305TBI to 350TBI

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TWISTER

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305 TBI
Thanks.. now you guys have me thinking again.. I was choosing the carb route because I thought it was the best solution for what I want. I just cant spend hundreds of dollars trying to make the TBI work. I planned on a Q jet for this Vortec because I have one and there is one on my 84 plow truck that has never failed me. There are also a couple locals that are very good with Q jet tuning if needed. But I have time for collecting parts before I do the swap so there is no telling what I may find..lol
 

TWISTER

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305 TBI
There is a system available from Dynamic EfIs Called the EBL. What he does is take the factory ECMs and modifies them to where they are flashable. No more chips. You can tune them yourself. It also has a learn mode to where it will "fix itself". I have used it on my son's 454SS when we changed cam, heads and intake and kept the TBI. I tried to use chips and it just wouldn't run right. When I used the EBL it was night and day difference.
I have friend who has a TBI '87 with a radical cam, aluminum heads, intake, headers, MSD, flat tops. He tried chips and it wouldn't run right either. We put the EBL on it and I was able to get it running right.

It is really inexpensive when compared to the other aftermarket stuff. My system was $465. with cables.

I used a NB O2, but you can also tune with a WB and it is better. You can turn off the EGR circuit and actually use it as a NOS controller if you want. It has so much more than the factory system.

In these factory ECMs there is a "Lean Cruise" mode. GM turned this off (something to do with emissions). What it does is when the motor is cruising without load it will advance the spark and lean the fuel. It really helps with gas mileage. The EBL turns this back on. On the SS we got 14.8 mpg at 70-75 mph. This was a big block with a TH400 and 3.73 gears turning 3000 rpm.


From now on when I convert on to FI or do changes to an FI motor I'll use the EBL. I'm sold on it.

That looks like a good solution for the chip issue but I would still have to come up with a bigger TB. I don't think a 450cfm TB is enough for a 300+hp Vortec. I think I May have another $600 into a bigger TB setup. Someone correct me if Im wrong here. That does look like a great product though.
 

Driver4r

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That looks like a good solution for the chip issue but I would still have to come up with a bigger TB. I don't think a 450cfm TB is enough for a 300+hp Vortec. I think I May have another $600 into a bigger TB setup. Someone correct me if Im wrong here. That does look like a great product though.

Find you a BBC TBI unit, It should be bolted to a 4-barrel adapter. Ive read alot of people switch to those to get more fuel delivery.
 

bucket

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Only the early ones had an adapter to mount it on an old 4bbl intake. The later TBI 454 motors had a dedicated manifold. Aftermarket adapters are easy to get though.
 

1911fool

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That looks like a good solution for the chip issue but I would still have to come up with a bigger TB. I don't think a 450cfm TB is enough for a 300+hp Vortec. I think I May have another $600 into a bigger TB setup. Someone correct me if Im wrong here. That does look like a great product though.

A 454 TB would help. The EBL will actually control two throttle bodies if you so desired later down the road.

You can pretty much use whatever induction system you want as long as the electronics do what they need to do.
 

Stewzer55

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Tuned port controllers will control two TBIs as well, but thats a trick some Crossfire Injection guys use to make them not be Ceasefire Injection.
 

68post

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The Aftermarket EFI systems, like Holley, and FAST will self tune for mods, an OEM system wont. I replied to your pM, i dont show up here much anymore. If Carb is what you really want, go for it, but take my air cleaner recommendation into consideration...very important when operating in cold climates, especially with a vortec, where you have no exhaust crossover in the manifold to heat things up. EFI Dry Manifold is Always superior, and in the long run is alot less headaches as far as cold driveability, especially with the Holley Avenger EFI Multiport.

Beside using port EFI , what are you suggesting for heat when using a carb ??? (heat stove off of the header - ?) thanks !
 

MadOgre

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I like the crate motor just put a carb on it and be done lol.

I have not tried it but supposedly you don't need a crossover with an electric choke carb. Any one know otherwise ?
 
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68post

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I like the crate motor just put a carb on it and be done lol.

I have not tried it but supposedly you don't need a crossover with an electric choke carb. Any one know otherwise ?

If you want a choke without a crossover - it must be an electric choke, but the crossover is for more than just the choke when you run a carb !
 

bucket

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Tuned port controllers will control two TBIs as well, but thats a trick some Crossfire Injection guys use to make them not be Ceasefire Injection.

I thought they use a regular TBI harness/ecm and buy an adapter harness from Painless? Even though Crossfire has two TBs, each TB only has one injector.
 

Stewzer55

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Using the Tuned Port ECM is a trick some Crossfire guys will use since TPI uses many of the same sensors and parameters but is not as primitive and can be tuned easier.

Sent from my SPH-L710 using Tapatalk
 

bucket

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Interesting, I have not heard of that. I have read that the biggest problem with the Crossfire is the early stupid ECM, and simply updating to the later TBI ECM was a big upgrade. That's the route I had planned on using, I'll have to look into the TPI thing.
 

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