GT500Steve

Get the rear O2s turned off in the tune and you will be fine. If ordering a CAI/pulley/tune combo. go ahead and get the big CAI. Personally, I would suggest either the JLT 123mm plastic or 127mm carbon fiber unit. Then, there is no need to upgrade if you ever buy a bigger blower... plus they will work better with your new throttle body. (make SURE to tell them about the TB when you get a tune)

Speaking of tuning, either Justin at VMP or Jon Lund. Used a Lund tune with the stock blower, and when I upgraded went with Justins tune. It is spot on.... lots of power and perfect drivability.

And yes, 3.73s are great... don't waste your time on 3.55s.

adidasUNT8

Steve when are you going to go down the 1320??

GT500Steve

Apparently NEVER at the rate I'm going lol. I was supposed to run True Street at Bristol last month, but had a couple of minor issues with the car (PM me and I will give you the details). Ended up not making the race, and the car has been down for over 3 weeks now. Hopefully will be going back together soon, and will have a Thump tensioner and the new VMP 2.4" pulley. I was getting a little bit of belt slip before, so with the addition of the tensioner and smaller pulley I might pick up 3psi over what I was running before. So hopefully that will translate into some more ET & mph.

Also, the stock clutch is toast... it is getting hard to go into gear, and it feels like you have to stand on the pedal to get to the floor. SO, I am going to put a clutch in it before I take it back racing again, and I might add some long tubes too. Probably looking at early fall before I get any 1/4 mile numbers... the plan is to load it up in my buddys enclosed trailer, put some slicks on it, some good gas and crank the timing, and let 'er rip. I will probably take it back to the track on radials before then to get some 1/8 mile numbers though, that way I will see if the new clutch helped find some of the ET I am missing.

05 Mustang

I wouldn't say it's a problem....but swapping the gears from 3.31's to 3.73's will definitely make the car "feel" better all around, IMO....taking off, driving, down shifting...as people say, "seat of the pants"...

I just can't imagine trying to plant all the additional power with 3.73's.....it was hard enough with the stock 3.31's, lol

I personally wouldn't consider the 3.55's or 4.10's....3.55's because I've always heard that if you're going to swap gears, you should always go up 2, which would put you in the 3.73's.....4.10's, IMO...just too much of a gear that you really don't need....but that's only my opinion.

Blacksmoke

I HATE K&N!

I especially hate how they were advertizing such huge gains without a tune even back with the 05GT's.

Made me angry they were spewing crap out of their mouth and people believed it.
Even though they showed on THEIR dyno chart the gains I have NEVER heard of anyone getting NEAR the numbers they claimed for the "no tune" CAI.

Heck the tune is the major part of that sort of upgrade's power in the 05+
Mustangs.

04AZUREBLUEMACH1

I got my 2.5" pulley, 90mm idler, JLT 127mm CAI, and tune from Justin installed this weekend. Now the car plants me back in the seat when I get on it... I love it.

The only problem I encountered was that the 90mm idler pulley seemed to be too tight of a fit under the intercooler lines. So, I placed it on the idler arm instead. Then I realized that it wouldn't have mattered, because the belt would have gone UNDER the red arrow pulley, not OVER it...

GT500Steve

When you say you put it on the "idler" arm, do you mean the actual tensioner arm that keeps tension on the belt?? Or somewhere else?

04AZUREBLUEMACH1

Yes, I replaced the pulley on the actual tensioner arm... the pulley there was the same size as the one at the top of the engine that I should have used.

GT500Steve

Just a word of caution about that. I have heard of a couple of guys with the larger diameter balancers say that the stock tensioner arm smacked the balancer on shifts. Granted, you have to be spinning 6K plus rpms and shifting like there is no tomorrow, but it is something to double check. You have the stock balancer, but you have increased the size of the pulley on the tensioner, which will still put them closer together. I would make SURE you have plenty of clearance between the two, just for safetys sake.

My car has the 10% OD balancer, and it was VERY tight with the stock tensioner. I actually just upgraded to the Thump racing tensioner with the smaller pulley for more clearance and better tension on the belt.