2.80 or 2.93 pulley?

[HIGH ROLLER]

JT, I assume your making around 13.5-14 pounds of boost with your current setup,i agree with Jim that anything over 15 pounds is creating alot of heatsoak so why mess with the crank pulley and spend $450 for 2 rings instead just try the 2.80 upper(1 pound more) alot cheaper or maybe a friend near you might have one laying around he is not using. Hell if i lived closer i would take mine off my car just so you could see the difference between them.

Jim, Very good and true comments,i could not agree more with you!

 

[jtfx6552]

The Torque required to turn the blower goes up as boost increases. At the same time making the upper pulley smaller give the belt less mechanical advantage over the blower shaft (the equivilent of using a shorter wrench to turn a tight bolt). I don't think a 2.76 can transmit the neccesary torque to turn the blower at high RPM, maybe even with extra wrap that idlers provide. With the same wrap, same belt width and tension, theoretically a 3.1 can transmit 12% more torque to the blower shaft.

 

[Cobra10thaniv]

Ok this may sound dumb.

But why doesnt a person just run the lower 4,6 or 8lb pully

1. skip dealing with all the belt slip
2. Buying idler pullies
3. everyone looking under the hood and seeing you have a pully right off.

What am I missing? Im sure it must be obvious Just cant be cost could it? I mean I know at certain boost you have to add the alt pulley. but everyone has to add the idle pulleys.

So what gives

 

[jtfx6552]

Originally posted by Cobra10thaniv
Ok this may sound dumb.

But why doesnt a person just run the lower 4,6 or 8lb pully

1. skip dealing with all the belt slip
2. Buying idler pullies
3. everyone looking under the hood and seeing you have a pully right off.

What am I missing? Im sure it must be obvious Just cant be cost could it? I mean I know at certain boost you have to add the alt pulley. but everyone has to add the idle pulleys.

So what gives

More expensive,

Tight as all hell cage bolt,

increased belt speed,

increased alternator speed, to the point of failure if you don't slow it down with a larger pulley when used with the 6 or 8 lb lowers.

Increased/changed mass on the front of the crankshaft.

 

[trey193]

JT you are familiar with which tune I am running, the night I tested my JDM interchangeables 2.93 & 2.80 the A/F on each of them you could lay right over the top of one another on the A/F graphs. They were the same. And its worth noting that the 2.80 had a healthy TQ and HP advantage down low and through the middle15tq and 10hp but as Jimmy V was saying from 6-6500 the advantage shrinks and was only 4 &4 but none the less the 2.80 was stronger everywhere and alot stronger on both sides lower in the rev range, and this was 90 degree heat to boot. I am with Roller go with the 2.80 for the next couple of weeks at the track and scrap the idea of a lower! I am certain your car will pick up at the track both et and mph wise if your clutch is still there.

 

[akaeric]

Man forget the pulleys with this kind of intake this car has all you need is a smell 50 nitrousshot installed right in the intake tube or more depending what you are looking for and you wouldn't even need a cold air intake and take a chance of sucking water in the motor all though I have a cold air intake thats what I'm going to do next and maybe put the factory filter back in because I have seen these cold air intake suck water by just going through a water puddle because they are so low to the ground wheather sheild or not. nothing gets any cold air than that nitrous and its not that expensive to fill a bottle.

 

[drkchk03svt]

Originally posted by KevinJKD
mkdiehl - what I meant was, for the people who want just alittle more hp than what an exhaust/CAI will give them, than a 3.1 pulley can do the job. But even if your not in boost with the 2.80 pulley the blower is still spinning faster all the time. So far this does not seem to be a problem, but it will create more heat and you might want to change the blower oil more often. The better heat exchanger from PHP would be a good idea too.

It just depends on how much hp you want.

I want 500 with the stock supercharger damnit! Before I had a cobra I saw two - three dyno at 500 at Speedworx in Lewisville, TX. All I know they had was a pully, CAI, throttle bodie, x-pipe, and exhaust. They custom burn your stock computer.

 

[running10s]

Well guys I have to say this much. I have spoken to Amazon racing,(he runs 2.76) Kenne-Bell and Brian at Apten. They all are telling me the 2.76 upper will not over work the supercharger. Now what they are saying is that with 2.76 and a 2lb or higher lower thats its not safe. So i guess no-one really know who is right or who is wrong. Get the pulley you feel comfy with.

