herzog

I've been considering this for a bit now, and I'm curious to hear from any who have done this. I have the book "Chevy TPI Fuel Injection Swapper's Guide" and have thoroughly reviewed the site http://www.chevythunder.com , but I am a little concerned about clearance issues with the belt-driven accessories. At a glance, it looks to me like the power steering pump is going to be right in the way of at least the water neck and possibly the throttle body as well. I'm anxious to find out what brackets/accessories I will need to acquire. Also curious to know if an 85 or later fuel pump will be a drop-in replacement (I realize I have to upgrade the lines). Interested in hood modifications for the air intake, although I figure worst case I could put an air filter right on the end of the MAF sensor (I think I read somewhere that K&N makes one that fits there).

I should state that my car is completely stock, and will only be driven on the street. I am only doing this for a little more power/efficiency and, of course, the "fun" of it. Not too long ago, I acquired an '85 Corvette TPI setup from eBay (complete intake, injectors, fuel rails, sensors, ECM, wiring harness, relays, MAF sensor, air cleaner, distributor). Unfortunately, I'm missing the MAF controller (separate on 85). I'm considering looking for an 86 ECM and just buying an aftermarket harness, but I believe I'll then have to deal with the VATS issue. Thanks!

bogus

you know, for the $$ you might want to look into the aftermarket options. Holley and such all make a rather nice stand alone injection system that will provide more power potential than a stock TPI system.

Check Summit Racing for some pricing options.

CFI-EFI

The last one I know of to do this conversion was back in 1985...Chevrolet. You will spend waaaaay too much money for waaaaay too little gain in performance, if any. The fuel pump is a drop in. The fuel lines, at least to about the rear of the block, are the same. After that, the distributor MAY be the only other reusable item in the induction/emissions package. The ECM is different, The engine wiring harness is different. And as you noted, the front of the engine accessory package is different. Do yourself (and me) a favor. Get a good sized shovel and use it to fill a bushel basket with CASH. Package it up and send it off, prepaid to me. Then call the project complete. This will save YOU, lots of money, time, and aggravation. It will give you basically the same performance, fuel mileage, and be WAAAAAY cheaper.

Plan B? Trade the car that would be more suitable to YOUR tastes.

RACE ON!!!

plainswolf

Change the distributor, get a good dual plane intake manifold and carbuerate it.

TheStef

I have to agree,

I wouldn't even jump in a engine mod like that knowing that little HP would be gained.

I would go for an engine swap before doing that, maybe putting in an LT1 or LT4 would be a better idea or selling the car and buying a TPI.

Frizlefrak

As the others said, major pain in the rectum for little performance gain. Don't go backwards in time and technology and hack up your car... just improve the crossfire. Start by going here.

http://www.crossfire.webhop.net/

These guys are experts in the crossfire induction system, and can show you how to easily make your crossfire smoke a stock (or even modified) TPI like a fat one. Your intake is the major restriction on the crossfire, and there are several options you have to overcome that limitation. Either port your stock intake, or go with an X-Ram

http://www.x-ram.com

If you're good at fabricating, there are other intakes you can use as well.

Nothing quite as funny as the look on a Tuned Port owners face when your crossfire hands him his butt.

joesred84

I also agree, the cost and efort will be significant. One of the biggest concerns may be the hood clearance. The 84 hood does not have as much clearance over the intake as the 85 and up. The 85 and up GM fuel pumps are a direct replacement and may provide a pleasant suprise in improved idle and throttle response. Especially if your existing pump is original. It is an easy change the pump is removed through the filler area, you don't have to remove the tank or get undr the car. If you want to play with your car, check out the crossfire forum listed above. If not, a trade up to a TPI car will probably be the least costly and stressful.

