what k&n is selling is a highflow filter, but in its lowest stage. like alot of things thier are stages to the filters. an example is arlen ness big suckers they have a stage one(like yours) and a stage 2. woods rates his in cfm, cubic feet per minute(flow). so if you break it down he has stages 2-5 no one else goes as big as he does, that i know of. he's not impying that his filters are better than k&n and everyone else, simply larger.

throtle body wise the gains were not crazy. the beatiful thing about it though, is the gains are linear. anytime you can gain top end without losing bottom end, let alone gain some is a great thing. I dont think youll be unhappy with the stock t-body, your just leaving somewhat cheap performance on the table, for no change in reliability.

but anyway good luck on the build, and i hope you enjoy it.

 

Think im going to go with the 50mm throttle body and injectors. I want this build right. However im having issues with Bob Woods big air filter. It's BIG ! its hard to hide it to be honest. I did find a high flow oversize K&N filter from Zipper in J&P . Its a K&N high flow filter upgrade kit and my origional football cover will still fit if i want to put it back. 402-470 $72.99

That's one of the nice things about coming here. You can learn so much and save yourself from learning the hard way. I've had a bad time with the Harley shop here. Lots of lies. I've really enjoyed this new mechanic I found over in Alabama. H&D Cycles. Don own's it. Great guy. Took the time to talk with me and help me choose the right build for me. Im sure I will be much happier with this build. And with all the questions I ask on here, it's not that I don't trust him, it's the fact I learn so much from asking.

 

That zippers highflow kit must still be a stage one, which is no different than what you have other than the backing plate. the stage two kit will not fit the stock football cover. and woods filters stage 2 or 3 isnt that much bigger than a stage 2 ness but his stage 5 is absolutley huge.

One thing that alot of people seem to realize is just because you read it dosent make it fact be it a magazine or a forum. someone in a shop not only is telling you to your face, but has a reputaion to defend, but that dosent mean its the truth either. bottom line you should go with your gut felling, and pray that you have a good gut.

 

Well the thing is there's no test to compare with. K&N filters makes Bob's filters out of the same meterial as the others. The only difference is the design. His filter stays the same or a little bigger to the end. As for any improvements in power tq because of that little change ??????? I would have to see dyno results with two filters tested. It would be interesting to see.

Im also trying to figure the difference between the stock 48mm and the 50 mm other than 2 mm. Im changing out the injectors anyway so im getting more fuel as needed, but to argue 2mm ?????? Like I said, I would have to see the dyno sheet for that one also. I think some people split hairs with some of this stuff. I went to Bob's site and checked out some of the dyno runs and noticed a lot of 48mm getting massive numbers. Bet they changed the injectors and left the throttle body.

that's the good thing about this site. You can see test and comparisons. Wish we had some of these to situations.

 

Your stock throtle body is a 46mm. and truthfully you do not need a woods filter, but i would say you do need at least a stage II from anyone. If you called boob he would proablly suggest a 300 cfm which is slightly larger than a stage II ness for like 6 dollars more than the one from j&p.

 

I am running the SE 58mm and the SE HD injectors on my 103 and they work great, with the FI ,throttle body sizing( going too big) is ,within reason ,far less of an issue than with a carb. Don't believe the all too often used phrase"going too big will hurt your torque" as HD uses the 50mm TB stock on their heaviest(touring) bikes rather than the smaller units that they have readily available in the parts bins at the assembly lines.

 

We can say it works all day on here but without Statistics there's no way of knowing. It's like with the huge air breathers. You cant argue with facts. But throwing money at a build just to say you have it , is a waist in my opinion if you dont need it. If the size of the throttle body did make a difference, then I would think going from a 46mm to a 50mm wouldn't make much of a difference. Now a 58 mm might. What people don't realize is it's the injectors that give the fuel that makes the difference in these throttlebodies.

Again I would love to see some statistics on the differences. that would be nice.

 

The 46mm to 48mm is a 9% increase in cross sectional area. The 46mm to 50mm is a 18% increase in cross sectional area. If you are flow restricted by 10% the increase is significant. If not it is insignificant.

The HPI reworked 46mm to 48mm TB probably flows more than the H-D SE 50mm TB. I have seen data but can not find it at this time. That is why I would go with the stock reworked HPI 48mm TB and purchase the bigger injectors. I think the ideal solution is the HPI 51mm TB but it is pricey.

I have already stated that the stock injector size is an issue. I have seen that with my own eyes through V-Tune data from the TTS MasterTune.

I don't know if the air cleaner size is an issue.

B

 

I understand what you are saying about my statement of "it works great" as you don't know me and the fact that many embelish their statements to look good here however as so many have pointed out statistics can be skewed(dyno #'s) more readily than most would think. Ridability is what is key and those who read this can take what I am saying or not , I do not benefit whether they believe me or not, just providing info that I have personal knowledge of, not 3rd hand speculation. I am also using the SE MVA CNC Ported heads that many call torque killers and with the 10.5 SE pistons paired with this combo my SG is fun as hell to ride and that is what I think is the end result we are all after.

 

Now that was informative and it makes since. Who is this HPI ? I would like to look into the 51 mm TB . Makes since to get air to the engine and out. And im looking for torque for sure.