped to 33's it would definitely help but I bet your t5's would then be what is limiting you. But the shearers would pull your bike hard up top with 33'sthe like your describing. Check with NYUK he deals in parts and may have some floating around for you... Quote Link to comment Share on other sites More sharing options...
spurdy Posted October 16, 2011 Report Share Posted October 16, 2011 If you're serious about going faster I would change pipes to a set of inframe shearers or CPIs and and go to a 35mm PWK. I run the same set up on a 4 mil stock cyl with a very aggressive dune port and it is a very good match. Even a 39 PWK would net you another HP or 2 on top but I don't think it would be worth the fuel consumption IMO. The T5s are most likely holding back your Serval. Of course, you will need to gear it to go faster, you'll only go as fast as your pipes will allow you to rev and your gearing will take you if you have the HP to get there. It's all about the math. SP Quote Link to comment Share on other sites More sharing options...
ban99shee Posted October 17, 2011 Author Report Share Posted October 17, 2011 thanks for the feedback guys! I do have it geared kinda tall...but I can just feel the powerband level out. I just bought some new PWK 33s from the HQ for sale forum. I also plan on getting Shearer pipes. If some day down the road I decide I want to go bigger. Can the 33s be bored?..to was size being safe? Quote Link to comment Share on other sites More sharing options...
ban99shee Posted October 19, 2011 Author Report Share Posted October 19, 2011 Just bought some shearer small bore in frames with silencers....super excited about that. So with those and the 33s it should run some good rpms now. My other question is what are some of the better intakes for top end? I currently have aluminum Air Speed intakes that originally had 28s on them. I planned on just changing out the rubber flages to fit the new 33s. But after looking at a lot of used parts...i noticed there are many different designs of intakes out there. My intakes have a full "X grate" on the inside. I have seen some some just half that( or split in the center). I imagine this is to create smoother air flow...but the ones I have almost seem like they would be restrictive on top end because of so much surface area. What are you guys running for intakes? Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted October 19, 2011 Report Share Posted October 19, 2011 well it could be in there to actually MAKE turbulance... sounds wierd i know but its a proven fact that for motors you achieve the most power with a rough intake entry (as it helps atomize your fuel better and also break your fuel up more and spread it into the air molecules) and a smoothed out polished exhaust to get the exhaust fumes out as fast as possible..... so depending on the "grid" pattern you have in there it may actually be helping you.... Quote Link to comment Share on other sites More sharing options...
spurdy Posted October 19, 2011 Report Share Posted October 19, 2011 Just bought some shearer small bore in frames with silencers....super excited about that. So with those and the 33s it should run some good rpms now. My other question is what are some of the better intakes for top end? I currently have aluminum Air Speed intakes that originally had 28s on them. I planned on just changing out the rubber flages to fit the new 33s. But after looking at a lot of used parts...i noticed there are many different designs of intakes out there. My intakes have a full "X grate" on the inside. I have seen some some just half that( or split in the center). I imagine this is to create smoother air flow...but the ones I have almost seem like they would be restrictive on top end because of so much surface area. What are you guys running for intakes? Most of the diferent intakes out there are going to work just fine. As said, some turbulance in the intake tract is desirable. If you were to dyno test several diferent designs I would bet money you wouldn't see more than a HP difference if even that. I dyno tested 2 different intakes I had, one with the cross hair pattern and Trinity's "formula 1" swirl design (or what ever it is they call it) and had virtually no difference in numbers. SP Quote Link to comment Share on other sites More sharing options...
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