50mm or 55mm?

Gary M · Post by **Gary M** » Mon Sep 10, 2001 3:32 am

Hello.

I'm planning a FI conversion on a stock 2l type 4 motor (currently carb'd) that I plan on fitting to my squareback.

I have recently acquired a number of throttle bodies, all new. They are Ford parts and have the TPS fitted.

I have 36,50 and 55mm parts. Which of these would be best suited to my application?

Many thanks,
Gary

Post by **Tom Notch** » Mon Sep 10, 2001 12:33 pm

On your 2L I don't think you would see a difference between the 50 and 55 TBs. Your valve and runner size is the flow limiting part of the induction. I am running a 55mm GM tb on a hodge podge of T4 914 2L and bus parts on my 2.7L. Seems to be working fine. What brain will you be using? Pix soon on my web site.

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Tom Notch
Tom's Old VW Home

ray greenwood · Post by **ray greenwood** » Mon Sep 10, 2001 3:59 pm

I think tom is correct. On the stock 1.7 and 1.8, the throttle bodie was the limiting factor. Going to the 2.0 liter throttle bodie was a big difference...but above about 2.2-2.3...the intake runners will be more of an impediment than the throttle body. Making the TB too large can have a little bit of adverse affect if there are too many vacume controlled devices hooked to the manifold and you dump vacume too quick. This can give the pressure sensor too quick of a drop (if you are using D-type inj) and cause under-enrichment. I am working on ways to delay this drop as we speak. You could use either one of the larger either 50 or 55 mm just to get it running...tune it later...it will let you know....great power overall....very sensitive off the line...but no power under 2000 rpm. Ray

Gary M · Post by **Gary M** » Tue Sep 11, 2001 3:36 am

Cheers guys.

I'm still unsure about the brain, but I've been looking at products by DTA. Anyone used them? What are you using to do all the thinking, Tom?

The engine is currently carb'd, and I do not intend on using any of the factory fi equipment.

Thanks again,
Gary

kit · Post by **kit** » Tue Sep 11, 2001 4:19 am

Hi Gary
you could try using Emerald M3D injection settup.
Karl the programmer behind the system has a 1967 T2 . for more info try [email protected]

Post by **Tom Notch** » Tue Sep 11, 2001 5:45 am

I'm running a Haltech F9a. THe DTA stuff looks good from my little looks at it. Got some decent FI tech and links on my site if you haven't been there.

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Tom Notch
Tom's Old VW Home

Steve Arndt · Post by **Steve Arndt** » Tue Sep 11, 2001 9:44 am

Keep us updated on your project. I'll be converting a 2.1 wasser to center TB layout like Tom's T4 and turboing it in my Baja.
Steve Arndt