Just wanted to clarify, you don't need a tune to run the 74mm body correct? I just ordered a TB off ebay and I am building my own cold air intake, but a tune will have to wait until I have the budget for it.

 

No tune needed.. the cars computer can adjust for the variable.

 

NO, the PTCM will learn the new throttle body over time, don't expect it immediately however.
You SHOULD do a throttle body reset after the swap though.

( make sure you use a NEW O ring )

 

What George said...I did the 74MM mod and the car ran rough for about a week...thereafter, leveled out...really like the extra "pull"...Carl

 

And oddly enough.. my two cars took to the upgrade like a baby on a.. let's say bottle.. LOL.


After the throttle reset and only a couple minutes they were all happy over it.

 

New MAF, TB and engine cover and there were no hiccups at all on my old NA. A tune a week later and all was golden.

 

Almost same here, I did the TB, no problems.
A month later the CAI, again no problems.
2 months later the EC tune, ditto.

 

I am using this thread because everybody has done the change, i have two 05's a SRT and NA, both with a SCAI i put on. I got a SRT 74mm TB and had it worked on by Maxbore it is a 78mm now. this weekend i would like to put the 78 on the SRT and use the 74 on the NA. i have gotten the O-rings, so if i have both cars side by side to do the work how long should this take?
What is, how do you do, the TB reset?
Dan

 

Just swapping out the TB's, less than an hour.

 

Thanks! any info on this TB reset?

 

Turn key to on position , foot to the floor for 5 seconds ,with foot still down, turn key off , remove foot. Leave key in switch , in off position ,do not remove the key, for 2 minutes. Reset complete !

 

OK I put the MAXBORE TB on my SRT this mourning it is a 78mm bore now, and the car runs terrible, stumbles and surges. Also got a check engine light, so I put the stock one back on I did the reset also after the change and that did not help. So I am back to stock with a rough running engine and check engine light on.
Suggestions!
Dan

 

Sure sounds to me like you have left a vacuum hose off, or the O ring didn't seat correctly.
Use pizzaguy's test : while idling, remove the oil filler cap, if nothing changes then you have a vacuum leak.

 

Well I am sure it is not a hose because there is only one and it goes in the bottom of the TB, as for the o-ring it was in place. I have driven the car around the block and in stock form it is running OK now, I still have a CEL, how do I turn that off or will it go out by itself?

 

If you have a scanner of any sort you should be able to reset it, if not then I think Autozone can reset it.
A complete drive cycle may turn it off too.

 

OK. Well I went and looked at the NA and the TB has a different setup! The SRT has a different attachment with a spacer that is rubber coated to seal the TB to the SC housing. The TB on the NA goes directaly to the manifold and is “upside down” with the hose on top, I guess the O-ring is only for the NA! So should I try to put the 78mm on a NA, that will be a big jump from stock.

 

There an article or two around here that talked about having to allow a little bit of time for the ECU to realize its getting more air to it.. can't remember if it was Woody or Jim..
Post #20 in this thread talks a little about it. Did you use your original MAF on the N/A?

 

I've never known anyone going past 74 mm on an NA, kinda on yer own there.