[Hondakillr11]

my buddy just picked up a 94 t-bird. the v8 is really underpowered. so far we thrown in some new cylinder heads, and a cold air intake, removed the cats, and little stuff like that. it doesn't seem like the car is getting enough fuel, and i want to change the throttle body, if any one has any suggestions on what size to get there more then welcome.

[FoxThunder 5.0]

sounds like u got the main mods covered, and i presume more to come so I'd go with this BBK 70mm http://www.primediapowerpages.com/cg...0054&2D1004575 this will fit ur thunderbird, same motor and basically identical components, just much milder guts

[FoxThunder 5.0]

oh and for the running lean problem, just get an adjustable fuel pressure regulator from BBK and have a professional adjust it for ur application http://www.primediapowerpages.com/cg...0054&2D1004592 u could even try getting 24 lb injectors??

[lozinit]

What heads did you put on the car?

I'll tell you right now that the cold air intake isn't doing that much for you.
Neither is the fact that you removed the cats. That 4.6 relies on a certain level of backpressure to produce it's low end torque.
If you removed the cats, are you getting a MIL now?

The throttle body is not what is restricting you as far as the engine being able to breathe, at least not while you are NA.

The biggest restriction you had with the engine was the heads, as the 94-95 MN12 heads do not flow well at all.

if you are looking at more "off the line" feel, I have a couple simple and fairly cheap mods for you.

First, ditch the factory torque convertor. In it's place, bolt up a 1998 mark viii torque convertor. You will also need to buy the 98 flexplate and bolts as the mark viii convertor doesn't bolt onto the stock flexplate. Part number for the TC is: F8LZ-7902-BARM
This swap is fairly easy and cheap, it only cost me about 210.00 to do. It's a smaller convertor that has a higher stall. Being about an inch or so smaller allows it to spin faster without you worrying about it ballooning and losing a thrust washer.

Second, If you are serious about making more power, you will need to do a few things first. Keep in mind that the driveshaft is a limiting factor here, and spinning it up past 105 MPH is begging for trouble. Again, the mark viii enters the picture. The driveshaft from a mark however is only a little better in this regard, and I would consider it a band-aid fix. I'd look into a metal matrix driveshaft if you are serious about wanting more power.

Next in line - (You should have done this first really) Install a trans cooler. The 4R70W in these cars run at a hellishly hot temp, and you need to bring that puppy down a bit. It does nothing for performance, but, WILL increase the life of your tranny.
Give the trans a FULL flush and refill it with MERCON V fluid.
(More info on all this is available at www.tccoa.com. take a look at the tech articles in the tranny section. While you are there, read up about the "J-mod" to the tranny. Trust me, it's a great thing)

Another good item is a custom chip from FordChip.com. They are in my opinion the best out there for this situation.

If you care to entertain the idea, find a low mileage 01 Ford Explorer engine. (01, or 02, i can't remember, but it's the one with the aluminum block, and they only produced it for that one year for that truck) It offers more power than our engines, and is a fairly easy swap.


If you want any other mod ideas, let me know. Anything I've done my 95 will also work on your 94, so I can tell you what works and what doesn't and hopefully save you some time and money.

For the time being, leave the regulator and injectors alone, They are more than enough to power any NA mods you are doing. check your fuel pressure with the motor at WOT. Let me know what readings you get.
It could be a simple case of your injectors needing to be cleaned.

**EDITED for wrong part numbers**
The flexplate part number is F3LY-6375-A
The TC part number is F8LZ-7902-BARM

~Michael