ssjunkie

iTrader: (3)

Its the single center bolt style. What kinda boost numbers would 2.6 get me? Im not sure how high I can go boost wise and still be safe with a stock bottom end.

raven154

iTrader: (14)

Since it has a 3", I would suspect its a pretty early single bolt press on pulley. If that's the case, the link below should be what you need.

http://www.pulleyboys.com/store/prod...&cat=37&page=1

A 2.6 would probably get you around 8lbs. Problem with the 2.6 is belt slip with the 6 rib belt. A gator back belt can help here but they do stretch after a while. As long as the guy knows how to tune, a 2.6 will be fine on the stock bottom end.

Also, with these single bolt pulleys, they are pressed on. You will need a 3 jaw or similar puller to get them off. The Magnacharger pulleys are generally steel and can be taken off without damage on most occasions. The aftermarket pulleys however are all aluminum and will most likely be deformed or destroyed if you don't heat the pulley prior to removal.

I was never able to successfully remove an aluminum pulley without damage. Maybe mine was just a bit on the tight side? Not sure. Just know they can be a pain and heat is your friend. Just don't cook the front jackshaft bearing.

Is your jackshaft steel or carbon fiber?

DMM

Don't worry about that, you're a long way from having to worry about too much boost. The 2.6" may cause some belt slip since the pulley is so small, but will give you a tad more boost than the 2.8". No idea on belt size, you'd have to figure that out in the autozone parking lot with a hand full of belts to see which one works best.

ssjunkie

iTrader: (3)

The jack shaft is carbon.

Ok, The plot thickens. I was just out looking at the pulley again. I measured it with a dial caliper earlier to come up with 3". That was outside to outside. Anyhow, looking closer at the hub of the pulley I can see 2.8 writen(etched) into it. So I guess the measurement is from the ribs? In any case im sure its a 2.8. Which puts me back at looking for missing boost. Hummmm....kinda puzzled.

DMM

Based on what Gil said, it seems you're right on target with boost...my apologies for leading you down the wrong path. Going from a 2.8" to a 2.6" will not make a difference in the tune anyhow, so that can be safely done after the fact.

ssjunkie

iTrader: (3)

Ok, I'm done worrying about it. Gonna go next week and see what happens.

Took the belt off and it has a part number on it. So here are the belt details and a list of belt brands and the proper part number for each. Not that anyone cares but I can refer back to it if i need to.

Descripition
Outside Circumference: 3050.54 mm,120.1 in
Top Width: 21.34 mm, 0.84 in
Ribs: 6 mm,6 in


GM - 97300656
GM - 98035628
NAPA - 25061195
DAYCO - 5061195
GATESK - 061195
GATESK - 061195HD
Contitech - PK061195

John

punishmentcycle

iTrader: (6)

i personally just think you have a well flowing set up..dyno will tell

punishmentcycle

iTrader: (6)

idk man... i know hes not spinning that thing much but going from a 2.8 to a 2.6 is gonna change the A/F about .3.. and you never know what his timing tables look like.

its prolly gonna slip pretty good so it wont be a drastic change, but off the hit the air flow will go up somewhat substantually. id at least put a wide band on there and a scanner that shows real time data to watch iats and knock just to be sure.

raven154

iTrader: (14)

Dang I thought we may have been on to something there.

I would have to agree with punishment on this one. You'll just have to see what she puts down on the rollers. If you're going to put the 2.6 on, I would do it now and make one trip to the tuner and be done instead of worrying about what your A/F will look like afterwords. In all reality it probably wouldn't hurt anything especially if its tuned on the safe side, but better to know the extra air has been tuned in.

ssjunkie

iTrader: (3)

Do I have to grind down the snout(machine the boss behind the pulley) to fit a 2.6" pulley? Plus if the belt is going to slip I dont think im going to worry about it. Especially if it puts down 480 the way it is.

Thanks again for all the info guys. Ill post on the other thread with results next week. To be honest im looking more forward to ironing out some drive ability issues than the actual max power.

punishmentcycle

iTrader: (6)

dont grind on the blower..!!! 2.6 will fit with a little material removed from the inside of the 2.6 pulley! you dont have to go crazy, just needs a little taken off with a dremel.

i made a thread a while back on the gates RACING blue belts.. get the 101.5racing belt and never look back! part number is in that thread.. ill get you a link

punishmentcycle

iTrader: (6)

https://ls1tech.com/forums/cadillac-...ues-check.html

GFallen

I have a 2.6 but changed plans, I'm gonna do a 2.7 upper and the OD crank. If you're gonna do a 2.6 check out the ECS tensioner. Supposedly it really helps.