ITB onto 16V... Does it really make any power ??

[jondee86]

I have read a whole bunch of stuff in this forum, and elsewhere, on
the advantages of swapping ITB's onto 16V's. But I have seen little
(next to none) hardcore documented evidence as to how much power
can actually be gained by this swap.

The fact that ITB's plus cams and a standalone ECU made an extra
600 rwhp doesn't help, cuz you can't isolate how much was due to the
ITB's alone

Soooooo..... has anyone actually done a before and after dyno run
that can show that ITB's are good for (insert number here) extra rwhp ??

Cheers... jondee86

[Grrrrrrr!]

ITBs are about throttle response/bling factor, not HP (generally speaking)

The throttle response comes from the reduction in volume of air between the throttles and the intake valves. instead of the engine having to suck the plenum dry or wait for it to pressurise it only has to wait for the intake runners to pressurise.

If you want more HP and better throttle response barrel throttles give both by putting the throttle right next to the head and removing the flow impediment that a butterfly valve is.

http://www.su77on-se7ens.com/4616/10701.html <- near the bottom

[jondee86]

Yeah... impressive motor that, and the inlet ports are at the right
angle for maximum flow.

Aftermarket ITB's have been around for several decades, and are
considered to be capable of giving power gains similar to those of
twin sidechokes.

So, while the sound, response and bling factors may rate highly,
there should also be some power gains from properly set up
Toyota ITB's. I have read claims of 15-20 hp gains, but never seen
a dyno chart where the only change from before to after was ITB's.

Cheers... jondee86

[Grrrrrrr!]

So, while the sound, response and bling factors may rate highly,
there should also be some power gains from properly set up
Toyota ITB's. I have read claims of 15-20 hp gains, but never seen
a dyno chart where the only change from before to after was ITB's.

That would all come down to how poor the intake manifold it replaced was really.. so could be anything from 0hp to 40+hp, it could also cost HP by removing the resonance of a tuned intake. Or put more power up top and leave a hole in the midrange.

I suggest trying it and seeing what happens

[rollaholic]

since you need an aftermarket ECU just to run the ITBs wouldnt it make more sense to transplant a blacktop?

thats my plan anyway

[d1 mule]

since you need an aftermarket ECU just to run the ITBs wouldnt it make more sense to transplant a blacktop?

thats my plan anyway

yup bang on the money, i think they do run with standard comp but the fueling is so different it makes less power. o think way less fuel down low and way more up high. so yeah a 20v would probably be cheaper/easier, but im assumine seeing as you have a mint NZ new 86 you dont want to ;1 pot a 20v in and 2, cut a whole in your firewall for the dizzy to fit.

[jondee86]

I already got some ITB's from a silvertop And I am looking
at going to an aftermarket ECU with coil packs and a crank sensor
for ignition timing. The ECU would be the Stage One upgrade to see
how much extra power (if any) could be squeezed from the standard
16V single throttle setup.

Stage Two would be to swap in the ITB's, retune, and see what gains
had been made. However, since there is some serious coin to be spent
on doing these upgrades, I'm asking around first to see if the potential
gains make it a worthwhile exercise.

Oh, and I have a set of cams (said to be good for 15 hp) that will go
in before I do the ECU upgrade

Cheers... jondee86

[rollaholic]

there are ways around messing with your firewall, i have seen several pics of japanese cars with the distributor on the other end of the engine, just as one example. some kind of conversion kit.

[ChaosAD]

Or you could use the dizzy as a cas and make up a low profile cap for it.
Would need an aftermarket ecu though.

Bigger issue would be the water lines.

One benifit of itb's is it would be easier to tune them to suit your cams etc.
But there aint enough room in a fwd to get the correct trumpet lengths

[Mr Revhead]

i think the ITBs would be one of those mods to help exploit all gains from other mods.
on their own the increase would depend on how restrictive the stock set up is.
and i dont think its all that restrictive. on a road car you prob wouldnt notice.

however its hard to tell due to the tuning changes needed.... is it the tune that makes the gain? or the ITBs? or a combo of both?

imo if your doing head and cams etc for competition or play engine ITBs would be worth it, there are gains in throttle response and straighter intake path.
for a daily, i dont think its worth the hassle.

however.... theres the "WOW ITBS!" factor
id do it for the hell of it