I'm doing some upgrading work on a TBI, injectors/pressure reg/... what EXACTLY is the "ultimate TBI" I've heard about it a lot, and I'm wondering if anyone could explain it ...besides telling me it's an upgrade...
Thanks In Advance
:hail:

 

What it basically is is a slight port job on your TBI unit. There are two areas to pay attention to. There is a ridge of aluminum that surrounds the throttle bores. Is about 3/8" high and roughly 1/2" thick. You can take a grinder of any kind and grind that off and radius the edge into the throttle bore. The other area is to grind down the arm that hold the throttle butterflies in place. You have to be vary careful because if you slip here you can easily gouge the sides of your throttle bores. Because of that I did not attemp this part. I did however do the other part and you can see in the pic what it looks like. Just hold your stock TBI unit up to this pic and I think you will see what you jhave to do.

 

That was my practice job that i did on an old TBI unit I had laying around. In that pic I had not even sanded down the rough edged yet. It looks even better now. After I practiced I did it on the TBI unit on my car and it came out fantastic and looks like it came that way from the factory.

 

what sort of difference does that make... what sort of difference does that make WITH upgrading injectors/pressure reg/ and a chip
Thanks

 

The difference is pretty big once you get some mods. Removing that extra material and radiusing the bores allows more air to get in under your injector pod. If you look closely there isn't that much room for air to get into your throttle bores. Once you have done the ultimate mods you can see how much more space there is for sir to get into your TBI. Don't bother with upgrading your injectors until you get some serious power or switch to a 350. Same goes with the chip. The aftermarket chips are a joke and you really have to burn your own. You only need to do that when you have a substantial amount of mods done to your car. I pretty much have every bolt on my 305 and my car runs fine on the stock chip. AT the end of this summer I am putting in a LT4 cam with SR torquer heads. I will have a custon chip burnt then to get everything out of that combo. I will still be able to use my stock injectors and fuel pump. So save your money for other mods and just take some time to do the ultimate mods.

 

well, in combo with the TBI mods, i'm getting major professional ported heads, cam, headers, cat-back, intake, etc... So, I'll get a chip anyways...
thanks

 

if you are doing heads and cam, i woudl suggest upgrading to a 2" throttle body, either the holley, or a 454 unit from the trucks.