Im looking for something a little more unique then a turbo for the 7m i want the sexy sound of itbs on a 7mge so does anyone know where to find some cheap ones or how to make some for cheap?
ITB's anyone know where to get or does anyone make?
- Thread starter Setsuko37
- Start date
Before you go slapping on itb, you should research the effects they will have on the power curve and what other supporting modifications are required to actually benefit from using them.
They significantly shorten the intake runner length which will really decrease low-end torque, but they will increase high rpm performance as long as the engine is tuned properly. On a stock 7m with stock cams etc. they won't provide much of a benefit, so you'll end up losing a significant amount of the stock 7m low-end grunt at the expense of a little bit of top end hp. Not worth it imo. The only way you will really benefit from them is with bigger cams, internals with higher compression, and a really good header with 2.5" exhaust and higher rpm operation. Collectively these all work well, but not each component on it's own. I wouldn't build them cheap either because they need to be a specific length, diameter, taper, location of tb's etc... to make them work properly.
Were you planning on doing a higher hp NA build?
They significantly shorten the intake runner length which will really decrease low-end torque, but they will increase high rpm performance as long as the engine is tuned properly. On a stock 7m with stock cams etc. they won't provide much of a benefit, so you'll end up losing a significant amount of the stock 7m low-end grunt at the expense of a little bit of top end hp. Not worth it imo. The only way you will really benefit from them is with bigger cams, internals with higher compression, and a really good header with 2.5" exhaust and higher rpm operation. Collectively these all work well, but not each component on it's own. I wouldn't build them cheap either because they need to be a specific length, diameter, taper, location of tb's etc... to make them work properly.
Were you planning on doing a higher hp NA build?
Not really just wanted a little cool unique mod but i understand what your saying if you made the intake runner lengths a certain way like over the cam gear covers would that improve torque?
MPR;1832558 said:
ITB's don't necessitate change in power band on their own. They increase throttle response. Look at an E36 BMW that has ITB's and so does the RB26. It is the plenum size that determines your power band and if you simply put intake horns on the ITB's then yes you are going to be lacking flow but if you put a properly sized plenum on the ITBs then it will keep a power band similar to an engine that has the throttle body before the plenum.
Setsuko37;1832549 said:
I read this as: "I have a N/A and I'd like to make it faster, cuz right now it's slow. I can't afford a good turbo set-up so I'm wondering if I can do ITB's cheap to take advantage of the GE."
No offense, I was once there myself.
I will add that anything you try to do on a 7MGE without spending a LOOOOOOOOTTT of $$ will not make it much faster. CRE's well tuned GE was significantly quicker than a regular NA, but still slower than a basic, stock turbo. I can tell you he had a LOOOOOTTT more work, time and effort into that motor than a typical turbo swap would have been.
If you want to do something unique, build a subtle, CLEAN turbo 7M. Sounds simple, but that's actually pretty unique.
My NA was surprisingly fast but I put way more work into it than the average(sane) person would. If you want to know about ITB's then I suggest you spend some time over at celicasupra, it's a pretty common mod on the 5M. The methods used can be adapted to the 7M. That said, I don't recommend it without supporting mods or you will be doing a not inconsiderable amount of work for basically nothing.
Runner length has a huge effect on the powerband, then you need to find away around the stock RPM Limiter..
MightyAl;1832663 said:
I was under the assumption he wanted to run them without a plenum. But yes, you are correct. A properly designed plenum can and will broaden the powerband while using itb's.
They are also tricky to tune (but not impossible), because you lack MAP sensitivity and have to go more by throttle position(unless you use a collective vacuum source from each runner after the tb's). My point was they aren't as easy to run and tune as most people think.
To the OP:
The diameter, length and taper all have a significant effect on how well they work and at which rpm range. Get it wrong and they won't do their job, at least not at the rpm range where you want them to work. Take a look at the engine from the mazda 787b race car (perhaps the best sounding car ever made? lol). You'll notice it has 4 stacks (1 per rotor (it's a 4-rotor wankel engine)) and they are variable length. At low rpms they are long and as the engine revs higher, they shorten. This is done to widen the powerband range while not needing to use an enclosed intake plenum before the tb's allowing for the best possible airflow rate/velocity over as much of the rev range as possible. If you really want to do something cool and functional, try building a variable runner length itb setup.
I was going to build this type of setup for my honda a few years back, but of course, finances are a killer.
I understand if you want to do something different. But you need to ask yourself if it's worth it. It won't make much more power unless you spend big $$$. That's why I decided to go NA-T. It's the most effective way more power, hands down, hp/dollar.
IJ.;1832775 said:
It still won't make much more power unless they install cams that are designed to make power north of 6000... Also needs an exhaust system that will allow that kind of flow to exit the engine.
In my madness I made (actually my good friend Curtis and special thanks to Arnout) a 7M to RB26 lower intake manifold. I've had thoughts of casting it so both N/As and Turbo cars could benefit. Cost and how to go about it:dunno:
http://i1260.photobucket.com/albums/ii574/Defiant7M/IMG-20120511-00887.jpg
http://i1260.photobucket.com/albums/ii574/Defiant7M/IMG-20120511-00882.jpg
http://i1260.photobucket.com/albums/ii574/Defiant7M/IMG-20120511-00887.jpg
http://i1260.photobucket.com/albums/ii574/Defiant7M/IMG-20120511-00882.jpg
Last edited:
I'm not going to pretend like i know what i'm talking about concerning ITB's but for you guys questioning the method behind Defiant's madness in using ITB's you obviously haven't read his build thread. His motor is an absolute MONSTER and I really hope he goes through with it.