pulley questions.

Venix

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ok, based on this chart:

EatonPulleyCombinationsUpdated09-08.jpg


A 10# lower pulley would be the best thing to get for 14#s of boost. I was just wondering why the hell is it called a 10# pulley when it only produces 6 pounds of boost. The 8# only produces 5.5, the 6# does 5, and the 4# and 2# are correct. I want to run about 14-15 pounds, and I don't want to swap out the upper pulley at all. So is the 10# pulley the only option? Also, is there anywhere that sells them for a good price? I personally think $200-400 is ridiculous. Any help would be nice.
 

postban

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Venix said:
...snip... So is the 10# pulley the only option? ...snip...

I see about 6 options there in the 15psi range. None of which I would use. Eaton and 6lb/2.93 Billetflow go together like beer and pretzels. Perfect combo.

That 10lb stuff is WAY more than $400, also uses 10rib belts, tensioners, upper, lower.... $800 plus IIRC :nono:
 

Venix

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well why the hell does it get bigger? Why dont they just make a 10" lower pulley for the stock system? If i go with any kind of an upper it would be a 2.8 with no idlers...maybe, maybe the top one, but i doubt it. I just do not want to touch the blower at all when i could get more boost with less overspin with the lower. Ill go get a 10" ring off of something an make a 10" lower if i have to. Bet i could make one for under $50, i just dont want to have to go through the trouble. I want to change just 1 thing and thats it. No alt pulley or idler pulleys or anything else.
 
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postban

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Venix said:
...snip... when i could get more boost with less overspin with the lower.

"Overspin" is what is getting you the power you want. All those numbers except for the top few are "overspinning" according to Ford and Eaton, so what, we have been doing it for years, minimal issues except for heat. Use a quality HE like a gords, good reservoir like a P-fab to abate the heat and spin the piss out of it.



Venix said:
Bet i could make one for under $50, i just dont want to have to go through the trouble.

:bs: Not unless you steal the 1.5x14x14 20lb piece of billet aluminum you would need. Also figure machining time and anodizing.


Venix said:
I want to change just 1 thing and thats it. No alt pulley or idler pulleys or anything else.

Then you will really miss out on some potential. Single pulley setup of 2.76 and 4 idlers will give good power but not even close to what a properly ported blower (Steigmeier) and a 2.93/6lb will do.
 

IronTerp

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Venix my man, both the upper and lower pulley arrangements do the same thing: spin the blower faster. This in turn increases the boost levels which in turn, usually results in increased performance. If you popped your hood and looked down into your lower pulley arrangement, you will see that the factory pulley is part of an assembly unit and has a idler pulley which is to the right of it. When you upgrade the lower pulley, you need to remove that entire factory assembly and replace it with an aftermarket pulley and kit which relocates that idler so that the new, bigger lower pulley will fit without touching it.

This is why lower pulley kits are $300 to $350 dollars.

Occassionally, one of us will run a larger diameter lower pulley only to increase boost levels......most of the time, we'll run an upper pulley only (simple, easy, and cheaper), and the new thing is to run a combination of the two.....aka Postban's suggestion above.

Tons of information on this site for you to use to make the decision that fits you.
 

Venix

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postban said:
"Overspin" is what is getting you the power you want. All those numbers except for the top few are "overspinning" according to Ford and Eaton, so what, we have been doing it for years, minimal issues except for heat. Use a quality HE like a gords, good reservoir like a P-fab to abate the heat and spin the piss out of it.





:bs: Not unless you steal the 1.5x14x14 20lb piece of billet aluminum you would need. Also figure machining time and anodizing.




Then you will really miss out on some potential. Single pulley setup of 2.76 and 4 idlers will give good power but not even close to what a properly ported blower (Steigmeier) and a 2.93/6lb will do.

well big power is not what im looking for exactly, but overspinning as little as possible would be great. I never drive the car, and i think i put maybe 1500-2000 miles a year on it...but they are 75% hard miles. I am not going to port the blower because im going to spray it. I would rather just get the TQ numbers from the 100-125 shot then mess with all the other modding. The way i see it, if i never use the car, i dont need a bunch of money in it.

I did a little research with the lowers, and i hate that they require so much change....wish it was just a simple bolt on. After all is said and done i might just stick with the juice and a decient tune with the parts i have. I bet the motor would love a 150 on it. Nothing like 800+rwtq.
 

soccer8888

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Venix said:
well big power is not what im looking for exactly, but overspinning as little as possible would be great.
Then why are you changing pulleys?? If you don't want to overspin it (aka getting more power), just put on a 3.2 upper or something. If an easy way to a specific boost # is what you're going for, as it seems 14# is, do a 2.8 and be done with it.

Venix said:
I am not going to port the blower because im going to spray it.
Its no question that the Eaton loves the spray, however, a ported eaton is your best route. Cutting corners in modding only saves money in the short run.
 

Venix

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soccer8888 said:
Then why are you changing pulleys?? If you don't want to overspin it (aka getting more power), just put on a 3.2 upper or something. If an easy way to a specific boost # is what you're going for, as it seems 14# is, do a 2.8 and be done with it.


