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toolmantim
02-03-2012, 05:28 AM
I am looking for any information on the best system to convert a 1993 Suburban tow vehicle from the original throttle body system. The engine is a 383 (stroked 350) with a mild RV cam. I would like to hear comparisons on the different available systems, ie F.A.S.T, Holley...I have a donator TPI but it seems as though it will be almost as expensive to convert to that as the others by the time I change the wiring harness, etc. Any advice would be appreciated.

EagleMark
02-03-2012, 08:39 AM
I don't know much about aftermarket systems, except old ones are now boat achors because you can no longer get replacemnt parts? Yet you can still buy replacement parts for older GM systems.

What ECM/PCM do you have in there now? Why do you want to change?

They can all be tuned for your new motor. If it's an old 160 baud ECM lot's of guys are swapping to newer 8192 baud PCM. Huge difference, way more options to tune.

PJG1173
02-03-2012, 12:46 PM
93 burb if it has the 4l60e should be 16168625 running $E6 so It should be the faster pcm.

93V8S10
02-03-2012, 05:09 PM
93 burb if it has the 4l60e should be 16168625 running $E6 so It should be the faster pcm.
And it can be converted to MPFI.

EagleMark
02-03-2012, 05:42 PM
And it can be converted to MPFI.And the PCM can handle that with no mods other then bin changes? Wiring from TBI injectors to MPFI is?

93V8S10
02-03-2012, 06:52 PM
Just minor PCM mods required. Injector wiring is simple, 4 injectors to one TBI injector driver and 4 to the other.

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?303-16197427-PCM-Information-OD

Post #6

toolmantim
02-06-2012, 05:39 AM
I don't know much about aftermarket systems, except old ones are now boat achors because you can no longer get replacemnt parts? Yet you can still buy replacement parts for older GM systems.

What ECM/PCM do you have in there now? Why do you want to change?

They can all be tuned for your new motor. If it's an old 160 baud ECM lot's of guys are swapping to newer 8192 baud PCM. Huge difference, way more options to tune.

Thanks for the reply.
I don't have the equipment to program the old ECM. Is the PCM a part of the ECM? It seems the better system for my engine would be the TPI and I have that from a '89 Vette. But I have no sensors or wiring for this system. I assume I must replace the ECM to operate the TPI.

EagleMark
02-06-2012, 10:42 AM
Thanks for the reply.
I don't have the equipment to program the old ECM. Is the PCM a part of the ECM? It seems the better system for my engine would be the TPI and I have that from a '89 Vette. But I have no sensors or wiring for this system. I assume I must replace the ECM to operate the TPI.PCM is just a newer name for ECM when it also controls transmission.

Changing to TPI will be a huge job even then TPI is for 305 engine but then used on 5.7L engine and has flow limits. So guys are changing the intake out to a LT1 which is bigger and better TPI. You could use your PCM with coding changes mentioned above for MPFI but would still need some wiring harness changes from TBI to TPI/MPFI

Your motor is just bigger cubic inches with mild cam. You could spend thousands of dollars to buy something else but from what is said above looks like your PCM id the faster PCM to begin with and will run just as good if not better than any aftermarket system with a tune.

If you don't want to get into tuning which is not that expensive for this type PCM then talk to Dave at Old School EFI. You'll still need to data log while driving but he can set you up with a good tune.

Or couple hundred bucks for tuning equipment, software and a laptop if you don't have one and you can learn all you need right here?

toolmantim
02-06-2012, 04:50 PM
PCM is just a newer name for ECM when it also controls transmission.

Changing to TPI will be a huge job even then TPI is for 305 engine but then used on 5.7L engine and has flow limits. So guys are changing the intake out to a LT1 which is bigger and better TPI. You could use your PCM with coding changes mentioned above for MPFI but would still need some wiring harness changes from TBI to TPI/MPFI

Your motor is just bigger cubic inches with mild cam. You could spend thousands of dollars to buy something else but from what is said above looks like your PCM id the faster PCM to begin with and will run just as good if not better than any aftermarket system with a tune.

If you don't want to get into tuning which is not that expensive for this type PCM then talk to Dave at Old School EFI. You'll still need to data log while driving but he can set you up with a good tune.

Or couple hundred bucks for tuning equipment, software and a laptop if you don't have one and you can learn all you need right here?

