Porting The 2G TB Elbow To Match a 1G 60mm TB - Why?

[turboglenn]

yea, what is that big TB, and where can i get one? My 1g doesn't look near that big and i want a farily stock looking TB. And an extrude honed IM

None of this shit about the 1G TB (at the rear) measuring in at 54mm with a friggin 60-something-millimeter opportunity. Screw that half-assed attempt of the 1G TB from 60mm to 54mm decrease with the lip being about six millimeters long. The Evo 8 lip is nice and gradual, from 67mm to 60.5 in about 39mm. Now that's how you make the venturi effect proud.

So after I asked about the compatibility of the Evo 8 TB in the post I linked above, I spoke with 95GSXracer. This is the advice he gave me:

Very good info, and not to be a smart ass, but i wanted to point out that the pricnipal of airflow through a tapering passage gaining velocity is actually the Bernouli effect The venturi effect is when air passing through a passage causes suction through a side connected passeage at a 90* or simliar angle..like blowing accross a straw and watching the pop rise up it. Just like to make sure people get the right info on airflow theories, again i'm not trying to be a dick, but i knwo i hate when i read something and am talking about it all wrong teh next tiem i'm thinking it applies to what i'm doing. MY girl does that shit all the time

 

[dsm-onster]

Anthony, that is not a 1g turbo throttlebody. . . That other throttlebody, which looks similar to a 1g n/t throttlebody is an evo throttlebody?

 

[DSMunknown]

yea, what is that big TB, and where can i get one? My 1g doesn't look near that big and i want a farily stock looking TB. And an extrude honed IM

Anthony, that is not a 1g turbo throttlebody. . . That other throttlebody, which looks similar to a 1g n/t throttlebody is an evo throttlebody?

Anyone else overlook the link I gave in post #21? Yes, it is an OEM Evo 8 TB. Ain't it perddy? I wonder what the other one is though. As I have already repeatedly said, the beginning of the lip measures at 60mm, while at the rear of the TB it measures at 54mm.

 

[DSMunknown]

After all my bitching, whining, and complaining, I did something about it.

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Oodles better than porting the 2G.

Got this off a blow-thou setup from another DSMer. Definitely the way to go. Allows for the battery in its regular location. Thought I would have to go for a custom setup, but I got lucky. Eat my shorts, porting techniques.

 

[MrBoxx]

Eat my shorts, porting techniques.

Didn't want to get your hands dirty, huh, Anthony?

 

[DSMunknown]

Zing! Pwnage! Burn!

 

[dsm-onster]

Nice piece!! Only thing comparable would be a 45* elbow matching your IC pipe, a 1g N/T TB with the seals flipped, and $0.50 o-rings added. This has been the cheapest way for me both to upgrade a 2g setup or to do away the restrictive 1g elbow, from my experience.

But yea, that involves a screwdriver and an extra 10 minutes . J/K. Nice bolt-on piece there!

 

[turbosax2]

When porting the elbow, what kind of finish do you want to leave on the inside? This is how it is right now - I could leave it as is, polish it more, or I can blast it with extra fine glass beads.

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[DSMunknown]

You really that strapped for cash?

 

[turbosax2]

You really that strapped for cash?

Yup Plus I still have the stock uicp so if I upgrade the elbow to a larger one the uicp might not fit on it. Either way I got to port for the first time so that was fun.

 

[DSMunknown]

During your build, if you actually stick that POS back under the hood, I will personally come down there and beat the shit out of you. I've got your address, mofo. I don't know what your intercooler/piping plans are, but Brode is still making his UICP. I have mine matched to my Supra SMIC on one end, and a modified (aka cut) 2.5 inch 90* silicone hose which mates right up to the new TB elbow. (I have the pictures, but no way of currently uploading them, yet.)

I'm sure you've seen some of Mack's porting jobs. Timeless masterpieces. Here is a famous example of his work. Also look through this thread for some superb AMM examples. I know it's not the TB elbow, but these are things to mirror. Remember that mimicing great work will only lead to positive results.

