Bigger Throttlebody

[BFHOON]

kick it to me.

dosnt work mate sell it to me cheap.

[RAP1D]

If it's a larger diameter than the opening in plenums flange then there's no point using it... May accually cause turbulance and make less power.

But only way to know is back to back Dyno testing.

[JVK]

If anything you would lose throttle response off boost due larger throttle body and slower intake air speed.

[Ralph Wiggum]

BCL car made 5++ (forget exactly how high his final power figure was in the old blue beast) with the stock throttle body.

IMHO they look cool thats about it.

There's a excellent article on autospeed about swapping throttle bodies if anybody can be bothered to dig it up

[bcl]

I feel the closer you are to a standard system, piping, intercooler ect, and lower boost levels the more likely it is that this a complete waste of money.

With continous new products available over the past 5 years we have had improvements in the state of tune, fuel economy, power delivery and peak power.

I think it is too narrow a view looking at just peak power as an objective.

The throttle body is just one small component of the inlet.

Focus more on intercooler, especially end tank sizing, and with low pressure drop across the core, as this is far more important an issue. Also the less piping in the system the better.

Your conclusions will be only relevant to those that have a lower level of restriction in the inlet prior to the plenum. I say that because people with more restriction than you should focus on other factors first.

About 4 years ago I remember there were idle issues associated with these units, so I'd assume that has been resolved since then.

Ensure that your tuner does not adjust throttle sensitivity when tuning, as that would invalidate results. I.e make the throttle more sensitive to make you think it is more responsive.

Both my F6's still use standard throttle body. I've just never got around to testing a larger unit.

My gut feel is that it will make bugger all difference on a boosted car, but I also keep an open mind, so by all means do a test if you are prepared to fund the exercise.

Brian

[typhoon_freak]

well I shuld be doing the dyno run with a new plenum, so it will be prety much the last standard thing in line to the engine.. so I shuld find out soon. I think the standard size is 70mm, and the new one is only 75mm. they look a bit different when u compare the openeings together. but yeh. shuld be a good test, but if I see 5-10rwkw. I will still be happy, just dont want it to go backwards with turbulant air

[mic]

stock t/b is a little bit smaller than 3 inch, so unless u have 3 inch pipework dont worry bout it. if u do I think u will see a small gain. imo a bigger t/b is the least important thing. only when u are really tryin 2 squeeze those last few hp out with real big pipework will it be necessary.

[koppers]

Just measured up the ID of both a Process West plenum intake channel and SS Inductions TB I have sitting here and both were 72/73 mm. Unsure of the ID of standard (think it is indeed a bit smaller), but as said above, matching the piping will aid in dynamic flow. Spool and available air at WOT are the obvious advantages.

[Guest]

Will you be measuring the standard & new TB after the plenum is installed TF??

[typhoon_freak]

was going to do both.. once b4 the plenum and once after..