Sunday, April 23, 2017
× This is to post your solutions to various issues such as re-routing idle air pathways, location of PCV Connections, and anything else that benefits The Gadgetman Groove modification.

TBI 2"-Bored Units Require Medium Bit Size

13 Mar 2017 22:09 #1 by KGB_Oklahoma
Hello out there, this tip is from me to everyone out there to say learn from what I did.

This is ONLY for TBI Units that have been Bored out to 2" for 645 CFM airflow, 300+ HP.

The modified Throttle bodies as shown in the pics below will illustrate what I mean. The bored TBI unit only has 3.8mm thickness at the bottom of the groove, where the original TBI has 5.92mm. Can you guess what happened? Lets just say that I carved a slot big enough in the passenger side that I went through the bolt hole, the entire bottom groove and the iac re-route. I'll be saving for a new TBI but that will take a few months.

I also had the throttle plate pushed out 2.5 turns to allow for 15% throttle before the groove took hold.

Stay groovy, and even with the not so great groove she still wants to burn the tires off the axles.

Enjoy the pics, and ask questions if something isn't clear.


Attachment IMG_2305-2.JPG not found

New Bored Throttle Body, notice the thin section at the bottom?

Attachment IMG_3480.JPG not found

Measurement of new throttle body.

Attachment IMG_3481.JPG not found

Measurement of Old Throttle Body. (Large bit had no issues)

Attachment IMG_3493.JPG not found

First cut through bolt hole area, patching this while making it large enough for the bolt was plenty of fun.

Attachment IMG_3492.JPG not found

Picture looking down into passenger side groove, had to fill the entire IAC to regroove this.

Attachment IMG_3491.JPG not found

Other side was much thicker, only broke through a little on driver side.
The following user(s) said Thank You: TracyG
13 Mar 2017 22:50 #2 by TracyG
Pretty epic looking work there, Ken! Yes that thin bore wall section is a challenge all right. Thanks for the pics detail, I bet you have the Only one of it's kind on earth! :woohoo:

Tracy G

Tracy Gallaway
Carburetor Coach
Mood Elevator
Gadgetman Reno, NV
16 Mar 2017 22:01 #3 by KGB_Oklahoma
I have seriously thought about filling in that groove and using the medium size bit; but Ron's voice keeps echoing in my head when he was talking to the gadgetman in Nebraska about always using the largest bit possible even if the shape is a little off.

I'll see how this groove works and maybe try the other but not for a while; i'm having too much fun driving with the groove again. Ha!

Hopefully i'm not the only non-certified guy out here that kept watching tons of Rons videos before i'd even attempt at working on someones throttle-body. Trying to match how Ron held the tools in his hand really helps me to keep the groove consistent throughout the cut.
Time to create page: 0.372 seconds

Contact Info

Gadgetman HQ
Ron Hatton
Helena, MT 59601

Gadgetman Licensing
Tracy Gallaway
Reno Nevada USA 89503

Popup Module

This is the Popup Module feature. Assign any module to the popup module position, and ensure that the Popup Feature is enabled in the Gantry Administrator.

You can configure its height and width from the Gantry Administrator.