herzog

Thanks for all the replies! I hate to admit it, but I think you've all convinced me to abandon this project. Although I think I had already considered all the options mentioned (I've been planning this for a while). I am starting to feel the benefit is not worth the effort, especially in comparison to other options. The prospect of modifying my hood and chasing down accessory brackets is seeming less and less appealing to me. I think my original desire was due to the fact that I was feeling a little like I "settled" for an 84 when I was originally looking for an 85 or later. All the TPI C4s I had looked at in similar condition were at least $4k more and I couldn't pass up an 84 that I could pay cash for and drive home. I'm pretty certain I could do the project for less than $1200, not counting my own labor of course. Besides cost difference, the other reason I don't want to just look for another car is the "fun" of a project and having something that is a bit different in the end (I know, this has been done already, but still).

I had been strongly considering Edelbrock's stand-alone setup (thanks bogus), but my only concerns were cost and meeting emissions requirements. Although this does seem like a better alternative as far as effort/aggravation and certainly has way more potential.

TheStef, I definitely have to admit that an engine swap looks like a much better solution if I do want to go TPI (or LT1 or LT4), as mentioned. I have been looking at a complete (all accessories, wiring harness, relays, ECM) TPI engine from an 86 with fewer miles than mine on eBay. The LT1s and LT4s I've seen are beyond what I want to spend (not surprisingly).

Frizlefrak, thanks for the links, I have been a member of the Crossfire Injection Vault for a couple months now, I was just determined to convert to some form of port injection (even if it's batch-fire). I think one of my underlying reasons was efficiency/fuel economy, even though in practicality it is relatively insignificant (I'm nuts, I know). However, I do realize an X-Ram would be more bang for the buck, in terms of power; I will definitely reconsider going that route.

Now, anyone want to buy a TPI setup?

CFI-EFI

I understand wanting to face the challange. I've been reasonably successful with my Crossfire, for a very minimal investment. I have a ported stock intake casting. There are other, very capable, injection systems out there, but a stock TPI isn't a worthwhile alternative.

RACE ON!!!

Rohn

i took my stock CF and made significant mods to it. i went the XRam for induction as well. now i am removing the xram(2.00 TB's/ 80 lb injtors) next month and maintaining the single plane and adding the 7.4L TB. my measurements show more than adequate clearance to hood. i found in a cool environment the Xram was having diificulty with atomization and drivability until heat soaked. had i done this initially i may have saved a few $$$. my WB02 i feel confirms the Xram has bproblems with cold plenum. feel free to email me if you have any Q's on any mods you are contemplating. my car is not emmishions complient.

Ramanstud

Well...

I HAVE done the conversion, and it really wasn't that bad. Contrary to popular belief, there are a few good reasons to switch to a MPI system from the crossfire- I did it to pave the way for a much simpler forced induction package in the future and modest gains now. I do recommend avoiding a stock TPI setup, but it can be usefull to perform your overall GOALS in small steps- such as swapping out ECM and harness, intake, and working out the assorted bugs inherent in any such endeavor. Then when money allows, trade up for a superram (as I did) or other intake.

However, I also agree that you're better off getting a complete system (Holley, Superram package, whatever) to avoid some of the pitfalls that can crop up with tuning, ECMs and max performance. And frankly it's just easier when all of the parts needed come in the box.

Now for clarity: The distributor is the same. Any TPI-style intake WILL fit (except for the Holley Stealth Ram) and you CAN run air ducting through the normal spot if you remove the AIR pump (then one in the middle) and use a shorter 85" belt. The ECM and wiring harness will need to be replaced, though ChevyThunder has an *excellent* conversion harness should you decide to remain GM and go with a -165 ECM or later. Fuel lines are the same up and to the bottom of the block (where the block-off plate goes), a simple fix is to run braided line from that point to where ever you need it. I updated the rubber lines at the fuel tank with high pressure rubber lines. The fuel pump is the same. The TPI-style waterneck / thermostat fit fine with the AIR pump removed, and I made my own adapter to fit a MAF sensor AND a K&N filter on the end of the stock TPI throttle body without modifying the hood or radiator shroud. It WILL fit.

