Throttle Body upgrade options.

[Canyonero]

What are the common throttle bodies used to upgrade the stock 3x00? I know the billet on WOT of course, but those are out of stock. What donor engines should I be looking for? At what point is bigger not better? I think I have the 56mm TB now.

[bszopi]

Any other donor engines will require an adapter to bolt up to a 3x00 plenum. There are some companies that bore out the stock TB to a larger size (60-62mm), and then provide a plate for the larger openings. Some of these cost almost as much as the billet TBs though, so its not really worth it IMO.

[Canyonero]

If I'm going to send my manifolds in to be ported, should I go ahead and get the throttle body opening enlarged for a future upgrade? Or will that just create excessive turbulence?

Will more billet TBs be made? Thought I saw it mentioned that TCE didn't have time to produce more 60º parts or something...

[IanSzgatti]

if I could just throw in my 0.2, if you bore now for the future you'll at least be prepared... second, it makes a super cool turbo type noise!!! I shit you not, it sounds awsome... anyways, I dont think it'll hurt you that much... sometimes you must take one step back to advance forward... this post was sensible until I started with the philosophy...

oh yeah... if the other bored out ones cost as much as the billet on this site, why not go with them.. after all, THEY ARE OUT OF STOCK... i've been looking for a few weeks and it's always out of stock...

[Canyonero]

The TB on my 3.4 already whistles during light to mid throttle.

So what about the second part of that question? How big should I go? Are there diminishing returns after some point or in certain applications? I mean, if 65mm is always better, why make a 62mm?

[SappySE107]

I will have more throttle bodies soon. They have been redesigned again to look better:P You can bore the plenum TB opening out and use a stock TB. It won't create any issue.

[ForcedFirebird]

There's an easy way to see if you need a bigger TB, all you need is a vacuum guage.

Start with the stock 3400 TB and check the vacuumm in front of the throttle plate (intake tube is a good place) and check the vacuum behind the TB. If you have more than 2" of vac difference, the TB is too small.

[Canyonero]

There's an easy way to see if you need a bigger TB, all you need is a vacuum guage.

I don't have a vacuum gauge, and I want to have the intake worked over before I pull the engine out of my Trooper again. I'm looking for educated guesses.

They have been redesigned again to look better:P

Good.

[Superdave]

There's an easy way to see if you need a bigger TB, all you need is a vacuum guage.

Start with the stock 3400 TB and check the vacuumm in front of the throttle plate (intake tube is a good place) and check the vacuum behind the TB. If you have more than 2" of vac difference, the TB is too small.

I prefer the WOT method...

Hook the vacuum gauge up to the port right behind the TB and route the line into the car, then drive around a bit. If you put the pedal to 100% while crusing the vacuum gauge should drop to 0.. If not then the TB is too small.

[Canyonero]

If WOT-Tech makes a 62mm and a 65mm, why would I buy the 62mm? I don't want to buy two throttle bodies just so I can compare vacuum test results.

[Superdave]

I'd just go with the 65...

I had one and loved it, very well built piece.

[ForcedFirebird]

I don't have a vacuum gauge, and I want to have the intake worked over before I pull the engine out of my Trooper again. I'm looking for educated guesses.



Good.

I bought a vac guage for $12

Dave, your method gives the same results.

[IanSzgatti]

buy the 65. ah ah ah.... just do it!

[IsaacHayes]

FWIW I have a 52mm (stock 3100) TB on my 3500 plenum (65mm opening stock). It whistles like a turbo at certain load/TP.

Using a water gauge tube setup thingie (brain dead right now) for vacuum small vacuum will be best for figuring out that stuff.

The 62mm is for engines that are not modified a ton. It was the original upgrade size, then 65 came out and it makes sense as the 3500 plenum is 65mm...

[Canyonero]

I'll be running that Crane H260 Cam, a ported intake, and hopefully headers. I think I'll opt for the 65mm.