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[hard10]

Can I get a simplfied answer to: why do I need the Rev limit extended?

If two SEUC's are set up the same ie. same pipes/ac/pc why would you need to dyno? I know that all bikes are a little bit different but...

TIA, AJ

[RedDevil]

Can I get a simplfied answer to: why do I need the Rev limit extended?

If two SEUC's are set up the same ie. same pipes/ac/pc why would you need to dyno? I know that all bikes are a little bit different but...

TIA, AJ

AJ,
Good questions.  As far as the rev extender, there is probably someone more capable of answering that then me, but my theory is, that if you look at the dyno runs, the peak hp comes in around 6000 rpm, so if you like to be up in that range, you wouldn't be able to use your peak hp without the rev extender.  My dealer automatically put the rev extender download in before they loaded my ECM with the SERT, so I have it, even though I'll probably never get up that high.  As far as dyno'ing the bike, if you have the exact same setup as another bike that has been dyno'd, there's about a 95% chance that the other map will work perfectly on your ride and you won't need to do anything else.  It's still a good way to go even if it isn't just right, because it's a much better base map to start with, and if you decide to dyno, it will require a lot less dyno time. 
Cheers ,
Red

[hard10]

AJ,
Good questions.  As far as the rev extender, there is probably someone more capable of answering that then me, but my theory is, that if you look at the dyno runs, the peak hp comes in around 6000 rpm, so if you like to be up in that range, you wouldn't be able to use your peak hp without the rev extender.  My dealer automatically put the rev extender download in before they loaded my ECM with the SERT, so I have it, even though I'll probably never get up that high.  As far as dyno'ing the bike, if you have the exact same setup as another bike that has been dyno'd, there's about a 95% chance that the other map will work perfectly on your ride and you won't need to do anything else.  It's still a good way to go even if it isn't just right, because it's a much better base map to start with, and if you decide to dyno, it will require a lot less dyno time. 
Cheers ,
Red

That is kind of what I thought Red. I sak this question for a couple of reasons. 1st I hit the rev limiter the other night. I was leaving a parking lot trying to get out in traffic. In doing so I reved the engine up higher than expected before shifting into second gear. There was a noticable loss of power for a split second before I hit second gear. Under normal driving conditions I would NEVER intentionally push my bike to that RPM. So I'm just looking for some clarification.

[RedDevil]

That is kind of what I thought Red. I sak this question for a couple of reasons. 1st I hit the rev limiter the other night. I was leaving a parking lot trying to get out in traffic. In doing so I reved the engine up higher than expected before shifting into second gear. There was a noticable loss of power for a split second before I hit second gear. Under normal driving conditions I would NEVER intentionally push my bike to that RPM. So I'm just looking for some clarification.

AJ,
It's not something that you'd normally have programed in unless you've made mods to the bike.  On my '02 it wasn't programed in until I added the SE mufflers and opened up the breather and they did a Flash upgrade to the ECM.  The only time I ever went up that high was right after I got it back from the dealer...I just wanted to see if it would go that high and it did cut off at 6200 rpm.  On my Jester, I won't have to try that as my dyno printout shows that it's installed.  I don't know if it costs extra to program the rev extender in or not, as I had it all (SERT, pipes, AC) done at the same time.  It may be necessary to have it done when you do the mods, I don't know.   Someone that's more knowledgeable on this might be able to answer that. 
Cheers ,
Red

[RedDevil]

That is kind of what I thought Red. I sak this question for a couple of reasons. 1st I hit the rev limiter the other night. I was leaving a parking lot trying to get out in traffic. In doing so I reved the engine up higher than expected before shifting into second gear. There was a noticable loss of power for a split second before I hit second gear. Under normal driving conditions I would NEVER intentionally push my bike to that RPM. So I'm just looking for some clarification.

I'll bet those Rineharts were really barking!   You definitely were noticed, that's for sure.
Cheers ,
Red

[hard10]

Red., I've already done the mods ( Rhinehart True Duals, Roll Your Own A/C, and Power Commander) and had the dyno done. It was more of an informational question I guess. Tigertr1 gave me another map that he said may work better than what I already had. So this lead to the questions.

[Midnight Rider]

AJ...If you notice most of the Dyno sheets on our bike with the way we all like them to run...lot's of torque from 2500 to 4k...the rev extender is pretty much useless, as the TQ has fallen off well before the rev limiter.  If you had a bike that made all it's power in the upper end of RPM range, it would be useful.  It's still OK to have it in there because it won't hurt a thing.  I've hit the rev limiter on my bikes several times...it's very easy to do in first gear, as it gets there very quickly.  It just chops the throttle for you and reminds you to shift  If you ever are in a Dyno room, they routinely hit the rev limiter in 4th gear roll ons when they are doing the pulls.  With regards to using other MAPs, if you get one from a good tune, with the same setup as you have, it'll be within 3% of dead on from some of the tuners I've talked to, so you're pretty much good to go.  One way to have it checked is to take it to a Dyno and just have a pull done to see what the bike is doing with regards to A/F ratio and how flat it is.  If it is nice and flat, and in a decent place, it's good enough.  A dyno pull usually costs about 60 bucks...they will do 3 and take the best one.

[hard10]

I'll bet those Rineharts were really barking!   You definitely were noticed, that's for sure.
Cheers ,
Red

Yeah, they were loud!!!

[Midnight Rider]

One other thing...it does allow the HP number to sometimes be higher, as the HP is always made at higher RPM's.

[Hoist!]

The SE255 cams that come with the stock 110" fall down way before you hit stock rev limiter RPM. Therefore there's abosolutely no benefit to enabling the rev extend feature. You would use this feature with modified engines, not stock. You're better off leaning it alone for engine protection, as there's no performance benefit! Hoist!