Emissions will be tough to retain (visually) in a conversion, just because the parts are in different places and usually get in the way, are a pain to reuse, etc. But you can probably pass the sniffer with a well-running and properly tuned engine.

In short- you can do it without taking out a small loan or selling the car, you just need to decide what you want to do with it and how best to get there. I can provide pics and any advice necessary, should you want to convert your car. My initial swap probably ran around $900 including new SVO 24# injectors, but I upgraded piece by piece to a superram, aftermarket heads, and tuning equipment to where I am now at 325 HP and 465ft-lbs of torque (mild cam), compared to the stock rated 205HP and 320 ft-lbs. I'll get headers when the fundage comes in... lol.

I converted my car for (more or less in order):
1. naustalgia - I grew up with the car and wanted to keep it. It's special to me.
2. I couldn't afford to go *****-out with my intake swap, heads, injectors, etc, so I had to do it incrementally (and in a parking lot).
3. I want to eventually get a supercharger- these don't mix well with CFI though it has been done.
4. I thought it would be fun.
5. I want to do my own tuning.

Your reasons, budget and goals may be different. In retrospect, I would still have converted my car, but I would have saved up and gotten one of the "packages" that have been mentioned, such as the holley or Superram deals that has everything you need in a box.

let me know if I can be of help.

GiDvEtTe84

Read:
http://www.crossfire.webhop.net
http://www.speedtronics.net
http://prominator.homeip.net
http://www.thirdgen.org

The advances we've made on CFI/TBI injection are far to great to dump for a TPI system for a measly 25 or 30 hp. We also have something else up our sleeves but youll have to come over to find out.

ROYSREDROCKET

I DID THIS CONVERSION TO MY 84 AND WHAT I DID WAS BUY A BELT DRIVE ASEEMBLY FROM E-BAY FOR 200 BUCKS-A TPI FROM E-BAY 300 BUCKS PAINLESS WIRING HARNESS #60203 SPEED DENSITY HARNESS 300 BUCKS -VATS MODULE 25 BUCKS #1227730 OR 16198262 COMPUTERS ABOUT A HUNDRED BUCKS.

MidLCrs

Thanks for the info! I will look into it. I just bought an '84 with 120K miles. After a major tune-up, recharged A/C, TCC Solonid(?), alignment and balance, its running decent. I also have been looking at the best way to get more performance- street- out of my car. Am getting a complete Flowmaster next week.

Light84vette

Look for Joby on the Crossfire forum, he has installed a supercharger, if your have some fabrication skills then this to can be replicated. I dont know how much power he is making but it is pretty decent.

Or you can go back in time like others have complained not to, I have bolted on an airgap intake with a 750 vacuum seconday holley, it clears but the cover lid wont fit. So right now I just have a drop base with a 3inch air cleaner that snugs up against the hood to make a good seal so its only breathing filtered air. Other then that I also changed the engine for a 406 and dual 3 inch exhaust, but you could replicate the same thing without messing too much with fuel lines besides installing a fuel regulator.

Also the Crossfire heads are not that great at all, if you ever change up the crossfire injection setup with whatever you like, please change the heads with something that will flow better, b/c their too restrictive.

CFI-EFI

It all depends on what you expect for performance. Speed costs money. How fast do you want to go? How about a worn out stocker in the 13's for about what the TPI conversion would cost? And it's faster, too.

RACE ON!!!

Desertdawg

If you are anyone else reading this decides to switch to TBI or even a carburetor, I will gladly take all the crossfire crap off your hands.

You know you really don't want it sitting around collecting dust, just send it to me, I will take care of it.

DSKRALL

Ramanstud,

I know someone who is considering a CFI to TPI conversion. Although you created an air duct that held the MAF and air filter, will stock MAF ('85-'89) or speed density ('90-'91) ducting with air filter housing fit?