Are bored throttle bodies beneficial?

[Williford Racing]

Hey Jim,

I have been thinking about setting up a program to port all the way from the top of the tb. Only prob is getting a good shape for the tb blade and not creat a lip in the tb under the front edge of the blade. What do you think?

Rodney

[Competition CNC]

Hey Jim,

I have been thinking about setting up a program to port all the way from the top of the tb. Only prob is getting a good shape for the tb blade and not creat a lip in the tb under the front edge of the blade. What do you think?

Rodney

Rodney,  yea you def dont want any lips in there.  Blending like that is the way to go... you have the same machine we have so you should be able to do it.  Mounting the throttle body and getting repeatability is key.

[speedduck]

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.

How did this work ? I know the performance result, but what was the difference in power ?

[entropy]

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.

How did this work ? I know the performance result, but what was the difference in power ?

what performance result are you referring to???

[speedduck]

I thought you installed throttle bodies before Zack and Colt did their runs. Well, it`s not the first time i thought wrong. I`m curious how it changes power and AFR curve, just installed my own modified big throttle bodies and it felt ok, but needs tuning more than just the upper revs.

[Jonny Hotnuts]

One of the problems I have found with bored TBs is the OEM TB limitations and inherent problems with trying to oversize the stock TBs.

I dont know if this has ever been done but I think a really cool experiment for someone (*other then me!) to try is to ditch the 4 individual TBs, build a 4-1 manifold with injector bosses, and use a single larger TB. There are a poop ton of different TBs available from places like summit racing for 2-3 hundred.

I did the math and the (4X) 49mm busa TBs = 7543 total square.
A single 100mm TB would equal 7853 total square.

The longer runners of a 4-1 manifold would likely loose some low rpm HP but make it peaky on top (I dont know if longer runners would make any difference to a turbo).

Could yield some interesting results.


WHOSE GONNA TRY IT!!!!!?????

~JH

[entropy]

the bigger TB's lost a lil hp at peak tq, but gained 4-6 from 9-11.5k.

motor w/stock bodies starts dropping hp at 11.1, big bodies makes it keep climbing to 11.5 (limiter)

AF had to be adjusted everywhere.

[speedduck]

Ok, thanks. I had max hp at 10.4k ,let`s see how it changes with TB mod. Now AFR varies from 11.9 to 13.5, not in any logical order. TB`s are now 51.5mm where stacks are fitted, 49mm blades, 43mm before rubber to head.

[entropy]

I'm now running Carpenter's new short intake head and big diameter headers:

On Johnny Cheese dyno:
BC 1635 Kit with standard BC race head = 270-ish DJ hp

BC 1635 Kit with new style BC head & headers = 281hp (Greenie was config-ed this way when I sold her)

BC 1635 Kit with new style BC head & headers & OS TB’s = 285hp (next week the Salt bike is going to Bonneville set up this way)

I'll be selling/parting out the salt bike after world of speed.

Karl

[speedduck]

I gained 3-4hp with oversized TB`s, let`s see how they work on a mile. We use DIN standard measuring power (Dynostar) and now i`m about 30hp behind Greenie, that feels almost light year, but few things must be compromised to retain streetability.

[entropy]

, but few things must be compromised to retain streetability.

you mean you want to idle below 2000rpm?

[speedduck]

, but few things must be compromised to retain streetability.

you mean you want to idle below 2000rpm?

That is one thing, dyno guy starts to pull from 2000, so it has to be under that 
Another is that i have to use mufflers with noise killers on the street, otherwise i lose my plate if police catch up. Today, if it`s not raining, i`ll put my girl (woman) on the backseat and we go touring the countryside.

[speedduck]

http://www.sbdev.co.uk/Hayabusa/Hayabusa_fuel%20injection%20kits.htm

[badass1000]

http://www.sbdev.co.uk/Hayabusa/Hayabusa_fuel%20injection%20kits.htm

those look like alot of work and money to get them setup and working correctly.  I don't like how the gen 2's only use one set of different aftermarket injectors.  I guess it would be pretty nice if you were useing a standalone aftermarket ecu and were only runing one set of injectors.  Doesn't look like you can use them with stock air box either.  If you did use the stock air box you would have to cut them up pretty good and mount the plate to the stock air box.

Any idea how much they are?

[Malvina]

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.

**************************************************************************************************************
How complicated was to adapt the T/B GSXR 1000 K7 / K8 on a Busa? Any suggestion to make?
And how many HP could I win with this modification ?

[Malvina]

I'm from Argentina and I have a query, depending on your experience and knowledge

I have a Suzuki Hayabusa 1300 model 2006, equipped with: - Power to commander III + Power ignition + Hub + airbox modified + Air Filter K&N + - Exhaust complete Muzzys (4 to 1) + - Velocity stacks, Race (all short, 41 mm) + Wiseco Piston kit stock bore 81mm 13.1 to 1 + Elimination counter balancer + Intake cam on the exhaust (2 cams intake OEM) + cam sprocket adjustable + Scoop ram air + seal, ram air tubes (Carpenter) + chains EK 520 zzz + ECU Flash
Nowadays it got 206 HP in the rear Wheel with final speed in 335 kmh (210 mph).

My question -->
I would like to fit a 48 or 50 mm diam. throttle bodie. I’m looking for power in high Revs (from 8000 RPM)
What do you suggest? And how many HP could I win with this modification ?

Throttle bodies in study

a) Trottle bodies Suzuki 1000 K7 / K8 ?
b) Trottle bodies Kawasaki zx-10r 2011/13 ?
c) Others

Any suggestion to make?

Thank you very much

[fvance]

I don't think you would see any benefit with bigger TBs on a 1300, could possibly lose some HP. On my 1350 motors I use 1/2" shorter velocity stacks made by John Hartley. I get 3Hp out of them and it moves my max hp up about 500rpm.