2.76 upper and a 4lb lower? HELP!
- Thread starter NHRACobra
- Start date
Yeah, but your alternator would probably freak out before the Eaton did.
Definitely spinning the blower too fast. Try a 3.1 or even a 3.4 with the 4# lower.
I'm doing the 3# lower w/ my 2.76. Just waitin for my ported blower to return. :beer:
04MystiCobra said:
Let me know this combo works out,Im looking at doing the same thing!!!
vetkilr said:
they make a 3# lower?
Marc
Yeah, never heard of a 3 lb lower?!?!
In the Jan 04 5.0 Mustang and Super Fords, there was a guy running a 2.8 upper and 6 # lower. I thought that would be overspinning the blower myself. He was running 10.90's with it, so he was probably making pretty good power.
I have a 2.81 upper and stock lower, myself. Haven't yet installed it, as I am waiting to send off my S/C to steigermeir <-or whatever???
I have a 2.81 upper and stock lower, myself. Haven't yet installed it, as I am waiting to send off my S/C to steigermeir <-or whatever???
I have a 2.8 upper and had my blower ported. While waiting for that, I put on a 4# lower. After I got it all back together and running it seemed like it was way over spinning the blower. I guess you can do this and get away with it for awhile but I decided to go with a 3.1 upper to be a little safer. You get great low end torque with that setup (507 ft-lbs at 3000 rpm) but the blower rpm is about 21000 rpm on the upper end. Mfg. red line is 15,500. Also, probably making lots of heat if you do this too much.
The original Metco 4 lb lower is actually about 8.25"+/- in diameter and is considered a 3 lber. The true 4 lb lower is like 8.53".combatstang said:
Most of the fellas running the 2.76/2.80 go with the 2 lb lower and get excellent results. The jury is still out on whether a 4 lb lower needs a larger alternator pulley. Most say you don't need it, but a couple have had to get their alternators replaced.......
IronTerp said:
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I'm running a 2.93 and a 4lb lower right now and I like the everyday power it gives. I rarely go past 6000 rpm's with this combo on the street because it is so torquey. You'll find yourself short shifting alot. If you are looking for good street fun this combo works great.
My 4 lb lower which is from Mark at LFP, measures slightly more than 8 3/4" gross diameter........If you're at 9.25, then you have a 6 lber......badboy said:
My 3.1 Upper and 4lb Lower makes more power than my 2.93 & 4lb Lower, although the tq is less on the 3.1 Upper, about 15 ft/lb's to be exact.
3.1 & 4lb # 's 511whp 490tq SAE
2.93 & 4lb 508whp 505tq SAE
I may go back with the 2.93 & 4lb Lower
3.1 & 4lb # 's 511whp 490tq SAE
2.93 & 4lb 508whp 505tq SAE
I may go back with the 2.93 & 4lb Lower
I got my 3#'er from LFP. I wanted the tq of the 4#'er but was worried about overspinnin the blower. I almost got the 2# but when I spoke to LFP they said they had a 3# so thats what I got. Bad thing is I have no idea what belt length I need.
Tq is the name of the game for a daily driver so thats why I got it. HP will come by way of my ported blower. 5-10hp/tq, to me, doesn't prove any better or worse of a combo. You can get that swing in power just from changing gasoline comp's.
Tq is the name of the game for a daily driver so thats why I got it. HP will come by way of my ported blower. 5-10hp/tq, to me, doesn't prove any better or worse of a combo. You can get that swing in power just from changing gasoline comp's.
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LFP has 2,3,4,6,8lbrs!!!!!!!!!!
Im thinking 2.8 and 3lbr if its too much Ill put a 2.93 on top!!!
Im thinking 2.8 and 3lbr if its too much Ill put a 2.93 on top!!!
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