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If I go fuel injection (currently trying to cell my blow thru dells) which intake system is better. The Mexican intake or a German intake with CB end castings. Someone on the Samba has Mexican Fuel Injection components for $299. Seems like a good way to go. I am just not sure if it flows as good as a Geman setup with CB end castings. My motor is a turbo'd 2007 if that enters into the equation. I guess I am just looking for the most cost effective non performance limiting option. Or should I go with a dual CB throttlebody setup. If the carbs cell I am going to proceed so now it the time to help a fellow out. Any other advice would be appreciated. The ECU will probably be Megasquirt as well.

Thanks!

I have the Mexican, It takes some work to make it "hi performance". The German setup is easily a better choice if you want out of the box performance IMHO.

Limiting factor of the Mexican

1)Small runners under 1" ID
2)Throttle body needs to be ground out to work well
3)Injectors half way into the ports
4)Kinda need an idle valve IMO

German limitation

1)Need CB end castings for proper flow
2)That is all I can think of right now =)

The dual tb's are going to be over kill on a 2007. I just bought a set and probably won't use them for my current motor because I know I can flow enough with the single german 45mm throttle body. And I don't want to deal with linkage again.

My .02

Go with the CB EFI end castings, you won't regret it- I know I didn't.

I read that you have to do something to the German throttlebody to have it handle boost. What exactly needs to be done? I want to get a way from carbs because one computers are cool and two the idle kind of bounces around a little and there is a couple of flat spots. Thanks for the input guys.

Your decision should be based in HP potential and engine components. Anthony and I have calculated that unless you are progressing beyond 1915cc's (over 2L) and beyond 130 HP or so, the Mexican system (german engineering by the way!!) will handle the airflow. Although the comment about the 1" is correct, unlike the stock carb system which bleeds a wide tube from a plenum into two smaller intake manifolds, the mexican system is engineered better from the plenum down for airflow and it is my opinion that the CB manifolds are harder to tune and you lose out on the airflow stats. Accordingly, Vacuum and MAP may be an issue with the CB system. Dual TB's and linkage are issues as are dual TPS. If you look at the CB system the injectors are not as close to the intake valve as are the Mexican ones.

I stick by my guns that the Mexican system will feed most applications more than adequately, unless you are gunning for 150HP and above.

See my postings and pics on the carb to EFI conversion.

Current HP is probably over 220 hp with the blow thru dells @ 15 psi. I just don't like the driveability....I am kind of a perfectionist and there are a few transitional spots that just drive me nuts. So not wanting to loose any HP I should probably stay away from the stock throttle bodies and go for a 65 mm setup similar to 64bug. I just read thru his build post for the 10th time. I already have a Ford 4.6 liter throttle body with the sensor and IAC valve. So I think that I am going to fab up an intake similar to 64bug's just not nearly as good. All of this stuff is kind of confusing I just hope that it all makes sense as I go.

It seems arduous and confusing at the start but its actually easier...

When you get the laptop showing you your engine while its running and then having the ability to change and tune with the press of a button, that's the real impetus for me. Data logging is great as well and seeing where you can make improvements what those improvements will be - if you are a perfectionist, you will like this. Just takes a while to get up to speed.

What's the throttle plate size of a late 70s bug TB? I have a Mexi system I'm adapting to use with L-jet as of now. The Mexi TB is 42mm in diameter.

I looked at both systems before deciding to go with the Mexi one, for two reasons, fabrication would be a minimum and CB pissed me off royally. I actually will NEVER deal with CB again.

I called CB in Nov. to get some more specifics about their setup, mainly what how big the injector bosses are and how did the rails hold everything together(their catalog was pretty vague). I got some kid on the phone, well, after several questions he didn't know the answers and didn't show any interest, I said "I'm interested in buying these but I need to know what I'm dealing with." He told me he was too busy and started getting snippy. Too f'ing busy to pick up a set of calipers and find out! I don't need to give my money to people like this. I called back and got a manager on the phone and told them after several, several orders over the last 17 years I was done with CB. They could've cared less.

I got my Mexi parts exactly one day after I ordered them.

Anyhoo, being scientific about this, the mexi intake runners are actually better for flow as there's an individual runner for each port from the end casting all the way up to the base of the center section, the CB ones are like carb ones that split into two out at the end castings. However, credit where credit is due, if you use a Weber progressive center section and a Golf or Jetta TB (404 cfm) and the CB end castings, this will probably flow more overall than the Mexi setup with the smaller TB.

Truth be told though, all of this is heresay unless someone actually puts all these parts on a flow bench. I no longer have access to one. At one point in time I would flow everything I could get my hands on.

Funny I had EXACTLY the same experience with CB.

Here is a photo of my setup right now. Should have the alternator on tomorrow.



I ground off the intake pre heat risers and welded the O2 sensor in and repainted the header last night. Happy with the airflow now. Once I get everything on I am going to post some photos of all the mods I made to the stock engine to get the Mexi parts all up and running.

German TB is 45mm and a straight through bore.

Thats the german one in the picture. I have an extra if someone needs one otherwise it is going in the bus the summer after next. And yes it is 45mm.

Canuck70Ghia wrote:Thats the german one in the picture. I have an extra if someone needs one otherwise it is going in the bus the summer after next. And yes it is 45mm.

That is not a German throttle body and it isn't 45mm. It also has an offset bore...

Maybe I am confused...

The bore to my eyes looks straight through, there is no offset. When I measure the hole I get 44mm and little bit, inside diameter.

Do you have a picture of the 45mm straight bore TB? What are the performance differences? What is the part number?

Canuck70Ghia wrote:Maybe I am confused...

The bore to my eyes looks straight through, there is no offset. When I measure the hole I get 44mm and little bit, inside diameter.

Do you have a picture of the 45mm straight bore TB? What are the performance differences? What is the part number?

I'm not sure I follow. I measure the mexi TB from the bottom and 42mm with a set of calipers every time. The throttle plate looks even smaller to me, but I can't tell for sure.

Hard to tell with the focus of the picture, but it's 42.

Okay here are some pictures.

I get about 48mm on the top inlet side (ruler is just a guide LOL) and about 44mm on the inlet side. Offset means what? Looks pretty straight to me.