XS1100 Cafe Racer - Motorcycle Dyno (Dynamometer) Run and Horse Power Explained

[@duaneweldon296]

Hey Andy, great schooling about horsepower and torque. Never had it explained so clearly. Ive got an 80 1100 Special with the head ported and the biggest cams made in the day that you didnt have to groove the head for. The porting was done by an Engineer for Ford motor company that did combustion chamber design. Paid $350 back in 1981. A side job/hobby for him. I could immediately tell a difference in the exhaust note with the porting, and even more low end torque. Then I put the Andrews cams in her and degreed the cams. I had to take the idle air jet out of the carbs to get correct idle speed.. Synced the carbs over and over till perfect. Put a K&N air filter in and drilled holes in the bottom of the air cleaner. I read way back the stock exhaust actually breathed as well as the headers did back then. I drilled 8 equal holes in the back of each muffler and it sounds great. not loud cruising. I revs way past 10,000, but thats where I shift. Also a Barnett clutch and springs. Burnt the stock clutch up before 1500 miles. My motor sounds like music compared to stock. My last back tire barely made 1500 miles. Very hard to launch without smoke. Broke my first driveshaft clean as lazer cut. Barnett clutch grabs real hard. I highly recommend porting, and I didnt go way up on jetting as it is more efficient burning now. Went thru a bunch of plugs jetting it. The clutch grabs so hard, it stuck one of the carb slides when dumping it hard. polished em with cotton and mild aluminum polish to cure the problem. Good to see a UK one still going strong. Curious if you made the cafe racer parts. Gonna research Dynajet as they sold me the jet kit. I thought I was around 110-115hp guessing on how much stronger it revs and feels, but you have me wondering now. Keep up the good schooling.

[@ANDY5]

+Duane Weldon g'day mate. Thank you for your comments. I now have a Wiseco big bore kit, 3mm oversized valves, bronze guides, beehive springs and porting as well as a Barnett clutch. Coupled with the 36mm flat slides it is now a noticeable improvement. I want to get it back on a dyno to see where we ended up but haven't had an opportunity as yet. Yes I made the Cafe Racer parts and built the bike from a pile of scrap, have a look at the 'Basket Case' playlist on my channel if you're interested. Thanks for tuning in.

[@michaelhayward7572]

Interesting about the octane ratings and the effect on hp. I always thought the higher the cooler the better. Thanx.

[@nickrider5220]

I've revisited this video after watching it a few years ago - a great video Andy. Those dynos that hold the revs momentarily to record the torque are accurate, but far lower than dynojet dynos - your 1100 made only 20hp less than a 1500 on the same dyno, that's really good 👍🏻

[@daveking2084]

God I wish you were my Maths teacher at school it would have been so much easier

[@ANDY5]

+Dave King Ha, that's funny. Thanks mate, Andy

[@joeheydenrych1240]

Hi Andy,nothing wrong with those figures for an old girl!! Love the tech side of the video. Cheers mate

[@ANDY5]

+Joe Heydenrych thanks Joe, yes I know. But let's see if we can't improve a bit hey? Stay tuned, Andy

[@finnroen2334]

I bought my first bike, a 5K7 when I was 17. This dyno sheet at 15:00 explaines the 180 km/t brick wall. I have followed this project from the start and enjoyed every episode. Exellent work and very good entertainment. Thank you very much. :) With this dyno baseline, a bigbore kit, headwork, higher lift cams and no screens in the velocity stacks would be interesting. Keep up the good work.

[@ANDY5]

+Finn Roen stay tuned mate, we will turn up the heat a little, Andy

[@markrothery8719]

That sounds fuckin awesome

[@Hoggdoc1946]

I see you have changed the tach/speedo setup. I was watching the tach during the Syno pulls, did I see him run the bike to 10K RPM. I don't think that engine was designed to turn that fast, is the tach reading off? BTW I have to agree with your comments on the DynoJet HP readings, I have always felt they read high. But that being said their software allows for adjustments that could bring that back into the real world, it's just most turners like to show higher numbers to their customers to justify the $ they just spent.

