Ultimate TPI Reference
OK, with my new TPI setup scheduled to hit the door on Tuesday, I wanted to build a reference list to make sure I was covering everything. Now, please understand that I only know as much as I have read, read – no practical experience with this type of conversion. However, it looks pretty straight forward. I’m sure Chris and a few others will provide some excellent commentary where I am lacking knowledge. There are still a number of questions in my mind that I have stated after all the reference list stuff. So, here it is and please provide any input that you have. This will be long, sorry.
A. Setup - I am basing my conversion off of a ’88 IROC Camaro setup. I will be getting it complete with intake, runners, intake plenum, throttle body, injectors, MAS, ECM, stock wiring harness. Basically everything that came off the Camaro.
B. Wiring - I plan to order a Painless Wiring harness for a couple of reasons. The stock harness will have stuff I don’t want and do not want cluttering the engine compartment. I plan to keep my stock distributor (since I have installed an Ignitor II electronic conversion kit in it and want to keep my mechanical tach drive). To accomplish this, from what I can gather, if I put in an MSD 6AL, it should provide the electronic tach lead that the TPI setup needs. Also, while I definitely will use the Painless kit, with provisions for the MSD and TPI, I may also have them do the entire engine compartment to clean everything up (unsure on this as yet).
C. Fuel Distribution – While I might be able to use the two stock lines, they are very old and the last time I did anything with them, the larger feed line (3/8) split. The return line is 5/16, and I believe from one of Chris’ post, too small. Therefore, I will put in two completely new 3/8 lines. I am not sure whether I will run hard lines (most probably) or go with braided or Aeroequip. Fuel pump will be a rail mounted unit from Summit or Jegs more than likely with a Earl’s fuel filter in front of it. I’m not sure on this one, but I think the pump has to deliver a constant 42 to 45 PSI. Could someone confirm this?
D. Sensors – Here is where I am not yet sure what I can delete (probably nothing), anyhow here is what I know from reading “Chevy TPI Fuel Injection Swappers Guide”. Needed sensors – Coolant Temp Sensor, Mass Air Flow (MAS), Manifold Air Temp (MAT), Oxygen Sensor, Throttle Position (TPS), Vehicle Speed Sensor (VSS), Knock Sensor, RPM, Park/Neutral Position, System Voltage (I think this is part of the ECM?) OK, I think that’s it. Help me out on this one.
E. ECM Programming – Once I have determined my setup, I need to get a chip programmed. I am not sure what all info is needed for this, so I could use some help. I do know from reading that it needs to be a VATS delete (by the way, what the hell is VATS?) On issue here, is that my current engine is basically stock and I plan to build the 383 Stroker some of you have heard me talk about. I imagine I will have to have another chip burned when I get that done.
F. Exhaust – I am still undecided here. I know I can tap, or use one of the old AIR holes, for the O2 sensor. However, this may be an opportune time to upgrade to headers of some sort. Main issue here is that I have to tap one for the O2 sensor.
G. Air & Radiator – Need to order a K&N TPI filter. However, it will be right behind the radiator and get nothing but hot air. Possible fabrication of some sort of intake may happen. I have a Griffin radiator (Thanks again Chris) and may take this opportunity to change over to it. I think I will have to sans the stock fan setup. Looks like it will hit the air cleaner (help on this?). If so, I will put a in a set of electric fans on the radiator. Clarification on this would be helpful.
H. Cam – Seems like, from my reading, that I may have to consider a new cam. This could be the killer that makes me hold off till I build the 383. I have a stock cam, to the best of my knowledge. I’m sure that the TPI will work with it, but not sure how well. I need clarification on this. I know Comp Cams makes a number of TPI cams, as I am sure most cam manufactures do. I’m just not sure on this point. I would like to set this up on my stock engine and swap it over to the 383 later.
I. Misc – I will probably order a custom fuel cable kit from someone (Lokar possibly). Hopefully, I can get some custom brackets as well. I know the stock cable will not work. The TPI I am getting has already been cleaned and powder coated. I did a lot of cleanup and coating when I went through the top of the engine last winter, so no major expense there. I will probably also order a TPI body air foil, if the stock unit does not have one. I plan to look into the adaptation of a Corvette cold air package from SLP Engineering. This may provide the separation of hot and cold air I want to provide to the K&N filter if I can adapt it to a C3, as it is for C4’s. SLP also has TPI headers for C4 Corvettes that might adapt.
References – I got a lot of info off of old, and new, post to the Forum. I will thank Chris, specifically. He has provided lots of great info on this topic to the forum. As stated, I got some info out of the “Chevy TPI Fuel Injection Swapers Guide”. TPIS, also has a number of good books on their web site.
Process – I will map and take pictures of my installation (plan to hit the wife up for a digital camera). I will post these on a web page, instead of to the forum. That way I can be as windy as I want!!!!
I think I can give some suggestions.
A. Your set up sounds fine. You may find it better to run a "non" mass air flow system when you buy your wire harness.
B. Good plan on the harness. You will spend more time than it is worth retro fitting the stock harness to the C3. Plus, the wire length won't be the best. I suggest you strongly consider another option on the tach/distributor. I think you will come out better in the end by switching to a 1975-77 electric tach and dropping in an HEI. This will make everything apples to apples, give you cleaner firewall and smooth tach operation. Plus, if push came to shove you could sell your old tach, cable, and distributor with the pertronix for more than enough money to do the swap. An HEI can be bought for around $99 rebuilt at the local autoparts store. I suggestion you do like I did with the 69 EFI system and punch the wire harness hole through the firewall just to the passenger side of the distributor. This way the wires drop right in there nice and clean. This next tip will take you a long way. Pick up some street rod mags and study what they have done with the EFI systems. What you will notice is the way they "hide" the wires from view. Follow that lead and you will come out with one hot looking engine. Most C3 guys forget this step and end up with a cluttered looking mess.
