how much boost can stock eaton handle

[xxsuprachargedx]

the stock eaton max's out at around 18 pounds of boost

 

[Mint Julep]

I created an Excel sheet to do this based on stock lower, max recommended eaton RPM (15,500), and the different pulley sizes.

 

[LCCOBRA]

Originally posted by Mint Julep
I created an Excel sheet to do this based on stock lower, max recommended eaton RPM (15,500), and the different pulley sizes.

Want to send it to me [email protected] ? :shrug: Sounds like the 2.93 would be safe only a little over the max or maybe i'll just go with a 3.10 but everyone says that's a waste of time...Also were is everyone getting their info from is this fact or rumors...:shrug:

 

[sam]

 

[ALA G8R]

Originally posted by LCCOBRA
Want to send it to me [email protected] ? :shrug: Sounds like the 2.93 would be safe only a little over the max or maybe i'll just go with a 3.10 but everyone says that's a waste of time...Also were is everyone getting their info from is this fact or rumors...:shrug:

The 3.1 is definitely not a waste. But the 2.93, too me, seems like the sweet spot for the M112 on my car. The 2.93 will not spin the M112 at 15500 rpm until the engine RPM exceeds 6150. How often are you running at redline?

M112 RPM = Engine RPM x Lower Pulley Dia. / Upper Pulley Dia.

 

[sam]

Originally posted by LCCOBRA
Want to send it to me [email protected] ? :shrug: Sounds like the 2.93 would be safe only a little over the max or maybe i'll just go with a 3.10 but everyone says that's a waste of time...Also were is everyone getting their info from is this fact or rumors...:shrug:

i figured the 3.10 would give me 12lbs max. i installed an autometer boost gage when i installed the 3.10 and a metco idle pulley and wind up getting 13lbs boost. stock gates belt. this is not a waste of time. got a solid 13 lbs of boost.

 

[Bad03Cobra]

I have a Apten running 19 pounds of boost all the way to 6300rpm with no problems...........If it lets go I will buy a KB

 

[sam]

Originally posted by Bad03Cobra
I have a Apten running 19 pounds of boost all the way to 6300rpm with no problems...........If it lets go I will buy a KB

seems like your already preparing.

 

[fstagg]

I read somewhere, the Eaton M112 was efficient up to 18,000 and the 2.81 pulley would spin it to 17,500. unfortunatley, I cannot remember where?????

 

[sambandit]

Not sure why everybody is so afraid of blowing up the Eaton. Lightning guys have been spinning theirs at 18000+++ rpms for YEARS with relatively few failures. Spin the shit outta it and don't worry.... what's the worst that can happen?? lol...

 

[03RedCobra]

I have to totally agree with SamBandit on the Lightnings spinning the heck of their blowers and not having problems.

Correct me if I'm wrong, but, doesn't the Lightning have the M112 Eaton as well ?? They have a 2.93 pulley STOCK on their blower as well. I personally don't see FORD putting on a 2.93 pulley on the same blower as the '03 Cobra, and then putting it under warranty, knowing that it would have problems with that smaller size pulley. So, I guess it would be pretty safe to say that the 2.93 inch pulley is a good size for our blowers as well. Unless they have beefed up the Lightnings blower somehow.

 

[LCCOBRA]

I got your e-mail Mint Julep thanks. Also sambandit very nice cover can't wait to install and I can see how their is no restriction in air flow. But It sounds like the 2.93 is a go and will be fine or maybe i'll just buy both a 3.10 and 2.93. 2.76 is just to much for me want my engine to last...

 

[racerat]

Originally posted by davidmax
Dont forget your fuel return system above 500rwhp.It will run cooler and much more efficiently.You can get one off a 99 GT and use some Earls larger diameter.

