Okay guys, I am installing a TPI from a '86 TA 5.0 into a brand new 350, pushing about 300hp, then shoving it all in a '86 Caprice Classic.

Basically, I need some help finding some parts, and some of your expert advice.
I first need a new wiring harness, mostly so that I can convert from the MAF sensor to a MAP one, so I can just put a K&N on the end of the TB and be done with it. I found THIS ONE, and it seems exactly what I want, especially since it comes with a new chip, MAP conversion, and it seems pretty simple. However, I have never heard of this brand and am just worried about quality issues, as well as if the price is right. For comparison, I found a complete harness from Painless in my Summit for ~$300, and I think I can just get a '90+ year, and this will make it MAP.

also, what other stuff do you think I need to complete this? I know I need ~22lb. injectors just so the TPI can keep up with the 350, but what else should I consider? FYI, I really don't have that much money to start throwing around, so nothing really expensive. I am not worried about straight hp (going from ~150 hp from a carb to ~300hp from a TPI is good enough), just fuel milage, driveability, and pretty good simplicity (for ease of conversion).

So does anybody have any suggestions? Ask all the questions you want.
Oh, and a big :hail: goes out to everyone who can help me

 

You sound like you have it down pretty pat. But what about is your budget for this build-up. If you have the ECM and harness for a MAF then i wouldnt even worry about going with a SD set-up. Spend the money in Injectors, Prom, AFPR. What motor are you putting the intake on?

 

Also being a Caprice you prolly have a highway gear (2.73). Might want to check into getting a lower gear, more like a 3.42, or something close to that.

 

Don't know if this will help you any, but did you try this place?
http://www.speartech.com/

 

budget? Nothing
actually, I am about to turn 16 (but please don't look down on my because of my age. I am VERY advanced in cars, and know a lot of stuff as well) and I got the motor given to me, and I got a whole '86 TA for like $300, including a fairly new 305, pretty good TH400, he TPI, nice seats, windshield, back hatch, etc. In all seriousness, I work like crazy whenever I can, but I also have to pay for my insurance (talk about a PITA for a 16 yr. old), gas, and just about everything else for my car. Granted, I have about a year of insurance stashed away, and I have all the major parts to get this new motor done (my old motor runs fine BTW), but I just don't want to blow $700 on a stupid wiring harness if I can help it. Am I making any sense?

Also, for this crate motor, I got it (for free, as I said), and I haven't even taken it out of the crate and plastic yet to read some of the info. All I know is that is should be pumping out somewhere near 300hp, its a 4-bolt main, and-erm-thats it lol. I saw this motor in Summit that looks damn close to mine, but not 100% sure this is it.

I just wanted to bypass the MAF because, on the TA, many (if not all-except the MAF sensor) of the parts that go from the TB to the filter are either gone or in REALLY bad shape. I already bought a K&N that just goes on the end of the TB, so I just wanted to use that, but I dunno now. BTW, what is a AFPR? By prom, you just mean the chip, right? Of all the research I did, I never got a full definition of what a "prom" was.

And for the gearing, I just have to ask "why?". I know it would make performance easier and all, but I really have no need to change gearing. I just want this thing to cruise pretty nicely, and the gears in there right now will also save fuel, no? Remember, that is one of the things I am really looking forward to. Do you think I could salvage the gears from the TA? It had like over 200k on the odo IIRC, but I really don't know how good the rear end is. It seems pretty rough, but he might of had the gears redone, I dunno.



Thanks for the inputs, though:hail:

 

just sent an e-mail. Will let ya know what they say

 

AFPR=Adjustable Fuel Pressure Regulator
PROM=Programmable Read Only Memory (Chip)

The $300.00 your talking about spending on getting a MAP harness you can take to the junkyard and get a intake hose of another car. As for the K&N, all youll have to do is cut the intake infont of the MAF and put it on there. Although my 91' GTA has that same K&N and i made my own intake and put the K&N on that b/c when i had it on my TB it sucked hot air the whole time. If you want to go to SD then you gonna need more than a wiring harness.

Also is the harness you talking about $300 or $700?

 

I understand what you are saying about the K&N sucking hot air all the time. I might have to fabricate something that will route the air somehow. Anyways, for the harness, it is $300 for just a Painless harness for '89< cars (or whatever MAP cars were), but on that ebay site (look for the link on my first post), it had everything, but for $700.

 

I'd definately advise going with the SD system if you can. The GM MAF cars are really twitchy (I know because I'm living with one). The GM MAF system is garbage compared to the Ford EECIV MAF setup. GMs SD system is a lot better that their MAF (though still not better than Fords MAF). You will definately need a custom PROM with an SD system, or the car will run terribly.

You may be able to just convert your existing MAF harness to SD, since they use a lot of the same sensors. Do some checking on this forum, and/or call some knowledgeable people like AS&M or TPIS to see if this is feasible.

 

I know, I really do want to convert to SD. My only problem is actually finding a fricken harness that will complete the transfer

 

TPI installation into a brick Caprice has been done before, but usually into the 1989-1990 models. When this is done, it becomes a TBI -to- TPI convertion, so the ECM harness is already in the car, and many of the same connectors can be used.

