azmi951

I searched and came up with a thread from 2003 about bigger throttle bodies.

Is there another throttle body out there that is larger that flows better or is it not worth the extra $$ and effort?

Our throttle bodies just seem to be a bit small and the intake has a large opening on the throttle body flange that could allow some growth of the throttle plate.

Is there power to be gained here???

mark944turbo

No worthwhile power to be gained, making 500+ with the stock throttle is possible.

special tool

Yeah - its one of the last things to do. I have a completely stock TB on mine - recently rebuilt with Arnworx kit.

First thing to do on a 951 is change out that silly little turbocharger.

ENGINEERMAN

An engine is an air pump. The idea is to move more air so that you can burn more fuel and get more power.

The elements involved in potentially creating restriction (pressure drop) are (for a given/fixed bore & stroke & working backwards):

1) The head and valves
2) The Intake Manifold flanges and design
3) The Throttle Body
4) The hard pipe down stream of the InterCooler
5) The intercooler itself
6) The hard pipe from the turbo outlet
7) The turbo exhaust side and down stream exhaust system
8) The headers and cross over pipe

This is a simplistic description I know but let's say that you are running 18 psig boost. It is fairly well documented that you want to minimize the feed pressure to the turbo so that it is almost equal to the boost pressure if everything is well matched. With that said, meaure your pressure in the following locations and you will get a picture of how well the components are matched.

1) Pressure in cross over pipe
2) Pressure between turbo outlet and the intercooler
3) Pressure between the IC outlet and throttle body
4) Pressure in the intake manifold

By knowing the pressures at these points you will know whether the IC is causing a restriction or the Throttle Body. On my car with 18 psig at the intake manifold I am pushing 36 psig in the cross over pipe. This is a 2:1 ratio so I think that either my IC is too restrictive or the Throttle Body, or both. Having the 36 in the Cross Over is causing things to back up in the cylinder and causing the turbo to work harder and the engine to breath less. I think that I could benefit by reducing the pressure by creating less restriction through the IC and possibly the Throttle Body as well.

I am running a k27/8 turbo. anyone see any flaws in my logic? Please advise.

Thanks!

AL951

What do you have on the exhaust side? (test pipe, cat, no cat,3" downpipe)..the exhaust pressure looks a little high.


Regards,
AL

hosrom_951

Reliable sources informed me that the stock trottle body flows 450CFM and there is no need to go bigger, please don't bash or pick what i say, this is the info i recieved from them when i asked why don't they sell throttle bodies.

SoloRacer

What about independant throttle bodies? How are the gains acheived with them if it's not to do with the actual flow of air?

MPD47

ITB's are generally used to increase throttle response, sometime to equalize flow. If you want to equalize flow buy the Lindsey Manifold or have your stock one cut open and hogged out. There is very little throttle response to be had from ITB's on a 944 Turbo. Again, one of the last things you should be worrying about.

mark944turbo

"There is very little throttle response to be had from ITB's on a 944 Turbo. "

Where is that info coming from?

azmi951

Thanks for all the responses. It seems like a good test would be to measure the delta P across the throttle body at wide open.

SoloRacer

So are you saying that you disagree with Milledge's assesment on the benefits of his intake manifold with independant throttle bodies?

Guns951

So would I be spending $5600 on looks or actual function? NOT DOUBTING YOU TOOL, MPD47 OR HOSROM, just asking a question..... I mean even its its just for looks, this thing looks badass! This is how you set yourself apart at shows I would assume?!?!?

**Edit** Assume on a motor with all appropriate mods such as a standalone, MAF, 4 to 1 Headers & modified exhaust, Tial 46mm wastegate, fresh block built up to a 3.1ltr etc. I'm starting a list of motor mods and even if its just as good as the Lindsey unit - I'm seriously thinking about this just to be different...any potential drawbacks? I'm looking for an overall better design, reliability (if you can even say that when concerning a motor like this), and function, price not a factor in this equation.

I know the electrodyne car has this setup (similar too) is there a reason they did this as opposed to just casting a different intake? Is this just an "old school" antiquated way of redoing an intake mani?

special tool

I was talking about the difference between stock and a bored out stock TB only. It is one of the last things to do.
No doubt that this Milledge unit increases throttle response and probably high end also.
I believe even Milledge claims that it will give 20 HP at over 400 RWHP level. So you can see that even he thinks that his unit is one of the last things to do.

Guns951

yeah, I'm one of those...let do the project from start to finish before we start kind of guys - gettin' my list in order! Although I know there will be 8 billion things I didn't look for when i build it...but hey the suprise is the fun part right? special tool

hosrom_951

I was also referring to this, but i don't have a flow bench, nor have i flowed a stock 951 TB.

I don't want to start 'this vendor said this' crap, but this info is what they told me, so i shared it.

PM me if you want to know who mentioned this to me, don't want to start anything