[sdsting]

So I did a run through the mountains today to burn off what’s left of my rear tire, and I had an interesting encouter, I hit the rev limiter in 5th for the first time ever. I’m not sure what to make of this. For those of you familiar with the San Diego mountains, it was up in the Banner Grade run, not far from Mt. Palamar & Julian. This is the exact same strech of road that I did my speed-test runs right after the 30 pulley swap. As you may remember from those videos I held it wide open in 5th gear for about a mile, pushing past the 130 mark on the speedo and never hit the rev limiter. Today on the same strech of road I watched the speedo climb faster than I’ve ever seen it, just shooting through the 130 and going farther than I’ve seen it before on these same runs. When I first hit the rev limiter I backed off and made sure I was in 5th. Then I doubled back and ran that same strech again. Here is the 30 sec. video of that strech:

The rev limiter sputter is not that obvious on this audio, but you can hear it kick in just as I go over that slight arch in the road, then I backed off. I’m not sure what to make of this, the bike was clearly running stronger than the last time I did this same run, and I have done nothing different to the bike since then. The only think I can think of is the difference/change in the air. This was at about 5,000 feet. My previous speed runs were at abut 90-95 deg. temp, and today it was about 69 deg. Q: does that make the air thinner, make the bike run a touch leaner, faster?? I have no idea. All I know is the bike responded with more power today in 5th gear. It’s was actually kind of dissapointing because I ran out of top-end too fast. Not sure what to make of it.

(To head off the obvious question, I do not have an auto tuner, have a power commander that was dynoed at sea level)

 

[Guest]

At any given altitude, the air should be thinner the warmer it is, denser the cooler it is.

 

[Stryker2012]

r
The only think I can think of is the difference/change in the air. This was at about 5,000 feet. My previous speed runs were at abut 90-95 deg. temp, and today it was about 69 deg. Q: does that make the air thinner, make the bike run a touch leaner, faster?? I have no idea. All I know is the bike responded with more power today in 5th gear. It’s was actually kind of dissapointing because I ran out of top-end too fast. Not sure what to make of it.

Cooler air is denser, denser air needs more fuel to keep A/F the same. More fuel = more power. Same thing is happening up here in New England. Days are getting to be down in the 50's and 60's...my Raider just wants to fly ))))))))))))))))))))

 

[sdsting]

Makes sense. I find this rally fascinating.

 

[BOOLSHOT]

Cold air is denser, so more oxygen being burned. I will make the mixture leaner, but it it is leaner because there is more oxygen, not less fuel. More "bang" with same fuel. That's my opinion anyway.. but I don't know much.

Sent from my HTC VLE_U using Tapatalk 4

 

[Stryker2012]

Cold air is denser, so more oxygen being burned. I will make the mixture leaner, but it it is leaner because there is more oxygen, not less fuel. More "bang" with same fuel. That's my opinion anyway.. but I don't know much.

Sent from my HTC VLE_U using Tapatalk 4

Not leaner - just more: Air entering the throttle body goes by he MAP (manifold absolute pressure) sensor (some applications use a MAF -mass air flow- basically same thing) . Since colder air is denser, the sensor picks it up as more air flow coming into the throttle body, and therefore tells the ECU to bump up the fuel. Also works in hand with the IAT sensor (intake air temperature). This is the electronic version of a choke.

In a perfect world the ECU want to keep A/F at 14:1. When air is hot, there are less molecules in a given volume...lets say 14 parts of O2 ...the computer will inject 1 part fuel. If colder air is introduced, the molecules are closer together (denser) and the same volume may now hold 28 parts O2....so now the computer needs to bump up the fuel to inject 2 parts fuel to keep the A/F ratio the same. It's almost like natures way of supercharging your bike :thumb:
(and for those who are ready to pounce on the above explanation...yes we didn't get into adding fuel for accelerating or WOT operations just to keep it simple, but the principle is the same)

This is why cold air intakes are all the rage with cars.....

If you don't believe me...keep riding in the cold and watch your MPG compared to riding in the summer

 

[toby]

The cold air theory holds water. Add the fact that your tire is just a bit smaller in diameter due to loss of rubber and probably the biggest contributing factor, a strong tail wind.
Putting a 240 on will not only change your speedo reading about 4 mph it will also give you a few mph more in each gear than you had before. Also affecting your top speed.
Note where your rev limiter hits in each gear before you change the tires.

 

[yammyboy]

The cold air theory holds water. Add the fact that your tire is just a bit smaller in diameter due to loss of rubber and probably the biggest contributing factor, a strong tail wind.
Putting a 240 on will not only change your speedo reading about 4 mph it will also give you a few mph more in each gear than you had before. Also affecting your top speed.
Note where your rev limiter hits in each gear before you change the tires.

I tried a top speed test a week ago with my stock 210, 30th pulley , speedo healer corrected speedo and my mods in my sig. I started to struggle real hard once I started to pass a115 correct 115. I got up to 123mph then i shut her down as i crested a hill. Might be the enemy on the other side.lol. im haveing my EJK tuned in on a dyno in two weeks. They are also going to do a top speed run for me on the dyno. This will put the top speed with a 30th pulley and 210 tire to rest.

 

[toby]

I tried a top speed test a week ago with my stock 210, 30th pulley , speedo healer corrected speedo and my mods in my sig. I started to struggle real hard once I started to pass a115 correct 115. I got up to 123mph then i shut her down as i crested a hill. Might be the enemy on the other side.lol. im haveing my EJK tuned in on a dyno in two weeks. They are also going to do a top speed run for me on the dyno. This will put the top speed with a 30th pulley and 210 tire to rest.

