Fuel Injection

[Robby1870]

Alright, Im just curious on this stuff. I know what TBI, MPFI, and SFI are and how they work. But, Im curious as to exactly how TPI and Center Point Injection work. I think Center Point in like TBI, but I want know what is different. Hope someone can help me, or direct me to where I can find this info. Thanks!

 

Robby

[paulo57509]

Check here:

 

http://www.thirdgen.org/newdesign/faq/thirdgen.shtml

 

Scroll down to the Engine/Induction/Exhaust section.

[Guest TurboSedan]

as far as i know, TPI (Tuned Port Injection) like the Corvette L98 is really just another way of saying MPFI. i see our 2.8/3.1 MPFI engines as mini-L98's i guess....with the long tuned runners n'stuff. i'm not sure about the CPI, like the ones on the '90's 4.3 Astro Vans but i think it is maybe a fancy way of saying TBI. or it could mean Center Port Injection.

 

TBI just seems like a fancy carburetor to me. my .02 anywayz...

joshua

[Robby1870]

Thanks guys. Yeah, our 95 GMC Safari Van has the CPI. I Thought it was Center Point, but maybe Center Port, that makes more sense. And, I think it is like TBI. Good to know that about the TPI. Most TPI engines I have heard of dont make THAT much power. And, I guess I was just curious at to why. Yeah TBI is just a fancy Carb.

 

Robby

[GPRACER]

I think that CPI stands for computer port injection, but I may be wrong, The newer 4.3l vortec engines have what looks like TBI, but in reality its a type of MPFI or SFI, there are actually 6 injectors you just can't see them as they are inside the upper intake manifold. I wish I could find a picture, it's kinda hard to explain, the whole assembly looks like a big spider.

[GPRACER]

tried to post a pic, didn't work.

[NOHC_WBody]

Thanks guys. Yeah, our 95 GMC Safari Van has the CPI. I Thought it was Center Point, but maybe Center Port, that makes more sense. And, I think it is like TBI. Good to know that about the TPI. Most TPI engines I have heard of dont make THAT much power. And, I guess I was just curious at to why. Yeah TBI is just a fancy Carb.

 

Robby

 

Yeah, but the TPI's make a hellafied load of torque.

 

http://www.eecis.udel.edu/~dzug/92z28/406project.html

 

Scroll down and check out the dyno graphs near the bottom. Near 400 ft lbs of torque out of basically a stock motor

 

TBI's suck. I had a 305 TBI Really Slow Camaro a few years ago. Talk about having to make an appointment to get to 60.

[Robby1870]

yeah that is a shit ton of torque. Yeah the TPIs are good for torque, you are right about that 305 TBI. That thing is best used as a boat anchor. Chevy doesnt know how to make a 5.0L motor. Ford does, the 302 is potent. Chevy should have stayed away from a 5.0L. I Think they learned that though.

 

Robby

[NOHC_WBody]

[edit] Double Post

[NOHC_WBody]

Chevy made a BAD ARSE 5.0 back in the day. The DZ-302. 67'-69' F-Body.

 

The pitiful thing about the 305 was that it's just a debored 350 block. Same 3.48 inch stroke, but small bores, and crap heads. The only good thing about the 305 is that despite all it's shortcomings, it's still a SBC. Everybody and their brother makes parts for the SBC.

[Robby1870]

Chevy made a BAD ARSE 5.0 back in the day. The DZ-302. 67'-69' F-Body.

 

The pitiful thing about the 305 was that it's just a debored 350 block. Same 3.48 inch stroke, but small bores, and crap heads. The only good thing about the 305 is that despite all it's shortcomings, it's still a SBC. Everybody and their brother makes parts for the SBC.

 

Yeah, I forgot about those older 305s. I was mainly referring to the mid 80s and early 90s 305s. But you are right, there is a lot out there to build them up

 

Robby