REPRINT FROM OLD HTT: WHAT IS EXACTLY INVOLVED IN SWITCHING TO 3.37 GEARING?

[ClassicRider2002]

DISCLAIMER: THIS IS A REPRINT TOPIC FROM "OLD" HTT

I have saved many great topical discussions as "links" over the years and would hate to see these lost, so I am reprinting this TOPIC here, which may "perhaps" help some.

TOPIC:  WHAT IS EXACTLY INVOLVED IN SWITCHING TO 3.37 GEARING?   06-05-2005

From: Ratbelly_2004  (Original Message) Sent: 6/5/2005 7:34 AM   Message 1 of 19 in Discussion
What exactly is involved in switching to 3:37 gearing?  What are the benefits? I thought I read somewhere it gives you more low end torque?  Would that also take away from your top end?  Any ideas on the cost of parts and is it something I could comfortably do myself?  I am looking at adding a 95" kit in the future, with cams, possibly heads.  Would the gearing change contradict what I would gain with the big bore anyway?  

[ClassicRider2002]

From: jmorton10 Sent: 6/5/2005 7:55 AM   Message 2 of 19 in Discussion
37846-99a clutch shell(37T) $230.26
40269-85a compensating sprocket(24T) $38.08

These are the parts you need, you swap out the clutch basket & the engine sprocket.
The swap gives you more acceleration through the gears but a slightly lower top speed.
~John


From: 02roadcling Sent: 6/5/2005 8:20 AM   Message 3 of 19 in Discussion
You will lose about 8% of your top speed, but run next to me on the Interstate and watch my tail light. Better wait a couple hours though because I have a blue dot to install, lol.  You can do it yourself. Maybe need to have the clutch hub pressed although you could probably jerryrig a drill press in an emergency. If I had known about it I would of done it as my first upgrade. Kind of like putting 4:11 in your old hotrod.  Grinnin.  02roadcling
   Message 6 of 28 in Discussion   

From: heyjunior Sent: 6/5/2005 10:35 AM   Message 4 of 19 in Discussion
What differences do you notice at hiway speeds. Obviously the motor is reving higher. How much at about 70-75 mph? For a touring bike that you don't want to tour from gas station to gas station how did the gearing change affect the fuel mileage?
thanks,  Junior


From: jmorton10 Sent: 6/5/2005 10:53 AM   Message 5 of 19 in Discussion
It's about 300rpm higher at 70 mph.  My gas mileage is over 40 so I'm not worried about it.
~John


From: Mike52  Sent: 6/5/2005 10:54 AM   Message 6 of 19 in Discussion
Junior, you will only see about a 250-300 RPM increase at highway speeds, on most bikes, this will put the power band in it's "sweet spot". When you roll on the throttle to pass, you will love it.  Mike 
 

From: Ratbelly_2004 Sent: 6/5/2005 1:28 PM   Message 7 of 19 in Discussion
So on even a "stock" engine (stage 1 download, true duals & slip ons) doing this gear change would give me more "out of the hole" so to speak?  And even more so when I do the 95" upgrade later on? Sounds like a pretty cheap upgrade for the most part. 
 

From: ejk_dyna Sent: 6/5/2005 1:55 PM   Message 8 of 19 in Discussion
It is the next best upgrade for the $$ after the hi flow a/c, pipes...as long as you don't mind the extra 300rpms on the highway.
   

From: 02roadcling Sent: 6/5/2005 2:51 PM   Message 9 of 19 in Discussion
Ratbelly,
It's too late for debate! You are hooked, lol. Congratulations and enjoy your new gearing.   
02roadcling


From: JRB Sent: 6/5/2005 2:53 PM   Message 10 of 19 in Discussion
jmorton~~
"The swap gives you more acceleration through the gears but a slightly lower top speed."

Are you saying that you can actually hit the rev limiter in 5th gear with the lower gearing? 
Sounds like a good change for those who live in the Hi altitude states? 
   

From: 02roadcling Sent: 6/5/2005 2:56 PM   Message 11 of 19 in Discussion
I will add that only a couple guys have removed the gears back to stock. 


From: jmorton10 Sent: 6/5/2005 6:13 PM   Message 12 of 19 in Discussion
JRB~~
Are you saying that you can actually hit the rev limiter in 5th gear with the lower gearing?

Well, I never have -I live in the upstate NY & there aren't any roads long enough to do that around here.
~John
   

From: SlickFLSTF Sent: 6/5/2005 6:19 PM   Message 13 of 19 in Discussion
Guys, do you think this adds additional stress or wear to the starter, or is it a non-issue? 
 

From: Dartman Sent: 6/5/2005 6:23 PM   Message 14 of 19 in Discussion
Came standard on 99-01 Baggers with EFI so id say its a non issue.