Great, that was going to be my next question, the 210.:thumb:
I'm thinking with Terry's 30 tooth and worn down 210 his speedo is off nearly 10%?? at over 100 mph??

 

[sdsting]

My speedo is exactly +7mph
The needle rocketed through the 130 mark and was at where 140 would have been on the faceplate when the rev limiter kicked in.

 

[11Stryker]

A shot of JD will do that everytime!! HEHE

 

[sdsting]

11 – for me it’s tequila being down here in Southern Cal :biggrin1:

 

[11Stryker]

Hey SD, I'm just glad you have the nerve to do those runs. I chicken out when I get to the first 3 figures!

 

[sicontex]

Only reason you hit the rev limiter is due to 30 tooth. You can see my previous post where stryker11 and others got mad at me for addressing grunty ride on a 30 tooth stryker and loss of top end.

Thank you for reporting your observations as it helps persons make the right decision. I wouldn't buy used bike anymore after owning my stryker and see all the mods people do. You may end up buying used and wondering why it rides different not knowing big component changes like 30 tooth. Not bad just not for all. Too many disadvantages for our bike...fuel efficiency decrease, grunty feeling, high rev, loss of top end, not getting that much power compared to stock stryker on my test run a dealership.....again too many Cons to consider performing this mods.. ...hitting rev limiter on 5 th is a no no to me. I rely on my 5 the gear to stay just a car length from my buddy with a ducatti diavel

Everyone stated that yamaha should have built the bike this way...NOT...because if I was hitting the rev limiter on 5th on a stock bike after doing mods. I would sell it.

I know this thread and comment may agitate more people. But again the 30 tooth is not for me on my cruiser. I am not in a crotch rocket so don,t want to loose my top end when I need it on my cruiser.

Now if you have a 240 rear then it may compensate for the loss of take off but you will still loose top end but relative to you rear setup.

 

[toby]

Only reason you hit the rev limiter is due to 30 tooth. You can see my previous post where stryker11 and others got mad at me for addressing grunty ride on a 30 tooth stryker and loss of top end.

Thank you for reporting your observations as it helps persons make the right decision. I wouldn't buy used bike anymore after owning my stryker and see all the mods people do. You may end up buying used and wondering why it rides different not knowing big component changes like 30 tooth. Not bad just not for all. Too many disadvantages for our bike...fuel efficiency decrease, grunty feeling, high rev, loss of top end, not getting that much power compared to stock stryker on my test run a dealership.....again too many Cons to consider performing this mods.. ...hitting rev limiter on 5 th is a no no to me. I rely on my 5 the gear to stay just a car length from my buddy with a ducatti diavel

Everyone stated that yamaha should have built the bike this way...NOT...because if I was hitting the rev limiter on 5th on a stock bike after doing mods. I would sell it.

I know this thread and comment may agitate more people. But again the 30 tooth is not for me on my cruiser. I am not in a crotch rocket so don,t want to loose my top end when I need it on my cruiser.

Now if you have a 240 rear then it may compensate for the loss of take off but you will still loose top end but relative to you rear setup.

I agree. I wouldn't change to a 30 tooth unless I was going to pull a trailer. Then still probobly wouldn't unless the weight of the trailer was dragging my bike down. I like my freeway cruising rpm and the longer range gearing for twisties. You can race around in 2nd gear from 25 mph to 75 without shifting out of 2nd gear. Hitting a curve a 45 in 2nd gear throttling up to 70+ mph before you exit the curve, shifting into 3rd at nearly 80 mph exiting the cure. Same thing with coming out of a curve in 1st at 40 mph shifting into 2nd at 45 mph just as you straighten out popping the front end off the ground. Not having to shift while throttling up though a curve is priceless. You wont get those kinds of speeds per gear running a 30 tooth.:wink:
Ya, lol and you guys wonder why I go through tires so fast. The scary thing is, my wife is starting to ride like that since she got that Stryker:faint2:

 

[BrettRTR]

Love the way you ride Toby. I'm not there yet but I love hitting the curves hard like that. You are right, never coming out of 2ND until you get over 60mph is crazy cool on these bikes.

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[11Stryker]

So much negativity from those that have never tryed it.

 

[toby]

I'm not a hater. I understand why some have the need. I am on the other side because I bought these bikes to cruise. Wouldn't mind if they had even taller gears.:wink: In fact when I do power mods I will probably do a 32 or 33 tooth or some kind of pulley combo to get more top end and lower rpm for cruising. When I do that I will be waving at you guys when I fly by you when you are nearing near 110 mph shortly after a 1/4 mile and I'm hitting near 150 -160

 

[toby]

I think someone should do a 1/4 mile and a 1/2 mile run with the 30 tooth then the 31 tooth to see what the differences are.:thumb:

 

[Silkentek]

I'm not a hater. I understand why some have the need. I am on the other side because I bought these bikes to cruise. Wouldn't mind if they had even taller gears.:wink: In fact when I do power mods I will probably do a 32 or 33 tooth or some kind of pulley combo to get more top end and lower rpm for cruising. When I do that I will be waving at you guys when I fly by you when you are nearing near 110 mph shortly after a 1/4 mile and I'm hitting near 150 -160

And then THEY will be waving at you while you sit there getting a ticket... for speeding LOL
No pulley changes darlin' unless we move out of these mountains. We couldn't deal with the riding here if the gears were any taller then they are. I myself often wish my bike was not quite so tall in the gears, but I am learning to accommodate that and factor it in to the way I ride the back of the mountain here. It IS an entirely different riding style then I used on the v-star 950. The stryker just begs to be ridden hard and put away wet