6lb Lower Pulley

Dallasgt01 said:

I was wondering if anyone has put on the 6lb lower pulley with the 6lb upper pulley. I am going to Get the stock supercharger ported and also port my T/B intake i am at 18lbs of boost now i want more.... Let me know if anyone has done that if so what were the results

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All that combo would do is make a lot of heat, seriously over spin the blower, and cause a lot of belt slip. Possibly over spin your alternator in no time too I bet. From everything I read the best combo on the ported Eaton appears to be a 2.80 upper and a 2lb lower. You also might want to think about a larger heat exchanger at those boost levels.

U.M.

Uncle Meat said:

All that combo would do is make a lot of heat, seriously over spin the blower, and cause a lot of belt slip. Possibly over spin your alternator in no time too I bet. From everything I read the best combo on the ported Eaton appears to be a 2.80 upper and a 2lb lower. You also might want to think about a larger heat exchanger at those boost levels.

U.M.

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Sorry to interrupt but how can you only run 12.60's with 430 rwhp. Im confused. I thought 03's were faster than that? My 380 rwhp ws6 runs 12.20 with a 1.9 60. Im only asking because I am considering getting an 03 cobra

WildBill, there are plenty of mid to low-11 second 03 Cobras. I've read many of your posts on LS1.com. I think you know enough about what an 03 will do. There's more than enough info, posts and topics without questioning one sig.

Back on topic:

A friend of mine has a six upper and six lower. I've lost count of how many belts he's shredded along with his hood liner and a few hoses. It developed a knocking noise after we sprayed it on the dyno a few weeks ago. I thought for for sure the engine was hurt. After we left, the noise became intermittent. I figured then the motor was fine. He left it with me and I drove it for two days and it never knocked. Just when I was about to give up, it started to knock. I popped the hood and you could hear a knock on the driver's side head. I revved the engine by the throttle cable and I could hear a pop when I would let off. I moved to the front of the engine where I could look down when I revved the engine and the belt was riding up on the crank pulley and when I let off it would snap back down in the pulley. I figured either the alternator was bad or an idler pulley was bad. On the way home I drove the car easy. Just before I got home I pushed it a little to see how it felt. The car had no power and I looked and there was no boost. I pulled in and popped the hood. The belt was hanging loose over the blower pulley. I figured it broke. I decided I would swap out my idler pulleys with my buddies so I went and took mine off. I walked over to my buddies 03 and grabbed the belt to rip it out and it wouldn't come out. I looked down and it wasn't broke. I thought that maybe it had walked off the crank pulley. I was looking it over and that's when it caught my eye, the alternator pulley was gone. That was what was knocking. It probably was spinning on the shaft for awhile before it finally fell off. I think that a few of the belts he broke probably wrapped around the alternator pulley and when it broke and probably grabbed the pulley enough to break the nut loose. My buddy beats the mortal piss out of his car. He's into boost 75% of the time he's behind the wheel. If you are the same way, this is a bad combo. You are asking for trouble. Make sure to carry a backup belt or two and a pull handle. Mark does. You can drive it about 30 miles before the battery will be dead at night with the lights without the belt ont he alternator. Mark can tell you.

I don't drive mine too hard. I run a 2.93 upper for the street with a four pound lower. When I go to the track I swap in a 2.80 upper which and eventually ended up staying on the car. I have never broken a belt. I don't street race and I am basically easy on the car. Now on the track, I beat on it about as hard as anyone. I think this is about the best combo you can run if you have driving habits like mine. I milled 1/8" wide slots in my upper pulley at 45 degree intervals similar to S. Fla. Pulley's non slip pulley and I also bead blasted it. I made my own idler pulley bracket. With this combo it made 503 rwhp SAE and 550 rwt with very little belt slip. I live in the foothills of the Blue Ridge and it's pretty cold here. The other day it was in the low 30's on my way home from work. I decided to rip off a run to see how the car felt and how much boost I was making. I run 3.90 gears. I ran it up in second to about 40 and stomped on it. It immediately broke loose and I caught my needle crossing 19 psi before I let out. I went into third and the car got loose again but I made 20 psi. That was a first for me. If I could get down to Rockingham today, I know this sucker will hit 10's. But, I'm working 7 days a week and it will be a miracle if I can get on a track again while it's still cold.

