No Baffles...what are the consequences?

[vinniemac]

I took the baffles out of the drag pipes on my '84 Shovel in order to make the pipes louder. I know that this can cause some problems with backpressure.

Question #1: Someone has suggested using AR Cones to make up for the loss in backpressure, however someone else has told me not to use them. Both are bike builders. I don't know anything about AR Cones and had never even heard of them til now. Should I use them or not?

Question #2: Can I do some sort of adjustment on my carb to make up for the loss in backpressure? (however, I'm already having carb problems since I am currently running a G, but really should be running an E)

[djl]

Don't know anythign about AR cones but you are jumping from the frying pan into the fire as far as performance goes when you remove baffles from drag pipes. The consequences are a loss of performance and fuel economy and, perhaps, a ticket, depending on where you live.

Drag pipes, as the moniker implies, are designed to produce HP in the upper range. Remove the baffles and you will certainly make more noise, may make a little more HP up top but the torque, the fun part of riding a pushrod V-twin, goes in the toilet. I understand that pipe selection is very subjective and that how loud pipes are and how they look are the reason many select pipes. However, any 2:1 system and some 2:2 systems can provide sound, looks and performance that should satsify most. Your bike, your money, your choice; JMHO.

[middermax]

DJI is giving you the true scoop. Reversion cones are installed high in the head pipe to limit exhaust gases from contaminating the the combustion chamber. Drag pipes need to be cut to the correct length based on several factors. This is what drag builders do. Higher hp higher in the rev band. Lousy low/mid range tq. Oversizing your carb reduces intake velocity & just wastes heat/fuel giving poor performance. Do what you like but understand your choices affect where in the rev range you're going to make power.

[DaFish]

What you've been told is fact's.

Now that said.....You CAN drill a hole in the end of each pipe and insert a bolt with washers stacked inside of the pipes to give you more back pressure. You will still have the sound and the bolts/washers will add some backpressure.
Just stack washers on the bolts until you find the right amount of backpressure.

Personally I don't like drag pipes but like djl and Max said....It's your bike....Your money.

DaFish

[103 herritage]

i took the baffles out of mine in the past, love the sound, but the bike just doesnt run right without them period. its give and take go for sound loose perf. i think no matter what we have we are NEVER SATISFIED (wish i could fit that on my tag)

[middermax]

One further thought for your consideration. Remember the saying about not having you cake & eating it too? Same with engine configs. Torque is the twisting power of the engine to spin the wheels. It creates acceleration up to a given speed. It can be directly measured. HP is the ability to maintain the speed achieved. It is derived via a math formulae. To an extent you must choose which best suits your purpose. High acceleration & drivability or the ability to maintain high speeds at high rpm. Once torque increases can't keep up with the HP curve the game's up on acceleration. If you will, one is somewhat in conflict with the other. It's always the engine builders choice to make. Doesn't matter cage or mc. This though ignores the sound/noise business. Have fun.

[DaFish]

Max just brought up a good point...Have you ever noticed that torque and horsepower will cross at about 5400 RPM?

DaFish

[middermax]

You got it Ray. When we write specs for new trucks at work we accurately calculate the fully loaded weight, which is controlled by style/purpose of the vehicle & equipment & water carried. This is done before even thinking of the powerplant & drivetrain. Insufficient torque from either design or displacement means crappy acceleration on the street. A few years ago we were forced by the budget nerds/politicians to purchase some under powered rigs. Guess what, service costs & down time went nuts well beyond the cost of a better configuration from the start. Once I proved this via our records they backed off on future spec limitations. Go figure. Ya gotta love government.

[DaFish]

A torque bike versus a horsepower bike.
IMHO the torque bike is WAY more fun to ride.
Yea I've got both.

DaFish