2.76 or 2.93? Also what do I need?

[nytebyte]

I think I've finally decided to pulley the Cobra, especially since I'm probably the only one left in these forums who still has the stock pulley.

Question is, which size should I get? I'm assuming that Billetflow still makes the best stuff, so I've been to their Web site and they offer basically the 2.76 or 2.93.

My Cobra is also my DD and sees some occasional on-track racing. I'd imagine I will need to swap the blower pulley back to stock if I have an on-track event.

My original plan was to do a 2.93 will full idlers, but what are the pros / cons of going with a 2.76 instead? I don't really want to run DR's, so would a 2.76 be too much?

Besides the pulleys and tune, are there any supporting mods that I will require?

Also, does gas mileage suffer badly with a pulley upgrade?

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[Tom]

I think I've finally decided to pulley the Cobra, especially since I'm probably the only one left in these forums who still has the stock pulley.

Question is, which size should I get? I'm assuming that Billetflow still makes the best stuff, so I've been to their Web site and they offer basically the 2.76 or 2.93.

My Cobra is also my DD and sees some occasional on-track racing. I'd imagine I will need to swap the blower pulley back to stock if I have an on-track event.

My original plan was to do a 2.93 will full idlers, but what are the pros / cons of going with a 2.76 instead? I don't really want to run DR's, so would a 2.76 be too much?

Besides the pulleys and tune, are there any supporting mods that I will require?

Also, does gas mileage suffer badly with a pulley upgrade?

If you are going to pulley it... 2.76 upper.

You could throw a heat exhanger on there, but, know plenty of folks who have no problems running wo/ one when just doing a pulley w/ stock Eaton.

My 1st set up when I had that done looked like this...

AFCO H/E (single pass)
Speed Inc. Intake
Diablo MAFia (some need / some don't)
2.76 Upper
Stock midpipe
SLP LM II cb
Kurgan Tune

463 RWHP / 463 RWTQ


IMHO... MPG only kills ya a small fraction more if your heavy on the right foot.

 

[jaykruger]

The con of the 2.93 is that you will go to the 2.76 anyway.

You don't need anything else, not sure on why you want to switch back and forth. The 2.76 should be perfectly fine for both.

 

[nytebyte]

I was concerned about excessive heat for the on-track events. I wouldn't think a pullied Cobra would be able to last even one session with the Eaton, even with serious cooling mods.

I'd rather go back to the 3.65 stock pulley for when I run in those events. You really don't need a lot of power for on-track racing and a stock pullied Cobra is plenty.

 

[Slow99x]

That's alot of pully and belt swapping. I have better things to do so I've got a 2.8 and the 4 idler set.

 

[IZZy]

2.76 all the way!

 

[BlaqSnake]

The only other thing you might consider is a new set of plugs.

With a 2.76, NGK TR-6 are the magic ones if I remember correctly.

 

[Tom]

The only other thing you might consider is a new set of plugs.

With a 2.76, NGK TR-6 are the magic ones if I remember correctly.

Agree... Forgot to add that in my post.

 

[IZZy]

The only other thing you might consider is a new set of plugs.

With a 2.76, NGK TR-6 are the magic ones if I remember correctly.

thats what I got too:dancenana:

 

[hj16]

Question is, which size should I get? I'm assuming that Billetflow still makes the best stuff, so I've been to their Web site and they offer basically the 2.76 or 2.93.

My Cobra is also my DD and sees some occasional on-track racing. I'd imagine I will need to swap the blower pulley back to stock if I have an on-track event.

Doug basically has any size pulley you want. I'd say get a full Idler set for sure... then get a 2.76 AND a 3.4 or 3.65. Just swapping the rings on the hub will be easy and you could even get away with the same belt if you just remove the Aux Idler when swapping back to the larger pulley. Then just get yourself a handheld tuner with two separate tunes to flash between as you swap uppers. Add some NGK TR6s in there and you're all set.

Gas Mileage only suffers if you are always in the throttle. I get better gas mileage now with a 2.93/ported eaton then I ever did stock.

 

[PNSH3R]

<--- is still on stock pulley, too

 

[sonicblue2003]

go with a 2.76. and of course the plugs and idlers. If you have the extra cash I would do a CAI, MID pipe and cat back. You will be very happy with it... you dont need a heat exchanger

 

[cdh027]

I'd say get a full Idler set for sure... then get a 2.76 AND a 3.4 or 3.65. Just swapping the rings on the hub will be easy and you could even get away with the same belt if you just remove the Aux Idler when swapping back to the larger pulley.

I agree 100%. Although I dont think you would need a second tune for the larger pulley. If you get the car tuned for the 2.76 and swapped in the 3.xx ring, the tune should be fine if it was tuned via the MAF.

 

[sonicblue2003]

just get to 2.76 and leave it. You will be fine...u r not going to want to keep swapping them..

 

[ITLLOWNU]

just get to 2.76 and leave it. You will be fine...u r not going to want to keep swapping them..

+1 ..go 2.76 with the idlers. get a custom tune ,and if yor tuner uses sct software get a flip switch and have a tune for pump and race gas. then all u got to do is turn the dial:headbang:.

when you up the boost , you need a free flowing exhaust to get it out.
a set of long tubes and off road midpipe with a good flowing catback (not blow master) will see significant gains over just a pulley and tune.

my car made 474rwhp and 486rwtq SAE with just a 2.8 upper ,an o/r x and slp catback on 93

added headers about a month later and went back for a pull just to see if there were any gains in power and made 498 rwhp 503rwtq SAE

and as far as gas mileage goes, if your tuner does it right and tunes for drivability and WOT you should see great fuel economy. with the whipple on mine now and 22psi on 93 i see 16mpg city and anywhere from 22-26mpg highway and its been that way for 10,000 miles and with power and torque in the mid 600s:biggthump

we all already know this but i felt like preaching today

 

[nytebyte]

Keep preaching. The more info, the better.

I currently have an FR500 catback and a K&N intake, so I think I'm OK there.
I also have a Predator with a tune.

If I get a 2.76 and make respectable power, can I still run on street tires? I really don't want to run DR's if at all possible.

 

[IZZy]

If I get a 2.76 and make respectable power, can I still run on street tires? I really don't want to run DR's if at all possible.

I have street tires right now and its hard to hook at wot in 1st or 2nd, but you can run them, just be careful because that assend will come lose with little effort.

 

[rexisme]

I have street tires right now and its hard to hook at wot in 1st or 2nd, but you can run them, just be careful because that assend will come lose with little effort.

yep, i only have 452/452 and i had to start running dr's full time cause that ass end loved to come out w/ street tires.

 

[Ear Rak]

For just driving around, street tires will be fine. Its not like you're racing every light. Now if you do plan to run a car you might come across on the road, then you will be traction limited. But the added power would not scare me off from driving on street tires daily.