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2009 VRSCAW
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272 Posts
Discussion Starter · #1 ·
Hello all!
Put a set of Vance and Hines and a Fuelpak on my 09' AW a week ago and have since put 250 miles on them. Long story short the headers turned several shades of blue/purple. Bike runs great with the exception of a decel pop or two under hard engine breaking (not a backfire, simply a small pop). Idles well, pulls strong, no surging or cutting out at constant throttle, etc....
My question is, do you guys have an opinion as to whether or not this is normal and acceptable? I called the V&H techs and they said it is 100% normal and is simply due to heat and single walled construction which is why they use heat shields. In their defense, the original factory pipes did the exact same thing within 100 miles. They go on to say that the slight pop is normal as well due to the way the Fuelpak works.
I did a search and it seems like there are a lot of posts stating that discolored pipes and popping indicates a very lean condition which has me somewhat confused. I have had several air cooled V Twins and they all did this to some degree so I thought it was ok until I used the search function. Now I'm confused, a slight bit paranoid, and find myself searching through the gallery to see who has blue headers :D.
Any thoughts would be appreciated.
 

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Premium Member
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10,801 Posts
Who tuned the Fuelpak? You sound like it is lean, which is hot. Have it on a dyno, and see - for peace of mind. Might cost a few bucks, but way cheaper than a motor! Joe
 

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2009 VRSCAW
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272 Posts
Discussion Starter · #3 ·
CPTJAM,
Thanks for the reply.
The Fuelpak was programmed using the setting supplied by Vance & Hines. Since I used both their pipes and fuel management system they had a map for my model/year bike based on numerous dyno runs.
The tech guys said the pop is due to the Fuelpak cutting the fuel at closed throttle which is what it is designed to do except at idle (which is explained on their website).
If you get a chance can you expand on why you think it might be lean since it runs like a champ? Does it have to do with the header discoloration or the decel pop?
Thanks again!
 

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Bluing on cheaper chrome plating is normal, there is a better chrome process that "resists" bluing. Jet coated pipes also stay true.
Decel popping however, is not normal. Jam could be right, put it on a dyno.
 

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2009 VRSCAW
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272 Posts
Discussion Starter · #5 ·
Thanks Vambo!
Here is what V&H says about the decel pop when using their Fuelpak.
The Fuelpak has a function which shuts off the fuel when decelerating. No fuel=no pop. Obviously the Fuelpak has to turn the fuel back on at some point or the engine would die. Not all popping can be eliminated, but this feature does lessen it. Mode 23 controls the rpm where the fuel is turned back on. Try lowering this by one number and see if it helps you. If you have done this and have gotten to 14 or your bike is stalling when coming to a stop, that is all you can do and you will not be able to lessen the popping without changing the pipes or installing quieter baffles. The popping is not harmful, just annoying.
Does this sound like a load of BS?
 

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These pipes will definitely change your tune. Blueing of pipes is normal, with carburetor bikes it was a useful indication (in combination of plug examination) of where your tune is at. Less so with FI, unless your tune is WAY OFF - and plugs are still a better indicator there too.

Threw mine on the dyno for a pull after install - and - LOST 20HP (same dyno the bike was tuned on). OTOH, I also recently installed 58MM short/tall stacks (replacing the dual 59mm short stacks that came with my destroyer TB).

Previously had stock headers with V&H Widows.

So these pipes ARE going to change your tune. Not likely as radically on an "un-heavily-modified" motor, as on my level of mods - but, as always - a dyno tune is really the way to go to maximize power and get a spot-on-stable tune.

Now all I have to do is figure out where/how to get an O2 bung in a position for the rear pipe where we can get a wideband O2 sensor IN the damn thing - since the baffle in the muffler, combined with the way the collector is positioned makes putting a long "sniffer" into each individual cylinders' header damn near impossible.

Decel pop can be either too MUCH fuel - or too LITTLE (according to the SEPST tuning guide). I've got slight popping too, which I'd describe more as a "burble" than a pop, per se' - no flames shooting out, etc.

With just pipes and a/c, using a piggyback fueler and tested map can get your tune pretty close - even though every bike is slightly different. Once you get into cams, head work, TB, etc., you begin to reach a little beyond a "canned tune", and into the region where every change requires another trip to the dyno booth. Hell, when I (finally) get the BST wheel on my rear, I go back on the dyno (yet again), as the lack of weight will allow me (or force me as the case may be) to add more timing to my tune...

Let us know what you end up with, and how it turns out...

Rick
 

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durata membro
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Thanks Vambo!
Here is what V&H says about the decel pop when using their Fuelpak.
The Fuelpak has a function which shuts off the fuel when decelerating. No fuel=no pop. Obviously the Fuelpak has to turn the fuel back on at some point or the engine would die. Not all popping can be eliminated, but this feature does lessen it. Mode 23 controls the rpm where the fuel is turned back on. Try lowering this by one number and see if it helps you. If you have done this and have gotten to 14 or your bike is stalling when coming to a stop, that is all you can do and you will not be able to lessen the popping without changing the pipes or installing quieter baffles. The popping is not harmful, just annoying.
Does this sound like a load of BS?
Absolutely!
It sounds like a service writer lying through his teeth trying to cover for a mechanic that is filling in on the dyno while the true dyno tech is out on vacation.
Shop around,find someone that knows the V&H tuner you are using and have them set your ecm on a dyno.Probably gonna cost between 250 and 400 dollars,but if the mechanic gets it right,you will love the way a Revo runs when they are set up right.Better than the factory tune!:deal:
 

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2009 VRSCAW
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272 Posts
Discussion Starter · #8 ·
Thank you gentlemen!
I spent about 5 hours going through the gallery and checking the bikes on Ebay looking at header pipes. For the most part the vast majority of bikes where you can get a clear view of the pipe had headers the same color as mine even though I saw no less than 3 different manufacturer pipes. I guess I'll quit whining and stop worrying about the blue.
I will be taking the advice you fellows gave and have it dyno'd in short order just to see what it has to say about the a/f ratio.
Thanks again guys!

PS, Rick, I think burble is probably a better description than pop. Mine doesn't throw flames or backfire through the pipe or airbox. In hindsight I probably shouldn't have used pop as a description LOL!
 

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Absolutely!
It sounds like a service writer lying through his teeth trying to cover for a mechanic that is filling in on the dyno while the true dyno tech is out on vacation.
Shop around,find someone that knows the V&H tuner you are using and have them set your ecm on a dyno.Probably gonna cost between 250 and 400 dollars,but if the mechanic gets it right,you will love the way a Revo runs when they are set up right.Better than the factory tune!:deal:
Truth is, they probably can not eliminate the decel popping due to a design flaw in the pipes of some sort so they issue a bulletin saying it is normal. It is not. Issues with pipe designs are common. CFR has an issue with the butterfly's chattering at idle but admit it and also admit they can not tune it out without sacrificing design goals. It's harmless.
 

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2009 VRSCAW
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272 Posts
Discussion Starter · #10 ·
Thanks Vambo!
I called V&H one more time today and got a minor tweek to one of the modes. SHAZAAM, runs better than it ever has. Still gonna do the Dyno pulls when the Blue Ridge Bikefest rolls around but it feels and sounds GREAT. Amazing what changing one of those modes by 3 numbers can do LOL.
I also took the infrared thermometer and measured cylinder temps immediately after a 30 minute ride which included WOT runs and stop and go traffic. Front was 209 and rear was 205. From what I have found through the search function that's about spot on so no complaints.
Thanks again all who replied.
 
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