Bored Out Throttle Bodies

[DaveInDenver]

I'm considering rebuilding my throttle body this spring (something I should have done last winter, but I didn't). What that means to me is completely disassembling it, properly cleaning all the passages, cleaning the AAV and replacing the gasket, etc. So naturally that would be the time to consider replacing the TB with one of those bored out numbers. LCE claims theirs increase air flow by 12% over stock. Intuitively, sure it seems more air in the better. But does it do enough to be worth the money ($300)?

http://www.toyotacatalog.net/M1WebG...UniqueID=6083260B-A038-4F69-812B-AA1273165E87

 

[Uncle Ben]

On fuel injected motors more air = mo powa! You might consider sending you TB out to have it ported and flowed! Prolly be about the same price. That doesn't seem like a bad deal at all. At least you will know that it's still Toyota quality vrs a possible imported knock off! You will notice a difference!

I'm considering rebuilding my throttle body this spring (something I should have done last winter, but I didn't). What that means to me is completely disassembling it, properly cleaning all the passages, cleaning the AAV and replacing the gasket, etc. So naturally that would be the time to consider replacing the TB with one of those bored out numbers. LCE claims theirs increase air flow by 12% over stock. Intuitively, sure it seems more air in the better. But does it do enough to be worth the money ($300)?

http://www.toyotacatalog.net/M1WebG...UniqueID=6083260B-A038-4F69-812B-AA1273165E87

 

[DaveInDenver]

On fuel injected motors more air = mo powa! You might consider sending you TB out to have it ported and flowed! Prolly be about the same price. That doesn't seem like a bad deal at all. At least you will know that it's still Toyota quality vrs a possible imported knock off! You will notice a difference!

More info about who to send it to. Is this a local thing? I assume anyone who can bore them out would also have a source for the oversized butterfly, too?

FWIW, LCE bores out stock Toyota TBs. They charge you a core for your old one and you are getting someone else's that they worked on.

 

[Uncle Ben]

Here's another source for you for an exchange - http://toyota.off-road.com/toyota/article/articleDetail.jsp?id=306002

In the past I have had them sent to RC Engineering but they only work through someone with an account and I don't know anyone that has one right now. Christo might....check with him! There are several companies that do it but I have no experience with anyone else.

You can polish one and mildly smooth it but in order to bore you have to have CNC mill for both precision boring and also shaping of the new throttle plate.

 

[J Kimmel]

had an LC on my old 3.0, not much difference IMO and definately not enough for the cost! I figured if it gave just enough extra to help up the pass, great but it wasn't so...

 

[Uncle Ben]

had an LC on my old 3.0, not much difference IMO and definately not enough for the cost! I figured if it gave just enough extra to help up the pass, great but it wasn't so...

Like rejetting on a scooter if you don't increase the flow going out you cannot increase the flow going in! Should have mentioned that before. Increased air flow requires increase exhaust flow to add much benefit! If you add anything else like cams, larger pistons etc....the increases will also be greater. No, swapping on a bigger TB will not turn a slug into a tire smoking monster but it will usually widen your torque band and increase your top end. ....and of coure your results may vary.....

 

[DaveInDenver]

Like rejetting on a scooter if you don't increase the flow going out you cannot increase the flow going in! Should have mentioned that before. Increased air flow requires increase exhaust flow to add much benefit! If you add anything else like cams, larger pistons etc....the increases will also be greater. No, swapping on a bigger TB will not turn a slug into a tire smoking monster but it will usually widen your torque band and increase your top end. ....and of coure your results may vary.....

UB hit why I'm even considering it. Already have a header & 2.25" exhaust, mildly ported head, bigger cam. So it's part of the system (also thinking about finding a Supra AFM). The one thing I'm not gonna do is a K&N filter.

 

[Crash]

Dave, thanks for the lug info and here's your payback:
A handful of years ago, Robbie rebuilt the 3FE in the 62. All new OEM parts including the largest pistons available and a new OEM cam was installed. The head was shaved .060" and was gasket match ported and polished as were the intake and exhaust manifolds. Injectors were treated to an RC Engineering clean and balance. Power increase of all that was easily noticeable and satisfying. Next up was a complete exhaust system replacement with a 2.5" single cat/single muffler replacing the OEM nightmare. Another boost to the seat of the pants. Zero to the tunnel times were considerably reduced!
Then, on a whim, I sent the TB to Downey to have it bored. When it came back, the new butterfly sported RC Engineering's logo. Hmmm. Anyway, and I'm not exaggerating, with the new TB installed, the power increase was of the same magnitude as the rebuild/exhaust changes!!!! Seriously. Those changes were crying for more air and the bored out TB was the answer. Great $300 expenditure in my case and it may well be for you too.
I have since sent several 3FE listers directly to RC Engineering for TB updating and they have all been serviced without any sort of shop affilitation or account. Their website, as I recall, doesn't specify TB boring as a service but a call or email should get you the info you need. All who have used RC's service have been very pleased.

 

[DaveInDenver]

Well, there you go. Downey gets $294 for their service. I forgot, I did have Witchhunter do the fuel injector service and my head does have oversized valves, too. Sure seems like between what Crash and UB are saying that a bored out TB makes sense. Dang it, how is it I seem to be so darn good at finding ways to spend money? Must have too many X-chromosomes or something.