CJ Motorsports Fuel Systems Back in Stock

Just got a new batch of the best fuel system on the market for your NA or FI 350Z and G35

They are offered in Stage 0 as well as Stage 1 and Stage 2 configurations

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Adam’s NA Z33- Update

I just can’t seem to leave well enough alone. While I’m still working on finishing the ITB project, I picked up something to have some interim fun with. Much love to Viet for hooking it up!

Since I sold my nice 3 inch carbon intake tube I’m going to have to fab something else up. At least with the Haltech now in the car I don’t have to worry about a MAF housing (good thing, since I sold that too!) or a fancy intake (foiled again…sold the Gruppe-M one I was running). Word to the wise – don’t sell the old shit till the new shit is fully functional! I was going to go all psuedo hardcore and make a nice aluminum one, but who gives a shit…it’s an intake tube and it’s temporary, so some thin walled mild steel, will be just fine. Maybe I’ll even ceramic coat it (or maybe I’ll use ‘House of Krylon’…we’ll see). If I ceramic coat it, I “may” coat the plenum as well – haven’t given it much thought yet.

Not sure what throttle body I will run yet. The left side of my brain says to just put on a stock throttle body, convert the car back to DBW (easy thankfully) and have a go. The right side says…screw it, grab a Q45 tb, leave it as a cable throttle, port the inlet to the plenum (or cut it up and reweld the proper size flange on) and let her rip. Jury is still out…I’ll probably let the guru Steve (engine builder) make that call for me.

Tomorrow it goes out to be evaluated on the bench, see if we can maybe clean up some of the runners a bit so everything lines up nicey-nice. At least now maybe I can drive my car for a bit instead of just looking longingly at her!

Notice the true carbon endcaps…no Seibon/VIS wannabe stuff here. Cosworth always gives you the real deal.

For everyone who says this manifold is “overpriced”, you’re nuts, plain and simple. The asking price for it new, at full MSRP, given it’s thoughful design, cast manufacturing, and the real carbon endcaps and all the fittings to make it work, is a bargain. Is this the manifold for someone who has a stock Z or even one with a mild turbo kit? Nope, not at all (though it looks way nicer than stock!). But if you’re going all out, and want a plenum that will go there with you, this is a bargain IMHO. This isn’t a paperweight/canoe anchor design like some others out there, and it does, without question, solve the flow issues (of which there are many) that the stock setup has.

320whp of NA VQ35 Goodness

Figured some of you might want to see a quick video of my car in action.  This was taken last November, I think on Thanksgiving day, before headed to the parents for the festive meal (the run would have been significantly slower post-turkey!).  Since the weather here has been so crappy, and I’m dying to drive the car, I figured I’d post a quick video to remind myself what it feels like!

And here’s a picture of it before we dropped it into the car (spring 2007)

It’s not done yet – got a few more things to go !  Hopefully it all works out

NA is Dead? Pt. II

In the last segment we looked at the very basics of an Individual Throttle Body setup, and the very basics by which it works.  This time around I wanted to go a bit more in depth and explore the different types of setups out there.  I’m also going to attempt to give some insight into various technical features of each type as well.

Trumpet type – this is the image that most people have in their head when they thing of an Individual Throttle Body.  Each airhorn, or trumpet is responsible for feeding an individual cylinder.   However simple it may seem, the design of the trumpet itself has a tremendous amount to do with the performance that can be extracted from it.  First, there is the length of the trumpet.   Just like in a sealed intake manifold, the shorter the runner, the more top end power the engine will have, and the longer the runner, the more low and midrange power it will have.  Altering the design of the bell also has alot to do with the overall powerband as well.  These are the most simple type out there, as they use a simple butterfly valve to ingest air to the combustion chamber.  There are several key elements in the design one chooses for their trumpet style.  These will vary from engine to engine based on many factors, such as combustion chamber design, valve placement and diameter, cam lobe profile, etc.  The proper taper of the trumpet will give you the best of all worlds – sufficient low speed volume so the car doesn’t become peaky, but providing significant velocity when the valve is fully opened, to mid and top end power.   The trumpet design as mentioned, is highly interdependant on many other aspects of the engine.  If anyone is interested in some helpful math formulas, let me know and I’d be happy to post them. 

