Intake plenum and 911 throttle body

[geraintthomas]

So just to clarify, all I'd need to purchase is a 997 75mm throttle body, fit this onto the manifold and the throttle body, and fit the existing intake tube onto the other end of the throttle body? Sorry, seemed to be a couple of things that have changed on this page and the previous page in terms of tubing!

[mavis.d]

Originally Posted by geraintthomas

So just to clarify, all I'd need to purchase is a 997 75mm throttle body, fit this onto the manifold and the throttle body, and fit the existing intake tube onto the other end of the throttle body? Sorry, seemed to be a couple of things that have changed on this page and the previous page in terms of tubing!

You will need a Throttle Body and larger intake tube and bends from the MAF to the T/Body. I still have to tidy up the pipework but if you look at my running report in Boxa.net there's a couple of pics. If I'm not too delicate after Christmas tipple on Tuesday I might sort it out then
http://www.boxa.net/forum/index.php?/topic/61193-mavisd-running-report/

[Ben006]

You can't reuse the stock intake tube since it's made for a 68mm TB, the 74mm won't fit inside!

Making an intake tube is just a matter of assembling an aluminum tube and two silicon coupleurs

Mavis, we can't see the page :/

[mavis.d]

Originally Posted by Ben006

You can't reuse the stock intake tube since it's made for a 68mm TB, the 74mm won't fit inside!

Making an intake tube is just a matter of assembling an aluminum tube and two silicon couplers

Mavis, we can't see the page :/

As you can see from the second pic the angle needs to tidied up. The aluminum tube is 76mm and each of the silicon couplings are 76-83mm

[Gelbster]

Mavis - it would be really great if you could specify the adapter coupling - do you mean a 90 degree elbow reducer 76/83mm ? Or a different angle? Like this??
eBay item number: 282061203413

Imagine how much easier your project would be if the airbox was not in the engine bay? Yes , a CAI outside the engine bay - it can be done ! But I don't want to hijack Ben's Thread.

[mavis.d]

Originally Posted by Gelbster

Mavis - it would be really great if you could specify the adapter coupling - do you mean a 90 degree elbow reducer 76/83mm ? Or a different angle? Like this??
eBay item number: 282061203413

Imagine how much easier your project would be if the airbox was not in the engine bay? Yes , a CAI outside the engine bay - it can be done ! But I don't want to hijack Ben's Thread.

It's a 90 degree elbow but I think a 45 might work better so may give it a go with one of those. BTW your ebay number brings up no items

[Ben006]

If you use a 15 degree 3" tube, you need a slightly less than 90 degree coupler for the TB.
A 90degree coupler cut slightly shorter works fine.
I'll post pictures tonight!

Gelbster, you mean an air filter where the snorkle is usually ?

[Gelbster]

Originally Posted by mavis.d

It's a 90 degree elbow but I think a 45 might work better so may give it a go with one of those. BTW your ebay number brings up no items

Try EBay USA ! It works just fine.

[Ben006]

[Ben006]

Oh, what's that???


Looks like a GT3 TB

[CrisZenithBlue]

cant wait to get in on this action as soon as i finish with maintenance expenses! nothing like a more linear powerband with more usable low end grunt. coming from the honda S2000 i can say i miss the vtec kick at 5500RPM which was pretty damn cool but the reality is you dont get much of that daily driving.

when i met Ben a while back and drove his boxster i could REALLY feel the difference in the powerband and it felt so right, like it was supposed to be like that from factory. i personally like the max power output of the base boxster, it doesnt get you in guaranteed "jail time" speed right away, the only thing i would change is how that power is delivered.

good thing there's guys like Ben making this stuff happen!

[Gelbster]

Originally Posted by Ben006

Gelbster, you mean an air filter where the snorkle is usually ?

Yes Ben,
I cobbled together an experimental air filter from "UNI" foam and fitted it in the 'tunnel' where the snorkel usually is.It fits behind and is attached to the louvers.One screw and it all slides out.
The use of the tunnel as an air filter housing enables a very compact new arrangement in the engine bay where the old airbox was. Access to the Bank 2 - 4,5,6 inlet manifold area is now excellent from above.
The concept needs proving. And improving. I am (wildly)guessing that I have an acceptable compromise of filtration vs. obstruction.
I also fitted a finer mesh screen(like the997 has) .I also fitted an airflow straightener before the MAF. Who knows if .....
The project was not planed.I had to r&r # 4 injector and the fuel pressure regulator. Try that with the engine and airbox in place and you'll understand.
I am not advocating this as an effective project because I do not have test data.

[l3m]

I'm selling a 997 throttle body, 997 plenum and misc. hardware. It's listed in the Boxster Parts for Sale section.

[Ben006]

Originally Posted by Gelbster

Yes Ben,
I cobbled together an experimental air filter from "UNI" foam and fitted it in the 'tunnel' where the snorkel usually is.It fits behind and is attached to the louvers.One screw and it all slides out.
The use of the tunnel as an air filter housing enables a very compact new arrangement in the engine bay where the old airbox was. Access to the Bank 2 - 4,5,6 inlet manifold area is now excellent from above.
The concept needs proving. And improving. I am (wildly)guessing that I have an acceptable compromise of filtration vs. obstruction.
I also fitted a finer mesh screen(like the997 has) .I also fitted an airflow straightener before the MAF. Who knows if .....
The project was not planed.I had to r&r # 4 injector and the fuel pressure regulator. Try that with the engine and airbox in place and you'll understand.
I am not advocating this as an effective project because I do not have test data.

I'll take a look at the possibilities when I have the time



The first sold plenum is ready !




You'll notice the four ribs added. Just for security and further stiffening!
You'll also notice that my masking tape game is not the best one yet... ^^

I ordered a 996 plenum too.
I have a GT3 throttle body at home and a guinea pig who's willing to test it on his 996

Ben

[geetee]

how much is this plenum?

[particlewave]

Aluminum conducts heat very well and turns all your hard work into a hot air intake, probably negating any possible benefits from the plenum. You'd be much better off with a plastic tube with heat shielding.

[Gelbster]

This Plenum is plastic !
Agreed for conductive heat ,but the heat source in this case is radiated and convective,not much conducted because of the' rubber' boots. Which is why polished aluminum or 'chrome' coated ABS are usually used for commercial CAI systems. Spectre products has more info. Heat reflective tape may help ? The air charge in the CAI tube moves fast enough that it won't have time to absorb much excessive heat. Hot-Idling/Dyno would be a problem because of heat soak.
But some Track time would be more valuable than my theorizing.

[eddy]

The DEI gold reflective tape works great. I used it on the engine bay side of a custom airbox in my SCCA ITS Miata (the box was made from sheetmetal) along with some thin silver duct insulation on the filter side. temps were near ambient as a result.

[Gelbster]

Agreed but use ALuminum/chrome on a Porsche - gold is soooo Ricer !

[eddy]

It does have greater reflective properties than silver, plus with the race car it was on i wasn't headed to the local cars n coffee our two thread conversations are a welcome distraction from the spreadsheet i should be working on!