[Jason@JacFab]

Working on developing a series of intake parts for the 2.0t cars. Some have been done by others already, some haven't. I can't see myself paying over $300 for just an intake tube.

My first plan of attack is to adapt a bigger throttle body to the 2.0 intake. The 2.0 has an itty bitty 59mm throttle body. But the intake manifold has a 67mm opening.

The most logical thing to do was to adapt a 72mm v6 throttle body. Which I did today and conducted a flow test. I have not attempted to run it on the car yet because I need to source necessary couplers.

Here's a shot of the stock 2.0 throttle body next to a stock unmodified v6 tb



Because the inlet hole on the intake manifold is already almost 10mm bigger, this leads me to believe the throttle body may be a restriction. Thus far, I believe I am correct. I CNC machined a throttle body adapter with a tapered inlet. The front matches the 72mm throttle body, while the rear tapers down to 67mm to match the opening on the intake manifold.


Throttle body adapter, with oring groove for throttle body seal.


Adapter mounted to intake manifold.

I did the flow testing in house on my Super Flow flow bench. For the sake of trying to test bottle necking as much as possible I also did the flow test through the tube that attaches to the throttle body that comes back from the intercooler. Basically I tried bottle necking it down again before the TB because that tube is pretty small also. I plan on attempting to rebuild that tube in a larger size to flow more air also. Shown below is that tube taped to the larger throttle body, adapted to the stock intake manifold. I expect even better results adapting that tube with a proper silicone coupler, as it was just tapped it appeared slightly off center and it obviously wasn't optimal, but it was a good first test.



So tested stock tb through the tube, vs the bigger TB through the stock intake and stock intake tube... Just by changing the throttle body I saw a 6.5% air flow increase through all that, which is HUGE, for just changing a throttle body on something like this.

That's said, I am excited to actually try this on the car and hopeful that it will work. The silicone coupler I need is on order and I should hopefully be able to try this in the car next week if I'm lucky.

The other parts that will be rehashed in the aptly dubbed "Big Mouth" series of parts a make will be the tube that connects directly to the TB seen in the previous picture, and the tube that runs from the airbox to the turbo. It looks like a big restriction.



I'm sure you'll all start screaming "why don't you build a cold air intake?!"... Well at this point, I'm not sure that the 2.0 actually needs one. So far in my data logging completely stock, at speed, I'm seeing 2-4 degrees above ambient temps as read at the IAT sensor. I think getting rid of restrictions such as the things that I am working on, and perhaps a high flow drop in filter may just make a world of difference.

Btw, here is the intake tube from the air box to the turbo disassembled



The white thing seems to be a noise suppressor. Seems like some of the ATS guys have been pulling it out. I've read it gives a little more intake and turbo noise. People claim the car runs harder, but I don't see how, it would create a huge amount of turbulence in the intake tube if it was removed. I have debated building a solid insert to replace the white one, but I think the gains would be minimal at best. Might be good for California guys looking to fly under the radar.

Everything I do here will be Dyno tested adding one piece at a time. I'm hoping I can maintain the stock tune while doing all of this and hopefully show some nice gains. Eventually when I have to, I will start messing with tuning. But I'm hoping I can maintain the stock tune at least until I crack open the turbo.

Stay tuned!

[Evil-Bee-NH]

[rorymick]

Awesome stuff! Thanks in advance for doing the R&D on this stuff...I'll be keeping an eye on your work!

[Jason@JacFab]

The coupler is due to arrive tomorrow, so with any luck I can get some good before logs and then install, if it actually runs (I'm assuming it will), I can get some post install logs and see what/if there are any noticeable differences seen while logging, as well as driving impressions.

[RenegadeSS]

Crack open the turbo? So you are talking about a big wheel upgrade. I'm all for that. I had the Bat-mo-wheel upgrade on my LNF cobalt, and boy what a huge difference. All the benefits of a twin scroll down low, and much better top end like a big turbo. Vermont tuning already has a big wheel upgrade for the LTG, so you can see if you can improve on their design. Here is a link. http://www.vermonttuning.com/product...turbo-upgrade/

[RenegadeSS]

More power, and more boost is always good, but how will the plastic intake manifold handle all that power. My buddy with his LE5 one piece OEM plastic intake manifold blew his out at 18 PSI. Do you think that will be an issue for big power down the road?

[Jason@JacFab]

It is installed, and initial impressions are "WOW"...

Haven't looked real hard at the logs yet, but I did check the 0-60mph as logged with HPTuners... With the stock throttle body I logged two back to back 6.035 runs. Big mouth throttle body installed, ran a 5.886.

Obviously I still need to gather more info.

I am at the drag strip right now, will run 2-3 runs with the big mouth tb, then I will switch back to the stock tb and make some more passes.

Hopefully we'll be able to see something here!


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[AtlasGrey]

[Jason@JacFab]

Well it's pretty consistent I guess.

14.169 @ 96.31 DA 2109
14.220 @ 95.35 DA 1959
14.184 @ 96.29 DA 1693

Just put the stock throttle body back on. The air is getting great now so the stock tb will have an advantage.


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[Jason@JacFab]

Unfortunately due to several break downs and spills on the track I was only able to get one more run in. The DA had dropped to about 1400, best I've ever seen it here. All the stars, the sun, and the moon aligned and I got a great launch and ran a 14.022 @ 96.35 with the stock throttle body.

I don't think the testing at the drag strip was enough to be conclusive about anything as I didn't get the amount of runs that I had wanted to, and I'm obviously still learning to launch the car.

But it was fun!

I need to get a different coupler, the one I ordered ended up being too big on the TB side, and all the extra material didn't allow for a good clamp on the TB. I ended up blowing the tube off the TB under boost once. Luckily I had tools and could get it back on.

I will order another coupler and continue testing.

I plan on dynoing in the future, but I want to have some more things to take with me to test as I have to drive 3 hours to the nearest dyno, and 4 hours to the dyno that I've always used in the past.

[rorymick]

That V6 throttle body is A LOT larger. I cant see that doing anything but adding to gains. Intake. Big mouth throttle body. Tune. Is likely the route I'm gonna go first. DP and methanol injection after that!

[Ashium]

I'd like to see what a full 2.5inch charge side would do.

What were the charge temps looking like?

[Jason@JacFab]

Originally Posted by Ashiu

I'd like to see what a full 2.5inch charge side would do.

What were the charge temps looking like?

I haven't really paid attention to the charge temps yet. I'll have to look into that. I assume there must be a separate sensor that is different from the IAT for that?

I'm just waiting on some parts to show up (coupler and new tb) so and I'm going to be sending a setup to rorymick for some independent testing.



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[RedonBlackRS]

As soon as you have this verified and ready for production, I'd love to order a full setup. It seems like you really put personal time and passion into what you do, and I think that's great! Thanks for the updates, and good luck!