I have a 1992 camaro rs with a 305 lo3 (that's tbi...). I want to put a tpi in it. I already have the pair of runners, plenum and intake manifold. What else do I NEED (as apposed to what I should DO)?

 

Wiring harness relays and sensors, ecm w/prom, fuel pump, throttle cable, kickdown cable, dual fans, and a six pack (for afterwards)
I'm probably forgetting some stuff, but I did it 15 years ago.

 

Painless wiring sells a new TPI wiring harness but it's pricey. I'd look for a good used one personally. I'd also try to narrow down the year you are looking for. You can go MAF or speed density. If you decide on one or the other you'll need to get the appropriate stuff from the proper year range they were offered. You'll also need a matching ECM for that. If you have a 305 you'll need the 305 knock sensor as it's different than the 350 knock sensor despite looking the same. You'll want to avoid a TPI setup from 1985. It was a one year only wiring/ECM setup. It was available on both Corvettes (L98, 5.7L engine) and 1985 TRANS AMs/IROC-Z cars equipped with the "LB9, 5.0L" engine. You'll want a newer ECM and to flat out avoid the 85 ECM and wiring. 1987 through 1989 TPI cars used TPI with MAF sensors which also came on both 5.0L and 5.7L engine equipped cars. 1990-1992 used speed density TPI which eliminated the MAF sensor and extra duct work from the front of the engine bay. Additionally fuel injectors and fuel pumps differed between years and engines. 305CID TPI engines used 19lbs. injectors while 5.7L engines used 22lbs. injectors. In 1985 a 45PSI fuel pump was used while other cars had a 47PSI fuel pump in later years. Some year models use a 9th fuel injector which is also known as the "cold-start injector" while later year models simply dumped more fuel into the engine in colder conditions via all 8 injectors. If you have TPI fuel rails from a 1985 car and want to go to speed density TPI, you'll have to plug that 9th injector hole. I have heard of people installing the 9th injector and leaving it disconnected so that it can't fire. I do not know if this really works or how good this solution is in practice. There is a "plug" that someone makes for this type of conversion.

Not to scare you, it isn't as daunting as it sounds to do the conversion. It is just that the devil is in the details when it comes to this type of swap. You may also want to snag some LB9 heads as I believe they are better flowing than the L03 heads. In addition you may want to grab a different cam as the one in the L03 will be less than impressive even with TPI under the hood. Someone can correct me if I'm wrong but I believe you can use the L98 cam with a 305. I know you can use a LB9 cam, but you'll want to be careful what year models you snag the cam from, lest you end up with the dreaded "peanut" cam. It would be a good opportunity to throw in an aftermarket cam at this point and then have your PROM tuned for your new TPI setup. If the car is going to be down for a bit while you swap this stuff, you might as well do a few other things and boost your performance even further while you are at it.

 

so i NEED a new fuel pump, wiring harness, ECM, throttle body, throttle cable, kickdown cable, duel fans, MAF, and some 22lb fuel injectors?? do i need new fuel rails?

 

Are you swapping in a 350 or converting the 305?
a 305 would use 19lb injectors not 22

 

oh, thanks. did the rest of the list look good? i dont wanna start buying things if i dont need them

 

You need the following:

1.) Fuel pump
2.) Wiring harness
3.) ECM
4.) Throttle body
5.) Throttle cable
6.) Kickdown cable,
7.) Mass air flow sensor (MAF)
8.) MAF ducting,
If going with speed density TPI, MAF and ducting aren't needed.
9.) 19lbs. injectors
10.) Fuel rails
11.) TPI plenum
12.) TPI runners
13.) Idle air control valve
14.) Throttle position sensor

The dual electric fan setup isn't necessary. I've seen some cars that don't have them. My 1985 TRANS AM came with a single electric fan instead of the dual electric fan setup. My 1987 TPI car that I had a few years ago came with the dual electric fan setup. It may be a year by year thing, but I know of at least one person who had to wire up the second fan in the dual fan setup to a manual toggle switch as the relay that controls it kept failing. No SES codes have been generated from that, but given that the previous owner burned his own PROMs he may have changed the PROM in a way that eliminated the second fan from being controlled by the ECM. I don't know for sure as I've never had a look at the software or burned any PROMs yet.

 

wow, thank you so much. that's EXACTLY what i was looking for, but thanks to everyone else for your help as well. but would switching out the stock camshaft to a "performance" camshaft increase my horsepower? if so, by how much?

 

It will depend on how mild or wild the cam is. You'll need to have the car's PROM tuned after changing the cam beyond something only slightly more mild than the stock cam. You'd gain a LOT more by switching the heads out with the cam but that gets expensive and there are few options for the 305 in general. My guess is that a fairly mild cam would net you another 15-20HP depending on what you go with. I'm by no means an expert on cams so my guess is only semi-educated. Perhaps someone else will chime in on this. You might want to give Comp Cams a call and see what they'd recommend for your setup and what kind of gains you'll see with any given camshaft.

 

thanks for the advice, bro. that kinda sucks that there aint that many options for a 305. i want power, but with the ability to get over 15 mpg as well...a task wuite hard to accomplish on any built big block

 

The L98 (5.7L engine) will get the same gas mileage using TPI as an LB9 (305CID/5.0L) engine. Also the 350 is the same physical size as the 305 in regard to external dimension. Anything up to a 400CID engine or greater are also considered Chevy small blocks. With the right intake/fuel injection setup you can still get decent gas mileage and make a ton of power. Newer LSx engines do even better on gas mileage if your really concerned about it. I get about 16MPG/28MPG on my LS2 equipped GTO. It makes 400HP and 395ft. lbs. of torque at the crank. The car is completely stock and I can basically take most stuff on the street so long as I shift well. In a third generation car it would do even better. The F-bodies are MUCH lighter than the 2005-2006 GTOs are.