I have a 92 RS with a 305 TBI and i found this engine online thats a TPI 305 from an 87 iroc and it has 60,000 on it , and my engine right now has 120,000. i was wondering what kind of wiring/computer mods am i going to have to get to make this work.

i know i have a MAS sensor in the one i have now and i think in the 87 theres a MAV? possibly if i remember correctly.

also, if i got TPI from a 92 would i need to do any computer mods? i know id need to get a wiring harness to hook to each of the injectors.


P.S. I want a 305, I want more power then 170 in my RS, but not so much that im gona lose gas mileage, so no 350.

thanks lol

 

Are you swapping engines because of the mileage factor, or because you think you'll make more power with the tuned port setup....?

 

im swaping because i want to get more power, the cams and heads from the RS 305 are cr@p people keep telling me.
but im not so power hungry that i want a 350.

 

If you go with a stock TPI, you'll just be starting from scratch all over again with a system that still needs work to get you there anyway. Don't waste your money. Consider running a dual carb intake, but with two TBI throttle bodies (w/adapters of course), and have RBob hook you up with his EBL to control fueling and spark for both (Click Here). From there, your a set of cylinder heads and cam away from making some excellent power....

 

ok thanks. im gona look more into this engine tho, because he says that it has 265HP, but i know for a fact thats not stock, so im gona see what he has done to it.

also i was gona get new heads and cams anyway, but i really like the look of the stock TPI with the RAM air intake. :l

 

You'll basically be swapping the entire TPI system, including the intake hardware, computer, all of the computer wiring harnesses and sensors, and fuel pump. Along with the little things that are different like radiator hoses and throttle cables.

And the complete exhaust system. One of the main restrictions of the LO3 is the exhaust, from exhaust manifolds to the tail pipe tips.

 

what exactly are you saying?

 

Okay, I may have confused what you were saying with another member's TBI to TPI swap. But, along with replacing the engine, you'll be replacing the harness that goes from the TPI to the computer, dropping the tank to replace the fuel pump, and if you really want more power out of it when you're done, you'll replace every piece of the exhaust system now on the car. Don't forget the air intake/filter system (contains the MAF).

And replacing little things like the upper radiator hose, throttle cables, fuel lines from the chassis lines to the TPI, etc.

 

Or, you could just put the TPI engine under your TBI system, and replace the exhaust system. That may require computer retuning, but you may get by fine with a stock tune.

 

oh ok thanks. i already have a new exhaust system for what i have now, and ill do what i need to do for the radiator hoses.
but i know i would need new wires atleast to hook up the injectors. i knew about throttle cables, and fuel lines, the gas tanks already out so that wont be a problem.
how could i go about with getting the MAV sensor to work? or could i somehow use the MAP sensor i already have and install it into the new throttle body?

ive been reading --- https://www.thirdgen.org/tbitotpi --- to find out what id have to do using a new engine or just converting my stock engine over

 

It's much easier to remove the TBI computer and harness and associated sensors, and install the TPI computer and harness and associated sensors.

I know I guy who repinned a TBI harness to TPI - I thought he was crazy. He admitted afterward that it was.

 

haha ok then.

so would the computer i need to change be the same one/ones that are inside behind the dash?

 

Hope its not the exhaust that came with the LO3, that and the LO3 cam are the main parts to build a 305 that makes only 170hp, no matter wat EFI or carb you slap on it.

 

oh no no no, its a 3" magnaflow catback, im gona get headers when i pull the engine.
and yeah i know the cam is really bad,

 

http://www.tpiparts.net/home They have nice tech articles, covering the TPI swap and the MAF years.

 

Using a 90-92 TPI harness would cut down your modifications to getting the speedo to work. Moving a C207 pin and bypassing buffer box. Everything is plug and play

Its not going to get around the Lo3 heads or cam though. Why not save up for a little while longer for a better platform like LTx or LSx

 

Just so we all understand: Are you planning on putting a TPI system on your 305, or are you planning on swapping out your engine and TBI with an engine that comes with a TPI set-up?

You haven't been clear at all what you intend to do.

 

either or acctualy. im either going to convert my current engine to tpi and then replace the cam and heads. or get another engine. either way i do it i want to run a TPI not tbi, thats what im trying to figure out.