From: NickLallas Sent: 6/5/2005 9:11 PM   Message 15 of 19 in Discussion
As Dartman said the 3:37 ratio comes with FI.  Only worth doing if you have a carb on a touring bike.

     
From: Ratbelly_2004 Sent: 6/6/2005 6:01 AM   Message 16 of 19 in Discussion
Ahh, so with my '05 RK FLHRS-I, I already have this gearing set up?
.....And what would make this change have any effect on the starter?


From: willyshd Sent: 6/6/2005 6:10 AM   Message 17 of 19 in Discussion      
Ratbelly_2004 pay attention to what Dartman stated above:
From: Dartman 
Came standard on 99-01 Baggers with FI 

From: Ratbelly_2004 
Ahh, so with my '05 RK FLHRS-I, I already have this gearing set up?

No, you have the 3.15 : 1  ratio.

Roger


From: Ratbelly_2004 Sent: 6/6/2005 6:28 AM    Recommend   Message 18 of 19 in Discussion
*L* OH ok, I see it now.  I missed the years the first time around.  Looks like Zanotti's is going to be taking away more of my money.  Everytime I say I am done for awhile, along comes some new goodies. 

   
From: bagger2 Sent: 6/6/2005 10:06 AM   Message 19 of 19 in Discussion
I am trying to figure out in the owners manual what they mean by domestic and all others. I would like to assume my 02 RK (carbed) is domestic but I have been wrong before.     

number of sprocket teeth ( primary chain)
engine (compensating sprocket)
domestic    24 T
all others   25 T
clutch shell basket/ring gear
domestic    37 T
all others   36 T

read an earlier post   24/37=3.37 (correct)      25/36=3.15 (correct)


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Anything added beyond this point is new information.

Regards,

"Classic"


Bagger2 asks a great question above and points out something that over the years has created quite a bit of confusion, the "literature" ie: sales brochures as well as the Owners Manual (small booklet) states that the 2002 EFI bikes came with 3.37 final gearing however the EFI bikes came with 3.15 final gearing, which the Touring Service Manual correctly states.  The bottom line is all carbed 2002 Touring Bikes came with 3.15 final gearing.  With the MM EFI of 1999-2001 Touring Bikes were fitted with 3.37 final gearing while the carburated bikes all came with 3.15 final gearing. With the emergence of the Delphi EFI in 2002 ALL Touring Bikes came with 3.15 final gearing.  It seems the Corporation felt that the MM EFI was a bit slower in response so Corporation didn't feel they could expect the market to accept the EFI Touring Bikes to respond less favorably than the less expensive Carburated counterpart ($775.00 aprx. less) so they changed the gearing for the MM Touring Bikes to 3.37 gearing.

While Bagger correctly reflected the information accurately above, as one can see HD was communicating to the general public in a rather confusing matter when it came to their marketing as well as Owner Manual information.

SOME ADDITIONAL REFLECTIONS IN ANOTHER THREAD I FOUND ON THIS TOPIC:

From: RWJ Sent: 12/6/2001 8:46 PM
There is a slight gearing difference in the EFI bikes and the carbureated ones. The EFI bikes have a 3.37 overall verses 3.15, small but there. Was there a difference in the weight of the bikes?  Russ

From: HIPPO_   Sent: 12/6/2001 11:32 PM
I believe the difference in primary gearing was for the touring bikes.  

From: YFOPOS Sent: 12/10/2001 8:01 PM
Hello out there just signed up!
I have visited several HD shops( at least 6) and everyone of them said to get the FI but everybody else that I talk to, says to stick with a carb? ? ?   Like what the others have said here, only the dealers can remap the comp, so here we go.

From: HIPPO_ Sent: 12/10/2001 8:51 PM
No surprise there. The percentage of owners of carbureted bikes that do ALL of their own work is larger then the owners of EFI bikes, much more so with the Delphi then with the old Marelli. Even if you do the minor stuff, with EFI there is a lot of easy profit for dealers starting with remapping all the way to the repairs that require special equipment like the digital technician. They even cut almost all of the indy's out of the loop. They love little 5 or 10 minute jobs they can charge you 1 or 2 hours for because they are the only game in town, and many people have no basis to argue as they really have no idea what was done to begin with even if explained. The new EFI bikes are a gold mine for dealers.   As far as performance, out of the box Delphi bikes feel stroger then carb bikes, but it only takes about 10 bucks in jets to make the carb bike equal. Beyond that the carb bike will be much cheaper to own at any given performance level.  If you really want to build the engine, with a carb the sky is the limit, while there are some limits with EFI.  


From: HotRock  Sent: 12/11/2001 5:48 AM
Hippo......Then why is the gearing on touring  bikes different for carbureted and EFI? ? ? ?  With Carburetor being 3.15 ? ? ? ? and EFI being 3.37 ? ? ? ? ? ?     

