Janus wrote:
"As for fabricating throttle bodies (sound of inhaling on crack pipe), what, exactly, are the components of a throttle body?"

Essentially, a throttle body is just a throttle plate in a pipe, some linkage to open/close the throttle plates in unison and a method to attach it the cylinder head(s). Since only air is involved (much easier to move than fuel), one could design the inlet for optimum air flow taking into consideration optimum air velocity for a given engine operating speed. This usually means length and inner diameter of the throttle body. It's not rocket science. The harder part is fabricating the piece and the electronics to control the fuel injectors.

Sherwood Lee
http://members.rennlist.org/911pcars
Early 911S Registry

Throttle Bodies
 

Here is a pic of the Vellios throttle bodies that I bought for $1200 US Dollars.

That leaves me with $1800 for ECU and other goodies.

I was told that the reason you oversize the injectors is to reduce heat. If they are "ON" all of the time they get to hot and stick.

Randy Jones
1971 911

rlj, where did you purchase those throttle boddies from? i would like to inquire about some...thanks, brent

I bought them from my Dick Elverude, motor wizard and buddy. He bought them to use on "HIS" motor, then realized the will never have time to build his motor so he sold them to me, for his cost.

I think Dave at MSRoad and Race has a set but I don't think his price is wholesale.

I am trying to get in touch with Mr. Vellios. I would like to know more about the finish on these things.

Randy Jones
1971 911

Okay, you asked for it...but I will not be held responsible for any damage to your health, property, or social life resulting from the use of this URL...

http://www.backyardmetalcasting.com/

This guy is definitely huffing the fumes from his foundry. But, if you can get yourself just one throttle body, then in theory you can follow his instructions and use it as a pattern to cast the rest of your EFI system for the cost of raw materials (i.e. empty beer cans and lawn furniture)...

Good luck. You may need it...

As I boldly go where no man (ok, a couple) have gone before:

This guy did it with dellorto carbs:

http://www.angelfire.com/extreme3/group3j/induction.html

But I'm going to try something (maybe) with the throttle body setup from the "silver top" Toyota 4AGE engine - 4x 43mm throttle bodies for US$100...

Issues:

- adapt to either stock BMW 02 tii manifold (probably impossible), to a 02 ti manifold (twin side drafts - also unlikely) or, GULP, something custom.

- adapt EFI holes in Toyota manifold to suit MFI injectors

- check that throttle linkage is going to be suitable

- check that throttle bodies have sufficient adjustment to balance

A big ask. But for a starting price of $100, I'm probably going to give it a go.

No other manufacturer except BMW.....and Toyota.
There's no such thing as absolutes it seems.

Er, um, and Nissan:

http://www.japanperformancedirect.com.au/nissan_pulsar_gtir.htm

http://www.nissanperformancemag.com/september02/skyline/


Someone has done a Suzuki engine with the Mikuni's (they are a bit small):

http://members.iinet.net.au/~rospen/quadgti.htm

Hey Cam, I just remembered something! Back in the early days of Pro 5.0 Mustang drag-racing the was a N/A 302 car running a custom (handbuilt) individual runner EFI system in the low 10s, the car was later stolen and I don't know if it was ever recovered but 10's from a 302 in a 3000lb car was unheard of in those days. Anyway they fabbed the whole thing up in aluminum, including the intake. Just a thought but couldn't you use your intake gasket as a template for a custom throttle body/manifold setup?

Actually, this whole scenario gets weirder every second - after posting the stuff about the Toyota throttle bodies, I stuck it on a couple of '02 boards.

At the second one (Roadfly), a dude from Tauranga (also in New Zealand) had literally 2 minutes earlier posted about using the Toyota TB for an EFI conversion.

There must be something in the New Zealand spring air...

Why cant we pull an efi that has the ability to be reprogrammed via new chip off a v6 camero and adapt that system into a set of zenith carbs. Where the injectors are setting on top of the air filter ans shooting directly into the carb ? Or lift the carb about an inch with a riser plate and put the injector there ?

Get the scraps of the mass produced cars.

And by the way crack is bad for your health, stick with scotch.

Mukilteo asked me by email for any updates - I don't really have any other than to say I have been an enormous slacker (no job, but have accomplished little on my cars).

That will change! Soon! Soonish??

The Zeniths could (in effect) supply the butterflies and have manifolds adapted for injectors. I think that would work.

Cam

No experience of their work, but the guys seem pretty involved:

http://www.jenvey.co.uk/

Thanks Janus,

I totally enjoyed that link. Gives a new meaning to DIY.

For more goulish thoughts, how about a custom manifold that will flow 6 Honda TBIs common to the 90ish Civics. They have 2 injectors that are good for 1.5L by themselves. The Maps/ECUs could be stacked in a corner and a O2 sensor bung welded to each manifold.