Porting your TB

[A20A1]

http://www.ls1tech.com/forums/showth...2&page=2&pp=20

Some real good info there. You can do the same mod they did to the TB to your carb throttle plates.... be very very careful though on how you put it back together.

[speedpenguin]

That should go into the how-to where it won't disappear. It's very useful.

[EricW]

Good write up. I i had an extra TB i would probably start working on it.

[smufguy]

i will spend my money on a new larger TB. unfortunately this hacking up of a stock throttle body to get less than 2 mm if any is not worth my time and patience.

[rjudgey]

Well i've been on about doing this to your stock TB for ages but nice write up and pics, only thing though the butterfly shaft i wouldn't recommend hacking that in half, just in case the butterfly works loose, plus the Honda one is half the size of that one in the pics as it's flat on both sides, but what i did do was add two countersunk screws instead of the horrible massive round heads Honda put in with the thread sticking out the other side. I then ground the new ones flush with the shaft, also knife edged the butterfly but becarefull make sure you do the right edges if you get it round the wrong way your butterfly will no longer seal!! Then i reshaped the inside of the TB body with a knife edge on the outside edge leading into the intake tubing.
This is actually quite an easy mod to do took me half a day of mucking about and the gains were very good for a DIY mod that takes half a day and cost a couple of screws, what you have to bear in mind is that all the air going in goes past the TB so even though you may think oh this is a waste of time, any improvement you can to help speed up air going in is going to benefit, and even a 1mm or 2mm difference in inside port area freed up is going to make a significant difference yes putting in a Butterfly which is 4mm bigger would be better but it would still be worth doing the same mods with the bigger TB size too. In fact my Webers on my carbed track car i even modded the inside of those by doing the same thing to all four butterfly's inside the carbs, as well as cleaning up all the casting flash and imperfections inside, and also machined the inside of the chokes out so that you get a much larger internal diameter and better shape to help the air through the carb body managed to get the inside diameter to 42mm on a DCOE 45, made a nice difference at least 5bhp maybe more, but it's pointless unless the rest of the inlet manifold and head are all perfectly port matched or you'll just loose what you gained.
If you build everything up and have lots of little things done perfectly you end up with a large increase overall in peformance but if you have a bodged together engine and then just do one thing right it's not going to make a blind bit of difference, a lot of people think i'm mad when i show them my heads and inlet manifolds and tell them what i've done to them and howmuch time i spent working on them then i just remind them how much power it puts down!
If you want the best power output you have to be a perfectionist and nothing goes unmissed and everything gets moddified this is essential in engine building and tuning.