Its no question that the Eaton loves the spray, however, a ported eaton is your best route. Cutting corners in modding only saves money in the short run.
that 30hp $500 port is not worth it to me. At $28 a bottle i will be fine with the juice. Like i said, i never drive the car.
 

BlackSabbath

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Venix said:
that 30hp $500 port is not worth it to me. At $28 a bottle i will be fine with the juice. Like i said, i never drive the car.

It's actually closer to 50hp from the stage III port for $595 which to me is a great deal. The cost of the nitrous set up plus the refills will add up over time.
 

Venix

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the cost of the nitrous set up is free....i have kits laying around my room...several of them. Also, ported blowers and nitrous dont like eachother that much, and i am going to spray the car no matter what. I ran over 40 bottles in my last car and loved every bit of it.
 

Tranzlucent

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Best thing for you to do is to think about your options. The tune is going to have to be dead on if you are going to spray this car. And unless you had another 03-04, you have no idea of what you are getting into with the n20. Take things in steps. The supporting mods for the shot you want to run alone are going to be costly. The tune is not going to be nailed the first time, so you have a couple of dyno runs at it. Why not take the easy way out first and get used to things. You also are going to end up needing driveline upgrades and the rear needs some attention too. Patience young grasshopper, patience.
 

Venix

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Tranzlucent said:
Best thing for you to do is to think about your options. The tune is going to have to be dead on if you are going to spray this car. And unless you had another 03-04, you have no idea of what you are getting into with the n20. Take things in steps. The supporting mods for the shot you want to run alone are going to be costly. The tune is not going to be nailed the first time, so you have a couple of dyno runs at it. Why not take the easy way out first and get used to things. You also are going to end up needing driveline upgrades and the rear needs some attention too. Patience young grasshopper, patience.
its not like i have not had several mustangs...i currently own 5. Ive had this car for over 2 years, and ive been on this board even longer....nothing is new to me. Also, i have seen untuned cobra take 150 shots on a regular without problems. I have actually run nitrous on several cars and never tuned one of them for it. This is the first one i am even considering a tune on. Not everyone is a cobra noob.


Another thing...this car will never ever see a drag strip and maybe .01% of the time be lanched from a stop. I think the rear will hold from a roll. I have my drag car, and i have my daily driver....i only use this for autoX, roadracing, and putting a few shit talkers in their place. We have put juice on several 03's and i think 1 04'. This car has a pretty nice bottom end...so much that plenty of guys run 23# on a KB at 650+hp. I think with my experance that the nitrous is the least of my problems. I have only been spraying a 75 anyway on most of the 03's, and we have one guy running a 150, untuned....0 issues. I most likely wont be that brave, but i dont see a 100 at being harmful at all on a near stock car. My a/f right now is under 10! We have a place in town that lets you tune your car for $100 on their dyno. We like to take advantage of it. We also have another place that gives 3 pulls for $30 all the time! Depending on how busy they are they let us have time inbetween. Im not an idiot about this stuff, and i do not have any nitrous questions. Ive been using nitrous for several years. My questions about mainly about lower pulleys. I know all about the uppers, what they do, how much power they put out, and what the overspin does. I would just like to overspin as little as possible. This car does see at least one on track event a year, and heatsoak kills me as is. I was just looking at that chart and saw that the 10# lower was %5 more efficent then the 2.81 upper.
 
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Venix

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No one really answered one of my main questions....wth is the 10# so different? you can buy a 2, 4, and 6# without having to change anything but the crank...why cant you do the same with the 10#? Can they not just make it a 6 rib like the rest of the system to minimize the modifications?
 

soccer8888

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Define overspin please. The way you use it, it almost makes it seem like you are talking about belt slip. Of course, you're not a Cobra noob, so thats probably not the case, but I thought I'd ask.
 

Tranzlucent

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Venix said:
its not like i have not had several mustangs...i currently own 5. Ive had this car for over 2 years, and ive been on this board even longer....nothing is new to me. Also, i have seen untuned cobra take 150 shots on a regular without problems. I have actually run nitrous on several cars and never tuned one of them for it. This is the first one i am even considering a tune on. Not everyone is a cobra noob.


Another thing...this car will never ever see a drag strip and maybe .01% of the time be lanched from a stop. I think the rear will hold from a roll. I have my drag car, and i have my daily driver....i only use this for autoX, roadracing, and putting a few shit talkers in their place. We have put juice on several 03's and i think 1 04'. This car has a pretty nice bottom end...so much that plenty of guys run 23# on a KB at 650+hp. I think with my experance that the nitrous is the least of my problems. I have only been spraying a 75 anyway on most of the 03's, and we have one guy running a 150, untuned....0 issues. I most likely wont be that brave, but i dont see a 100 at being harmful at all on a near stock car. My a/f right now is under 10! We have a place in town that lets you tune your car for $100 on their dyno. We like to take advantage of it. We also have another place that gives 3 pulls for $30 all the time! Depending on how busy they are they let us have time inbetween. Im not an idiot about this stuff, and i do not have any nitrous questions. Ive been using nitrous for several years. My questions about mainly about lower pulleys. I know all about the uppers, what they do, how much power they put out, and what the overspin does. I would just like to overspin as little as possible. This car does see at least one on track event a year, and heatsoak kills me as is. I was just looking at that chart and saw that the 10# lower was %5 more efficent then the 2.81 upper.


