Hey all, I just got a four-barrel TBI unit off my friend! Has anyone in here used one of these things? And can I use the exhisting computer system, or do I have to go with the Holley commander system?

 

You can use the factory computer. Call Howell Engine Develoment located in Michigan. Hes usually in chevy high magazine! I had one of his 900CFM units on a 350 and had excellent luck. He has everything you need to get properly set up!!

 

unless the 305 has some hi performance heads, cam, and intake, i cant think of any reason why you should be using a 4 bbl TBI unit. even if you had these mods it would be a waste and definate overkill. I would just do the free ultimate TBI mods to your existing TBI and if you plan on upgrading the engine or swaping to a 350, go with a 454 TBI or holleys 670 TBI w/ 350 injectors, both have 2" bores

 

If your long term goals are to make ALOT of power then you are taking a step in the right direction. If it is a 900 cfm TBI you can get 65#/hr injectors to step down the flow a bit. to 700 CFM.

The eprom tuner can also tailor the Injection Volume with the 85#/hr injectors so there shouldn't be any major problems.

Then only other mod needed is a new intake manifold since the 4bbl tbi will not work with the stock manifold. An Edelbrock performer dual plane is a great street/strip choice. if you don't care to run an egr you can step up to the performer rpm "air gap" manifold which is a excellent intake and pretty affordable.
A slightly hotter cam is will wake up the motor also.

If you plan to upgrade to a 350 these mods will carry over from the 305.

305 heads are not high HP heads by design neither is the block which has a small bore which shrouds the valves... but a power adder will add alot of umpfff.

of course don't forget gears, torque converter, better tires, headers, etc. as you can see not one part makes a car go faster it takes a combination that works to together to increase performance.

Good luck with your performance goals.

 

Oh yeah I have a 350 block waiting in the wings. I was planning on using a Weiand Stealth manifold and shoving a Nitrous plate in there :-). As for right now I'll just grab that TB and set it on my work-bench for the next month as I peice my new setup together.

Just curious, whats the power-limit on this sort of thing? I've heard alot of negative, and then some good things about TBI systems.

 

I was noticing the other day that the Holley 4 bbl TBIs have 2 different CFM ratings too. I wonder how this can be altered by changing the injectors though as CFM is a measurment of airflow NOT fuel flow! Anyone haave any thoughts?

MHF

 

wait a second.......i thought you had to use the holley ECU with their 4-bbl TB......something about there being 4 injectors instead of 2......or am i just retarded?