[@ANDY5]

It did pull up to around 9K, that was the old engine. The new one revs higher without valve float due to a better valve train assembly, but hasn’t been dyno’d yet. Red had a bad sidecar racing accident and has never recovered fully. Maybe one day.

[@gilbertreeves2084]

Andy, you left out torque readings....so long ago, I know....Any figures for the 1179cc kit... to compare..? The xs-1100 was known for its torque...horsepower is almost irrelevant at legal speeds...Torque at any speed is intoxicating....Your vids are great....

[@ANDY5]

There was an issue with the Dyno and Red was unable to get a torque reading sadly. Obviously the software was reading the torque but we couldn’t see it or print it out

[@ryderDoO]

You are awesome bro! Very nice vids!

[@johnmeade6889]

Nice 👍 video mate

[@jhernandez77794]

This is great

[@BillAndersonNS]

At first, I couldn't figure out why the speedometer read 0 throughout the test but then I realized that the speedo works off the front wheel = duh!

[@ANDY5]

+Bill Anderson it's a GPS speedo Bill, works off satellites, Andy

[@hadynjones5405]

What was the peak toque ?? Love the bike BTW

[@ANDY5]

Sadly Red's dyno was configured to record the HP, AF and Road Speed. If and when I ever get another opportunity I will get a torque, hp, rpm and af read out.

[@g0fvt]

Andy I know this video was uploaded some time ago but the maths at approx 7 minutes looks wrong. I do understand how it is derived but I think the 2pi function is in error. 38hp would lift 200b a lot further than 1000ft in a minute, that would only take about 6hp. Multiply that by 2pi would be a lift of 6280ft. IE your 200,000ft pounds divided by 33,000 is 6. Sorry if I misheard something, my wife is drowning out my laptop with the tv turned up. (She has an Ace Café sticker on her car). Keep up the good work.

[@g0fvt]

I think I misinterpreted the diagram, looks like your bike will be fun!

[@ANDY5]

+g0fvt I'll have to go back and watch it again. It must have been right in the end because 5252 is the constant used in HP equations. In fact when you look at graphs with HP and Torque the lines always intersect at 5252 RPM

[@g0fvt]

Andy, I probably misunderstood the diagram, as I say wife had tv drowning out the sound.Your videos are excellent, keep up the good work!

[@ANDY5]

No problem mate, happy to be corrected if I was wrong. Thank you for watching

[@nightster6378]

fantastic 80hp at back wheel is not to be sneezed at, it would be interesting to know what it is at the crank as many hp figures are shown at the crank and bear in mind even with the mods its still 40 year old technology tweaked. Also woulda been interesting to have done a dyno with the CV's and air box. I bet the heart was at full rate when raving it out.

[@ANDY5]

I wish I wasn't so slack and had the dyno figures for the new engine. It is a NOTICEABLE improvement over the old.

[@fransterhorst3694]

Interesting as always, learned a thing or two there. So going to 91 Octane instead of what we here call " sjonnie-fuel" that is around 100, will Increase the output of your engine yes? Shell likes to sell you the "v-power" high octane stuff based on a whole other idea. ha ha

[@ANDY5]

Hi Frans, yes mate. Hi Octane fuels suppress pre combustion by burning slower, a requirement in high compression engines. But the XS11 has a 9.2:1 ratio so by the time the fuel reaches it's peak burn the piston has passed that 7 degree past TDC sweet spot to deliver the highest combustion pressure. Andy

[@sammyabramyan2401]

Hey I just bought an XS1100 in pretty bad condition, so I need a lot of new parts. I was wondering if you have a parts list, or list of websites of where you got the parts for your bike? Thanks!

[@ANDY5]

G'day Subie, thanks for watching. I bought a lot of aftermarket and new old stock bits and pieces from sites like ebay, lots of 2nd hand bits on line and at dismantlers too. Try this web-site for new parts www.cmsnl.com/yamaha-xs1100_model16834/ and your Yamaha dealer should be able to supply some parts too. Andy

[@sammyabramyan2401]

Andy's Motorcycle Obsessions thanks for that! Where did you buy most of the aftermarket stuff like the tach and headlight?

[@ANDY5]

The speedo/tach is from Legendary Motorcycles and things like headlight, tail light and indicators from ebay or just entering Cafe Racer parts into Google.

