Max boreing/porting on a stock tb...who has done it
01-01-2008, 08:00 PM
#1
Max boreing/porting on a stock tb...who has done it i was wondering what is the max that someone has bored out a stock tb from 75mm to what?? maybe 78-79mm and then obviously made another larger throttle body blade to fit the bore either on a mill with a rotary table or purchased one somewhere...
just curious...
just curious...
01-02-2008, 09:16 AM
#4
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you can go hog crazy b4 the blade opening,,watch the coolant lines on the bottom,,but really you can only go as far as the blade width when it comes to the neck.
here's a shot of how I hit the bottom, even that hump right b4 the blade area can be dealt with pretty well,,,
and another,,
and another,,,
once you get to your blade area,,the max is the blade width itself.
here's a shot of how I hit the bottom, even that hump right b4 the blade area can be dealt with pretty well,,,
and another,,
and another,,,
once you get to your blade area,,the max is the blade width itself.
01-03-2008, 01:42 PM
#5
you can go hog crazy b4 the blade opening,,watch the coolant lines on the bottom,,but really you can only go as far as the blade width when it comes to the neck.
here's a shot of how I hit the bottom, even that hump right b4 the blade area can be dealt with pretty well,,,
once you get to your blade area,,the max is the blade width itself.
here's a shot of how I hit the bottom, even that hump right b4 the blade area can be dealt with pretty well,,,
once you get to your blade area,,the max is the blade width itself.
01-03-2008, 07:03 PM
#7
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this looks like a stock ported one and its 80mm
http://cgi.ebay.com/ebaymotors/New-L...spagenameZWDVW
http://cgi.ebay.com/ebaymotors/New-L...spagenameZWDVW
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01-04-2008, 12:21 AM
#9
I machined one to 78 on a lathe and it broke thru in four places. I put epoxy from the outside then smoothed it on the inside after it cured. The new throttle blade was machined out of some 1/8" aluminum plate. It's not pretty and not worth the time, because as stated above the manifold opening doesn't support the larger bore. When I put the TB on I ended up with a lip all the way around, which will only cause turbulence and inhibit flow. I had an extra TB and the machinist at work said it couldn't be done. That was my motivation.
01-04-2008, 09:15 PM
#10
It can and had been done. To do it right is a PITA. Take your TB apart and bolt it back on your intake. Go ahead and fill all your thin spots with whatever epoxy you are using on your TB and the throat of the intake. Bore through it all with a 78mm bore all the way to the plenum to it doesn't choke down at your intake opening. Put a 78mm throttle blade in your TB. Now your have to measure everywhere that was cut so you don't have a failure later. If your epoxy is thin and you let off the throttle at 6500rpm to engine brake, it's gonna see alot of vacuum and you don't want it to break.
Is it worth it? My buddy did it. He has an ls6 with full bolt ons in his SS. He used 5% more injecter to get the same o2 readings as before. No back to back dyno. It must have done somthing.
Is it worth it? My buddy did it. He has an ls6 with full bolt ons in his SS. He used 5% more injecter to get the same o2 readings as before. No back to back dyno. It must have done somthing.
