harley exhaust help please?

Question

I have a 2005 Harley FXST softail standard with 88ci carburated engine, with Vance and Hines straightshots HS installed by Harley. I am wanting to put unbaffled Samson Groundpounders on it because I like the sound so much better. I am wanting to know if there are any pros out there who can tell me what if anything special I need to do to it first. I have heard lots of things about back pressure, reversion cones, torque cones, nothing at all, just slap them on. ect. ect.
I am needing help so I do it right. Any and all help would be greatly appreciated. Where I live nobody cares about the roar! Thanks in advance........

Answer 1

Your carb will very likely need to be jetted a bit fatter.

The torque cones and reversion cones your hearing about are supposed to help make up for the lost back pressure that comes with running uncorked pipes.
I've not been very happy with cones, they really are not the same as back pressure made in the middle of the pipes.

If you've got your heart set on running straight pipes, just re-jet and live with the flat spots in your power band ( usually out of the hole power is lost)

Consider cutting the baffles in half, better sound and still reasonable back pressure.

Answer 2

the dealer probably checked your fuel ratio & rejetted when they installed the V&H pipes so it would "probably" be close to right for the samsons too. it should be Ok to put the samsons on & try them for a while. check your plugs after a hiway run before you let it idle, for any blisters or melted electrode indications, the ceramic part should be tan ,brown or black to be safe. plugs will usually be black after it idles a while, that just makes them hard to read.the torque cones wont do you much good with a stock cam. but may improve your idle & low speed response. I'm experimenting with cones now. with 2'' drag pipes they kill the upper rpm range on the 96"with a crane 308b cam I,m trying them on, but with 1 3/4 pipes the cones work great, I,m goin to try a 3 step 2 into 1 with & without the cones next. trying to get that exaust reversion wave into a broad rpm range seems to be more alchemy than science so try the cones out if you have the time, their cheap.

Answer 3

I've changed the exhausts on all my Harleys. The carburated models are cheaper to do. First off, when you installed the V&H pipes, did you rejet the carb? you should have. If not, your gonna have to after you install the new pipes for sure. If you did rejet, you may not have to with the new pipes, but you have to have it checked on a dyno to be sure. Dyno time runs around $360.00 for 5 hours. If your dealership has already installed those pipes on that year and model bike, it only needs a 1 hour session on the dyno since they already have the proper "map" set up. If not, they will charge you for the full 5 hours.
The reason for the rejetis this: When you change out to a free flowing exhaust, you reduce the "back pressure" on the motor, this causes the motor to run leaner. Too lean causes overheating, pinging under acceleration, and flat spots in the power band. It can also cause engine damage. Also, it is always best to change your aircleaner set up to a high volume set up like the screaming eagle stage 1 kit. This allows the motor to get more air, which cause it to perform better. It is always recomended that you change this air cleaner when you install pipes. This will increase your horse power and torque. On my '06 Dyna wide glide, by installing SE2 pipes and the stage 1 kit, I got 12 HP more and changed the limiter setting on the rpms. On my '07 ultra classic, I installed python pipes, the stage 1 kit and gained 22.9 HP and went up to 90.3 ft pounds of torque. This of course after dyno tuning the motor on both bikes. On the dyna, they had a map already and it cost me for 1 hr of time. On the classic, it cost me for 5 hrs.

Answer 4

AAWWEE....the beautiful sound of a straight unbaffled Harley exhaust. After installing the new pipes more than likely you will be running lean. Running lean can cause piston failure due to excessive heat in the cylinder. You need to re-jet the carb after the install. There 3 jets in the carb that will need to be changed. Main jet, needle jet and pilot jet. These jets work over the entire range of throtle response. To check how you are running you need to do a Plug Chop. Wrap a piece of tape around the throttle, open the throttle all the way open and mark the tape at that position.(put a mark on the ignition housing to align marks with) Now position throttle half way between full and none and mark that. Now mark positions at 1/4 and 3/4. Now get 3 sets of brand new plugs. On a set of old plugs run the bike up to operating tempature. Put in a set of new plugs. Run bike at 1/4 throttle for atleast 5 miles. DO NOT let off the throttle, but pull in the clutch and kill the bike and coast to a stop. Pull plugs and ya want them to have a nice carmel brown color. Dark chocolate is too rich and white chocolate is too lean. Now put in another set of new plugs and do the same thing at 1/2 throttle. Check plugs and put in new set of plugs. Now do the same thing at 3/4 throttle. Again check plugs, looking for that nice carmel brown color. Adjust jets accordingly, too rich (dark chocolate) needs a smaller jet, too lean (white chocolate) needs a bigger jet.

LOUD PIPES SAVE LIVES

...............o~`o............Ride on and Ride safe

Answer 5

After you put them on you might want to take your bike in to the dealership and get them to re jet your carb. but that should be it. I run straight pipes on my 03. I was told all about loosing back pressure and how it would decrees power. But I have never experienced any power lose.

Answer 6

after they are on and running,
check the plugs, odds are the bike will be running lean.
not only does this hurt power but can damage the pistons.
don't let it go like that..rejet the carb as soon as you can !