Pulley Wars-Final Pulley Battle Winner

[03SoCalCobra]

I think I've posted this in a dozen simular threads, so what's one more

I did back-to-back dyno runs with a 2.93 and 2.80 15 minutes apart- the car never left the dyno. It was during a tuning session and ALL runs before and after were done with about a 5 minute cool down, which is about how long it took me to change the DUB pulley.

The net effect: a/f .3-.4 leaner, 2hp & 7 ft/lbs gain at peak, 5-25 ft/lbs gain down low and equal amount of HP. Little more tuning improved the numbers to what you see in my sig from a 456hp/458tq baseline with the 2.93. it also shifted the entire power curve down by about 500 rpm which makes it even that much better for the street.

Yes, the efficency drops off more but at least with the 2.8 the overall gains are still there.

 

[Kimcobra]

What about the lower pulley?I am also new to the Cobra & to mods.Just wondering if you use the 6lb lower with a 3.0 upper pulley what would be the out come.Also isn't it easier to change the lower pulley say for warranty work??Just asking.Thanks

 

[MikeW]

Originally posted by Kimcobra
What about the lower pulley?I am also new to the Cobra & to mods.Just wondering if you use the 6lb lower with a 3.0 upper pulley what would be the out come.Also isn't it easier to change the lower pulley say for warranty work??Just asking.Thanks

Kim, the lower pulley is a pain to put on and remove compared to the upper. It may be easier to get by the tech at the dealer for warranty work if the lower were to be removed and put back on, but if it is a major warranty issue they will dig the PCM to see if you have monkeyed around with the tune. If you were to run a 6lb lower you would need a chip/predator and they would be able to tell if you had raised the boost with an upper or lower pulley. A lower pulley will give you less belt slip than just an upper but it cost way more. An upper non-slip pulley with idlers should not see much belt slip at all. The 2.80 pulley seems to be most popular right now and thats the route I will most likey go when I do the pulley. Metco makes a lower pulley systems that looks and performs awesome if you decide to go the lower pulley route, but again it is not warranty proof. To sneek past warranty issues you could do a 3.1 -3.4 upper with a different Eaton snout and most likely not need a tune and just swap out the snouts if you need motor warranty work done. That way there would not be any marks on the upper pulley snout.

Just my $.02:burnout:

 

[Kimcobra]

Thanks 97Topless snake.I have read every post on pulleys that I have found on here.I think I'll just let Dan handle it.Trying to do some stuff myself,But I am sure Dan will have the last word.I have also heard that the L/Ts would lower the boost?Can I get that back with the pulley?So when is dyno day going to be?I really want to get a base on this car first.Haveing the windows tinted Monday.I did see where Amason racing will be at the NMRA event.Maybe I'll wait till then and just let the do something to it.Take care and keep me posted on the dyno day.

 

[MikeW]

Originally posted by Kimcobra
Thanks 97Topless snake.I have read every post on pulleys that I have found on here.I think I'll just let Dan handle it.Trying to do some stuff myself,But I am sure Dan will have the last word.I have also heard that the L/Ts would lower the boost?Can I get that back with the pulley?So when is dyno day going to be?I really want to get a base on this car first.Haveing the windows tinted Monday.I did see where Amason racing will be at the NMRA event.Maybe I'll wait till then and just let the do something to it.Take care and keep me posted on the dyno day.

Amazon is good and I may let them pulley my car at the BG race this year if not next. Our dyno day is set for October, where I dont know yet. Long Tubes will drop your boost a bit but the power will not go down you will just have more effeicent boost. When I added my cat back and x pipe I lost a half pound of boost or so but when I added the CAI I got that back and then some. I think when Carlton with from a catted x pipe to long tubes and off road H pipe he picked up like 10 RWHP. If he had it to do over again I dont think he would put the $$ into Long Tubes for that amount of power increase. He did get the Long Tubes free and installed free so I think thats why he dont it. I think if you and Dan wanna get to 500rwhp you would just need to add the Apten ported blower and a 2.90 pulley and a tune. If you want more than 500rwhp, then a Whipple or KB would be in order and then you would have to upgrade the fuel system other things. I think I will do the 2.90 upper and then add a 30 shot down the road. If I add the upper and I'm 450-480 RWHP I will stop there if I can.

 

[Kimcobra]

Thanks 97Topless snake,There is a couple things Dan is doing to the Bullitt,Then he'll start getting it ready for the NMRA event.Iswear he babies that car.Except when he drives it.But he also cleans mine everyday when I get home from work.Like you I think 480rwhp will be enough for me[really the way it sits is fine with me]The main concern is the car is my daily transportation[Because I just love driving it]I really don't want to mess it up any.I think Dan called 3rd shift performance to try and setup a dyno run,I don't know if he got through or not.I'll keep you posted.Thanks again

 

[CobraBob]

Only one pulley I'd run -- the 2.90 RR but that size wasn't listed so I picked the 2.93. I tried both the 2.90 and 2.80 and was much happier with the 2.90. So was my Eaton! LOL!

 

[513SPEED]

Originally posted by IronTerp
JKD,
Agree with you totally about the superior performance that can be derived from the 2.80. But, I question the degree of difference. Of course the TB switch is the unknown variable here, but you gained 48 ft lbs of torque with the pulley change? That's a significant improvement, to say the least. I recently went from a 3.10 to a 2.90 and gained 7.5 ft lbs. I know that there will be improved performance with the 2.80, but don't feel it's normally as dramatic as some potray.

