Dragon Stang

Hey Matt... I guess I must be old school. Can you remind me what was the purpose of an underdrive pulley? From my days of engine building for high RPM conditions, as I was taught,it was to keep all the spinning accessories at an acceptable level before they self destruct. Any HP gain was considered a bonus. On the street, it really makes little difference as the engine will only see high RPM for a few seconds at best but, when you consider things like NASCAR, you can see the reason for under drives. Am I wrong?

howarmat

The underdrive pullies are suppose to reduce the accessories draw by about 25%....its like when you turn the AC on and you can feel the car lose power because of the extra draw on the system.....well the UDPs will release some extra power by minimizing the draw from the accerories The car will feel a little quicker like it gets the RPMs up a little faster.

CapitalG

you seem to be in the know so I'll ask you wires like these

http://www.youtube.com/watch?v=cKvEcSitkiY
http://www.southernmustangparts.com/...res-p-146.html

don't really add hp/tq ?

also is it really worth it switching my stock spark plugs isnt the Mustang supposed to have high performance ones stocked if not what do you suggest and what kinda gains can I expect.

Also again I was always told that a general rule is anything that either helps your engine breathe better or gets more cold air to it is a good thing and improves performance but everyone talks bad about Throttle bodies especially in the v6

http://www.bbkperformance.com/produc...le-bodies.html

arent these products dyno tested and tested and tested and tested once more cause BBK is respected performance company

mygt500

To the OP......IMO the small mods dont add up and the intake tune and gears are the best bang for the buck. UDP's are ok and are not necessary for street driving unless you just dont want as much power lost when running accessories. Appearance mods (I have many) will add about 10-25 HP at a car show but no where else...LOL....hope that helps

wmtheflash

Don't waste your money on the plugs, they won't do anything. Everyone from oil manufacturers to the people that sell the turbonator will make horsepower claims.

I'm very skeptical of underdrive pulleys. I honestly can't see 8-10 rwhp, but I'm sure someone will come up with a dyno to prove me wrong. The problem is if those gains are real (I think 5 hp sounds more like it), the chances are they take place as an very high RPM, like above 4k or 5k rpm. You won't feel much of a difference there.

The other problem is, mods don't directly add. That is, if something adds 10 hp, you can't find another mod that makes 10 hp and expect a 20 hp increase. Chances are it will be a lot lower than that.

The truth is, there are a lot of mod addicts out there that are reaching for that last 0.1 of a second at the drag strip. If that means adding an electric water pump, CMCV delete plates, x-pipe, shorty headers and underdrive pullies, then they're going to do it, no matter what the cost!

My advice would be to stick with what works.

If were me, then I'd at least look into the following...

1. Intake and tune. (You already have that!) I wouldn't spend the money on a new tune at this point. You can always come back to that later.

2. Gears. Gears work. Period. You'll accelerate much faster. You just have to make sure you're willing to deal with the gas mileage loss. The numerically higher the gear the more top speed you'll loose and the more acceleration you'll gain, not really an issue on a street car.

If you're planning on doing forced induction, then you'll need to think carefully about which gears you choose.

3. Limited slip differential. Probably a good idea. GT has it standard, V6 doesn't have it all. T-lock is added when you do gears. If you get forced induction, then you'll want a limited slip.

4. Dual Exhaust. Doesn't the V6 gain a good bit from dual exhaust? I would think so. Heck, I think they even get a little from GT mufflers. I'd do a little research. This mod is probably worth it if you're going with a supercharger later down the line.

5. Lower control arms and a GT sway bar.

My GT handles like...well junk compared to my C5. I can't imagine how much worse it would be without a rear sway bar! Unless you have a pony package you don't have one. Cheap mod. Get a GT takeoff and bolt it on yourself.

Lower control arms are great for less wheel hop. My GT seems to have better traction with mine. Quite a good mod and if you make more power down the road (supercharger or nitrous), or even if you're stock.

All that stuff has to cost at least $1,500. That should keep you busy for a while and you'll need all of those modifications if you want to make more power.

After you've done all that, then you'll probably be in a position to decide which way you want the car to go. Better handling? Drag racing car? Force induction? Nitrous? Maybe some comsetic mods. Or maybe sell it and get something else?

You could also look into a driveshaft. Seems like you can pick up 0.2 in the 1/4 mile with these on a GT. That's a pretty good gain. V6 probably has to have some gains here, too.

The dollar returns seems low to me. You'll need the shaft ($600) and adjustable upper control arms ($200) to set pinion angle. If you add labor then that's about $1000.

As far as headers, that's a personal decision. I won't run without cats, pretty irresponsible, illegal and makes the car smell rotten when you drive it. You could always get high flow cats, I suppose, still removing a working cat is illegal, I believe. Shorty headers won't do much, a few horsepower for $300.

It's hard to argue with nitrous oxide, too.

Here's a Zex kit installed on a V6. They gained 75 horsepower at the peak. What's cool here are the gains at lower RPM. Notice that they gained as much as 95 horsepower at 4.1k RPM!

http://www.mustang50magazine.com/tec...kit/index.html

GT4HUTCH

those buick fender holes ought to give you a few. If you already have an intake and a tune. As stated earlier, get a set of gears. To me that was still THE most noticable bang for the buck mod.