Are bored throttle bodies beneficial?

[tyboogie]

Understand this has been spoke on before, but are the bored throttle bodies for the gen 1 worth it. I see at leats 3 builders advertising them RCs, Lee, Carpenter.

[Johnnnycheese]

your ? is flawed.
it is like asking is a thropy wife benefical?

in otherwords add the following
what,bore head and cams?

[tyboogie]

1397 may go to 14441, or 1507..head 405 in 395 ex cams

[moparict]

1397 may go to 14441, or 1507..head 405 in 395 ex cams

Post pics of the 14441 build!!!

[Johnnnycheese]

1397 may go to 14441, or 1507..head 405 in 395 ex cams

not worth the money too small cams and bore

[Penianator]

14441 bore!! I think you need more than bored throttle bodies 

[entropy]

...it is like asking is a thropy wife benefical?

I've been wrestling with that question myself. 

[TROUBLENC]

Going to the dyno soon with bored throttle bodies will know results within a week with the same motor and cam combination as mentioned above

[Johnnnycheese]

...it is like asking is a thropy wife benefical?

I've been wrestling with that question myself. 

That was wife #1 Karl
I up graded and cost me less money

[tyboogie]

Thanks to all with helpful info, and to those with the unnecessary comments please stay off the thread. Anyone can see it was a typo guess some people don't have anything to better to do.

[Pat Dietrich]

Thanks to all with helpful info, and to those with the unnecessary comments please stay off the thread. Anyone can see it was a typo guess some people don't have anything to better to do.

Are you kidding with that comment?? Its the internet bro. Its full of jokesters like myself

[tyboogie]

Pat I understand that, and it's all good. , but unless I have had some sort of a prior contact with someone I keep my comments to myself even if they are a just kidding sort of thing. Just me showing respect. I just have to deal with at least one  a day and had just wanted some useful info...Never have had any contact with the other two..

[entropy]

Thanks to all with helpful info, and to those with the unnecessary comments please stay off the thread. Anyone can see it was a typo guess some people don't have anything to better to do.

twisted knickers, eh?

Cheese was asking a a real question, which you sort of answered.

What's the issue?

BTW:  I am getting ready to test a set of oversized Montogmery TB's & custom Hartley stacks against stock TB's on a maxxed out 1635 Carpenter kit.  Unless yr stacks are OS to match the TB's...

[Penianator]

All in good fun ty...if im the worst ahole you meet on here, then you haven't met kirk   so...my appologies.....but ya might wanna loosen up some. And by the way.....im 5'10  medium build and I like long walks on the beach. Lmao, now you know me

[tyboogie]

Entropy was just seeing if the bored TBs worked or was just hype... Pen well since you put it out there just to let you know I am not a cheap date...lol

[Johnnnycheese]

Entropy was just seeing if the bored TBs worked or was just hype... Pen well since you put it out there just to let you know I am not a cheap date...lol

what part of my answer didn't you understand.  IT IS NOT BIG ENOUGH, IT IS NOT BIG ENOUGH,IT IS NOT BIG ENOUGH,IT IS NOT BIG ENOUGH,IT IS NOT BIG ENOUGH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Damm don't ask a question if you do not like the answer

[Jonny Hotnuts]

The problem I have seen with bored TBs is that while increasing the internal volume would seem like an automatic way to gain HP especially on bigger ccs what happens is:

1-The profile through the TBs is changed.
2-Those '3 ridges' inside of the IN side of the TB are trip fences, designed to induce turbulence before the butterflies are removed.

Changing the profile of the tbs and removing the trip fences will lower HP....but after a while the bigger displacement/cam combos can benefit from the larger cfm values.....
But personally for these reasons I would not be surprised if people seen a loss with bored TBs on many applications.

Ideally....if there was a way to make an exact copy of a tb just a few MM bigger without changing profile or trips, along with properly matched cams, larger displacement, head porting, valve size (*and here one never discussed) but ALSO changing the distance between TB and head will all have a difference.


