4agte 16v itb or tvis

[DR86FT]

What will be better to use on my 4agte itb's or rwd manifold or neither?

[Cerby86]

Itb's are harder to tune, plus harder to fit into the bay plus more custom parts. If it all comes together right I'm sure they will be a good thing but you could probably get bigger power gains spending the money elsewhere and also have the KISS benefit! Of course if your doing a balls out build with the best of everything then go nuts!!

[DR86FT]

Itb's are harder to tune, plus harder to fit into the bay plus more custom parts. If it all comes together right I'm sure they will be a good thing but you could probably get bigger power gains spending the money elsewhere and also have the KISS benefit! Of course if your doing a balls out build with the best of everything then go nuts!!

Yeah its a decent build i have both can always change it back :-D
will have enough time and materials to get it 100%

just dunno what ecu to run it all

[Sam-Q]

I can't see it making a difference in the power, I don't think it's worth the trouble.

[DR86FT]

I can't see it making a difference in the power, I don't think it's worth the trouble.

Was thinking it might be better flow and response

And other cars such as gtrs rb26 come with itb's must have a reason behind it

[TODA AU]

Response is better, marginally.

[FAST EDDIE]

also if you dont have a well made plenum for the itbs you will run into issues with leanout in cylinders

[slide86]

going by more of a scientific approach, if you measured the surface area of all 4 throttles and compared the surface area of a stock rwd throttle body, you could technically justify the airflow into the engine????

Of course its not that simple, but people can understand where i am coming from? you would need precise supporting mods ie size of plenum, cams, head and exhaust system to reap the full benifits....but

size of the throttles on ST20v are 42mm at the choke? thus, using the formula for surface area (Pir2) we can determine that the surface area is 131.94 mm2, times that result by 4 to get the overall surface area of the combined throttles = 527.76 mm2

the diameter of a RWD throttle body is 55mm, and the surface area is 172.78 mm2.........alot less than the quads

someone correct me if i am wrong...........this is the way i see it. But like i said, there are so many different variables that this maybe made redundant in the long run

[Sam-Q]

yes its as you said a lot more complex, this is because the main single throttle body can allow for the pulse of one cylinder after another in a row, but the diameter of the individual throttles has to be big enough to deliver the whole airflow of a single cylinder at once. This is much like how the secondaries on extractors are only a little bigger than the primaries, if the pulse had to exit at the same time though it would be a different story

[Sam-Q]

Was thinking it might be better flow and response

And other cars such as gtrs rb26 come with itb's must have a reason behind it

got to be response, however I think with a 1.6L engine off boost it won't help much, well unless you have a reasonable compression. As far as I know almost all japanese tuners turf the throttles when doing work to the engine, that's not to say it's a good idea though.

[stefan]

In my car i kept the itb's but only cos they're there, its a 20v head, no real benifits, if it was n/a build then yeah i'd go itb's but not for turbo, and yeah rb26's have them but when they make big power most people go to single tb, but at the end of the day it's your car so build it how you won't, i'd personally spend the money elsewhere.