Rajun_Cajun

Not to thread jack, but I have a question...

I have 4.30's and an E cam. I personally feel like that is too much gear for that cam. I plan on going to an F-cam soon. Would 4.10's or 3.73's be better suited for my setup? My powerband drops off at about 5200 right now. The F-cam makes power to 6000. I am passing through the traps at about 6000 rpm in 3rd gear at 80mph. First gear is useless, even with slicks. I have a set of 4.10's laying around right now, but my mechanic/friend keeps to telling me to sell them and get 3.73's. I completely trust him but want to get other opinions. My car is the only T-5 car that i have ever driven, and it came with the 4.30's and E-cam, so i have nothing to compare it to. What do you guys think? I am slightly (very slightly) concerned with gas mileage too, as I am going to be making a 1600 mile trip soon.


So, considering my setup (in my sig), what gear would you say is best for me? Please base your answer on the facts, not what you prefer. thanks.

Mustangkiler

f cam id go with 4.10

07 Shelby GT

If you are going to the drag strip all the time then I would agree about the 4.10's. However, if you are going to be using this for your daily driver then I would say not to get the 4.10's. I personally would get a tuner, then gears 3.73's and then finish off with exhaust.

If you go changing your headers and don't retune you could cause a lot of problems down the road. You are going to be changing your back pressure which may not affect you now, but will down the road when you get into the miles. I realize that the stock headers/manifold on the gt's is real similar to a shorty, but it will still affect your back pressure. You might want to consider this before slapping mods on your car. Just my opinion.

Putting headers on your car will increase the back pressure up to you cat's/precat's. This will cause your engine to lose torque which is exactly what your shorty's should be giving you..more torque during mid-range rpm's. It is not wise to spend that much on headers if you aren't going to change everything down stream. You are going to be force feeding your cat's pressure that it can't relieve causing a higher pressure in your cylinders which will cause incomplete evacuation of all the exhaust fumes. If there is still exhaust in your cylinders then obviously this will raise the pressure in your cylinder during the intake stroke which will not allow the appropriate fresh-air/fuel mixture inside your cylinders. This will also cause carbon build up which will affect your fuel economy once again.

My advice is go to a professional and ask some questions in your local shops. They will be able to tell you what will work and what won't. Simply slapping headers on, which are in the middle of the whole system may not net you the affects you are looking for. If you're going to replace your headers...I would suggest changing cats as well. Like I said I suppose everybody has their own opinion, but I would do it right the first time...don't skimp just because you have a certain budget at a certain time. Wait until you have the money to do it right. You won't be sorry.

Jfsram

Not taking et or SOTP feel into the equation.

He is correct. Steeper gears equals less mileage.

I daily drive my Mustang and am hating the 3,73 gears right now. The only time I do appreciate them is when I'm at the track ON A TIRE.