BTW, really enjoy reading your posts on this Forum....been great teaching tool for me.

A few things to consider here:
--The blower's efficiency is xxpsi at xxxxrpm. Not necessarily xxpsi.
--HP is derived from TQ, so peak HP numbers are irrelevant, as well area under the TQ curve is more important than peak TQ.
--It's better to make TQ higher up in the power band to take advantage of gearing.

When you swap to a 2.80 pulley, you WILL peak more torque. SOTP will always feel stronger when a car makes torque lower. The point of it is though, you don't race your car at 3000-4000 rpm, so even if you gain a whole lot there, it's really irrelevant. You want to peak torque as high as you can (this is what cams do) and as a result of the HP function, your HP gains will be a LOT higher than peaking torque at 3000. Now before anyone goes off, I know that cams change the flow pattern of the heads, but in essence it shifts your torque curve higher. The real comparison would be torque under the curve from 4500 rpm to 6500 rpm.

 

[JSHTROD]

Where's the 2.76 option?

Love the tq! See sig..

:beer:

 

[NHRACobra]

RR non-slip 2.80 pulley, and BilletFlow 100mm idler:thumbsup:

 

[rACeRs]

Im sure its different for every car, but when I went from the 2.93 to the 2.76 upper I gained 10 rwhp and 20 rwtq and these were just the peak numbers. And these were back to back runs on the same dyno same day. Maybe its because Im running the apten that it can use the smaller upper? Im now wanting to add a 2lb lower to it to gain back some of the torque.

 

[RiffRaff04]

Go upper and lower!

 

[HotRodHarry]

Makes total sense to me !

A few things to consider here:
--The blower's efficiency is xxpsi at xxxxrpm. Not necessarily xxpsi.
--HP is derived from TQ, so peak HP numbers are irrelevant, as well area under the TQ curve is more important than peak TQ.
--It's better to make TQ higher up in the power band to take advantage of gearing.

When you swap to a 2.80 pulley, you WILL peak more torque. SOTP will always feel stronger when a car makes torque lower. The point of it is though, you don't race your car at 3000-4000 rpm, so even if you gain a whole lot there, it's really irrelevant. You want to peak torque as high as you can (this is what cams do) and as a result of the HP function, your HP gains will be a LOT higher than peaking torque at 3000. Now before anyone goes off, I know that cams change the flow pattern of the heads, but in essence it shifts your torque curve higher. The real comparison would be torque under the curve from 4500 rpm to 6500 rpm.

 

[04Chris]

i just bought a sfph 2.8 non-slip upper and a steeda tensioner from pennywisegt. i also have a bassani catback at need-4-speed waiting to get installed. a few more things and i can be a pullied cobra owner

 

[dougwg]

this thread is useless IMHO

It proves and settles nothing

 

[§ilver§nake]

A few things to consider here:
--The blower's efficiency is xxpsi at xxxxrpm. Not necessarily xxpsi.
--HP is derived from TQ, so peak HP numbers are irrelevant, as well area under the TQ curve is more important than peak TQ.
--It's better to make TQ higher up in the power band to take advantage of gearing.

When you swap to a 2.80 pulley, you WILL peak more torque. SOTP will always feel stronger when a car makes torque lower. The point of it is though, you don't race your car at 3000-4000 rpm, so even if you gain a whole lot there, it's really irrelevant. You want to peak torque as high as you can (this is what cams do) and as a result of the HP function, your HP gains will be a LOT higher than peaking torque at 3000. Now before anyone goes off, I know that cams change the flow pattern of the heads, but in essence it shifts your torque curve higher. The real comparison would be torque under the curve from 4500 rpm to 6500 rpm.

This is why I opted for the 2.93. I have the Crower Stage 3 cams. The 4.10s and 2.93 give me plenty of low end torque from idle to about 3200. At that point I hit the powerband of the cams causing the car to lunge forward as it accelerates faster to my shift point of 6000. To me, it seems to be a perfect match.

As a side note...the cams allow the blower to pull a solid 14.5 lbs of boost. I think a 2.93 alone gives about 13. Someone can correct me if I wrong.

 

[HotRodHarry]

Well....I am going ahead and putting the 2.80 very soon from Terry at www.SouthFloridaPulleyHQ.com . I do miss the awesome initial bang that pulley has over the 2.93 I have on now. For having fun on the street with blasts starting at 3,000 rpms in any gear...its like no g force a roller coaster ride can produce

I always liked the 2.80 on my first Dark Shadow Grey 03 Cobra.
www.TeamJDM.com had already set me up with a 2.80 tune in the Super Chips Tuner I got from them.
All should be good.

And with all the votes for the 2.80....those votes are from people who seem to be pretty happy.

 

[04SilverSerpent]

This is why I opted for the 2.93. I have the Crower Stage 3 cams. The 4.10s and 2.93 give me plenty of low end torque from idle to about 3200. At that point I hit the powerband of the cams causing the car to lunge forward as it accelerates faster to my shift point of 6000. To me, it seems to be a perfect match.

As a side note...the cams allow the blower to pull a solid 14.5 lbs of boost. I think a 2.93 alone gives about 13. Someone can correct me if I wrong.

I know this is offtopic, but what did you graph look like on the topend? I am assuming that the HP did not fall off nearly as bad? What cams did you consider before you decided on the crower stage 3's?

 

[Fast Willy]

You didnt put any combo with the 2.93 pulleys. I am going to run a 6lb lower I think with my 2.93.

 

[Slythrin]

8# lower