For those of you that aren't on other boards very much I present.
http://my350z.com/forum/showthread.php?t=306264&page=6
I didn't think these guys were actually gonna come through.

 

Meh, they said they gained 40whp on a stock motor...after a standalone tune. For all that money, I don't think it would be worth it....also not knowing if the standalone tune was the majority of that 40whp.

But an advancement nonetheless....good find Broan.

 

still not much info on it. i remember reading that thread earlier and i figured it was dead. at least SOMETHING is coming from it. ill wait for more details to make a judgement though

 

You can't judge ITBs on the basis of power per dollar from one dyno chart on an otherwise stock engine.


1. ITBs need supporting mods. The bare minimum would be big cams, an extended rev limit, and a free flowing exhaust. If you don't have those, the low-end losses won't be worth the high-end gains so it's not worth even talking about. However, it is a good bet that if they make 40hp on a stock engine, they will make a LOT more with supporting mods.

2. Power gains are not even the whole point of ITBs. The point is power plus lightning-quick, razor-sharp throttle response. Nothing can touch them for that – not even the freakish infinitely variable valve control that BMW and Infiniti just rolled out, hence why BMW's M engines still use ITBs.

3. Unlike forced induction, ITBs don’t require any additional oil, generate any additional heat, create any additional drag or inertia in the engine or exhaust, or add any additional weight on the front end.

4. If you do want forced induction, ITBs can make it even better. All you have to do is build a plenum around them and feed the charge air into that (<cough>RB26DETT</cough>).

 

BMW's M5 V10 is "small"? Or are these not ITBs?

 

Looks like it to me

 

...I never said the smaller engines were the ONLY M engines that used ITBs.

But either way, my bad. I had forgotten that the E60 M5 used ITBs as well. Post edited.

 

you listed the boosted with common plenum, but the m5 uses a common plenum as well, i dont see why we couldnt build a custom plenum around THESE ITB's and connect that to an intake pipe so it would be possible to retain stock ECU control. obviously, going with a standalone would be a lot more useful and if youre getting ITB's you probly already have a standalone. but for some people, getting a common plenum w/ITB's and a stock ECU might sound nice. it would, after all, increase driveablility if its on a stock ECU

 

You're right, that would probably work. The only question would be whether a plenum of useful size for NA would fit under the stock hood, but boosted guys would be fine either way.

 

I imagine if BMW can make it work, so could others. Unless these ITBs are too tall to fit a plenum. From what I see, the M5 plenum comes pretty close to some of the sides of it's ITBs. As long as it doesn't shroud the port or force a restricting airflow, it should be okay.

FIY, I've seen a carbon fiber plenum over a set of Nissan Z ITBs already. Can't remember if it cleared the hood but I believe it did.




http://www.worldcarfans.com/7060726....35-coupe-cpv35

 

arent those the topsecret ITB's? wonder if they cleared the hood. that looks a little taller than stock, but not much

 

Found on Europeancarweb.com:

Looks like you're right. It can work with limited space. It just has to be shaped correctly.

 

yeah, definitely doable. it wouldnt be better by any means, but would certainly be easier to deal with

 

After seeing the Top Secret pics again I'd be willing to say that this new setup is better at half the price. Top Secrets runners are not as straight as the new design.

Slightly OT. Never noticed this before but its interesting to see that the almighty TS decided to do away with VTC. Why would they not use 30 chain covers then?

 

yeah, theyre gone in the first pic but not the 2nd, not sure wtf's up or why they would even do that, not like there is power MADE by that

 

My point was more aimed at the fact that there is a well respected tunning shop removing vtc's on their projects. I found it interesting because people on this board love to give sooo much **** to members that opt to go the stationary cam route.

 

Same reason there are VTEC killer kits for hondas. When you're at high RPM (beyond the stock redline) 100% of the time in a track environment variable cam anything isn't necessary. Anything short of this driving condition and VVT has its merits, no doubt.

 

This board is for family cars, not race cars that live at high RPMs all day. That's why people get roasted for compromising usable torque just to shave off a small amount of valvetrain mass. This Top Secret car is a different story.

EDIT: Damn, beat to it...

 

like everyone else has said, its not an issue for topsecret because of the nature of their engine. they can also drill th cams any way they like in-shop to make them perfectly match the powerband. most people here cant do that and must live with a certain balance of max power and driveability. that means that when compared to the vtc'd engines, they make less power everywhere except a small range where they might make equal and unlikely but possibly more