I woulkd like to know what everyone thinks the pros and cons of a "TBI" system and a "TPI" system. I am just trying to get as much information on both systems so I can decid what way I would like to go with a rebuild.

Thanks
I will also be posting this in the TPI section so I can try to make an unbiassed decision.

 

I love my TBI. As far as beggining building blocks the TPI will be faster, but I think it's easier and cheaper to work on TBI. In the end it just really depends on what your future plans for the car are...

Bruce (90RS305)

 

Basically, what 90RS305 said. There have been many, many debates on the subject and pretty much all of them lead to what are your overall goals, and how much money are you willing to spend. Do a search on both boards.

 

TPI = money money money

But you have regular heads so you could buy an HSR or the like and be done with it...your L03 heads will suck though....

I REALLY wish I had spent the extra money on the ZZ4 Crate motor so I could have regular heads...If I had gone that route, I would definitely have TPI by now. Buying the damn scoggin dickey base alone is 400 dollars and there is no short runner tpi system for Vortec.

R90 and I have got into it about TBI vs TPI in a previous thread not to long ago...My posts will show you how long and expensive the TPI road is. His posts show how TBI can be exploited and how cheap it is comparatively. You can make around the same power with TBI for less money from what I've read versus a long tube TPI setup... Here is the thread.

https://www.thirdgen.org/techbb2/sho...hreadid=214627

Then again, TPI will open your world to supercharging. Basically, if you have cash coming out the wazoo and patience, go for TPI...But also realize, if you wreck the car you will NEVER get the money you put into it back from the insurance company, this is my main deturrant from going TPI...I have yet to decide.

 

This a very well brought up point. That is why I kept my TBI and decided to go through with a cam swap and what not. I am looking for some great street power after it is tuned. It will never be as fast as my stock 95 Z but it can be close and will still be fun to drive until i swap motors. But I wrecked the car and cancelled my collision insurance on it a week before I wrecked it. I was bummed until I found out that they would have only given me like 2000 for it. Hell I have more than that is the freaking wheels and tires. So it is a lose lose siutation kinda. But these cars a dime a dozen and you can always transfer your stuff over to another one. So now it is a project car that will get scary stuff plus mucho insurance.

 

At this stage of the game, I think it's time to run a TBI single plane, with a TPI computer. The syclone ecm allows for running a dual butterfly TBI without any internal ecm changes.

Take 2" bore Throttle body some BBC injectors, and start programming. Years ago I was running mid 13s with a cross fire, at a time where ecm hac'ing was in it's infancy.

One other avenue is using a late model E series tranny with a PCM. While I have gotten to the stage of having a fair amount of time in reprogramming it, my 91 BBC 4L80E setup runs glass smooth.

SBC, with a Weiand 7525, moderate cam, would make for neat setup in my book, and you can do that for alot less then any Port system would run you. And if you wanted to go port at some time later, add the injector bungs to the manifold, some fuel rails, and pump, and away ya go.

 

Grumpy, I'm considering if my transmission goes south, to look for a 4L60e and use the late model TBI pcm mask 0D to tune the whole thing. It has the faster aldl and trans controls with lots of features like an extended vol eff table. It's either that or syty ecm with a T56. This is all going to happen when the trans kicks the bucket or when somebody donates an ecm and/or etranny my way.

 

Grumpy, can you expand on this idea? I'm curious how to use a TPI computer with a TBI single plane. What exactly is the difference with the syclone ecm as well?