Converting TBI- to Multipoint Electronic Fuel Injection

[oldstonewall33]

Im planning on building my 350 tbi here soon and despise the TBI setups. Was wondering if anyone has had experience doing this swap.
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http://www.jegs.com/i/Edelbrock/350/3502/10002/-1#


any input on this??

 

[GRINCH]

A few us run it. Do a seach.. I'm sure it has been discussed before. I have it and NO I would not run it again. I would run MPFI from some one else.

You still use your TBI except you pull the injectors out. Same ECM, Same TPS, IAC, EGR.....

Not sure if I gained any MPG or HP. I swapped in a 96 Vortec motor at the same time.

I have had no serious issues except Edelbrock had to send me a new Chip. They had to pull some fuel out of the curve at idle and lower RPMs.

I have had it on for about 6 or so years now.

my .02

 

[dyeager535]

Check out thirdgen.org. You can run TPI off of the TBI setup IIRC, it's all over there.

How much power you looking to make? TPI is pretty restrictive, but makes great bottom end torque. If you want upper end, it would likely disappoint you.

Sequential injection vs. batch is pretty meaningless, so don't think it's worth the extra expense.

Why do you hate TBI so much? Not much different than TPI (for instance) except that it has 6 fewer injectors, and is cheaper to make big power with.

 

[Thunder]

Seems like a waste of money to me.
For 1000 bucks you can modify Your TBI & engine to make way more power and torque than that system makes.
Also.
It is not true MPFI. It uses the stock ECM. So it is batch fire similar to TPI.
If you want true MPFI. You would be better off going with Edelbrocks Pro Flow systems. Or other programable MPFI systems made by Holley, Accel, ect.

 

[Blue85]

It is not true MPFI. It uses the stock ECM. So it is batch fire similar to TPI.

IMO, multi-point just means you have an injector for each cylinder, regardless of the injection timing. Actually, it's not my opinion, it's just the definition ("Multi-Point Fuel Injection"). The whole point is that you don't rely on the intake manifold for even fuel distribution from cylinder to cylinder. You rely on matched injectors. This gives a lot more flexibility in the design of the manifold, of course.

Sequential can smooth out your idle, but it doesn't make any more power inherently than batch fire. In fact, the factory sequential systems run batch fire at higher rpms anyway. Sequential has an edge in emissions, which is why all of the car makers use it. Eventually it will probably all become direct injection.

I'm sure you already know this, I'm just throwing it out there. But I do agree with your conclusion. What do you really get for this $1000? The must be cheaper ways to achieve the same benefits.

 

[k20]

I ran it on my 496, would I do it again, HECK NO! Hadta build the motor mild, hadta stick within certain parameters, had 0 power at highway speeds, punch it and it just got a little louder. Pulled it off, put on a carb, picked up some higher rpm power, not alot but some, blew that motor up, rebuilt it within some cajones, now we are ready to rock w/ a carb. Granted this truck doesnt wheel anymore.

Now wheeling when I never got any real RPM it performed well. I did not like all the wiring, if it broke, start swapping sensors.

 

[Thunder]

Blue. Totally agree with you about TPI and the EDL system being MPFI. I guess I was just trying to get across the piont that spending 1K or more for MPFI a system that wont give any more power. A TBI with the same or less $$ invested will out perform that system no problem. That edelbrock system is not tuneable for engine mods and very limited as to what it can do. It uses the stock 480cfm TB. Which is good for mabe 280 FWHP? I just cant see where any performance can be gained by it.
He would be better off building a TBI motor with bigger TB, injectors, custom chip. Or going with aftermarket programable MPFI if he wants to see any benifits for $$$ put into an engine.