Would somebody compare and contrast the positives and negatives of the GM TPI system versus the GM TBI system? Thank you!

 

What you are asking for could turn into a huge report depending on what you are looking for. I'd recomend you just do some searches on these boards and you'll be able to find any info you need on what each system can do . Be wary of the TBI guys though, if they don't have slips/dyno sheets don't believe them. they carry a big chip on their shoulder being saddled w/ the worst top end GM ever put on a SBC and like to tell stories about how they made it fast. Not that it can't be done, just watch who you listen to, make sure hey are believable.

 

A little bit of info to set the tone.

TBI - Throttle Body Injection - Proven original fuel injection method from GM, used mostly on trucks and on weak car engines (LO3), 2 injectors on a carb bowl setup, 20% increase or so over carb setup.

TPI - Tuned Port Injection - Proven batch fire fuel injection setup, uses 8 injectors (one per cylinder), claims 30% increase over TBI. (not a true multi-port).

So anyways TBI is GREAT for a daily driving easy to fix reliable hassle free setup, if you don't want all out power TBI is your setup, it will never make as much power as a carb or TPI/multiport setup because most manufactures don't toy with it as it is an economy setup. Where as TPI there are hundreds of aftermarket parts for it.

Ok so pros and cons

TBI -

Pros - excellent fuel economy, easy to service and work with. DEAD *** reliable.

Cons - not a power making induction setup. Not alot of aftermarket selection.

TPI -

Pros - Excellent power making setup, you need torque TPI is your guy. Better fuel economy.

Cons - Must burn your own chips to achieve max power out of it when modding. Stock unit is very limited in airflow for large apps 350-400ci+. MAF sensor is expensive (SD is alittle cheaper but we wont go there right now)


Overall TPI is better for power TBI is good for ..... someone help me out here cause if your on this board you want more power plain and simple. But if you goto the TBI board, they have great ideas for TBI, which is almost the same as carb. if your on the TPI board then here is where all the possiblities have been achieved or are soon to be with stock and aftermarket TPI setups.

I know I have left huge wholes so hopefully someone will fill them in but I hope this helps for now.

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1989 Trans Am GTA, L98 5.7L TPI, TH700-R4, T-Tops, dual cats, 9-bolt rear, 3.27, Dynomax muffler, K&N
1992 Camaro RS, LO3 5.0L TBI, T-5, T-Tops, 3.08, L69 Dual Snorkel, K&N - Sold

Honda engines ROCK, I have one on my lawn mower but I still have to push it.

[This message has been edited by Drakar (edited September 19, 2001).]