ITBs on a street car

Is there any reason that running individual throttle bodies would be a bad idea on a street car?

BMW has done it plenty of times, Toyota 4AGE 20Vs, and I'm sure more than a few other cars.

I forgot about the Toyota 4AGE 20V and also I know a lot of bikes do it. Does it really give that much extra power to be worth the work?

just make sure to install some sort of air filter setup...

because they're typically mounted to very short intake runners, they kill low-end torque. motorcycles can get away with it because they need to make power to 14k rpm. your civic does not.

I must have forgotten to select the versions that kill low end torque Both of my engines that have been converted to individual throttles maintained the bottom end and gained up top. Not huge amounts, but we're talking naturally aspirated power. 10% gain or so.

But the biggest problem with them on a street car? They're LOUD. Not necessarily in a cool way, but they make an incredible hammering noise. I've tried running with a plenum, but that didn't help much. You can even hear the faint echoes of this hammering on my M5, muffled by acoustically engineered plenums and a thick insulation pad on the hood.

They're also a bit crotchey, but it's no worse than a hot-rod Mini on SUs in that regard. Come to think of it, the noise isn't much different.

exactly.. think of them as IDFs on an older car.. but more sophesticated with fuel injection...

All the benefits, none of the disadvantages

I'm installing a pair of ITB's on one of my 240Z's. Converted the SU's to dual ITB's using the factory SU intake manifold keeping the runners exactly the same length as they were with the carbs. It's not finished yet, but shouldn't have any loss in low-end torque. Depending on the ITB setup, you can gain low end torque.

My father's old 260z used an odd intake with a single Weber IDF.. I think it was a 44. Basically three cylinders fed off of each throat. Made for some awesome noises and acceleration

One of reasons you don't see ITB on more production cars is that you give away a free source of vacuum.

The whole engine tuning, PCM tuning, etc- can all be overcome. Heck, even MS does a good job with the blend between throttle and pressure maps.

There are a lot of things that use vacuum to operate, so it's hard to give it away. And that source also makes purging easier.

But if this is a toy- go for it!

Eric

I was just thinking out loud. Don't think I am really doing to it.

ITB <3 I'd risk the noise, I want them, now them vs turbo is my issue

the biggest problem with ITBs is the same problem with any multi carb install.........

syncronization

NickF40 wrote: ITB <3 I'd risk the noise, I want them, now them vs turbo is my issue

Do both, problem solved.

Ahh there we go! Instead of ITB's, I believe in the bike throttle bodies, 2010 R1 TB's for $80 hell yes!

The Dellortos on the J-H (basically 4 long ITB's with float bowls in between) have a 'bullfrog' sound which has a 'hammering' undertone to it. It doesn't lack bottom end, in second gear it will pull away easily from a stop.

m4ff3w wrote:

NickF40 wrote: ITB <3 I'd risk the noise, I want them, now them vs turbo is my issue

Do both, problem solved.

like this? http://www.youtube.com/watch?v=hbcRRPAcwWg&feature=related