If my memory serves me correctly I believe the stock "L" pulley is 2.93 not 2.80. Harley pulley stock is 3.25 so if this helps you then my typing was worth it.
I have a factory 2.93 pulley I was planing on swapping out but it think swaping the lower pulley for a 4# or 6# would be a better choice. If you leave the bigger pulley on the blower you will have more belt contact and hopefully less chance for belt slip.
I plan on swapping out my lower for a 4# upgrade which should yield 12# of boost.
Also remember that if you change the intake parts to flow better you will pick up 1-2#'s of boost as well.
If you put too much boost into these M112 Eatons blowers i hear they will pump out way too much heat and therefore the air charge temperature will suck the life out of the increased boost.
Most people say 13-14#'s of boost is about the max you want for this motor anyways.
Are you saying it's not necessary to change the stock belt if you use the 4# lower pulley? Also, what intake parts are you referring to? I was looking at a package that includes the 4# pulley and belt along with the cold air intake that they actually call a "Mass Airflow System" It claims an improvement of 50 average hp and 75 peak hp. It sounds pretty impressive and not a bad deal for $700 IF it does what it claims. I'm new to the 5.4 world and only have experience with modifying 4.6 Mustangs. Is that package in line with what those who have actually modified Harleys are finding? I only want to do fairly light mods to the truck, but love free/cheap hp.
No, if your change the lower crank pulley you will have to get a longer belt for sure. As far as the cold air intake goes, I am installing a JLT cold air intake and conical filter system, an Accufab Oval throttle body, and C&L upper plenum piece. All of these pieces will flow about 40% more volume of air into the supercharger therefore improving the boost and decreasing the charge temperature. HP increase for sure. Also Reichard Racing has an aluminum spacer that goes under the supercharger to raise it up about 3/8" and by doing this changes the way the boosted air comes out of the supercharger port and hits the intercooler rad. This will apparently increase the flow characteristics into the cylinder heads for approx. 20HP gain. Makes sense. Unfortuneatly nothing is cheap in this arena but if you want to make some more ponies I would suggest 3 things. Cold air first, pulley change and tuner next. After that it is up to you if you want to start changing out exhaust systems and custom tunes for different fuels.
I will let you know what gains I get after getting everything installed and tuned in. I hope to get at least 450rwhp and about 525 lb/ft torque with these mods. Then I will go for the exhaust changes and wideband O2 sensors etc, etc, etc.
Thanks. I look forward to hearing about your hp gains. I can tell you from dealing with Mustangs, it never ends. The more you get the more you want and the further you go the more expensive each hp gets.
wow sorry to hear only14.19 1/4 mile i have an 02 harley and ran a 13.6 and plan on lower numbers with custom tune and some drag slicks my factory junk goodyears burnt the whole 1/4 mile the first run had to feather it on the other runs lower pulley conversion to 12# boost preditor tuner cold air and magna flow exhaust from convertors back very respectable for a 4 door pick up
I got 13.56 with my lightning with mods at 102mph. 98 without. You have one fast Harley. Hmmm maybe it is because I weigh 360 pounds and stress my poor L to go so slow. Hmmm but I was the fastest L on the track that day and there were about 5 other L's there.Most went 98 to 100.
hey guy's my truck does have mod's as i described above i just wanted to let you know what these trucks are capable of and i will get into the high 12's i need some slicks and i have a dyno tuner available to me the best in the country thats going to dial it in i'm sure all your trucks are fast and i'm not claiming to be the fastest because there is always somebody faster this is what my truck did for the first time at the track and i was pretty impressed with it