Dan claims that by going from 68.5mm to 71mm he can gain you 1hp with the cost of some low end torque.

F&B throttle bodies has a 73mm throttle body and according to their dyno charts, with a mostly stock 4.7l, you gain a little less than 14hp.

 

I think you mean 72mm. I have looked at both and if my tax return is what i expect i may try the 70 mm F&B just to be different. Airram has a quite a bit of info about the size choices on his site.

http://airram.com/product.php?catego...productid=1052

 

Pretty easy install. You need a special star drive for a couple of the screws. Took me about 45minutes. I took my time as it was cold out. Nothing special about it. If you haven't done one before I would suggest a Hanes manual.

 

Just a little tip for the high idle problem on start up after installing a modified TB. Disconnect the negative battery terminal for 1-2 minutes before starting the engine. Let the engine idle (DO NOT REV THE ENGINE) until it comes up to operating temp. Switch the engine off, restart and go for a drive making as many stops as possible, such as stop signs. Try to avoid going WOT for the first 25 miles or so as the PCM is still relearning the new increased airflow and part throttle settings. This technique will allow for a faster PCM relearn and will greatly help to eliminate the high idle problem.

 

hmm...can I start over now that I already have it installed and am experiencing idle issues? What you say is what Rengnath said to do as well but maybe I didn't stop/start enough, I just drove around the block which has 2 stop signs.....and, of course, I'm sure I was WOT quite a lot during the first 25 miles....

 

Yes. This allows for a faster PCM relearning process although the PCM will eventually relearn on its own. Since the TB bore is larger, the PCM has to make adjustments to the IAC sensor while at idling and part throttle situations.

Just to verify this process and for my own peace of mind, when I changed my TB to a larger one, I started the engine without doing this procedure and the idle was very jumpy from 800-1500 rpms and would not settle down at all. I shut down the engine, disconnected the negative battery cable for the 1-2 minutes, reconnected the cable, started the engine and it settled at 650 rpms almost instantly. Let the engine come up to operating temp, shut it off and then restarted. Went for a drive and even pulled into a Church parking lot doing some stops and veried my rpms up and down from idle up to about 3K. Back out on the road and about 25 miles later I went WOT and my RT is working flawlessly!

 

The other procedure I sent you Kent was one that Nick from Airram posted on another forum where a guy was having trouble with his fastman. Ill PM you the link. It seemed like anything I tried though, I could never get my idle right. I drove that thing like a grandpa for weeks after several resets, and all I got out of it was a few middle fingers and I was hardly ever on time for work. Lol. Try what Bwdakrt said though; he made the first throttle body I tried on my truck.

On a sidenote, I did get my truck to idle right 2 different times for about 200 miles or so. After a while though, the problem came back.

 

wish i had that info when i put mine on! lol it was ideling every which way but right! lol i disconnected the negative side of the battery after 3 days of crap idle and it got rid of it real quick! negative cable equals miracle restart button! lol

 

i went with the 70 mm, because of the nitros and larger injectors, fantastic product and well worth the money

 

did the procedure twice. still have the high idle. i'm beginning to think this tb is fubar. it's too bad the dude wont work with us on this one. obviously there is a problem with it.