Fellas, and perhaps the ladies as well,

I just installed a viper shorty exhaust and have the following problems.

1. The first time I started it the idle was really low. About 6-700 rpm. I adjusted the idle and all was well. Would the lack of stock backpressure cause a decrease in idle speed?

2. I went to ride and starting out in first gear I noticed quite a bit of hesitation. It bogs down and takes a few seconds to power out of it when I give it more gas. Kind of embarrasing at stop lights! If I really rev it then it's fine. But that's kind of embarrassing to have to do as well. No other gear or RPM does this. Only 1st gear. All other gears are crisp and responsive. Shifts are the same way. Would the lack of stock backpressure cause it to bog down in 1st gear only?

I think the stock ECU should be able to adjust for small changes like a slip on.

Your thoughts?

 

A slip-on wouldn't make much difference, but you put a shorty exhaust on there. Less back-pressure, less low-end.

Do a search for shorty exhaust on here, plenty of info.

 

I'm constantly adjusting my idle since i put on my Level One Racing pipe. Warming up it idles at 1.5 then raises to 2 once its warmed up.

 

i also have a viper shorty exaust and i dont have any problems that u listed ?

 

That is odd. I'm running a stock setup except for the exhaust. Do you have a Power Commander or other ECU installed or is it stock? Any other performance mods?

 

nope ...im not even running the stock 02..i have it zipped tied to the frame lol....

 

I think the reason you're seeing it in 1st gear only is probably because you leave a stop at a much lower RPM than you shift between other gears at. For instance you may leave a stop at 2200rpm. But you shift between the other gears at no lower than 3500. You're putting a greater load on the engine (moving 500lbs from a dead stop) at a very low RPM with not much power. Versus shifting between gears (2-3, 3-4 etc) while already moving and somewhat higher in the powerband...

Maybe, I dunno, just a guess.

 

it works the same way as a car or truck with a bad exhaust leak

no bottom end power and i bet it won't want to idle at all if it gets really cold outside

 

this is exactly what my bike did when i ran it without exhaust for a day, there is not enough back pressure, which is common with cheap shorty pipes but not it viper cans. where did you get it from

 

I got the 20cm can and pipe from www.flyncycle.com.

If it is indeed a problem with backpressure then would a power commander III or something like this do anything for me? If I am not mistaken then PC3s just adjust the fuel flow and not engine timing. Doesn't seem like this would fix a backpressure issue.

Maybe I should find a way to cap the tip a bit to increase backpressure. Then take it for a ride and see if this solves my lag.