TPI conversion - what's the best year and car?

[MaineShark]

I keep thinking about TPI. And I keep seeing cars with major rear-end damage, or similar troubles, where I could buy the TPI system from the owner.

But what car (Firebird, Camaro, etc.) is best to look for, and what year(s)? Also, how much trouble is it to use the 305 system on my 350?

Joe

 

[patsnitrovette]

Im using a 87 trans am mass air flow setup,alot of guys like to use the speed density setup because of ease of installation and cleaner look.You could use any of them really 86-and up,stay away from 85's they had a different setup.Check out my website i started, shows alittle bit how i did it and what i used.I still have a few more things to change but mostly its almost done.Also i forgot to add my setup was a 305 ,i changed the prom and the injectors to 24lb and it works fine.If the tpi you look at is a 305 and it has the larger hei dist.you need to change that to a 350 one but if its the small cap and external coil they are the same 350 and 305.

 

[MaineShark]

Actually, thinking it over, a MAF system is probably better for putting on this car, since I have no way of knowing, for certain, exactly what's been done to the engine, if anything.

When I build my '73, it will definitely be speed-density, because I will know exactly what's in it, and can get a chip to match.

So, I guess I just have to keep an eye out for a TPI setup.

I know I need a fuel pump, and lines (feed and return). I've also heard that replacing the alternator with a higher-amp unit is a good idea.

Anything else that I need? Brackets, etc.?

Will the stock computer be able to handle my engine, or will I definitely need a new chip?

The new distributor just drops in, right? No changes on the bottom end?

Joe

 

[patsnitrovette]

Checkout my website youll see the things ive done.Definitely higher amp alternator,not knowing what cam you have i cant say the stock chip will work.
http://www.angelfire.com/nj4/patsvette/index.html

 

[KANE]

So you know what the heads are fro the castings.... a compression test can give you the answer for the squeeze... and then just use the timing marks with a timing gauge..... if anything doesn't line up with what you are supposed to have you can tell its not stock by the process of elimination.

Unless your car really lopes at an idle, I am willing to say that you have a stock grind or mild cam. If it lopes a little, then its more aggressive. If it sounds as if its going to idle between 300- and 700 rpm but not consistanty at one or the other than its really steep. This is all assuming you don't have a serious vacuum leak.

With all of that said, I recomend using speed density from the ACCEL system. Its completely programable and easily updated vis PC.

If you find out precisely what you have, then go with a GM speed density computer. They have a faster processor speed and are more reliable than MAF.

I have really enjoyed mine. I will never go back to a carb!

 

[69MyWay]

Hijinx here on the site just bought one a while back, and I don't think he is going to use it now. You might get with him and see. I think it is even powder coated for really great looks.

This topic comes up often, and it is important to determine exaclty what you are after and what kind of budget you have.

The only problem I see with a stock, or stock style TPI is that you are limited on upper end hp by the nature of the design. By the time you start to mod it to get more air flow and more custom variations in the tuning, etc. you could have bought a complete stand alone EFI system that has better high end flow characteristics. However, for good strong torque, good reliable running, great looks, and ease of diagnostics, etc. you can't beat the stock TPI systems.

I would agree with what has been said here. Try to stick to newer than 85 systems. The best really are the 88 and up. All the runners and intakes are the same size for a 305 or 350 TPI system, it is the size of the injectors that makes the difference.

Check with Hijinx on his system, and if no deal for you there, go to the swap meets, etc and try to pick up a intake only (distributor would be nice as well) for $250 or less. Call up Summit racing and get a set of the accel/ford injectors coming to you. Get an adjustable fuel pressure regulator from www.tpis.com or anyone you want. Go to Painless, Street and Performance, TPIS, Howell, etc. etc. and get a stand alone harness and you can get a computer at any autoparts store. Just specifiy in this whole thing speed density or MAF. Finally, get with -=Jeff=- here as he can work with you on burning a chip and he has good experience with them.

Now, plumb your air intake, fuel lines, mount your high pressure pump and run a new feed line......and you just about have it.


Or, call Summit, Tpis, etc. and order a complete EFI system in the box with everything at one time and have it installed in a weekend.

You have many choices, and they are all great just depending on your budget, time, and performace desires.

 

[patsnitrovette]

i agree about jeff with making the chip i just recieved mine last night and put it in for the price it cant be beat.

 

[Hijinx]

Chris, is correct. I still have a full TPI setup (with distributer and all) that I am willing to sell. The only thing missing is the injectors, but that was something I wanted to buy seperately anyhow. If you want to get stock injectors, you can score some off Ebay for around $50-60. Let me know if your interested. It is powdercoated as well, and ready to install, harness and all.

 

[Hijinx]

Oh, one thing I forgot to mention. Its off of an '88 IROC Z.

 

[phoenix73]

I'm waiting to receive my custom EFI setup from Affordable Fuel Injection. They custom make a kit depending on what you want. They were MUCH cheaper than the big names, make it themselves, will reprogram chips for you, free support, available by email or on the phone.

I had an intake, runners and throttle body (injectors too). They set up a kit for me with everything else, all sensors, distributor, fuel pump, rails etc...

After the cam and headers, the entire conversion is still going to be only about $1000.

