I have searched and there are so many different pulley combo's that I am lost is there a best combo out there? is it best to do a lower and a upper and idler's ? if so what size? do I need other mod's 1st ? I ordered a cai that's it so far. any idea's???
picking pulley's help.
- Thread starter MIKEC501
- Start date
That is kind of a loaded question. IMO I think a Billetflow 2.76 and the four idlers are a great pulley combination. It will give you good power. They are very simple to install. You will need a tuner to adjust your car for the added boost the 2.76 will give you. The four idlers are required but recommended. You will need a blower pulley, auxillary idler, smaller belt, a tuner and tune. If you buy all that brand new be prepared to spend well over 500 bucks.
"best combo" , depends on a lot of factors.
I do know that technically, as posted a ton of times... 18,500 RPM is the max limit of the unported heaton. at which point is creates too much heat and begins losing HP..
I couldn't be happier with my current setup, I'm running a 2.80 upper, with 1 idler, a 74.5" gatorback, and no belt slip.
2.80 puts the blower at max RPM right about 17,600 RPM or so..
I do know that technically, as posted a ton of times... 18,500 RPM is the max limit of the unported heaton. at which point is creates too much heat and begins losing HP..
I couldn't be happier with my current setup, I'm running a 2.80 upper, with 1 idler, a 74.5" gatorback, and no belt slip.
2.80 puts the blower at max RPM right about 17,600 RPM or so..
MustangThief said:
do you have a picture of your setup I would like to see how it looks with the one idler pulley ? thanks.
get 2.76 if youre just planning to run upper. run 2.93 and 4# lower if you want to run upper and lower. i made 470/504 with my 2.76 setup. i have a 2.80 now and im planning to run that with a 4# lower with my ported eaton.
HandoZiZle said:
see that is where I start getting confused mustangtheif has a 2.8 and his sig. say's 414 hp. you say a 2.76 made 470 hp. :??: :??: I am not calling :bs: I just want the right set up the 1st time.
MIKEC501 said:
My numbers are from a Mustang dyno. These generally give about 30-50 less HP than a dynojet. This could be where the discrepancy is coming from that you're looking for.
Also, My 414 RWHP (mustang dyno numbers) was on a VERY conservative tune, that tune is 19* timing with 20.5* max timing.
my performance tune on my xcal is for 93 octane also, but it rolled out a little over 440 RWHP (mustang dyno numbers), which was more aggressive timing and A/F. It saw about 22* timing with a max of 23*.
I'll take a few pics of my engine bay, but it looks good.
The UPR pulley is stockish looking, and the idler is where the pulley-guard bolt goes, just to the 5 o'clock position below the blower pulley.
You can't go wrong with a 2.76/2.80 upper as long as you don't have any belt slip (i saw no slip even with the stock 75.1" belt but bought a 74.5" gatorback anyway)
I personally, reccommend waiting to install a lower until you go for a blower port, but that's just me.
Billetflow 2.76 w/ 4 piece idlers FTW!!! :rockon:
MustangThief said:
ok thanks for making it a little clearer for me.
yea it all depend on many aspects. again i was on a dynojet rather mustang dyno(which is more accurate). i also have a 93 octane tune.weather, tires, humdity, sae or std numbers can all affect your numbers. mods are o/r x, magnaflows, JLT CAI, 2.76/idlers, h/e, plugs. dyno was alsoo done on a 85* day and about 58% humidity. i also recomend getting the idlers because i think i'm having a belt slip with my stg IV right now and its really robbing some power( only gain 17 whp after the port)
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I don't have dyno #'s but, I have a ported blower w/ a RR 2.8 and replaced all the idlers. I was able to use the stock belt. I have no belt slip and my car has run 11.60 @ 123mph w/ 1.78 60' on Nitto DR. I was braking when I did this because I was bracket racing. I wish I hadn't so my best time would be even better. I am currently adding a 2# lower, 60#inj, and 2800 MAS. This will probably be it for pulley changes. A good tune is the key. I am hoping to get into the low 11's. Hope this helps you decide.
so will a BF 2.76" max out an unported eaton??
So where can I find this max RPM listed, technically? There's always been a lot of speculation in the forums about the theoretical maximum RPM of the stock M112, but has Eaton publically posted or stated that figure (18,500RPM's) is correct?MustangThief said:
U.M.
well I just ordered a billetflow 2.76 and the 4 pc idler kit and a new 75.1 belt from billetflow $459.90 shipped. sounds like that should do the job. thanks for the help guys.
snake134 said:
That is my combo, with the stock belt, and and RWTD tune. It is making 465RWHP / 475RWTQ SAE corrected. I am thinking about going with the RR 2.65 upper and a STG IV port on the Eaton.
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