TOPIC: big mouth throttle body

Ok has anyone done a groove on one of these 90mm power throttle bodys

Matt- what engine would this be going on?

Basically I foresee power increase. I've not done one of these aftermarket TB's yet, don't recall seeing any posts of one of these yet. So you get to introduce us to this!

How much an increase in bore diameter over stock TB is this one?
Bigger bore equals longer Groove w/ corresponding increase in length of the center 25-30% critical area of the Groove. This is because as the throttle blade opens, the center area is the first part to see effective airflow. You would want to carefully examine the casting thickness where the Groove will pass above that IAC well- the square-ish opening beside throttle bore, as well as casting thickness along entire length of the Groove. Use metal epoxy to back-fill any likely areas of bit breakthrough. This one wants the big bit, just hold the bit against bore end to judge how deep the bit will cut.

I think Grooving this one will give a nice off-idle torque boost. Wouldn't be surprised to have to re-learn how to drive whatever GM engine this goes on! A couple years ago somebody in Las Vegas Grooved a Mustang w/ aftermarket trick TB, cold air induction, etc., then posted and told us a wild story of a Mustang w/ wheel-spin going sideways on some Vegas street...

Matt remember to keep the bit shaft aligned w/the center of throttle shaft."Point" the bit shaft towards the center point. You could make a magic marker dot on center of throttle shaft as an aim point.

Looks real interesting Matt, keep goin'!

Tracy G

This will be going on my silverado 5.3 motor.. I believe that the original size of throttle body these motor have is 75mm-80mm not exactly sure and this particular one is 90mm and they make up too 102mm. So imagine the groove on one of those! ... I'll keep you updated and see if I did correct, I'll post some pics up tomorrow after I apply the groove thanks for the tip!

Matts silvy

I'm about to groove the throttle body on my wife's 2006 BMW 325I 4 door sedan. Anyone done one befor ? Looks simple like ur average drive by wire throttle body .. what els can I do for this car to save gas ?.. and here's some pics of the throttle body

make sure you double the business card I had to redue a groove for one of our fellow gadgetmen that did it by the throttle mark its too close dont push to hard on card either expect about 4 mpg increase happy grooving dan

Ok Dan thanks will do

Matt, Dan is right, fold a business card in half put between butterfly and TB wall to position the butterfly. I too had a DBW tb, an '06 Chevy Avalanche, I cut Groove too close to fully closed, so at idle, it wouldn't idle at less than 20 MPH! OOPS! Owners lived in a 15 MPH zone too! I filled Groove in and re-cut this TB as seen here. It still made great power, MPG hiway went from 12-ish to 18 owner kept records on trip to Yellowstone...and it whistled loudly.
So the wife didn't like that whistle, I had to replace TB w/ a reman one un-Grooved!! Bummer!

I've included pics to illustrate idea of keeping bit aimed at throttle shaft center point, tool held to show this-just to show idea. Gadgetman Karl Fortner showed us the idea of using modeling clay as an aid using a big wad of clay against the throttle butterfly to hold in position, an option in some cases w/ DBW TB's. The clay only cost~$9.00.

If it whistles- you most probably cut a good Groove!

Matt- when you post again re: this beautiful Bimmer, would you mind doing a separate post, perhaps in Foriegn Manufactured topic section, list yr, make, model, etc. in title so when the post finally drops off the main page of Forum it will be easier to find in the Index? Index has become pretty large, 100's of posts in there, it's our reference Library...thanks!

Matt good Luck, Keep goin' you're doing Great! and- thanks for the Pics!!

Tracy G