If you are running 75-150hp on an already FI motor with no tune, you have a timebomb. I hope that no one is paying you to work on their cars. Yeah you might check an a/f ratio here or there, but what happens when it gets colder/warmer. Things do change. The other think you just stated you think the rear will hold from a roll? Even with drag radials, you can experience severe spin from a 40-50mph with enough power. You also run into issues with twisting the input shaft on the tranny with enough power. Plenty of people have done that. Also if you do stick it from 40-50, you still put tremendous pressure on our weak rear differentials. You just might be the Cobra noob you alluded to earlier. NO ONE, THAT'S RIGHT, NO ONE would consider running 75-150 shot untuned on these cars. I'll give you that the stock tune might be rich, but it has several spikes in it and goes lean from here to there.
 

Venix

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soccer8888 said:
Define overspin please. The way you use it, it almost makes it seem like you are talking about belt slip. Of course, you're not a Cobra noob, so thats probably not the case, but I thought I'd ask.
The over spin on the blower its self. The "optiomal" range that sems to be agreed on is under 16000rpms, but i know i would be closer to 17000. I am just trying to get as little as possible, but i know i will still have it none the less.
 

Venix

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Tranzlucent said:
If you are running 75-150hp on an already FI motor with no tune, you have a timebomb. I hope that no one is paying you to work on their cars. Yeah you might check an a/f ratio here or there, but what happens when it gets colder/warmer. Things do change. The other think you just stated you think the rear will hold from a roll? Even with drag radials, you can experience severe spin from a 40-50mph with enough power. You also run into issues with twisting the input shaft on the tranny with enough power. Plenty of people have done that. Also if you do stick it from 40-50, you still put tremendous pressure on our weak rear differentials. You just might be the Cobra noob you alluded to earlier. NO ONE, THAT'S RIGHT, NO ONE would consider running 75-150 shot untuned on these cars. I'll give you that the stock tune might be rich, but it has several spikes in it and goes lean from here to there.
Well they have yet to have problems.....and we have dynoed all of the cars. I dont do this for a living its just a hobby with a group of freinds. Most of the guys no better then to spray the car at anything under 60mph, and i think all but me have nittos or MTs. One of our guys just happens to rebuild trannys as a hobby. He rebuilt mine after my reverse went out and now it works like a dream.

On the no one would run without a tune? Dude, its a combustion motor....its got 10 year old stuff in it....im pretty sure people have been doing it for much longer then you or I have even had our cars, infact, i know so. Its only a car! If it blows up, then you fix it, you dont have to bury it and start over. If your to scared to try new things, then you should not be modding your car.

I just picked up my most recient dyno...it has the af in the 9s by then end of it. Thats the dybo after i pulled my predator off of it. With the pred it was all the way up to 11.9@5500., and then droped down to a 10.2@6400. We have tuners on the cars with bigger shots, but the only thing messed with is a little fuel here and there. They is no reason to go spend $500 and have a shop do it when its the same damn thing. But every car with the tiny 75 shot on it is untunned! The guy with the 150 also just watches his af. You ack like we arnt prepared or something. Out of the 8 cars 5 of them have wide bands in them. When you can see your AF every second you will push things to the limit.


One last thing, im currently working on getting my own dyno. We use them do often that it would be nice to have. They are fairly expensive, but in time will pay themselves off. Its a nice toy to have anyway. Im not attacking you dude, just showing my experance. I dont need any help with the nitrous, but thanks for the input. If you want to yell at me more then send me a PM. No hard feelings or anything. :beer:
 
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soccer8888

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Venix said:
I am just trying to get as little as possible, but i know i will still have it none the less.

Call me an idiot, but I still don't understand this statement you keep making. If you are trying to get as little "overspin" as possible, don't change your pulleys and you won't have any!! And zero overspin is as little as you can possibly get.


Now on the other hand, like I said in my previous post, if you're goin for a specific boost number, there is a certain RPM that the blower has to spin to reach that. Boost is boost is boost, it doesn't matter what route you take to get there. Its not like a certain lb lower is going to give you X amount of boost, while another size upper will give you the same about of boost, but spin the blower less. Personally I believe the "10lb" line in the chart is a typo in the RPM column, there is no way it spins the blower at exactly the same rate as the 8lb and makes more boost. Its not possible.

So as I said earlier

soccer8888 said:
If an easy way to a specific boost # is what you're going for, as it seems 14# is, do a 2.8 and be done with it.

And dude, get a tune! Even if your car isn't blowing up yet, you are a) putting some long term damage in it, and b) not getting the full benefit of your n2o shots.
 

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