Upper Plenum showdown....
 

Keep your eye on this one. It'll probably answer a lot of questions you guys have about the performance #'s with the bigger upper/TB combo:
Introducing the Contestants!!!!!!!!

The results: Showdown Part II

Those results are really dissapointing if you ask me. Lots of $ for a few horses. Am I missing something here? Can anyone make me feel good about my investment? Do those horses really translate into better times?

Anyone know what numbers we'd get with the accufab plenum and STOCK throttle body???

I saw in one of the other posts that the stock throttle body is 80mm... and that dyno sheet says the accufab tb is only 75mm
Why use a smaller than stock tb? Whats up with that?

It would make sence that if we use the accufab plenum with the stock tb we'll get more airflow, and with that... higher numbers that the 272hp & 310tq

opinions everyone???

And will the stock tb fit the accufab plenum?

The stock TB on my 2000 is 63 mm, I think. I don't know for your year, but it is probably the same.

Stock T/B's are 65mm for all 94-04 GT's. The problem that I have with the data is that everyone is geting excited about the Accufab unit because it gives an extra 1 Hp gain. It costs 100 bucks more! It is real nice looking but for a hundred bucks I'll pass. I got the Dragon plenum and 70mm T/B for under a hundred bucks off e-bay. Polished them both and they look and work great. If I had a newer model I would get the 75mm T/B and the cheaper of the bunch of upper plenums. Port the upper a bit and be within 1-3 Hp max of the overpriced Accufab unit. 1-5 HP is not going to win or loose a race, or improve your track time.

Remember, that's REAR WHEEL HP....on a dyno....so, it's not too bad considering it's just an intake flow improvement.......anything that nets a half-dozen HP reliably sure helps even stock. When combined w/exhaust, timing, etc it's a no-brainer, you'd need it anyway. I'd like to see that same test w/a stock exhaust, prob would make even less gain.....it's old news but most mod's wind up improving other mod's....where to stop is the trick....

They tested the Accufab with the stock TB in round one and it made more power and torque (by 1 or 2) than with the 75mm in the more recent test.

but lost as much as 15 hp at 3000-4500

Well my question was based on the fact that someone said it has a 80mm tb stock... which now I know is not true! It is 65mm stock...

so it makes sense that a 70 or 75mm tb will yeild better numbers.

Any word on a 80mm tb coming out??

and.. BIG question.. when is Ford Racing gonna start making stuff for our new stangs???

their website and catalog is still aimed primarily at the 5.0's!!

like the my last post t/b without changing the plenum some a 1-2 hp increase at peak but lose up to 15hp from 3000-4500
so in turn a t/b will slow you down

and there is no need for a 80mm t/b unless you have a built stroked motor running a blower or turbo pushing 20+ lbs of boost

I want to see a Ford Racing 75mm tb and plenum released!!!!

Thats what I'd go with. I am partial to sticking to Ford parts, I guess its the heritage in my blood or something. haha :)

what ever you dont get the ford racing 70mm t/b it sucks all it is ,is a 65mm t/b bored out to 70 with a new butterfly
and it is not 70mm all the way it starts at 70 and gets smaller

ok, good to know

thanks!

ok, but what about changing to a c&l plenum and 75mm throttle body together. would there still be a horsepower loss from 3000-4500 rpm? or a gain throughout the entire rpm band?

i've just looked at your post again, and saw that you said the 75mm throttle body made more power between 3000-4500 rpm. my bad. average power across the entire powerband is what really counts anyhow.

Talk about reviving a dead post...............


As long as you go with a plenum AND TB, you will be in good shape.

Always keep in mind your goals when modding the car. Some mods are better at higher rpms than others. Take for example an X Pipe vs an H Pipe. H Pipes are generally better for adding hp and trq down low, while X pipes can actually cause you to loose both down low but add it up top.

If you drag race, an X-pipe is a better selection than an H Pipe for example. There is ALWAYS a trade-off with any mod even if it is nothing more than cost.

well said

its all on what the use of the car will be for

like mine I only drive it maybe 200 miles a month now the rest it spends its time at the drag strip