Bored Throttle Body Question

A couple of questions regarding bored throttle bodies for the normaly aspired automatic PT Crusier.

Does a bored out throttle body (to 55mm) help an automatic PT?? (I don't plan to turbo or supercharge, in the near future anyway). Not looking for huge gains, but basically is it worth the money??

Does the 55mm have any negative effects? I have an AirAid intake, and will have a Dynomax muffler installed (when I find a tip). Does it make the auto any worse off the line? (Thought I read somewhere that if the throttle body was too big, daily driving would suffer)

Also, what is the common charge if I was to buy a bored one, then return my existing one for a core charge credit?

I need to drive the car, so I can't really send it out to be bored out, and be without one.

I'm not looking to make this a race car, but a little oomph wouldn't hurt.

Thanks!!!!

[Ant]

With the basic mods you have done, a 55mm TB would not be a good choice. A TB of that size would be best suited to a heavily modded car or one with forced induction. The larger TB is still not used to its potential on those applications because of the openining of the intake manifold. Because it it is plastic it makes it difficult to port match or extrude hone to match the larger hole in the TB, however it can be worked a little.
In a nutshell, the bored TB for your particular application will not yeild positive results. It may bog the car off the line on WOT and be very touchy or jumpy at low speeds under normal driving conditions.

[Ali N I]

What would be the point of just putting a bored throttle body on an engine which doesnt have a larger volume intake. unless you make the runners bigger to the engine as well you arent getting any more air to each valve.

[Powertrip]

Originally posted by Ali N I
What would be the point of just putting a bored throttle body on an engine which doesnt have a larger volume intake. unless you make the runners bigger to the engine as well you arent getting any more air to each valve.

Runner size doesn't matter - displacement or cam profiles do.

[GR8FLPT]

Add a header, it will help. I liked the postive effects on my auto. Also, changing the tranny fluid to Amsoil seemed to help also.
Maybe its just "snake oil" but then I like being bitten by the mod bug

[MYREDGT]

GR8FLPT, I though these little Mopar Automatics required special Chrysler Spec fluid? You can put in Amsoil with no problems with shifting or the computer?

[GR8FLPT]

Originally posted by MYREDGT
GR8FLPT, I though these little Mopar Automatics required special Chrysler Spec fluid? You can put in Amsoil with no problems with shifting or the computer?

My custom cruizer shop is where I had the work done. He specializes in PT cruisers. I am 1 of about 6 cruzers in the area that switched over to synthetics for both motor & tranny fluids. I plan to switch coolant at next flush. I have almost 10,000 miles since the change over & not a bit of trouble.
I think it shifts better since the switch. But then it could be just me. But I don't have the work done at the dealer anyway unless it's a warranty service charge. I do as much of my own work as possible, did so for last 12 yrs on my other car.
The heavy duty repairs, I get help on, or I see my cruzer shop.

[Mel K]

I didn't get a chance to read all of the threads, but if you are putting the turbo on a standard aspirated engine there is a big difference in the compression ratio with the new turbo pistons. Does your conversion address this situation?

[RAMCRZR]

I agree with Ant it will not make a diff if your not going to super charged or turbo your motor,,,save your $$$$$$

[GregsPT]

Originally posted by GR8FLPT
Add a header, it will help. I liked the postive effects on my auto. Also, changing the tranny fluid to Amsoil seemed to help also.
Maybe its just "snake oil" but then I like being bitten by the mod bug

I hope you are out of warranty because you are voiding your warranty. You can use any oil you want in you rengine but use anything in your transmisson but Chrysler approved fulid and you just voided your transmisson warranty