Driveline Performance Posted July 26, 2015 Report Posted July 26, 2015 Sorry for the delay: The first testing is on my 7mil motor. I strictly drag race this bike so the port timing is 198/128. I wanted to do the testing in stages so on this set of cylinders all I did was port the exhaust and the triples. I did most of the work on the main exhaust port re-shaping it and raising it to the 198 duration. The triple ports were also raised and opened up slightly. The intakes are as casted and the only thing I did to the transfers is match the bottom of the cylinder sleeve at the transfer point to the same radius as the pistons have on the sides of the skirts ( If that makes any sense). I did use my new pistons with the raised intake windows which definitely helped the intake volume on these cylinders seeing as there are no boost ports. The domes I used are not optimal at all but I was not able to cut a set the way I wanted in time so I used what I had. They are 19cc domes with a 9.5mm wide squish band and .053" squish clearance. ( When I re-cut a new set I'm looking for .040" - .042" clearance) The cranking compression came out to 175lbs so I used 110 octane Race gas. The carbs are 38mm Keihins with v-force 2 reeds and UPP intakes (I hate billet intakes) 7 degree's advanced ignition timing. I tested it with 2 sets of pipes so far the first test was Shearer big bore inframes and it made 94H.P. with 50 lbs of torque with peak power at 9800 rpm's. The second set of pipes were Shearer small bore OOF's and it made 96.5H.P. and 51 lbs of torque with peak H.P. at 10,000 rpm's. The big bore inframes had a stronger front side on the curve but made a little less peak power. I want to test with a bigger set of carbs and fix the squish clearance in the near future and hopefully try to reach a 100H.P. I do have graphs to post and will try to get them up as soon as possible. If you guys have any questions I will try to answer them as best I can. 2 Quote
#1JUANstunna Posted July 26, 2015 Report Posted July 26, 2015 The only question I have isn't about your cylinders. BansheeHP is really the janitor at your shop isn't he? 1 Quote
Driveline Performance Posted July 26, 2015 Report Posted July 26, 2015 He does clean up a lot.. 3 Quote
trickedcarbine Posted July 26, 2015 Report Posted July 26, 2015 Friggin eh! Interesting results with the big bore vs. Small bore. Being a fella that hot laps, that is an important factor. Wondering how well something with say a 194ish exhaust and lots of transfer work and proper domes would run with some CPI's. 2 Quote
BANSHEE HP Posted July 26, 2015 Author Report Posted July 26, 2015 Blue- big bore shearer inframes Red- small bore oof shearer Quote
possum Posted July 26, 2015 Report Posted July 26, 2015 The sb oof would be faster in drag race. 8500-10000 is where the shift points are at. And it has more overrev at 11000 2 Quote
trickedcarbine Posted July 26, 2015 Report Posted July 26, 2015 For sure. For me I would love the over rev on big 1/2 mile ovals, but my inframe shearers start to get heat soaked after about 5 laps on big tracks. I would love to try a big bore pipe to see if it would resist that a bit and if it was that close in performance I would totally settle for a little earlier curve and couple less peak. It's only a 4mm though so not quite apples to apples. 1 Quote
locogato11283 Posted July 27, 2015 Report Posted July 27, 2015 You should get a hold of Gary at Sniper. I bet his pipes will pull 100+ on that same setup. Looks very good! Quote
SOUTHTHIRTY Posted July 27, 2015 Report Posted July 27, 2015 Can you giv us any base lines graphs for some stock bikes.. just to see where your dyno stacks up.. sounds like you guys are having some fun in the shop.. 2 Quote
BANSHEE HP Posted July 28, 2015 Author Report Posted July 28, 2015 This was a stock stroke trail port we did on a bike a few months back. Stock head, 30oko, full air box, fmf fatty with spark arrestors. The green line was baseline, red and blue are after tuning. This is a stock 2006 yfz. Red is baseline Blue is air box lid removed, k&n filter with a pre-filter screen cover, the stock spark arrestor swapped for a vitos higher flow version. The dyno is a dyno jet 188. Basically the industry standard as far as chassis dynos go. WIth new a/f meter this year, new tower software the year before. It reads that same as many dynos around the country. Quote
registered user Posted August 1, 2015 Report Posted August 1, 2015 Are these just a slightly tweaked athena or what ? Alittle info what what we're getting for $375 would be good Quote
registered user Posted August 1, 2015 Report Posted August 1, 2015 Hey doosh go back to the handle bar changing thread Quote
registered user Posted August 1, 2015 Report Posted August 1, 2015 Just looking for a real answer. Besides what I can tell from the photos (inlet looks taller) what sets these apart from athenas ? Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.