Tpi Noob Questions???

[sta500666]

I finally realized how bad carbs can be off-road esspecially my edelbrock 1406... Now I have to choose between a Holley Street Avenger or some sort of fuel injection, preferably TPI, cuz I'm a die hard Corvette fan!!

Anyway a complete L98 can get a little pricey, so I was just wondering how hard it would be to convert my 1976 350 4-bolt main into a TPI set up? Lets say I get everything from the intake manifold up, then buy computer sepreatly. Will I need heads too? If so should I go with alluminum or Cast Iron? If alluminum will I have cracking problems??

So basically all those what if/what to use questions!!

-Thanks

 

[4X4HIGH]

All you need is manifold on up. With your truck being a 76 you need a 1985 or 1986 manifold to be a direct bolt on. Starting in 1987 GM changed the angle on the 4 center intake bolts so if you don't mind doing a little modification to the manifold then any year will work. You will also need to install a high pressure fuel pump, change any rubber fuel line to high pressure fuel line and also install a return line to the tank.

 

[dyeager535]

It gets REAL pricey to put one of these setups together in pieces. I highly recommend you drop any idea of doing that. Buy it complete, or don't buy it.

As mentioned, get the early base and it will bolt right to your motor. They tend to be a bit difficult to find in my experience, but I think the fascination with TPI is dying off just enough that the parts are a bit more reasonably priced. Obviously a 2 year intake could be potentially more expensive. This would be one component that I would consider buying seperately since it obviously will save a bunch of hassle and everything else from another year will bolt right up to it.

If you want the AL L98 heads, probably best/easiest to just get a complete setup off of a 'vette. Of course, the 'vette ran the accessories, fuel lines, and probably other stuff opposite of the Camaro, so you might run into some issues that way. Again, trying to piece together the oddball Corvette setup would probably be very frustrating too.

Stay away from the cold start injector setups (since you are starting from scratch) and decide if you want MAP or MAF. MAP is a heck of a lot easier to deal with regarding intake routing, while MAF is a BIT more forgiving on being able to run it without tuning, but fairly expensive/complex to route the intake tract. Either way you'll want a custom chip burned to get the most from it.

thirdgen.org has a pretty good classified section, haven't looked for complete setups for awhile, but it's a good place to look.

Ahh yes, and forgot the most important part (to me)...truck sits for two months or two minutes, turn the key, let the pump prime, hit run, and she starts up, every time, every temperature, and never even thinks about stalling after startup.

 

[sta500666]

It gets REAL pricey to put one of these setups together in pieces. I highly recommend you drop any idea of doing that. Buy it complete, or don't buy it.

As mentioned, get the early base and it will bolt right to your motor. They tend to be a bit difficult to find in my experience, but I think the fascination with TPI is dying off just enough that the parts are a bit more reasonably priced. Obviously a 2 year intake could be potentially more expensive. This would be one component that I would consider buying seperately since it obviously will save a bunch of hassle and everything else from another year will bolt right up to it.

If you want the AL L98 heads, probably best/easiest to just get a complete setup off of a 'vette. Of course, the 'vette ran the accessories, fuel lines, and probably other stuff opposite of the Camaro, so you might run into some issues that way. Again, trying to piece together the oddball Corvette setup would probably be very frustrating too.

Stay away from the cold start injector setups (since you are starting from scratch) and decide if you want MAP or MAF. MAP is a heck of a lot easier to deal with regarding intake routing, while MAF is a BIT more forgiving on being able to run it without tuning, but fairly expensive/complex to route the intake tract. Either way you'll want a custom chip burned to get the most from it.

thirdgen.org has a pretty good classified section, haven't looked for complete setups for awhile, but it's a good place to look.

Ahh yes, and forgot the most important part (to me)...truck sits for two months or two minutes, turn the key, let the pump prime, hit run, and she starts up, every time, every temperature, and never even thinks about stalling after startup.

I like the idea of starting without hasstle...and never stalling haha! Could you explain to me what MAP and MAF is???

The parts I could possible buy would come with the 87+ intake manifold... So I suppose I would have to get 85-86, As far as chips I think I could get one off ebay, I have seen them for around $100. For the fuel pump, could I just run a on-block High pressure pump, or does it need to be an electric pump??

 

[dyeager535]

First off, go over to thirdgen.org and register. Then search just about any question you have. It's more than likely been covered, but isn't truck specific for the most part. Talking about a truck application (even though it's stock TPI) is typically a no-no over there.

