Hey guys im a newbie to this world and ive been reading up on my new car that im about to get whitch is a 92 Camaro RS and the only difference is that it has TBI fuel injection rather than TPI. I was just wondering what the difference is between the two other than 20 horse power.?

Thanks

 

try a 50hp difference. the TPI heads are better and has a better cam. the TBI motor was very restricted.

 

while you are in this board, TBI is better for everything, including performance, as long as you replace the heads, cam, intake, exhaust, and gears. seriously though TPI as a larger aftermarket and is considered a higher performacne system by many.
others can tell you many other differences and i am sure somebody will toss the metal spyder thing in...

 

Money is another difference. The aftermarket is huge for the TPI but it is also very pricey. TBI stuff is relatively cheaper and is easy to modify. That is prolly because you have to modify it to see any power.

To me TBI also has the old carb look when you open your hood.

 

Well, to make the comparison more even, let's take the LB9 automatic rated at 190hp and the L03 is always rated at 170hp. The difference in the heads is at least worth the 15hp. The exhaust systems are relatively the same and the camshafts are the same, we can also assume that the 5hp is made up of because the TPI uses it's MPFI batch fire to achieve this better efficiency. But if we take into consideration that the stock TPI throttle body is rated at 500cfm (I think I'm right, someone correct me if Im not), and the stock TBI is rated at 520cfm dry flow (480cfm wet flow), then you have to figure that the TPI is moving more air into the cylinders.

 

TPI is also quite restricted in airflow (stock TPI), but at a HIGHER level than our TBI. So it does perform better (from the factory) than the TBI cars, but you hit a brick wall when trying to cam a stock L98, for example.

Iroc22, I think our Rochester 220s are rated for far less flow than 480cfm!!
I'm thinking ~300.
Someone might know for sure.

 

Well i think that explains it then. The first thing that i learned about motors was that the more air flow through the carb the more power you get. Im thinking about getting a Cold Air Intatake and one of those big K&N filters. The exhust is modified on my car. I have Duel Flowmaster with a 3 inch pipe on each. Does the exhust help give more horse power also? I have heard that it does but i have also heard its just there to make it sound louder.

 

How about the 230hp Lb9 305 TPI? Lets not forget that now.

 

The reason why I used the auto LB9 as comparison, is because it uses the similar sized exhaust and same cam. It's the closest TPI engine to the equivalent TBI. The 230hp LB9 has a bigger cam and the entire exhaust is bigger; from the manifolds to the muffler.

 

camaroboy92RS

A better Exhaust System is good because it helps the Engine Breathe and Perform better. It's like the difference between breathing through a straw or breathing through 10 straws.

Hope I explained it right.

 

TBI looks like a garbage can lid, and TPI looks like a metal spider humping your engine.
Just had to say it!

 

Not on my car! or any 91-93 Caprice for that matter.

 

It sounded to me like you were looking for more of an explanation of the mechanical differences. TBI if pretty much what the abbreviation means TBI= Throttle Body Injection, which means that it uses injectors (2 in most cases) to add fuel just above the throttle plates, which makes it a wet manifold system because the air and fuel both travel through the intake runners to the engine whereas Tuned Port Injection which uses 1 injector per cylinder to add fuel just before entering the head, which is refered to as a dry manifold system because on air travels through the intake runners.

 

All things considered, if we compared a TPI vs TBI with identical everything save for the injection method, a TPI will hold that 20 HP and 25 ft/lb boost over the TBI injection simply from air fuel delivery method alone. We're talking more air, more fuel and at that an even distribution of fuel to each cylinder. The only problem I find with TPI is that its giving it fuel not when each cylinder needs it, hence why I'm such a SFI fan.

As for modding no matter which engine you get, from the factory they are probably the most restricted engines ever designed. Intake and exhaust are jokes. Need to replace them asap. The cam on the LB9 and LO3 are peanut cams. Need to replace those.
The only thing you'll find is that TPI systems are expensive. Do not use the multecs. They are crap and almost always guaranteed to fail. Also quite costly to replace.

As far as what the TBI stock can flow.. I don't even think it can do 480CFM well... Either way, its a straw breather that will eventually have to be ditched.