I wouldn't go over four on the bottom. But, if you are like Mark, I would go ahead and get a KB or ProCharger if you want the big time, trouble-free power.

WildBill WS6 said:

Sorry to interrupt but how can you only run 12.60's with 430 rwhp. Im confused. I thought 03's were faster than that? My 380 rwhp ws6 runs 12.20 with a 1.9 60. Im only asking because I am considering getting an 03 cobra

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First and foremost those videos in my sig are over a year old. They were filmed the very first time I took my car to the track. I didn't have as much horsepower back then as I do now. I need to get back to the track and try to improve. I always tell everyone that my car is capable of high 11's, but the driver isn't! My best in the car was a 12.5@113 the same day as the videos were made, figures that run didn't make it onto tape.

The hardest part of getting a good ET with the new Cobra's is the launch. If you can get this car out of the hole with minimal tire slip and no wheel hop then you will be on you way to a good ET. The IRS coupled with all that torque available down low makes it really hard to get a good clean start. Plus it doesn't help that my car with a full tank of gas, and me in it weigh in at a portly 3916 lbs!

U.M.

I ran a 11.9@119 with very little practice.
We're talking about leaving the line at 1500-1700 RPM and just "driving" down the track. The car is capable of 11.60's or a little faster at 122-123 mph.

Anyway....don't do a 2.8 upper with a 6 lb lower.
I have a 2.8 uper by itself and may consider a 2 lb lower with a ported blower in the future, but THAT is the safe limit of the stock blower. (some may argue)
A friend is running 11.40's with my mods (minus the headers and h-pipe), plus a ported blower. (this is with a stock lower).

Also, if you are considering a 6 LB lower by itself...don't do it. The 2.8 upper makes more power than a 6 LB lower. I've yet to seea 6 LB lower make mroe than a few LBS.

Also, any pulley upgrade that makes more than a few LBS should have an upgraded heat exchanger. This is a mega priority on my list.

Hey Meat:
98yellowstang brought his 04 cobra up yesterday.
Stock runs averaged around 355 ish HP at the tire, and 330-335 ft lbs of torque.
My first file made 380 HP at the tire and 374 FT Lbs of torque....drivability kicks ass too!
This is before any tweaking to the file, the first 04 Cobra file.
He was pretty happy, I had him in and out in a few hours.
As soon as I get the data averaged correctly (you know how I am about unbiased data), I'll post the runs up here.

11's

I always tell everyone that my car is capable of high 11's, but the driver isn't! My best in the car was a 12.5@113 the same day as the videos were made, figures that run didn't make it onto tape.

U.M.[/QUOTE]

Meat:

If you break the 11's with stock pullies and no spray, I will call you "Uncle"
If you end up at 12.05, then you know all you need is my tune for me to call you uncle! ;o)

Dallasgt01 said:

And oh yeah ... Vic what is the difference between the Superflow Dynamometer and a Mustang Dynamometer???

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Nothing... Just a name.



I'm kidding.... I'll let Vic answer that.

U.M.

Why don't you just buy them from JDM lke I did?
I bought mine there.

As for your Superflow/Mustang question.....

A Mustang is also a "quality" dyno.
I prefer the superflow because the data acquisition, plotting, etc....it a little nicer but both are respected dynos.
A Dynojet still "works" but they read high and are really good for comparison only.
Also, most dynojet are inertia only which means you can not simulate load (basically means a car can't be tuned as efectively as it could be on a mustang or superflow dyno)
You can compare WOT runs on a dynojet and that's about it. No shifting on the dyno, no load simulation, no step testing, etc.
SOME dynojets are capable of load simulation, but most people who own a dynojet do not have this option as it is expensive. Any way you slice it, Superflow/Mustang is vastly superior to a Dynojet.

Almost forgot about your heat exchanger question:

JDM makes a heat exchanger and so does Pauls High Performance.
Jim D'Amore unit is a little bigger, but you do have to cut small notches in the back of the bumper. (not a big deal). It is silver (looks cool), but many paint it black so it looks stock.
The slightly smaller PHP unit supposedly bolts right in and has an option for auxiliary fans on it. It is also $$$$$$$$$$ compared to JDM's unit. I don't know if one performs better than the other.....logic would say the JDM unit because it's a little larger.

There is also another out there, I forget the name.
I am still up in the air in my choice.