I still will have to get an electric tach, but I am planning on all new gauges too.

I received an email from them that I should be receiving everything tomorrow (1/16/03).

 

[MaineShark]

Thanks for the information.

Another question: what's the deal with the cold start injector? I've seen a couple instances of people saying "avoid these systems," but I've never seen any reasons given...

Joe

 

[patsnitrovette]

I have it on mine and stayed with it,its an extra injector on the bottom of the drivers side runner that will inject fuel when cold when you start cranking the engine over.Theres a sensor on the front of the intake that when it gets up to a certain degree itll shut off that injector.Some guys like it some dont.Heres a website thatyll really help you under stand tpi and whats needed for a conversion.
http://www.chevythunder.com/index.htm

 

[Jack]

TPI w/ Vortec ?

What years, makes & models came with TPI ... and Vortec heads (if any)?

Similarly ... what years, makes & models came with TPI ... and "regular" heads (if any)?
JACK:gap

 

[MaineShark]

Yeah, I've been reading through the Chevy Thunder site. It's been a huge help.

I still can't figure out what's supposed to be bad about the cold start injector, though. Only thing I can come up with is the expense of a ninth injector.

Joe

 

[patsnitrovette]

Basically if the thermotime switch goes bad itll be hard starting when cold,whereas the ones without are computer controlled for cold starting.Yes that chevy thunder site is very helpful.Good luck with your swap.

 

[MaineShark]

Thanks, that makes sense.

Of course, it's hard to start cold, right now, so I'm not going to worry about some potential future failure like that

Speaking of failures, do you have any problems with the EGR system? From the sound of things on the Chevy Thunder site, the computer will look for temperature changes in the EGR piping after it opens the valve, and set an error code if it does not see that change. Is this something that can just be ignored, or are some modifications necessary?

Also, did you have to use any different/custom brackets for your installation?

Thanks,
Joe

 

[patsnitrovette]

Well i had the egr turned off in the chip when it was made so no light will be on,my heads have no egr passage so left the egr there and hooked up but its not working.I used everything from the donor car,trans am,so the alternator brackets ,waterpump and belts were used from that car.I used my factory power steering pump and brackets and they bolted right up with a small shim behind it.Only thing im having a problem with is the oxygen sensor is located too far down in the headers at the collector,so i put a heated oxygen sensor in to help aid in heating it,havent really run it too much since then so i dont know if it helped alot.

 

[MaineShark]

I forgot that EGR is in the heads, not external piping (was confusing it with the AIR system, which I don't have, for some reason). So I guess I probably have that (yuck), so it shouldn't be a problem. Maybe I will eventually disable it, and see if I can make a circuit to fake the computer out (when the computer tries to open the EGR valve, have it instead trigger a relay to show it the "correct" resistance that it expects from its temp sensor, so it thinks that exhaust gas is actually flowing).

I definitely think I will just go with a heated O2 sensor, from the start. I never trust un-heated ones, and I'd rather just do the wiring once, instead of having to re-do it if the un-heated sensor doesn't work out.

A few more questions:

Is it necessary to remove the mechanical fan? I know some do, but can the system be routed to avoid it, without removal?

If it does need to be removed, it's just a matter of un-bolting it, right (no balance issues)?

Will I have enough cooling with only the stock electric fan? (at least, it says "Delco" on it, so I assume it came stock) Or would I need an aftermarket fan setup?

Joe

 

[sscam69]

Joe

I see you also have a 79 L-82

From my understanding it was just an auxillary fan and I don't think it would be able to handle the thermal load from the engine.

Mine either didn't come with one or was removed by the idiot/idiots who abused my carad before I got my hands on it.

Spal makes a dual fan setup that should be able to handle the engine. I bought the system along with a new radiator and never saw under 200-210 deg until then.

Are you going with a GM EFI system for the cost?

Frank

 

[MaineShark]

Joe

I see you also have a 79 L-82

From my understanding it was just an auxillary fan and I don't think it would be able to handle the thermal load from the engine.

That was my guess, but I figured I should make sure.

Mine either didn't come with one or was removed by the idiot/idiots who abused my carad before I got my hands on it.

Please don't get me started on that... This will be my first upgrade the the car. Everything until now has simply been to fix the problems.

Spal makes a dual fan setup that should be able to handle the engine. I bought the system along with a new radiator and never saw under 200-210 deg until then.

That's what I've been looking at. Luckily, this post just showed up. Now, I just need to decide if I should bite the bullet and do the radiator at the same time, or just the fans.

Are you going with a GM EFI system for the cost?

Frank

Well, I like the idea of the low-end torque increase, and the ease of use provided by EFI. Plus, at a current 15 mpg, any increase in gas mileage would be appreciated. The look of the GM system is also very nice.

The cost is also a factor, though. Not so much in that I saved money, but that I'm not willing to invest too much cash in this car, so I never would have spent the money for a fancy aftermarket setup. Actually, looking at it that way, it cost me money

When I do my '73 383 project in a few years, I will be willing to spend more. I'm still thinking about the GM system for it, with a few modifications (aftermarket controller, porting, better runners). I'm going to do some more investigation of the possibilities, as time goes on.

Joe