PixelHarmony

Scott from B-Series Racing

That sounds pretty mean.

rmpage

Sweet vid. I'd get IRTB's in a second if there were a set for our car that was viable.

CCColtsicehockey

I would definitly get a set if they had a set that worked with the drive by wire.

peter_bigblock

Is there some kind of air filter that fits over all four tb's? I'd be all over it if they made one compatible with DBW.

peter_bigblock

. . . and a specific reflash to go with them, I suppose.

xizor

you'd probably have an air filter for each one, I think that's how s2000's run ITBs

Schizm

How is this advantageous? I could see how there would be less resistance b/c you are not pulling air through a bent/twisty pipe. However, it appears as though the hot air from the engine bay would be pulled in.

Also, I know that on the exhaust side of some cars use an X or H connection in their pipes to synchronize the individual puffs (if you will) to pull the next one behind it and create a faster flow. Wouldn't the same physics be applicable here? If so you would want all of the intakes pulling from the same pipe.

Hopefully someone can set me straight

rmpage

IRTB's make an engine MUCH more responsive. Normally, intake air has to come through the intake piping, clear the throttle plate, fill the vacuum in the intake manifold plenum, then make its way down each of the four intake runners before it even hits the cylinder head. With IRTB's you have a much shorter intake tract (just a tuned pipe several inches long), which results in an engine that revs much more freely. The video shows this effect nicely. At WOT, you should actually be able to see the intake valve opening and closing. It would follow that the intake would flow more freely as well, especially because each of the velocity stacks atop the IRTB's can be built to maximize charge velocity at a given flow rate/RPM (usually in the higher rev range for racing engines).

Also, IRTB's allow you to ensure that each cylinder gets the correct volume of air fed into it. When you're using a conventional intake manifold, some runners will get less charge air than others, based on what kind of internal turbulence the manifold's small imperfections generate at different volumetric flow rates, pressures, temperatures, etc. With IRTB's you have a way to ensure charging is much more consistent and much more uniform for all cylinders, across all conditions. Same reason why direct-port nitrous injection is better than a single dry fogger.

Basically it is a much more refined way of handling intake air, because it lets you control a lot more things. They are apparently a six headed bitch to tune though.

narci

This was what set the E36 Euro M3 from the North American M3 apart (and about 100 more horses)

sho-one

so with no air filter, is the engine more vunerable to damage?

Dan Martin

rmpage

Generally not an issue with race engines. Those things get rebuilt after almost every race anyway.

kwjustin89

So getting ITB's for a street car would be pretty stupid then if there are no filters?

Dan Martin

Yes, that would be very risky, although it's not hard to add an air filter.

Schizm

I also realized that the X and H pipes are for unimpeded flow. The advantage would be nullified once the air goes down each intake and hits a valve.

What kind of numbers would you expect from this? Is it more so the fact you can rev the engine back to the peak HP faster rather than actually raising the peak?

Dan Martin

Here's an RSX with ITB's: http://www.youtube.com/watch?v=L4EcWJi-ghE&search=RSX



Needs slicks to put that power down.

sauceman

aaronng

For engines like the K24A, filling efficiency is also partially limited by the size of the throttle body. So having ITBs would solve this problem. Also, for race engines they have intake slits on the bonnet so cold air can be drawn in. For a road car, a custom airbox is made to enclose all 4 throttle bodies and leads to an air filter.

The H connection in the exhaust is usually for cars with more than 1 row of cylinders, such as V6-V12 engines.

PixelHarmony

I wonder when someone will get rid of DBW on our cars... From what I recall we can put an Accord TB on our car to remove DBW correct?

rmpage

The ECU requires DBW so that VSA can modulate the throttle when it detects wheelspin. It also uses it to control idle speed and therefore HVAC as the engine needs a bit more idle throttle with the compressor engaged. There is no idle air controller on DBW cars (this is a good thing).

jpt

screw ITBs, i'm waiting for variable valve timing to get good enough that we don't need a throttle body at all.

aaronng

You mean like Valvetronic?

afici0nad0

bumping an old thread.

is the r&d on itb's for a tsx still on hold?

dbw and ecu configurations still the show-stoppers here? is the itb clearance in the tsx engine bay a non-issue?

ThirdLane

The thing is you sacrifice low end power production for big gains in peak power. ITB's would not make it a good mod for a daily driver since you lose the tactability of daily driver. but it is nice