[Rich Moran]

Riding last week, I pushed the V-rod to somewhere in the mid 8's on the tach, and the rev limiter kicked in when I was trying to get around slow traffic. Was in 1st, and t cut off what seemed like one of the cylinders, and made the other miss consistantly.

Was wondering, if you've hit the rev limiter, what RPM were you at when it occured?

 

[mjw930]

~8000 cold (something less than 120 degrees engine temp I think), 9100 warm.

In first gear the sprint from mid 8's to 9000 would happen in a split second. Perhaps you glanced at it as it was sweeping through the mid 8's ?? Just a thought

 

[Vinny]

Mark,
I thought that the limter kicked in at 8800?I could be wrong,but I coulda swore I read that somewhere.
If I'm wrong I stand corrected.

 

[Rich Moran]

Yes, In 1st gear things happen really quick, was suprised when it hit so fast. The overlap into 2nd came into play too, as it seemed it was but a hearbeat, and onto 3rd before the bike started to pull again. Since the tach on the bike is an electrical feed, I am wondering where others see the rev-limiter kick in.

 

[mjw930]

Mark,
I thought that the limter kicked in at 8800?I could be wrong,but I coulda swore I read that somewhere.
If I'm wrong I stand corrected.

Vinny,

You know, that's a very good question. I'd have to go to the manual to see what the spec says. The RT and the SE flashes bump it to 9100.

 

[Super Kaz]

Had the bike been warmed up to 150-160 degrees?If not the rev-limiter kicks in 1100 rpm sooner! :bash: It's a factory ECU Parameter.

 

[Vinny]

So then HD must think that the motor can handle 9100.When I get my PCusb I'll raise it up then.

 

[Shawn Nelson]

Vinny it can but i am not sure what kind of torque ( if any) you will have up there.

 

[Vinny]

:angeldev: :ride:

 

[Rich Moran]

The bike was in its operating temperature range, no doubt. We were about 20 miles from home in 80 degree weather when it occured. Thinking more about it, the engine started to miss, and that is when I looked at the tach to see where it was at. That short quick look showed the needle between 8 and 9 grand area. Since I was moving out pretty fast, i wanted to be in road control mode more than motor control mode since the limiter does its job, no sweat from me. Was suprised how fast it comes on though. i've been through the gears with this bike, but not up to kick in the rev limiter, so I thought after 13,000 miles the motor is ready for a little abuse like that, althought he run up was not doen intentionally. Knowing the limiter is there, makes life easier.

One time on a Moto Guzzi I owned, I was racing a friend accross the Sunshine Skyway between St Petes and Bradenton. I dropped an intake valve in 4th at somewhere around 120 MPH. It was bizarre. loosing an intake valve means that any oil pressure you have makes the oil escape through the carb in this case. it was from the left cylinder, and by the time I got the bike to the bottom of the bridge, my left leg was ready to be turned on a Bar-b-q, with all the oil that was on it. When the V-Rod hit the limiter, I thought I heard what i believe was valve float, as you can actually hear some banging around going on. It sounds like sharp clatter, and not like pre-detonation.

Anyone have any idea on what the clearance is between the top of the piston and the valve bottom when they reach this limit? i do not know if the manual gives that info. I think they do it by giving the shim height recommendation when checking the spec between cam/valve in the valve adjustment.

I now if the valve hits the top of the piston, the noise gets really nuts before it comes apart, but with the valves bouncing off the seats, and with enough space, you can hear noise, and it is not a normal motor noise.

Maybe I was hearing things, who knows.

The bike runs fine, as i have been riding it with no problem since then, maybe they built this one like the idiot books that are written? An idiot proof Harley, now thats a concept.

 

[mjw930]

Rich,

You didn't float the valves, the motor can live @ 10K if you want to really go nuts but the power drops off rapidly above 9K so why bother

If you didn't load one of the SE flashes or program it via the Race Tuner then 8800 is your redline. When the ignition cuts out the bike makes some nasty noises, too bad they didn't put a "soft touch" rev limiter in the code like MSD and others have for cars.

Vinny, you're not going to change the rev limit with the PCusb or any other add on device. That can only be done with the race tuner (variable) or an SE flash (9100).

 

[Vinny]

Rich,


Vinny, you're not going to change the rev limit with the PCusb or any other add on device. That can only be done with the race tuner (variable) or an SE flash (9100).

That's not what my tuner said today.I don't want to argue about.I haven't seen anything on PC's site saying anything about a rev-limiter.So,I will know when I get mine.http://www.v-rodforums.com/forums/showthread.php?t=3053 That is my situation I am in.I could tell him to forget it and jump in on the forum RT special.
If I get the RT, are changing the fuel and timing the same as the PC.My tuner has been sent to dynojet school,not RT.Will he be able to tune the same way as the PC.He can get it real close then I can do some datalogging.to fine tune it.

 

[Rich Moran]

I know that after the area where torque and HP cross, that things slow down, even if speed increases. You've passed over the optimum power zone. So what happens if you went to heavier springs, longer duration and higher lift cam? Would the peak area move up in the RPM range when HP and torque cross? I have not asked the Zippers guys about their mods with the Tilley kit to see where the HP/torque cross is at, but I would think if your doing a build up, that you can safely pull more RPMS and move the the crossover point up also.

That part that is the clincher, without heavier valve springs, bad things are going to happen.

Just thoughts on this is all, as I am not going to be doing anything as yet, and am still gathering info on motor build up, and waiting to see what will be coming out in the next couple of years. Would be great to have a 200 HP V-rod to scoot around town on. I am a little slow on jumping on the build up bandwagon, as once you are into it with your plan, it should be the best one for the money you are spending.

MJW, your probablly right about the noise coming from the motor when the rev limiter kicked in, its at peak RPM, and all of a sudden the spark gets cut, and fuel is entering a hot motor.

 

[mjw930]

Rich,

You're never going to get the crossover poit to move, that's fixed at 5252 rpm. It's part of the math used to calculate HP. What you can do is move the torque peak higher or better yet, extend the torque curve so it doesn't drop off as fast on the high end. For a real fast street motor your torque curve should look like the top of a table, a very tall table :diablo:

 

[mjw930]

Vinny,

I don't know what to tell you other than there's no way to increase the rev limit without reprograming the ECM. There's no way to fake the rpms. As for being able to use the RT with just the dynojet school, that really depends on whether he was educated or trained! What's the difference you might ask. Well, training is something you can do with a monkey, education usually takes a bit more intellect

The RT in it's base mode has the simple AFR and timing offsets. If the tuner is sharp they should be able to make the transition. If you want him to get into tuning the complex settings then I would hazard a guess that there's only a hand full of people in the world with that skill, based on what I've seen the the Florida market.