 

[xVENOMx]

ok how about a 3.00 upper pulley
and a 6lb lower pulley
good hp and a load of tq

a 6lb lower is crazy on a kb

 

[Mxr]

How bout a no-slip 2.90 upper and a 6lb lower?

what kind of psi would you end up with that combo? pretty safe on pump gas?

 

[JaketheSnake]

now im really confused...so undecided and its almost crunch time!!!
what about headers? wouldnt that drop you down in boost and therefore you could run something higher? or am i wrong?

 

[hedstrosity]

ok... these damn ildlers :??: ..... how many are there, and how many are necessary? how do they stop belt slip, and do they always stop slip, or do you get them just in hopes they do?
are they the same diameter as the stockers?
ive seen people in this thread say the 2.80 pulley is overkill, but with the idlers its not :??: .
is a rr ultragrip 2.93 pulley slip proof, or should idlers always be installed with a smaller pulley?

i think this whole thread is more confusing than it is informative :shrug:

another question... as far as idlers and pulleys go... is there a manufacturer that is "THE BEST", is it a matter of opinion, or is it a matter of price?

 

[hedstrosity]

ok http://rpmoutlet.com/03cobraasp.htm#1
i see theres three idlers.....
should all three be replaced the Auxiliary and the other two?
the other two have two options.... a 90mm one and a 100mm one..
would 100mm idlers and a 2.80 pulley be ok cause it would spin a little slower?
i guess the better question is whats the diameter of the stock idlers..... damn this shiats confusing. im not fighting for every hoerspower, but i dont want slip either.

 

[Black Chip]

Originally posted by ygohome
I may put on the 2.80 upper and get the idler pulleys at the same time. I wouldn't get the 2.80 without the larger idlers... but then it will become blatently obvious that the pulley is on because the pulley shield won't fit with the larger idlers (i think(.

:beer:


untill then, I'm happy with the 2.93

So you have the 2.93 with no idler? Any slippage?

 

[akaeric]

I was told that you can get good results from a pulley off a lightning truck I don't know what size it is. I have one of those S.Florida none slip interchangable pulley kit with a 2.80 still in the box and their big idler and The Goodyr. belt. I didn't like like their pulley puller it scares me that I might break off that sorry little screw inside the SC shaft so I was going to order the Amozon's puller kit but I have a nice chrome pulley cover and if this outfit want fit under my cover I don't want it plus now I have my eyes on that K.Bell twin screw SC replcement. and then I'll know I'll get a bang out of my bucks but big buck though.

 

[drkchk03svt]

Originally posted by King03Cobra
So is there much of a difference between the 2.80 & 2.93 ? Sounds like they both slip, one worse then the other meaning that the 2.80 is slipping more, isn't the HP pretty close to the same because of this ?

If you get the RR ultra grip and the billet flow idlers and a new gates belt it will NOT slip.

 

[drkchk03svt]

Originally posted by hedstrosity
ok... these damn ildlers :??: ..... how many are there, and how many are necessary? how do they stop belt slip, and do they always stop slip, or do you get them just in hopes they do?
are they the same diameter as the stockers?
ive seen people in this thread say the 2.80 pulley is overkill, but with the idlers its not :??: .
is a rr ultragrip 2.93 pulley slip proof, or should idlers always be installed with a smaller pulley?

i think this whole thread is more confusing than it is informative :shrug:

another question... as far as idlers and pulleys go... is there a manufacturer that is "THE BEST", is it a matter of opinion, or is it a matter of price?

The idlers apply pressure to the belt to keep from slipping.

 

[DA_MYSTIK_1]

I have the 2.9 pulley have no slippage what so ever. So imo I would stick with this pulley. If you go to a 2.80 or 2.76 for more hp n tq thats up to you to but yur going 2 wind up with the same results like every has stated and you never know when that darn eaton is going to blow 2 boot. So far not anyone has had any serious problems so its just boils down to what you want a daily driven devil or a 1/4 mile monster. The best time I have run with my set up is a 12.1 but my friend can get it into the very very low 12.002-12.005 but I know with my new suspension setup im fixing to buy in the hi to mid 11's .

 

[vbguy01]

2.8

 

[Venom25]

So you all suggest us new comers should get a 2.8 pulley with a 100mm idler and a gatorbelt to avoid slippage? This set up should put 14-15 pounds of boost?