The above pictures shows a typical trumpet style ITB setup on a modern V6 engine.  Note the taper of the trumpet that continues to the intake runner itself, providing a balance of low, mid and top end performance.

Slider ITB – Slider style throttle bodies were born out of logical belief that with the traditional butterfly valve style, you are giving up prescious air volume and velocity by having a shaft in the center of the bore.  In a slider ITB, there is no throttle shaft.  Instead, there is a door that slides open and closed to ingest air.  As you can imagine, the packaging requirements tend to make these more space hungry and more expensive to produce.  These are also said to give non linear throttle response, making them difficult to drive at lower speeds, and difficult to maintain a steady state speed.

Typical Slider Type

Roller Style – the roller style throttle body is the third type of individual setup out there.  In this type, you have two barrels, one that rotates inside another.  These are essentially combining the linear throttle progression of a traditional butterfly setup, with the pure flow of the slider type.  As you can imagine, these are the post costly to produce, and leave the least margin for error, as you no longer have the ability to alter runner length, taper,  etc for a given application.  Each component has to be machined on it’s own, meaning it’s got to be perfect out of the gate.  The inner roller uses ball bearings for smooth and linear actuation. 

Get your math right, your patience high, and a bunch of buddies to chip in on a CNC machine, and the roller is clearly the way to go from a packaging and performance standpoint.  But there really is no margin for error.

Here is a very neat video showing a roller throttle body in action on an STi

So, now we’ve seen the different styles of ITB’s out there.  In the next segment, we’ll get a bit more into design considerations of the most popular version, the butterfly style.  This will include injector placement, trumpet location, and what all is needed to actually make one of these setups run a car.

Stay tuned!!!

NA is Dead?

All too often on the web, you see guys talking about making big hp on cars through forced induction. Whether it’s a supercharger, turbo, twin charged, etc., there is always someone pushing the envelope here.  But what about good old fashioned NA power?  No boost, no having to inject various concoctions of combustible chemicals to be able to crank the timing – just plain ordinary air? I think it often gets left by the wayside.

I wanted to start a multipiece series on NA tuning, with particular emphasis on what to many people is the pinnacle of an NA setup – the Individual Throttle Body, or in web language, ITB. Let’s just get a basic understanding of what an ITB is and how it works.

As the name implies an Indivdual Throttle Body (ITB) means each cylinder has it’s own dedicated path for the air to reach the combustion chamber.  The bodies are linked together so that they open and close together, thus allowing the engine to ingest the air required for the combustion process.  There are several benefits that an ITB setup can have over a single throttle body.  First and foremost is cylinder balance.  With a single throttle body, you have little to no control over how much air is ingested into the the combustion chamber for each cylinder.  As a result, you end up with air reaching the combustion chambers in varying amounts, at various speeds, which can leave you with cylinders producing different power levels.  The amount this differs of course varies by the application.  With ITB’s there is no sharing of air.  Each cylinder is afforded unlimited air, and through tuning, the user can ensure that each cylinder is ingesting the exact same volume per air, at the exact same velocity. The second benefit is throttle response. With each cylinder now able to ingest it’s own dedicated stream of air, the combustion process starts quicker, and the engine responds faster to throttle inputs.  Furthermore, because you now have individual paths of air vs a large single path, the volume of air and the velocity that can be ingested into the engine as the throttle plate opens is often more than a single throttle body setup allows.  We’ll go into more detail on this last point in a future installment, as well as determining the right manifold design for a particular application, all with real world testing, graphs, videos and dynos!

As best I can tell, the first production car to use both ITB’s and fuel injection was the very rare BMW M1. This car was manufactured from 1978 to 1981, and used a combination of ITB’s and a mechanical fuel injection system developed by Kugelfischer and Bosch.  BMW still uses ITB’s today on their M series engines.

In the next installment, we’ll look more in depth into various ITB setups as well as design differences, etc. In the meantime, take a look and listen at this clip from Option Video from Japan of a tuned Acura with ITB’s.  If this doesn’t make you fall in love with an automobile, it’s pretty safe to assume you have no soul!