Think I might of gotten ripped off
Club Member
Joined: Mar 2016
Posts: 11,680
Likes: 22,217
From: Clearwater, Idaho
just re-read the thread and had an after thought with my sport.
on mine, the carb is more or less a restrictor plate. if i would increase mine, it would pull up rpm much quicker than it does, i just need more open road to pull max rpm. i sorta left it that way as a protection to myself. when i drop out third, the speedo is history. i am not saying the carb is the problem because TOOOOO much carb is even worst. the same could be carried over to efi.
on mine, the carb is more or less a restrictor plate. if i would increase mine, it would pull up rpm much quicker than it does, i just need more open road to pull max rpm. i sorta left it that way as a protection to myself. when i drop out third, the speedo is history. i am not saying the carb is the problem because TOOOOO much carb is even worst. the same could be carried over to efi.
Elite HDF Member
Joined: Jul 2010
Posts: 3,830
Likes: 302
From: Lorain Ohio
what is the power band on that cam? peak numbers don't mean a lot if you never get into the higher rpm's where the power is. Also it seems most cam makers recommend a cam that makes less peak power an more mid range power to get the heavy touring bikes rolling. power to weight is key...as was brought up earlier...if a lighter bike is making less power it will still out run you if it has a better power to weight ratio. You might have a conservative tune as well. do you have the paperwork from his saying what all he did an what he charged? I'd probably take it to a indy with a good rep an show him the paperwork an pay him to inspect the bike an maybe have another dyno tune done. maybe throw some money at getting the heads worked. If those numbers are accurate I don't think it's a bad build but maybe not getting all you can out of it.
Club Member
Joined: Mar 2016
Posts: 11,680
Likes: 22,217
From: Clearwater, Idaho
what is the power band on that cam? peak numbers don't mean a lot if you never get into the higher rpm's where the power is. Also it seems most cam makers recommend a cam that makes less peak power an more mid range power to get the heavy touring bikes rolling. power to weight is key...as was brought up earlier...if a lighter bike is making less power it will still out run you if it has a better power to weight ratio. You might have a conservative tune as well. do you have the paperwork from his saying what all he did an what he charged? I'd probably take it to a indy with a good rep an show him the paperwork an pay him to inspect the bike an maybe have another dyno tune done. maybe throw some money at getting the heads worked. If those numbers are accurate I don't think it's a bad build but maybe not getting all you can out of it.
Sponsor
Joined: Dec 2007
Posts: 12,084
Likes: 829
The heads had to have bee set for the .630" lift, springs, valve to valve, collar to seal, chamber volume, etc.
I'd start your exploration in the cam chest, and if we can be of any help, just call, as WE, can get your wheels rolling in the right direction.
Scott
I'd start your exploration in the cam chest, and if we can be of any help, just call, as WE, can get your wheels rolling in the right direction.
Scott
Seasoned HDF Member
Joined: Aug 2011
Posts: 11,814
Likes: 5,120
From: SW Ohio
Given his poor electrical practices, that would more than explain how his shop burned down.
Stellar HDF Member
Joined: Mar 2012
Posts: 2,017
Likes: 599
From: Columbus, OH
OP if you're in Indy a couple of hours south of you in Evansville is Sheffer's Performance HD, give Daren a call. If I were in your position I would take it to him and have him evaluate what you have. Tuning is his specialty and he is one of the few people I would trust to do engine work.
Seasoned HDF Member
Joined: Aug 2008
Posts: 5,052
Likes: 993
it is no secrete that a larger carb can add power to a certain point but when you pass the magical number, flow rate will cause fuel drop out since the engine can not take advantage of it. in a round about way very big injectors will lead to extremely short on times and couple this with high frequency, heating issues can arise. injectors must be sized for applied load and capability of the engine.
hd cams are not long winded and drop like a rock so as rpm rise, power drops. the longer you can extend the power band past the peak the more power is applied in the upper range. as i mentioned, if i can pull 500 more rpm with extended or after peak and gain 10 mph on the gear, it will leave the other in the dust. a lot of times, a smaller or less capable machine can kill the larger because of this. also of note, every shift is also a delay. remember the old two speed power glides, great on the track since around 90 mph was a shift point with right gearing. seen them smoke way larger machines who had to shift multiple times.
my sport runs int'l gearing and in order to pull it, the transmission is geared down except for 5th. in stock form it ran 120 mph @ 5400 rpm. now it will turn up to 7500 rpm. i am running n4's but retarded timing so it pushes my power band around 500 rpm up scale at a loss to low end, however, with lower gears reduction, you will never notice it and it still out performs the stock all around. if i can the 40mm and maybe go up to 45mm intake, i can reach redline quicker.
http://www.twistgear.net/page%20html/sportgear.html
numbers are low in the chart as my first is around 60 and second around 90.
hd cams are not long winded and drop like a rock so as rpm rise, power drops. the longer you can extend the power band past the peak the more power is applied in the upper range. as i mentioned, if i can pull 500 more rpm with extended or after peak and gain 10 mph on the gear, it will leave the other in the dust. a lot of times, a smaller or less capable machine can kill the larger because of this. also of note, every shift is also a delay. remember the old two speed power glides, great on the track since around 90 mph was a shift point with right gearing. seen them smoke way larger machines who had to shift multiple times.
my sport runs int'l gearing and in order to pull it, the transmission is geared down except for 5th. in stock form it ran 120 mph @ 5400 rpm. now it will turn up to 7500 rpm. i am running n4's but retarded timing so it pushes my power band around 500 rpm up scale at a loss to low end, however, with lower gears reduction, you will never notice it and it still out performs the stock all around. if i can the 40mm and maybe go up to 45mm intake, i can reach redline quicker.
http://www.twistgear.net/page%20html/sportgear.html
numbers are low in the chart as my first is around 60 and second around 90.
Last edited by bustert; Feb 12, 2018 at 10:38 AM.
Road Warrior
Joined: Mar 2013
Posts: 1,923
Likes: 587
From: Alorton, Illinois
Sounds to me that you have decent parts that don't play well together. You have a TB, cam, injectors, and exhaust that should do well in the upper rpm area but heads that don't. Compression seems low fro that cam also.
Get it a part and see what is in it. Then you have a choice. Adjust heads/ compression to get the top end of the 9f or change cams to suit the compression and focus on low and mid power. TQ could rise quit a bit. HP will depend if the heads are the choke point.
Can you post the sheet so we can look at the shape of the curve?
Get it a part and see what is in it. Then you have a choice. Adjust heads/ compression to get the top end of the 9f or change cams to suit the compression and focus on low and mid power. TQ could rise quit a bit. HP will depend if the heads are the choke point.
Can you post the sheet so we can look at the shape of the curve?
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