C. You are on track with the fuel line. You don't have to do braided line (that is very expensive). You can do the blue 250 psi line that Edelbrock uses in their kit. It is not an Edelbrock exclusive line as I have seen the same stuff at our local hydraulic supply company, and I believe Summit and Jeggs sell the same stuff. The truth is, you can get away with a 5/16" return and a 3/8" feed. There are a dozen fuel pump companies to consider. Most places like TPiS, Street and Performance, etc. can suggest the best bolt up pump. You want the most quiet pump you can find. You have the right idea on the filter. As long as you mount the pump lower than the tank, all will work fine.
D. Again, on sensors, I would suggest you convert to "speed density" to allow you to toss out the mass air flow. This will happen between the wire harness you use, and chip. It will also give you more room in front of the throttle body to work up a good clean air filter install.
E. Programming is the last thing to worry about. If you stick with the F body Puter, you will need a VATS delete chip. VATS is the system that is tied to the computer chip in the key as found in 88-F bodies, and 86-Vettes. The whole thing can be programmed out with the change of the chip. (VATS-vehicle anti theft system)
F. The exhaust is a piece of cake. Most muffler shops now carry an O2 bung. It is basically a round nut threaded to match the O2 threads. The muffler shop will drill a hole in the header and weld the bung in. Now, the O2 just screws right in. You will want to play with the final location of this to make sure that you are mounting the O2 in the upper side of the pipe (otherwise moisture will collect on it and damage it), and that it is at least 4" back from where header collects. So, mount the header, and play around underneath looking for the premium spot, then mark it. Please note, you can put the O2 in the collector (pipe side), and the engine will run without the O2 even installed. This will allow you to drive it to the muffler shop if you are going to have them weld the pipe side collectors and exhaust in anyway. It won't run great, but it will run enough to get it to them. In this same regard, you will want to convert to a "heated" O2 for premium performance. No worries. Just call TPiS and order it. It will hook to the orginal one wire coming from the harness, plus you will add a power and ground. I installed one in the 90 Vette and it makes a world of difference getting the puter into closed loop fast for better performance and efficieny. This also makes your header decision easy, as you can install ANY header designed to fit a small block C3. Later you add the O2 either to the header, or to the header collector that gets welded to the rest of the exhaust.
G. Have some fun with this one. This is one huge benefit of the "ricer crowd" as they are always having tubing made for the turbos etc. Find out where the local guys are having mandrel bent tubing done in 3 to 3.5" diameter, and have a special 90 degree pipe made to come off the throttle body and turn down and around away from the radiator. This will be up to you in terms of how creative you want to get. Heck, you might even dream up a intake mounted air cleaner much like the ram air F bodies that more or less mates to the cowl induction part of your new hood. This would require having a tube made that comes off the throttle body, then turns up and backwards to hood into a large square bodied filter on the top of the engine.
H. I like the Crane series of cams. However, I think you may very well get away with what you have. However, you need to know exactly what you have to get the chip make proper. Look at it this way. If you have the hood off, radiator out, and intake off, then you are just a hop skip and a jump away from changing the cam. I like the 2050 series of flat tappet cam from Crane. The computer likes them too, and will give you tons of low end tire roasting torque and mid range acceleration with that TPI manifold.
I. This is all part of how clean you want it to look, and any extra ponies you want to pull out of it.
Good luck, and a photo archive would be awesome.
Remember too, you can always go back in later after the basic set up is up and running and start tweaking for more power. You will find that different injectors, regulator, larger throttle body, porting work, computer work, etc. etc. cam reap some might fine rewards.
You will have fun hanging out in the "C4" L98 area as in the future any mods or problems will have been covered many times over by the C4 guys.
Awesome feedback Chris, as usual. My wife just called and said the TPI is here.
Cant wait to get home to check it out and see what all is there. Of course I would have an event tonight that will not let me get home till late. I hope to pick up a digital camera this weekend and get some shots of it and the hood. I'll be back posting on this thread soon with details. Thanks
Well, got everything pulled out of the box and I am short throttle body and injectors. The guy is supposed to be shipping them this week. Overall everything looks pretty good. The powdercoating is pretty good, not great. The runners have a few dings in them, nothing bad.
I got all the main (big) stuff and it all lines up. I also have the ECM, fuel rails, short hard fuel lines, Distributor and some large heavy plate that I do not recognize. May be what the ECM sits on. On the Mass Air Flow Sensor, should the little hair wires all be connected in the center? I have one that looks to be hanging loose.
The wiring harness is a nightmare. However, it looks to have the relays still connected to it and possibly a sensor or two. I will go through it this weekend. I'll take account of everything then.
It's much more difficult o fit under the hood, but a MAF system is much more forgiving of engine modifications than is a MAP system. I used MAP for simplicity. If I do another, I will save what I need from the stock harness and save the few hundred I spent for the Painless. A few hundred is NOT painless!!!
Well, I might be doing this about the same time you are. I sold the complete 90 long block with the TPI for $1,000 to a buddy of mine and we are going to drop it in his late 80's Trans Am.
I had him get a harness from painless, and some headers. He still needs to get a computer box and chip. Since the motor is certainly running and broke in, our swap should be a weekend quicky and he will head back to Central Florida.
We are going to do it Street Rod Style with nice neat clean everything.
This will happen in the next couple of months.
Keep you posted.
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