10# lower

[BUstang]

Hey guys, i have a quick question. I just purchased a 03 cobra with 9k miles and the following mods:


C&L 95mm mass air meter

K&N 13” conical air filter

Accufab polished throttle body

2.8 upper pulley

Metco lower pulley setup w/10lb pulley

Stiegemeier stage 5 port

Bassani mid length ceramic coated headers

Bassani stainless mid pipe w/o cats

Bassani catback stainless exhaust

SCT flip chip w/ xcal2 programmer on 2nd setting

Chicago cyl. Head coolant bypass modification

Boost bypass mod

3.73 gear ratio

Aluminum diff cover brace

Kenny Brown front diff brace

Kenny Brown Aluminum diff bushings

MGW shifter

Odyssey PC680 battery

D&D Super heavy duty clutch (26spline)

upgraded T56 tranmission

FMS firewall adjuster

FMS aluminum clutch quadrant

I feel the previous owner modded his car very tastefully and babied the hell out of it for the most part. he said he occasionally auto-crossed it and took it to the drag strip. Anyways.. i'm kind of scared about the 10# lower pulley as i've never seen anyone running one. He assures me his car has never over heated or shown signs of heatsoak. He drove it from UT to colorado for a rocky mountain mustang show and he experienced no issues. Should i change the pulley, or should i stop worrying?

 

[BadAzztt]

A 10lb lower is not the problem, it's the 10lb lower combined with a 2.8 upper, wow! That is going to be spinning the Eaton into the upper ranges for sure. Peak power would probably come in around 5200-5500.

Have you verified his claims? Meaning have you measured the pulley to make sure it is actually a 10lb?

Also when did you purchase the car? Stage V was just released recently when did he get the blower ported?

If it is indeed running that much boost and he truly had no problems you still have another factor to add in ...elevation. He lived in Utah (probably 4000ft) and drove here to CO most of that drive he is 5500-8000 feet elevation. You will see considerably less boost at that range.

It's gonna be your call...I would be interested to see you throw it on a dyno just to see that power curve.

 

[BUstang]

He had it on the dyno before the stiggy was added and he said everything looked fine. The first thing i'm doing is taking it to Gearheads here in Dallas to get everything checked out once i receive the car. Also, what upper pulley could i purchase instead of the 2.8 that would compliment the 10# nicely?

http://i22.ebayimg.com/02/i/000/d2/06/b851_12.JPG

There's the pic of the lower pulley

 

[19COBRA93]

This was my brothers car. Any questions feel free to ask.

I always thought he had an 8lb lower. Regardless though, that thing makes monster torque. To give you an idea... I ran a stock lower with a 2.8 upper and ported heads. My motor made all it's power up top, so I ran 4.30 gears. We ran each other at the track several times. With his 3.73's and my 4.30's we were shifting at the exact same time. Basically his power band was 1000 rpm lower than mine, but he also made almost 100 lbs of torque more than I did on the dyno, but his hp would fall off a lot quicker.

I'm not sure of your elevation, but we're almost 5,000 ft here which is why we have to spin the crap out of our blowers to make any boost (with a 2.8 I made 11 lbs, and with a 4lb lower and 2.8 I made 14 lbs). Going to Vegas which is about 2000 ft or something, I would pick up 3 lbs of boost. So, depending on your elevation, you'll probably have to drop down on your lower pulley size because you're going to pick up a good amount of boost, and I doubt you'll be able to do it on pump gas.

His/your car is as reliable as the day it left the factory. I've been right along with him on the CO road trips with zero issues. This is THE cleanest 03 cobra around, and "babied" doesn't even describe it. I know this car inside and out so don't hessitate to ask, I'll be straight up with you.

 

[Tractionless1]

The 10# will make tons of torque down low but fall off faster as well. It you are fine with that go 3.3 on the top for just under 17psi. If you don't want to burn the tires off at 1100rpm go with a 4lb lower and your 2.8 (just below 17psi), or even a 2lb (just below 16psi). Steg. likes to see a max of 17psi on the ports, after that they to are inefficient.

Do away with the boost bypass mod, and get it retuned for the ported blower asap. I wouldn't even get into any boost, even part throttle.

 

[BUstang]

This was my brothers car. Any questions feel free to ask.

I always thought he had an 8lb lower. Regardless though, that thing makes monster torque. To give you an idea... I ran a stock lower with a 2.8 upper and ported heads. My motor made all it's power up top, so I ran 4.30 gears. We ran each other at the track several times. With his 3.73's and my 4.30's we were shifting at the exact same time. Basically his power band was 1000 rpm lower than mine, but he also made almost 100 lbs of torque more than I did on the dyno, but his hp would fall off a lot quicker.