 

[turbosax2]

Hey, I'm at the point in my build and budget where I need to stop buying parts that aren't necessary and/or hard to change out later. What intercooler / piping plans? Stock ftw I've got plans for my dream fmic though - Garret 1000hp core, cast end tanks, aluminum piping, Adel Wiggins clamps, oh yeah...



Trust me, I've probably read every post Mack has made on porting turbos. But my question was intake pipe specific. Like we all know, you shouldn't polish intake ports on the head to a mirror finish. But does that apply to throttle body elbows and intake manifolds as well? If you port the runners of an intake manifold should they be polished or left with a roughed finish?

I was talking with someone about this and this is how I thought of it:

I was under the impression that polishing the runners on the intake manifold is a good thing. I know that the intake side of the head shouldn't be polished because that is where the air and fuel mix and it needs a roughed surface to atomize better. But in the intake mani the fuel still hasn't been introduced so I thought a smooth surface would be better for flow. I would think sheet metal intake manifolds have smooth runners too since it's all sheet metal?

And this is what he thought:

My understanding of fluid dynamics in the intake manifold is a bit different. I won't say that it is 100% bombproof, and couldn't be bested by some tuning wiseman, but it goes like this:

Polishing versus scuffing deals with the boundary layer of air flowing over a surface. In aerodynamics you are shooting for laminar airflow, in which the theoretical "streamlines" are organized and continuous as they flow over a wing surface. This is the lowest drag, most efficient type of airflow over an object. The other type airflow is a non laminar flow. This involves a very chaotic boundary layer which oddly enough allows the airflow to carry greater energy. It was a hard concept for me to grasp and I may well be explaining it poorly, and certainly not extensively. I suggest reading some aerodynamics stuff on the web.

Basically, it's the reason a golf ball is dimpled instead of smooth.

As you can tell, neither of us is experts on the subject. But if a mirror finish is what I should be aiming for, then I'll make that elbow as pretty as Mack's turbo.

 

[DSMunknown]

Eric, it's only a TB elbow. Don't think too much about it. Just do it.

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When you got some free time, come talk to me about end tank design.

 

[turbosax2]

I know, I know, I'm overthinking it.

All my (limited) knowledge of end tanks is from Maximum Boost and Albert's paper on his design. BTW, your pm box is full.

 

[romeen]

All my IC piping is polished on the inside (mirror finish). IMO go as smooth as possible except at the intake ports of the head.

Does it make a noticeable difference? Who knows. But it satisfies my OCD mind and it certainly won't hurt performance.

 

[DSMunknown]

I'm sure you're well aware, but keep a close eye on the thickness (or thinness) of the walls. There's not much there as it is. I would be taking constant measurements at a multitude of points to ensure no risks were being taken.

 

[turbosax2]

Yup, I kept an eye on that. I didn't take any measurements, just felt with my fingers to make sure there was still enough material there. I tried to keep most of the porting right at the flange then gradually blend it back. I'm all done porting though - I just have to polish it more if I go that route.

 

[turbosax2]

Finished polishing it with an extra fine cross buff and Mothers Mag & Aluminum polish. It's not perfect, but close enough.

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[romeen]

Cross buffs work awesome. I use WD-40 with mine. Never thought about using metal polish. I may have to try that next time.

Good work.

 

[turbosax2]

I used the cross buff dry. Did the WD-40 help much? I did notice on the packaging it said they could be used with a lubricant but I forgot to try it out.

 

[romeen]

I can't say how much of a difference the WD-40 makes since that's the only way I've done it and have nothing to compare it to. I use that because the porting/polishing guide from Standard Abrasives recommends using a light oil with them. I can say that I have had excellent results using the cross buffs but maybe the results would have been as good using them dry.(?)


Even though I initially misunderstood you it does make me wonder what kind of results one might get using a fine rubbing compound or metal polish with the cross buffs. I'll try it out this week and let you know.

 

[turbosax2]

My sentence was misleading. I meant to say that first I used an extra fine cross buff, then I used Mothers polish. I didn't think of combining the two either - sounds interesting.