It might be easier to duplicate that approach -- by finding a boneyard brick-style Caprice having the TBI (1988 with the 4.3 v6, or 1988 v6 TBI 4.3 Caprice, or any 1989-1990 Caprice, all TBI), and then obtaining the entire harness to use in your 86 Caprice. Then you could use the many TBI -to- TPI swap posts here on TGO to deal with converting from TBI to TPI.

You MIGHT also be able to use the wiring harness from any 1991-1993 Caprice, since they were also TBI, but keep in mind that the ECMs used on the 91-93 Caprice was different than used on the 1988 and 1989-1990, and you really want to choose the harness based on the one easiest to swap into TPI use. So that means you need to do your harness homework first. IOW figure out what ECM you want to use with the TPI, which means you need to choose MAF or SD, and THEN look for compatibility between that type of FI and the Bcar harness you want to use. You are probably also going to want to have an FSM (factory service manual) for the model/year of TPI.

Lastly, it's not that hard to remove and rework GM connectors. This means removing the old pins and replacing them with new pins + wire. I learned this from a neighbor so now I keep a collection of connectors on-hand for various automotive projects. This would be a very handy skill to have in your project so that the swap looks factory when you are done.

Here's one swap I know of, TPI into a whale style Caprice

http://www.geocities.com/quincimus_max/prowl.html

http://www.geocities.com/quincimus_max/prowl2.html

I don't know whether there are any clearance issues for the distributor under the cowl, but IIRC it's easier to install a TPI into a brick Caprice than it is to install into a whale Caprice.... but the swap has been done before so there is a way to make it work. GM stuck a TPI into a brick Caprice stationwagon a few years ago and they used it as a repair/chase vehicle when they tested the mule (protoype) Corvettes. I've also seen other examples on the web, if you search for them.

As someone said, John Spears has done TPI installs into Bcars (whales) but I'm sure he could do them into a brick as well; website:

http://www.speartech.com

I suspect though that you would be better off using a factory harness, so long as you can get a complete one.

Other useful stuff:

http://home.earthlink.net/~gellett/tpi.htm

http://www.factoryautomanuals.com

HTH.

 

The TPI won't make 300 hp at the flywheel. Do some back reading here to find out why -- TPI is great for torque at mid engine speeds, but it was not designed for big power at high rpms. TPI was designed to overcome poor fuel distribution in the L83 engine, to have Corvette-capable looks, and to provide good-enough Corvette power, for the 1985 Corvette L98 350 engine. GM's highest rating on the L98 was 250 fwhp IIRC, and it's tough (and expensive) to get much more than that from it --- because of the small size tube runners. TPI can make more power, but it's also easier to jump to a different intake manifold like the Superam, or the LT1-intake, because these overcome the factory Midgley-designed TPI intake.

AFPR = adjustable fuel pressure regulator

PROM = programmable memory, i.e. this is where the code for the computer-controlled engine management resides. Also called an EPROM for electronic prom.

You will need to read a LOT to learn some of this stuff, and my best advice to you is to keep the engine bone stock for now. You will have enough trouble getting the engine installed and running, and adding a TPI-capable fuel pump and return line, nevermind messing with mods. Especially if you have no money. HTH.

EDIT: get a 91-93 Caprice plastic fuel tank and use it. It will allow you to bolt in an L98 or LT1 fuel pump (fits directly) and the tank already has the feed + return line. The tank will bolt into your 86 Caprice because the frame on all 1977-1996 Caprice/Impalas are the same.

 

No stock TPI made 300 FWHP, but plenty of modified ones do. You do have to change a lot to get that kind of power though. For an NA TPI you'd need different heads, highly modified or aftermarket intake system, a better cam, and a full exhaust.

If you want to huff on it them it's easy to get 300+ FWHP from a TPI with a blower without any other modifications.

 

all of your help is great, and I really do apreciate it.


However, I think that I am just going to go with everything stock for the electronics, maybe a new PROM, and that is it. I will do a bigger TB and 24lb. injectors, but that should be all. I think that going to SD is a bigger hastle that its worth to me, and since I really don't care that much for performance, I wasn't planning any engine mods at all. I am really just wanting good fuel mileage, and I will like the torqueness of the TPI sytem. Also, since my crate engine redlines at about 5500, the TPI is a better setup than the short runners anyways.

For literature, I was just planning on getting the book that is like "How to Install TPI on crate motors" or somethin like that. Hopefully this will be relatively simple, and I won't have to worry about to much electronic BS, as it seems very expensive

 

Don't waste your money on a bigger TB. On a stock motor it isn't necessary and won't improve power much, if at all.

 

even if its a new crate motor 350 (or more importantly) at 300hp? Remember, my TPI is off the 305.

 

The 305 TPI intake is the exact same intake AND throttle body that GM used on the 350.

The only difference is the 305 has smaller injectors and a different PROM chip.

You will need bigger injectors for your 350.

 

ok.
Is the TB on a LT1 any different? Are they interchangeable?