Quick answers: MAF is Mass Air Flow, which measures the air coming into the engine. MAP is Manifold Absolute Pressure, and measures the pressure inside the intake. MAF was '85-89 (stay away from the '85 electronic portion) and MAP was '90-92. MAP is more refined, ("smarter" programming if you will) while '89 MAF setups were the best of their type.

Yes to '85-86 manifold unless you get the heads that match the intake.

No you can't get a chip off ebay. You need to deal with someone that burns chips, (dyno tuning is a possibility too) or get into that yourself. Search "EBL" or "Embedded Lockers" over at thirdgen, or the website is dynamicefi.com. No one can accurately burn a chip without "seeing" how your engine is currently running, then make changes based on that data. Cam specs, engine size, not enough info to make a decent product.

You need an electric fuel pump, my preference is stock in-tank, running the appropriate TBI sending unit.

 

[sta500666]

thanks for the info!!

 

[Thunder]

What is wrong with TBI? Corvettes came with TBI too.
Way cheaper and easier to do a TBI conversion than TPI.

 

[sta500666]

What is wrong with TBI? Corvettes came with TBI too.
Way cheaper and easier to do a TBI conversion than TPI.

I guess I hadent considered that, would that be the cross fire injection??

 

[Thunder]

Yeah Vetts came with cross fire. had 2 TBs. The system as it came out was not that good but if you upgrade to a newer ecm you cam make it perform fairly good.
But
As far as trucks are concerned a TBI system off a 87 and up truck will work great. Can be had and installed for $500 or so. and can be made to perform just as good as TPI. TBI builds very good torque. and will run up side down.

 

[dyeager535]

Can be had and installed for $500 or so. and can be made to perform just as good as TPI. TBI builds very good torque. and will run up side down.

For the posters benefit, I gotta bring this back up and respectfully disagree. I just want to make sure we are absolutely clear I'm not trying to bring tha hate!

A wet flow intake setup (TBI or carb) will NEVER equal MPFI (dry flow) in performance. There is also no way uneven length runners can possibly be made to perform like an equal length runner setup, especially when fuel is being dispensed from one or two locations. To qualify that, I'm talking in lower end performance. It would probably hold true for upper end power as well, but when talking niche applications like dragsters and what not, the cost and complexity would be exponentially higher.

If TBI could perform as well as MPFI, it would still exist on factory GM performance applications. Even when TBI, carb, and TPI were used in the same platform (the F-body) nothing came close to TPI. The factory power numbers, and track times are there to prove it. Doesn't matter if we are two decades removed from that time, the same advances applied to both TBI and MPFI shows that MPFI is the end-all (at this point) in injection setups.

Anyways, that's my two cents. Both setups, built with the same attention to detail/tune, MPFI will come out ahead.

 

[Thunder]

I will agree that TPI is a better system. And wont argue the fact it will make more power with equal modifications. I guess i should have said TBI could be made to perform "almost" as good as TPI.
When TPI came out in 87 Camaros and Birds it made 225 Hp and 330 Tq. TBI= 210 HP 300TQ, in 350 engines (1/2 ton L05 trucks and vin 7 engines). Also TPI had L98 heads which flow better than the TBI heads and way better cams,
In later years TPI came up to 240 HP 340 TQ or somewhere around those numbers.
It is not that hard or costly to bolt on 30 Hp and 30 TQ to TBI. Even with TBI heads.
I was just trying to point out that you can make good power with TBI for less money and hassle. Unless you can come by a complete TPI system cheap.
With a few inexpensive mods he can make similar power as stock TPI for a lot less money.
All he needs for TBI. Is a TBI adapter plate for his manifold,(dont have to change heads) the throttle body, Wireing harness, ECM, TBI distrubutor, Fuel pump and ECt from a donor truck. Which are fairly easy to find in salvage yards. A computer grind cam and a custom chip would also be a very good idea. The older heads and intake flow better than TBI heads and will need a chip tuned for them and the cam.
I am not trying to say TBI is better. I was just pointing out a different way to get reliable fuel injection if he was on a budget build.
If you can afford TPI, find or have a system cheap go for it.

 

[dyeager535]

I assumed that's what you meant, just wanted to give some more opinions to the poster.

TBI isn't that bad, it's still injection, and IMO that's what really counts when talking carb, TBI, or TPI. I'd still take TBI any day over a carb, most of the benefits you get are from the general aspects of EFI, not the particular system used.