~jh

[entropy]

bahahahahahahahahahaha
now johnnie has his knickers in a twist.

Hey JC, Carpenter is with you, he said even a 1635 doesn't really benefit from OS TB's or OS valves.

But we'll find out if a 1635 with his new short intake head & bigger valves & even bigger cams works better with OS TB's.
It be a direct comparison with Greenie's (stock TB's) NICE results on yr dyno a couple mo ago.
Can a 1635 make even more hp???
We'll see in less than a mo. 
Karl

[tyboogie]

Ok Johnnycheese I was just replying back to Entropy about why I asked the question. I understood from your 2nd reply that with my current setup it would not be of much help. I do not understand your last post, me not liking the answer? Who said I did not like it?? I know I did not reply back insulting your experience with the TBs, so why the last post?

[entropy]

...
Ideally....if there was a way to make an exact copy of a tb just a few MM bigger without changing profile or trips, along with properly matched cams, larger displacement, head porting, valve size (*and here one never discussed) but ALSO changing the distance between TB and head will all have a difference.
~jh

JH,
that's the experiment we'll be doing on JC's dyno.
(matching the stacks to the TB's is also an issue, solved by a call to John Hartley)

I'm building that motor right now, woo-HOO!
Experiments are cool.

[Jonny Hotnuts]

JH,
that's the experiment we'll be doing on JC's dyno.
(matching the stacks to the TB's is also an issue, solved by a call to John Hartley)

I'm building that motor right now, woo-HOO!
Experiments are cool.

I dont know if John has developed an airbox for the V but without helmholtz these engines loose a good 10-15%. All the pics I have seen have open stacks.

BTW:
I have a set of thin wall TBs if you want to experiment.

~JH

[glenn71]

i port matched my gen1 throttle bodies to k7 gixxer 52mm short stacks,prob affected torque but i dont need more torque on my 1507 swb,the hp up top is pretty good.Turbulence is for torque,flow is for hp when the rpm allows the port speed to create sufficient combustion turbulence,so pick your priority with the build and go with that.

[Competition CNC]

In our testing we have seen power gains with our bored 47 mm throttle bodies on stock zx14 engines of 8hp.
On a built 1570 we have seen 13 hp.   Dan Millholland among many other people will confirm this.

On the gen 2 busas replacing the 44 mm units with our 47mm units will pick up about 6 hp on a stock motor and 13 hp on a busa motors with a ported head and cam. Cecil at HTP is one of many that will verify this as well.

Now here's the deal.  All bored throttle bodies are not the same.  Ours are bored all the way threw and are never smaller than the butterfly diameter. There are at least two laces selling "bored" throttle bodies out there that have the stock size blades or they leave a huge lip in the bore.  Don't even waste your time with them.  We tested them and they don't do a damn thing.
If there is any part of the bore that is smaller than the dia of the blade then don't waste your time with them.

With that being said,  the gen 1 busa throttle bodies are 46 mm stock and there is very little gain with going to a larger bore on the gen 1 busa throttle bodies ON A STOCK MOTOR.  However, on a built motor of 1507 or bigger there is a gain with going to the larger throttle bodies.  And the more radical the head and cams are the more power you gain. 
Again, they have to be done properly and have smooth bores of no less than the new over sized butterfly diameter.

[entropy]

hey Jim, great info.

The Montgomery OS TB setup i have is:

52mm top of the Hartley stacks where they start to bell out

51mm at the TB/stacks connection

49mm at the blades

below the blades there is a tapered section, goes  from 49 down to 44.8

44.8mm where they go into the head.

You think that config will work any better than stock TB/stacks with Carpenter's short intake/big exh head & 465/425 cams, 18.3-18.5:1 CR??

One of these days, i'd like to try yr new big exh head 

[speedduck]

So, is it any good to open up std gen1 bodies after butterflies to 46mm ? Of course matching the head to it, with 1507cc, .433/.415 cams.