Pulley Help.

[How2003cobra]

Hi

On the original owner of a 03 cobra convertible pretty much stock except for a new throttlebody. I just found out that I need a new belt tensioner pulley. Since I’m replacing that pulley, should I replace any other pulleys if they look good and also should I go with a slightly smaller police for my stock Eaton.

Thanks for the help

 

[1FastFord]

I would definitely replace all the idlers if stock. As for the eaton pulley, changing that would give you more power but you would also need a tune.

 

[03cobra#694]

^^I second what he said.

 

[stangfreak]

Like stated above, I would do all the idlers. Maybe do a 2.93 upper pulley. 13lbs of boost. Throw a catback. I like the steeda cold air bc it retains the stock intake. looks all stock. simple install. Done deal. You will hve yourself a reliable, safe street car.

 

[01yellercobra]

You can spin the pullies by hand and if they feel rough definitely replace them. But I like the look of aftermarket pullies better, so I'd replace them anyway. I had a 2.8 on my blower and it was a lot of fun. Gave it just enough pep to make things more fun. At this point tuners like 04sleeper probably have a tune on file that will work that set up as it's pretty basic.

 

[Venom351R]

Its not a matter of if but when the stock idlers will shred themselves apart

 

[mysticsvt]

2.8 with a 4lb lower should get you about 17lbs of boost which is about as much as you want to get out of the stock Heaton. 100% get rid of those shitty stock idlers. I killed the lower one which ended up nicking my lower pully and shredding my belt leaving my stranded.

 

[01yellercobra]

No need for a 4lb lower and 2.8 upper with a stock eaton. It'll just be a heat generator at that point. If it's ported that's another story.

JMO, but I think the OP would be pretty happy with a 2.8 to 2.9 since it's been stock all this time.

 

[mysticsvt]

No need for a 4lb lower and 2.8 upper with a stock eaton. It'll just be a heat generator at that point. If it's ported that's another story.

JMO, but I think the OP would be pretty happy with a 2.8 to 2.9 since it's been stock all this time.

Yeah mine was....so long ago.

 

[CobraBob]

No need for a 4lb lower and 2.8 upper with a stock eaton. It'll just be a heat generator at that point. If it's ported that's another story.

JMO, but I think the OP would be pretty happy with a 2.8 to 2.9 since it's been stock all this time.

For sure, Bob. For reference, going from a stock setup to, say, a 2.90/2.93 upper (with a billet 4-piece idler set) with a good tune will net about a 80whp gain, the difference is definitely going to be felt. AND leave a huge grin on @How2003cobra's face. I still remember the day back in 2003 when I made that exact upgrade and the car felt SO much better that I literally did not want to park it. My wife and I were at Maple Grove Raceway for the install, and she thought I was being a bit much not wanting to bring it back to the hotel we were staying at. Seriously, driving a 457whp car (479wtq) was just SO much freaking fun.

 

[How2003cobra]

For sure, Bob. For reference, going from a stock setup to, say, a 2.90/2.93 upper (with a billet 4-piece idler set) with a good tune will net about a 80whp gain, the difference is definitely going to be felt. AND leave a huge grin on @How2003cobra's face. I still remember the day back in 2003 when I made that exact upgrade and the car felt SO much better that I literally did not want to park it. My wife and I were at Maple Grove Raceway for the install, and she thought I was being a bit much not wanting to bring it back to the hotel we were staying at. Seriously, driving a 457whp car (479wtq) was just SO much freaking fun.

A few questions. What is the size now of my orig Eaton pulley ? Should the pulley for the Eaton spin freely since it feels a little tight. Also what manufacturer should I go with for the pulleys, A friend recommended VPM Can I tune the car myself and until I get the tune can I drive the car for a little.

Thank You for the help

 

[Venom351R]

The stock pulley size is 3.65 and get double ball bearing idlers. Metco makes a great set and other company's

 

[How2003cobra]

One last question I am looking at a UPR double pulley any good.

 

[TP03]

One last question I am looking at a UPR double pulley any good.

I've been running them for about 5 years without issue. I'm happy with them. The black accent matched my look rather than Metco bling.

 

[CobraBob]

I've always recommend Metco, but UPR pulleys are very good. I might just boil down to your personal taste in how it looks.

If you install a smaller upper pulley, I don't recommend that you drive your Cobra without a tune temporarily. Could you? Sure, but due to how lean the A/F will be you're taking a chance if you, for example, forget it doesn't have a tune and get on it. A general rule of thumb is to at least install a base, temporary tune to get you to your tuner, or avoid driving your untuned Cobra as much as possible before you take it for a tune (or get a tune loaded on a tuner device). In other words....granny shifting!!

 

[01yellercobra]

More than likely the UPR pullies are just copied Metcos anyway. So they should be good.