99 GTs have a returnless system.

 

[HotRodHarry]

My first 03 Cobra was pushing 22 lbs on the stock Eaton....SFP nonslip 2.80 upper...JDM 6 lb lower...BF idlers...etc...the power/torque down low and in the mid range is simply amazing! up top she must have been losing some compared to lesser pullied cars....I ran 116 octane leaded fuel and had a little shot of nitrous to cool things down. Fun car! Even more fun now...a buddy of mine in Hawaii bought her and put a KB on ...9 inch solid rear...automatic...rollcage....just awesome!

 

[HotRodHarry]

My mod list from that first 03 Cobra

Hood Vent Mod(Me)
Front Swaybar removed(back on now for street use)(Me)
9 inch Powerstack(SFP)
CAI cover(Amazon Racing)
2.80 Upper Pulley(JDM)
6 lb Lower Pulley(JDM)(custom lower pulley cage)
20 lbs of Boost till 5700rpms(17 till 6400 rpms)
Gates Belt (774)
DIABLOSPORT Chip (Nitrous Pete)
NGK TR6 plugs(Nitrous Pete)
BilletFlow Upper Pulley Wrap Idler(Nitrous Pete)
BilletFlow 100mm and 92mm Billet Idler Pullies
Bassani Exhaust(no cats)
Nitto Drags 315-35-17(Downs Ford)
AutoMeter Boost Gauge(Downs Ford)
Dump Valve Mod(Nitrous Pete)
BilletFlow Throttlebody/Plenum(Nitrous Pete)
Headers Custom Mid-Length(Nitrous Pete)
Steeda Tri-Ax Shifter(Nitrous Pete)
Steeda Adj. Clutch Quad/Firewall(Nitrous Pete)
Compucar Nitrous System(Nitrous Pete)
10's here I come!!!!

 

[JB]

Originally posted by 03RedCobra
....Correct me if I'm wrong, but, doesn't the Lightning have the M112 Eaton as well ?? They have a 2.93 pulley STOCK on their blower as well. I personally don't see FORD putting on a 2.93 pulley on the same blower as the '03 Cobra, and then putting it under warranty, knowing that it would have problems with that smaller size pulley. So, I guess it would be pretty safe to say that the 2.93 inch pulley is a good size for our blowers as well. Unless they have beefed up the Lightnings blower somehow.

the L's do have the same M112 blower and they do have a 2.93" pulley but their lower pulley is smaller than ours...

 

[IronTerp]

Have seen too many "what size pulley is best" threads lately......I'm real satisfied with the 2.90 myself, but there seems to be tons of guys doing the 2.76/2.80 route and loving it. I personally shift at 6,200 or so.......who out there is actually going to 6,500??? And still producing great power? This would obviously impact the maximal blower speed issue.......

 

[Shanezam203]

Originally posted by sambandit
Not sure why everybody is so afraid of blowing up the Eaton. Lightning guys have been spinning theirs at 18000+++ rpms for YEARS with relatively few failures. Spin the shit outta it and don't worry.... what's the worst that can happen?? lol...

I'm not sure either. I had a 4# lower and a 2.8 upper on my truck. I was making 15#'s of boost and that in my opinion was pushing the limits of the truck. Yeah I kept the internals internal but still everytime I got on it I'd wonder if something was going to let go. There are guys running bigger lowers, or same boost + nitrous I dont know how they do it. But then there are other motors that have let go with way less boost than I had.
As for the cobra, I am debating over the 2.8 and the 2.93. I think once I find a tuner I can trust I will be safe with the 2.8. I don't want to go much above 15psi with this Eaton either.

I just wanted to comment I've seen rotters flake in the Lightning blowers, but I have not heard of 1 failure. You know how many blown motors and broken rods there are. But why haven't there been any smoked blowers? There may be some, but for everybody that spins these blowers like we do I think the Eaton holds up more than we give it credit for.
:coolman: Shane

 

[DR. WU 2000]

My final decision after reading this thread. I am not touching the pulley. I won't have anything to worry about if I do that. Peace.

 

[JaketheSnake]

Originally posted by DaTruth
I know if three 03 Cobras running 19 to 20lbs of boost locally.. Stock Eatons.. I do not know how they do it, but they ride out..

you would be surprised at what boost I ran you with!!!