From: HIPPO_ Sent: 12/11/2001 2:53 PM
When they started with EFI (99'--01') they were using the Marelli system, and I believe the difference in price was something like 800 bucks. Everything else being equal the carb bikes then had better performance then the MM EFI bikes. It just wouldn't do for a cheaper bike to blow the more expensive one away, so they ran a 3.37 lower gearing in the EFI bikes while the carbs were at 3.15 final gearing attempting to balance them out.

Earlier this year in August, for 02' when they introduced the Delphi on the baggers, if you looked at Sales Literature and then at Factory Service Manual and then at the Owners Manuals there was/is conflicting information as far as primary ratios for different versions.  Now it looked like the difference in ratios was still there for the domestic models, but the confusion might lead one to believe they were at least considering just one ratio. 

As it turns out, now that the bikes have been out for awhile, we now know that with the Delphi EFI the final gearing is 3.15 and that the final gearing for the carbs is also at 3.15 thus at least dometically they actually did decide to run just one ratio. 

See, I do not totally believe that the very heavy use of EFI these days is just EPA related. Emissions are not averaged like CAFE, and if they can produce some bikes with carbs they could produce all of them with carbs if they wanted to. Sure they have to produce SOME with EFI to get ready for what may be coming in 04 and some people like them, but not to the point where many bikes ordered with carbs show up with EFI.
I'm convinced, in part also by how the new system is integrated with other systems, that the two main objectives are an attempt to totally lock out indy's and some of the aftermarket from the performance improvement and even the reapir market and increasing built in profit for dealers. Yearly meaningless changes to software make it very hard for most to keep up and make it hard for medium and smaller aftermarket companies to recoup engineering expenses when a product just applies to one year model bike.  It's just my opinion of course, but I go with my hunches and will not play THEIR game.

The days when you could have a discussion af carb vs. EFI are long gone. Now you not only have the old Marelli bikes and the new Delphi bikes, but there are software differences between different years of Delphi bikes. Any sort of discussion without specifically mentioning the exact EFI version is basically meaningless.  

From: MrripperHD1 Sent: 12/11/2001 6:36 PM
Hippo you know you're !#%@!# right Harley wants to marry you to the dealer with their EFI . So it looks like if you keep it stock just slip ons EFI is fine, But if  you want more carb is the way to go.  Thanks for the info .  Now to change my order Ya right that won't happen. 

[ClassicRider2002]

I actually have a excel spread sheet that was provided within a THREAD here at HTT by:
From: Fuzznut5197 Sent: 6/13/2008 7:01 PM
Anyone have any use for this driveline spreadsheet? It was posted here back in 2003, and I thought is was saved somewhere in HTT, but I can't find where.

Hopefully all will be able to down load the EXCEL PROGRAM below next to the "paper clip"

If you plug in your actual gearing (comp sprocket "T"ooth size, clutch shell basket/ring gear "T"ooth size, rear wheel sprocket "T"ooth size, transmission "T"ooth size as well as rear wheel diameter then it will factor RPMS and such which would aid you in determining what level of gearing you might benefit most from........then if you wish to ponder some other options for your comp gear or your clutch shell basket gear or perhaps your secondary gearing which might require a different belt you can see what might create the biggest bang for your buck.....

[NOTE: Please remember that putting your cursor next to the paper clip icon below will allow you to open this EXCEL PROGRAM, if you desire simply choose to save the program to your computer as well]

[attachment removed after 60 days by system]

[ClassicRider2002]

Hello Everyone~~~

Through out all of the "old" THREADS that deal with the 3.37 Gearing Modifcation to our TWIN CAM BIKES I really enjoyed reading them....and after all of the valuable input from everyone whom posted, I eventually did the MODIFCATION to my 2002 RKC.  Like many before me have stated and I must concur, this MODIFICATION has to be ONE OF THE ABSOLUTELY BEST MODIFICATIONS I have done to my "BAGGER", it's such a wonderful "bang" for the buck invested....

Thus I put together a detailed THREAD about the modification, if you are interested in reading about such Simply CLICK, VIEW, & READ the Attached "LINK" below:

3.37 MODIFICATION GEARING INSTRUCTIONS FOR 2002-2006 TWIN CAMS 

I happen to be "ClassicRider" @ V~TWIN FORUM.

Regards,

"Classic"

[Tsani]

Hey Classic, ya still have that PDF?

[ClassicRider2002]

Absolutely I do and happy to share it with you just send me a private message with your e~mail and I will forward it to you.

Regards,

"Classic"

[Tsani]

Hey Classic - Thanks! Nicely done! You put some effort into this. It will be a big help when I change mine up.

[ClassicRider2002]

Tasni~~~

You are welcome.....I hope you will come back to this THREAD and let other's know how you like the 3.37 gearing modification. 

Glad to help!!!!! 

Regards,

"Classic"