Disappointing Dyno numbers
Thread Starter
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Cruiser
Joined: Dec 2013
Posts: 198
Likes: 1
From: Lakeland, TN
IMO a cam is like a great temperamental actor. You give them exactly what they want and they will create a masterpiece, you don't and they will bring down the performance of all those around them. A couple of thoughts about what could be going on here: as stated before, the change in exhaust alone could have netted a loss in numbers and the gains from the cams could just be compensating for the loss, so no real gain in the overall numbers. Another thought is what led you to choose the 204 cams? Did your tech talk to you about your riding style and expectations of these mods? If you look at the chart in the SE catalog the 204 only has .024" more lift, look at your feeler gauge set, it's not much. The big difference between the stock cams and the 204 is the valve timing, which for the most part is going to affect where the power happens in the RPM range. The other thing that I question is the ability of the tech that performed the dyno tune. You stated that he has a title and some sort of pedigree, I have worked in shops at the dealership level in heavy truck/equipment fields, most of the time in my experience these guys aren't always the best hands on guys. You may want to post about your situation in the SE tuner threads, there are a lot of sharp guys on here and they may be able to spot something wrong with your tune. It may not be your parts it may just be that the tune needs further adjustment.
I called him this morning, waited all day for a call back, and after 5:00 passed, went for a ride figuring he wasn't calling. Of course, he called while I was riding. He said he'd try me again in the morning.
Ultimate HDF Member
Joined: Dec 2010
Posts: 7,776
Likes: 2,252
From: wet coast BC
That's because most people won't pay the cost of a good tune ($350 or more) to go with the Stage 1 air intake and exhaust changes. I have heard the service writers at my local HD dealership tell customers who are experiencing sticker shock that "you don't HAVE to do the tune right now", in order to not lose the Stage 1 sale. So, the customers don't really get all they could have gotten. Then, later, they have the cams done, and are told they MUST get the tune, so they then get all the benefits of the cam PLUS the Stage 1 benefits they did not see by bypassing the Stage 1 tune.
The "evidence' you cite makes perfect sense.
Jim G
The "evidence' you cite makes perfect sense.
Jim G
in most cam threads I ask if the stock bike was tuned, if the stage 1 bike was tuned before adding a cam and doing a full dyno tune. No wonder the seat of the pants feel is so great for those guys. untuned to tuned plus cam and stage 1.
Few, very few it seems get the most from what they already have.
OP, did you have an expectation of HP/TQ before you started? you had great numbers before the cam with Stage 1 tuned. not sure what more to be expected from the 204. did the tuning guy expect more?
Thread Starter
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Cruiser
Joined: Dec 2013
Posts: 198
Likes: 1
From: Lakeland, TN
BINGO
in most cam threads I ask if the stock bike was tuned, if the stage 1 bike was tuned before adding a cam and doing a full dyno tune. No wonder the seat of the pants feel is so great for those guys. untuned to tuned plus cam and stage 1.
Few, very few it seems get the most from what they already have.
OP, did you have an expectation of HP/TQ before you started? you had great numbers before the cam with Stage 1 tuned. not sure what more to be expected from the 204. did the tuning guy expect more?
in most cam threads I ask if the stock bike was tuned, if the stage 1 bike was tuned before adding a cam and doing a full dyno tune. No wonder the seat of the pants feel is so great for those guys. untuned to tuned plus cam and stage 1.
Few, very few it seems get the most from what they already have.
OP, did you have an expectation of HP/TQ before you started? you had great numbers before the cam with Stage 1 tuned. not sure what more to be expected from the 204. did the tuning guy expect more?
Stellar HDF Member
Joined: Mar 2012
Posts: 2,008
Likes: 596
From: Columbus, OH
Yeah, he asked me lots of questions about what I wanted. I told him I wasn't looking for a 150 hp street racer, just more passing power. I like that pull you get from hard acceleration. I don't want to go 140 mph, but rather a better 0-60 time. He looked over the cam book while I was on the phone and picked the 204 after comparing all the numbers.
I called him this morning, waited all day for a call back, and after 5:00 passed, went for a ride figuring he wasn't calling. Of course, he called while I was riding. He said he'd try me again in the morning.
I called him this morning, waited all day for a call back, and after 5:00 passed, went for a ride figuring he wasn't calling. Of course, he called while I was riding. He said he'd try me again in the morning.
Do you have the SE tuner software? If I remember right the disk was around $20. You can open the tune on your bike and take a look at the different tables. You can even post your tables just like you did with your dyno sheet. I would head over to the tuning section and post about your situation one of those guys could take a look at what you have and see if it fits your combination of parts or even make suggestions to change your tune. This may make a significant improvement in how the bike feels.