[@sammyabramyan2401]

Andy's Motorcycle Obsessions alright! Thanks a bunch!

[@newscooler12316]

I know this is an old vid and you may have learnt this already but high octane fuels do not burn slower than lower octane fuels and I'm surprised your tuner doesn't know this! the reason why lower octane can make more power is because it has a higher energy content due to less anti knock agents. Still a good vid tho!

[@ANDY5]

The calorific value of petrol doesn’t change, regardless of octane rating. The octane only impacts the auto ignition temperature, the energy release is constant. Higher octane ratings allow for higher compression ratios without the risk of pre ignition. In some low octane rated fuels, such as LPG, there is a much lower calorific value and requires very high compression ratios to compensate for the lower energy value.

[@ANDY5]

I guess what Red was trying to point out to me is that running too high an octane can shift the ignition point, and subsequent flame front propagation, if you don’t have the aid of higher compression to elevate the charge temperature, and I believe that to be correct.

[@XS-ry6ig]

How did your HP go down ? These came stock with 95hp . WOW I am confused

[@ANDY5]

95HP at the crank, not rear wheel HP. Take away about 20% for transmission, middle box and final drive. Since that video was made I have added a Wiseco big bore kit and a modified cylinder head with 3mm oversized valves, porting, bee hive springs, titanium retainers, bronze guides and viton seals.

[@XS-ry6ig]

Back in August of 2017 I bought a basket case like yours. I did not turn it into a cafe racer like you did. I restored it back to the original black and gold it came out pretty nice

[@kasperkjrsgaard1447]

As far as i remember a stock XS 1100 should have around 65 rear wheel ponies.

[@saschaesken5524]

My XS 1.1 81 original state measured 104 hp on back wheel

[@llewvirtue861]

Andy you failed to mention the loss in power the xs has through the drive shaft. On my xjr 13 the manifold rubbers OEM don't match the ports. The fj 1100 has a manifold rubber coded 36y the match perfectly OEM. The xjr timing is preset, with a plate that is fitted on a locator. On eBay you can buy a plate that advances the timing by 4 degrees which Benifits the xjr . I have a set of k&n ,a pipe that Noel at pipeworx in nerang built me, a little shorty out the side. On Steve at powerhouse performance in nerangs dynos it made 125 HP bearing in mind, it's chain drive and it's 200 Cc bigger. The fj 1100 has apparently got the ducks nuts OEM cams and a set of fourty MIL flat slides would be the go. Then I think to myself, wake up you old bastard you 63 125 HP is more than you can handle, as if you floor it you seriously need to hold on. Ahh who knows maybe one day in my madness. There is a bike shop in Melbourne, he takes the xjr to 1400 better cams and flat slides, he is pulling 140hp on the rear

[@yamaha550xz]

Make a vid on head porting ???

[@ANDY5]

Stay tuned mate, I will do something.

[@oldcaferacer]

Dr Andy's workshop 1 o 1 kool

[@ANDY5]

+oldcaferacer lol, it's a bit easier to use than the old note pad, thanks for watching, Andy

[@Garageratto]

You want power.......boost is your ansfer :D go for turbo :P

[@ANDY5]

lol, yes that would work. Both my wife's and my car are turbo so I know where you're coming from. Thanks for watching, Andy

[@duaneweldon296]

Saw one with a turbo kit at the dragstrip. He couldnt ride worth sheet. He never even got off the line half decent not letting boost build. Never even broke a 12 second quarter with it when he should have been in the low 10s.

[@thatguycalledart6270]

www.motorcyclespecs.co.za/model/yamaha/yamaha_xs1100%2078.htm 95 stock??

[@ANDY5]

At the crankshaft, yes. Then you have to factor in the parasitic loss through the transmission, middle drive and final drive so 80 rear wheel horsepower is still respectable. Thanks for tuning mate, Andy.

[@thatguycalledart6270]

I guess yeh, if it was me id put on a chain drive but each to his own, nice build

[@ANDY5]

+ThatGuyCalled ART the build isn't finished yet mate, chain drive maybe on the cards. Check out my other videos for what performance upgrades I have made since, I will dyno it again soon to see what improvements I have made.