FAQ- Engine

Q. Will underdrive pulleys make my car overheat or make the alternator not charge?

A. No, with the right underdrive pulleys you should have no problems what so ever. Your batter gauge may go down just slightly and your temp. gauge may go up just slightly but there shouldn't be any problems at all.
The one thing you have to watch out for when buying pulleys is that you don't buy the "Race" version and install them on your street car. Many companies sell street and race versions of their pulleys. The race version pulleys don't let the alternator spin fast enough, so you will have charging problems when using them on the street.

Q. I'm thinking of buying a throttle body, what size should I buy? Is bigger better?

A. No, bigger isn't always better when it comes to throttle bodies. Most mildly modified engines only need a 65mm throttle body. Many people tend to install a bigger TB such as a 70, 75 or even 80mm, but anything that is bigger than you need will only make the car slower. I know you may be saying "yea sure, a bigger Throttle body is going to make my car slower" but it is true. It's been proven many times.
Muscle Mustangs and Fast Fords magazine performed a dyno test on a near stock engine using 65mm, 70mm, and 75mm throttle bodies. They noted that the 65mm TB made the most improvement in hp and torque, while the other two actually took some torque away at certain rpm's.
Just to prove that you don't need a huge throttle body to make power is the fact that Saleen uses a 65mm throttle body on their 500+ hp engine in their $150K S351SR widebody Mustang.
Usually you only need to go to a bigger throttle body when you are using a big psi supercharger or blower. Motors using 14 or more psi love big throttle bodies.

Q. Intake manifolds, which one is the best?

A. It all depends on your "combination". Basically you will want a long runner intake manifold such as the Ford Motorsport Cobra or GT-40 if you are looking for more midrange power. You'll want a box type or short runner intake if you are looking for high rpm power.
It really depends on what other things you have done to the engine, and what else you are planning to do. Your best bet is to probably contact a reputable performance shop and ask what their opinion is on your setup and what they recommend for you.
Usually if you are using a big blower then you'll probably want a box, or short runner intake to take advantage of that high psi. If you're just looking for a fast street/strip car, then you might just want a GT-40, SVO Cobra, Edelbrock, etc long runner intake manifold to take advantage of their low rpm power.

Q. I've installed a bigger mass air meter, but now my car runs like crap! What's the problem?

A. A common mistake by many stangers is to get a mass airflow meter (MAF) that isn't calibrated to their injectors. The same can be true of someone buying bigger injectors. You need to have your mass air meter calibrated to the size of the injectors you are using. Many aftermarket mass air meters have a way of being adjusted, so you can calibrate them to the size of your injectors.

Q. I've heard that I should do something with my timing, what is it that I'm supposed to do, and why?

A. From the factory your Mustang came with the ignition timing set low, usually around 10 degrees. Ford set it at that to be conservative, and to prevent engine damage in extreme situations. In reality you can usually bump up the timing to 16 degrees or more, although anything over 16 isn't recommended. The usual place for most Mustang-ers to set their timing is at 14 degrees. Setting the ignition timing usually doesn't result in any more hp, but it will make the car pick up better, and once in a while you may notice better fuel mileage too.
One thing to remember is that Ford set the timing at 10 from the factory so you can use low octane gas, so if you do bump it up you'll need 92 octane or higher to prevent pinging. Also, bumping up your timing to the point that it will ping can cause bad things to happen like blowing holes in pistons. So be careful.
--Check out our tech aritcle on bumping up your timing----Here--

Q. My oil pressure gauge is low all of the time, what could be the problem?

A. Although it could technically be a bad oil pump, or many other things one of the most common problems is the fact that the factory Mustang gauges are crappy to say the least. Many Mustang-ers have the same problem with the gauge being low. Usually if the engine is running good, and you don't hear any knocking then your problem is probably that your oil gauge is bad. (which is very common on mustangs)

Q. I've heard that changing the oil pump is a real pain in the horses ass, is that true?

A. Yes it can be a real pain in the rump. The reason its a pain to change the pump or even just the oil pan gaskets is because of the way the oil pan is made. It has a hump in it that's there to clear the front cross member. So if you have to change the oil pump, or oil pan gasket you will have to basically lift the engine out of the car to get the oil pan all of the way off. Its not that big of a deal if you are taking the engine out anyway, but if your not, then get ready for some real work because you will probably have to lift the engine out most of the way.