Ultimate HDF Member
Joined: Dec 2010
Posts: 7,776
Likes: 2,252
From: wet coast BC
Yes, I was given the impression that there would be a substantial increase in power. I even mentioned twice in the conversation that the bike was already at stage I and that they had the race tuner on file there at the shop. There's no way that there was any misunderstanding of where we were or where we expected to be.
you do have the tuner and could do some smartune datalogs and see what changes/ how much changes. Of course save the dyno tuned map.
On a quick look around at other graphs you are in the median range of numbers so may find some more.
at this point it mostly depends on whether you are chasing the numbers or looking for seat of pants satisfaction
I went with the SE255 when I upgraded the cams. My thinking was it was a low end torque cam and that's what I was after, that mid range pull, also that was the cam that came with the 103 and the 110 kits. So when I did upgrade to a big bore kit I wouldn't have to change the cams again. I looked at the 204 but my thinking was that the numbers were not much different than stock and I probably wouldn't get as dramatic results. two years later and I kinda wish I would have went with the 254, they have a little bit more top end pull. Overall though I'm happy with the results.
Do you have the SE tuner software? If I remember right the disk was around $20. You can open the tune on your bike and take a look at the different tables. You can even post your tables just like you did with your dyno sheet. I would head over to the tuning section and post about your situation one of those guys could take a look at what you have and see if it fits your combination of parts or even make suggestions to change your tune. This may make a significant improvement in how the bike feels.
Do you have the SE tuner software? If I remember right the disk was around $20. You can open the tune on your bike and take a look at the different tables. You can even post your tables just like you did with your dyno sheet. I would head over to the tuning section and post about your situation one of those guys could take a look at what you have and see if it fits your combination of parts or even make suggestions to change your tune. This may make a significant improvement in how the bike feels.
Outstanding HDF Member
Joined: Oct 2011
Posts: 3,492
Likes: 19
From: Illinois
My engine was already built but I wanted to take full advantage of my SE heads so I had them pulled then flowed, ported, polished with bigger valves and springs. I knew by doing that I would have to change out cams to get the full benefit out of my motor and the new head work. I had my 211 cams pulled and we put a set of Reaper 574 cams back in it.
It's at the Dyno guys as we speak so I am anxious to see how it runs. I put a little over 100 miles on it for my pre dyno tune. I never hit it hard because of it being new but man, what a difference it has made. I'm going to ride it when I get it back and then evaluate everything and then post up some numbers and how she runs.
It's at the Dyno guys as we speak so I am anxious to see how it runs. I put a little over 100 miles on it for my pre dyno tune. I never hit it hard because of it being new but man, what a difference it has made. I'm going to ride it when I get it back and then evaluate everything and then post up some numbers and how she runs.
Intermediate
Joined: Jul 2013
Posts: 47
Likes: 3
From: Flushing
I would say that with what you had done I would be pleased you may have lost a bit of power but if you study your charts you'r power band is a lot healthier than it was before. Across the whole curve you are higher than with the stage 1.
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Stellar HDF Member
Joined: Mar 2012
Posts: 2,008
Likes: 596
From: Columbus, OH
My engine was already built but I wanted to take full advantage of my SE heads so I had them pulled then flowed, ported, polished with bigger valves and springs. I knew by doing that I would have to change out cams to get the full benefit out of my motor and the new head work. .
The problem with cams is that there are so many variables which either help or hurt the cams overall effect on the motor. The cam that made your motor come alive may hurt the performance of mine. Just because the numbers are bigger (lift,duration), doesn't mean that it's a better cam. Compression ratio, valve and port size, cylinder volume, throttle and exhaust sizes all have to be matched for a cam to work right and to receive the full benefit of the cam's grind. Then you get into the variables of the cam specs: lift, duration, valve timing, lobe center line, valve overlap.......and so on and so on..........
Outstanding HDF Member
Joined: Oct 2011
Posts: 3,492
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From: Illinois
Thanks' Fat11Lo, as well know it's a labor of love. I knew I wanted my heads done and that in doing so I would have to address the cam issue. I also knew that with doing those 2 upgrades that it had to go back to the Dyno guy. I shake my head when I see or talk to someone and they explain how they did this, that or the other for performance then short change themselves with skipping the Dyno.
Also, I talked to my Dyno guy before I even pulled the heads or had the cams. Then I talked to my head guy, then all 3 of us talked. They had to be on the same page in order to get the heads right, proper valves and springs then dial it all in.
Also, I talked to my Dyno guy before I even pulled the heads or had the cams. Then I talked to my head guy, then all 3 of us talked. They had to be on the same page in order to get the heads right, proper valves and springs then dial it all in.