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Discussion Starter · #1 ·
If so, how is your TQ and HP now ? I have a stock 88, SE breather and dragpipez ( Samson M133). I can't get it right. the engine is hesitating when accelerating and some time also at the same continuous rev when cruising...:thanks:
 

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Do you have the stock cam?

I am no expert but I do know the stock cam has almost zero(6 deg) of overlap. I think this means that there is very little exhaust tuning effect possible because there is never any physical connection between the input and exhaust tracks. If what I just said is true the drag pipes should not be causing too much of a problem for you tuning wise.

I think the reason the stock cam has no overlap is because of EPA. With no overlap there is little chance of sending unburnt fuel out the exhaust pipe. Similarly there is little chance of sucking intake charge into the cylinder with the exahust pulse.
 

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Discussion Starter · #3 ·
to DRAGFORCE

I have the SE203 cams and the SE open filter.
What i want to know is that it is normal that with a "zero map" the engine is hesitating when accelerating ? It's like having hickups. When I open the throttle a little more it runs fine? But it is hesitating again when riding at the same speed after a while.
I will try again with the PC disconnected. And when the weather is better i'll drive to a dyno tuner.

But any input is highly appreciated....

Patrick:whistle:
 

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I think it might be...

With the 203 cam you will have exhaust tunning and detunning effects. Drag pipes have a torque dip in the low rpm range. This could be what you are describing. The torque dip is caused ( I think) by exhaust gas reversion. There are way better people on this board to go into detail on this however.
 

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We did an FI motor for a guy with dragpipes and it was a real chore to try to get it to perform well at all speeds. A big dip in the lo-mid range that was impossible to tune out. It was loud-yes. Very poor choice of pipes, but I like a quiet bike. Friday www.dyno-power.com
 

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Hellbound Train
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No amount of tuning will correct for the amount of loss that drag pipes are causing. Drag pipes are good for one thing, drag racing. If you want to lay down on the tank and hold the throttle wide open then get drag pipes.
 
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