Bad Dyno
#1
Bad Dyno
Just dynoed my softtail again and I'm very dissappointed. 85 hp and 95 tq.
I have not found a Harley that can beat me from a roll-on. I was expecting 100 and 100. Last time two times on the dyno, the bike produced 84 hp and 102 tq. I have installed bigger cams, had the heads ported, bigger carb, roller rockers, and the numbers didn't change. Any ideas as to what is going on with my bike.
I removed the air cleaner and the numbers went to 91 hp and 96 tq.
I know dynos are all different but I spent alot of money on performance changes and the bikes is faster than before all the mods.
Sorry I'm rambling.
The details
95 cubic inch
44 CV screaming eagle carb and intake
Jim's roller rockers
Ported heads-bigger intake and exhaust valves
2-1 hooker exhaust
Forcewinder intake
Dyna ignition
I have not found a Harley that can beat me from a roll-on. I was expecting 100 and 100. Last time two times on the dyno, the bike produced 84 hp and 102 tq. I have installed bigger cams, had the heads ported, bigger carb, roller rockers, and the numbers didn't change. Any ideas as to what is going on with my bike.
I removed the air cleaner and the numbers went to 91 hp and 96 tq.
I know dynos are all different but I spent alot of money on performance changes and the bikes is faster than before all the mods.
Sorry I'm rambling.
The details
95 cubic inch
44 CV screaming eagle carb and intake
Jim's roller rockers
Ported heads-bigger intake and exhaust valves
2-1 hooker exhaust
Forcewinder intake
Dyna ignition
#2
#3
dyno tricks
To get bigger numbers on your dyno you can do the following, just like some people who produce these larger than life.
1) over-inflate the rear tire
2) run cold air directly into the carb/EFI
3) re-adjust the dyno
4) You get the idea
Why not just tune the bike to produce actual performance or have your kid draw a graph with crayons and put the numbers you want like I see other shops do. From what you are writing above, you have indicated you have a for-real tuner who knows what they are doing. Go back to them and ask them how to achieve the numbers you wish. I think they can suggest which components are needed to be changed. This is what I have learned from experience. Imposable numbers or numbers out of parameters are usually just that. 103 CU inches and 150 HP? Without knowing your circumstances and details, I hope you understand my point, I may be wrong so be your own guide. Good luck.
1) over-inflate the rear tire
2) run cold air directly into the carb/EFI
3) re-adjust the dyno
4) You get the idea
Why not just tune the bike to produce actual performance or have your kid draw a graph with crayons and put the numbers you want like I see other shops do. From what you are writing above, you have indicated you have a for-real tuner who knows what they are doing. Go back to them and ask them how to achieve the numbers you wish. I think they can suggest which components are needed to be changed. This is what I have learned from experience. Imposable numbers or numbers out of parameters are usually just that. 103 CU inches and 150 HP? Without knowing your circumstances and details, I hope you understand my point, I may be wrong so be your own guide. Good luck.
#4
The dyno tuner does have a ton of experiance and he builds 90% of the bikes in the area. He did almost the same build on a Fatboy, same cams and head work, carb was different. And got 102 hp and 102 tq. He was couldn't understand the difference in numbers either. Combintion is key also, I'm assuming that my combine is good because I have can walk away from a friends bike that dynoed way higher. He can ride and it was from a roll, so it was a fair run. Removing the air cleaner concerns me that the forcewinder is holding me back. On the dyno you don't receive the ram air effect that the intake is designed for. But 7HP just by removing it, tells me that I need a new air cleaner.
#5
#6
Forcewinder is a known cause
The dyno tuner does have a ton of experiance and he builds 90% of the bikes in the area. He did almost the same build on a Fatboy, same cams and head work, carb was different. And got 102 hp and 102 tq. He was couldn't understand the difference in numbers either. Combintion is key also, I'm assuming that my combine is good because I have can walk away from a friends bike that dynoed way higher. He can ride and it was from a roll, so it was a fair run. Removing the air cleaner concerns me that the forcewinder is holding me back. On the dyno you don't receive the ram air effect that the intake is designed for. But 7HP just by removing it, tells me that I need a new air cleaner.
#7
Trending Topics
#8
Just dynoed my softtail again and I'm very dissappointed. 85 hp and 95 tq.
I have not found a Harley that can beat me from a roll-on. I was expecting 100 and 100. Last time two times on the dyno, the bike produced 84 hp and 102 tq. I have installed bigger cams, had the heads ported, bigger carb, roller rockers, and the numbers didn't change. Any ideas as to what is going on with my bike.
I removed the air cleaner and the numbers went to 91 hp and 96 tq.
I know dynos are all different but I spent alot of money on performance changes and the bikes is faster than before all the mods.
Sorry I'm rambling.
The details
95 cubic inch
44 CV screaming eagle carb and intake
Jim's roller rockers
Ported heads-bigger intake and exhaust valves
2-1 hooker exhaust
Forcewinder intake
Dyna ignition
I have not found a Harley that can beat me from a roll-on. I was expecting 100 and 100. Last time two times on the dyno, the bike produced 84 hp and 102 tq. I have installed bigger cams, had the heads ported, bigger carb, roller rockers, and the numbers didn't change. Any ideas as to what is going on with my bike.
I removed the air cleaner and the numbers went to 91 hp and 96 tq.
I know dynos are all different but I spent alot of money on performance changes and the bikes is faster than before all the mods.
Sorry I'm rambling.
The details
95 cubic inch
44 CV screaming eagle carb and intake
Jim's roller rockers
Ported heads-bigger intake and exhaust valves
2-1 hooker exhaust
Forcewinder intake
Dyna ignition
I do have to question who suggested those parts tho, a 95" motor should be running something like a Mikuni 48mm carb setup and a large NO NONSENSE high flowing K&N air filter assembly. Even the exhaust is questionable, hooker is not known as a hi performance exhaust for the Harley platform.
Last edited by SuperAhcmed; 09-07-2008 at 12:52 PM.
#10