I'm not sure of your elevation, but we're almost 5,000 ft here which is why we have to spin the crap out of our blowers to make any boost (with a 2.8 I made 11 lbs, and with a 4lb lower and 2.8 I made 14 lbs). Going to Vegas which is about 2000 ft or something, I would pick up 3 lbs of boost. So, depending on your elevation, you'll probably have to drop down on your lower pulley size because you're going to pick up a good amount of boost, and I doubt you'll be able to do it on pump gas.

His/your car is as reliable as the day it left the factory. I've been right along with him on the CO road trips with zero issues. This is THE cleanest 03 cobra around, and "babied" doesn't even describe it. I know this car inside and out so don't hessitate to ask, I'll be straight up with you.

Awesome! I hope i didn't come off as questioning your brother, he is probably one of the nicest/most honest person i've ever dealt with in a long time. I just wasn't sure about these pulley sizes as i am kind of a newb and still learning. So guys, would buying a 2 or 4# lower be a good idea since i'm 100 feet above sea level? On top of that, if i buy a different lower, what else will i have to purchase?

 

[BUstang]

Well i just got off the phone with LFP, and i think im gonna go ahead and purchase a 4# lower ring and a new belt. If i get this installed, and drive it under 2500 rpm to dallas from houston (200 miles) i wont run into any problems correct?

 

[CobraRyan]

If this is going to be a DD in Texas heat i think a ported 2.8/4lb will be plenty hp and torque. With my steggy stage IV 2.75/4lb i made 510/540 and the hp was still in the 500's past 6k almost 6250. Its a real fun combo.

 

[19COBRA93]

The 4lb is a good idea. Man what sea level would be like...

Your 200 mile drive will be fine, I assure you.

 

[Quick Strike]

I think I would keep the 10# and find an upper that spins it at the same RPM as the 2.8" and 4# combination. That way you will have less belt slip (more contact) on the upper and do not have to change the alternator pulley again.

 

[IronTerp]

Wow.....2.8/10 lb combo!?!?!?!? That's awesome! I know a fella that ran around on the street with a 2.80/8 lber, but that's the highest boost I'd seen on an Eaton till now.

Switching out to a 4 lb ring would certainly be the simplest/cheapest way to get that boost more in line for lower elevation performance. I too question the Stage V though.....They just came out within the last couple of weeks except for some possible test blowers. You sure it's a V and not a IV?

 

[jm@ReischePerf]

You sure it's a V and not a IV?

I heard someone say on here that Steggy told him the latest stage IV ports should be considered a V :dw: Seems questionable to me.

To the OP, I think the 4lb sounds like an easy way to fix the situation. I am a little concerned that the car has no fuel mods. You need to get this car on a dyno and check out A/F before you start getting on it. No doubt it will run lean with a 10lb at close to sea level, not sure with the 4lb pulley though.

 

[BUstang]

I heard someone say on here that Steggy told him the latest stage IV ports should be considered a V :dw: Seems questionable to me.

To the OP, I think the 4lb sounds like an easy way to fix the situation. I am a little concerned that the car has no fuel mods. You need to get this car on a dyno and check out A/F before you start getting on it. No doubt it will run lean with a 10lb at close to sea level, not sure with the 4lb pulley though.

Yup, not gonna be a problem. If she starts leaning out on the dyno i'll put her in the garage until i can afford the fuel upgrade.

 

[03CobraDom]

Wow.....2.8/10 lb combo!?!?!?!? That's awesome! I know a fella that ran around on the street with a 2.80/8 lber, but that's the highest boost I'd seen on an Eaton till now.

Well technically the fella with 2.8/8lb was probably running more boost considering he wasn't at 5000ft elevation

 

[19COBRA93]

The port has to be a 4. We both thought it was a 5 for the longest time, but obviously since the 5 has been out for just a short time, it couldn't be a 5.

 

[BUstang]

The port has to be a 4. We both thought it was a 5 for the longest time, but obviously since the 5 has been out for just a short time, it couldn't be a 5.

Hmm ok. I'll just call your brother to confirm this! Either way it's gonna be a badass ride.

 

[03cobramanIII]

a 10 lb dam what size is that 10 inch?

 

[IronTerp]

a 10 lb dam what size is that 10 inch?

Actually, or coincidentally, I believe the 10 lb rings are 10.10".......

 

[03cobramanIII]

Actually, or coincidentally, I believe the 10 lb rings are 10.10".......

dam! know i seen a video of a 30 psi k/b 2.8. or might have been a 3.4 whipple? with that much boost wouldnt the intake temps be though the roof ?:burn:

 

[IronTerp]

dam! know i seen a video of a 30 psi k/b 2.8. or might have been a 3.4 whipple? with that much boost wouldnt the intake temps be though the roof ?:burn:

Actually, a couple of fellas have run this boost on stock long blocks and the issue is keeping the heads on the block.......