Thank you for your reply.
As I understand the LT1 is better for top end and the TPI is better for torque from the comments I have received. I had not heard the LT1 system referred to as a TPI although I know it has injectors in each port. Looking at the TPI I can see tuned runners. I can't see the inside of the LT1 plenum so I don't know if it has tuned runners or not.
I have information from Dynamic EFI (dynamicefi.com) and he offers a computer and tuning interface for $500. This seems like a good way to go. I am poised to pull the pin and order it unless I hear something negative soon. He has the pinouts and wiring instructions and splits the PCM from the ECM so I keep my original computer for the tranny control and use his ECM and tune it for the engine control. I am not looking for top end with this system. I simply want a tunable system and I want to start with the best one.

1project2many
02-07-2012, 12:01 AM
Howdy.

TPI or Tuned Port Induction was a marketing name for the long runner port fuel injection system used from 85 to 91 on Camaros and Corvettes. It was designed to make peak power at low rpm and produce high torque numbers. On a 350 it begins to have problems with flow somewhere around 4000 to 4500 rpm depending on the cam. The LT1 uses a short runner port fuel injection manifold designed to make peak power at a higher rpm than the TPI engine. It is also "tuned" but for a different power band. My personal feeling is that the tuned port engines were seome of the greatest truck engines that GM never put in trucks. For a truck that tows or works, the TPI can be a very good addition.

It's really unnecessary work and expense to replace a very capable, very versatile, and completely usable computer with one that is less flexible. Additionally, with two computers you'll have a mongrel system which may scare off even the most adventurous technicians if you have a problem. The stock computer in your truck is able to do the job of controlling the TPI intake just fine. If you're willing to do the work to build or replace the wiring harness for a "dual computer" system, then making a few simple modifications for the tuned port installation shouldn't be an issue. In non-electronic terms the solution recommended by affordable efi might be similar to a hot rod shop telling you they can replace your smallblock Chevy engine with a flathead Ford because they know how to work on the Ford but they just don't know how to make the Chevy do what you want.

The option for support and one-stop shopping to get started is very attractive. If you can get the tools to tune including a laptop, emulator, burner, and datalogging / scantool software for the pcm currently in your truck for $500 then it's probably worth it. If there's no emulator you're going to want one. If there's no tool to burn chips then you're at someone else's mercy each time you want a chip made. If you're getting Tunerpro tuning software in the laptop then it's easily downloadable anywhere and can be used for free if you're just tuning your own vehicle. I'd find out what hardware and software you're getting for the money.

In short I would use the pcm you already have (better, faster, and stronger unit), ditch the idea of mating two computers on one harness (soooo 1988!) and start gathering the tools you'll need for the tuning (laptop, cable, emulator, and software).

gregs78cam
02-07-2012, 12:27 AM
Rbob/DynamicEFI has real good stuff, and it would no doubt work fine, but from sounds of it you don't need to go full tilt, unless you have big plans in the future. I would have to agree with most everyone else, stay with GM PCM, it is more than adequate for what you have. GM likely put more man hours into getting EFI right than probably all aftermarket EFI companies put together. And yes TPI really should have been put in trucks as well. The only possible issue I see with putting the TPI on a 383 is airflow, the factory 350's ran out of air by 4500rpm, and even a slightly warmed over 383 will run out of air way before that. So if you don't plan on keeping your foot in it to redline, it should work great. But the torque will be AWESOME!!!!

Is this engine just stroked and cam, or does it have heads and intake as well?

If you can find the correct JY harness for the 'vette TPI(w/ or w/o cold start injector, and speed density or MAF) then it shouldn't be real hard to repin the connectors to plug right into your PCM. Your may have to add a couple of wires, but that should be easy. thirdgen.org should have lots of info on wiring and differences. Once you have the proper schematic it is just a matter of swapping pins.

EagleMark
02-07-2012, 01:49 AM
You'll never here anything negative about Dynamic EFI products or tech support so put that issue to rest. Road trip mechanic is out of the question and may have emissions test problems.

But you have everything you need right now, just tune it and it will be more then you need with TBI. You'll never feel difference in going TPI unless you get dyno numbers. road trip mechanic readily available and emissions should pass.

Now if you want to go to the TPI intake you still have everything you need except wiring in MPFI injectors and changing the fuel pump in tank to TPI pump needed for TPI/MPFI pressure. Then are going to probably loose some top end power WOT high RPM... road trip mechanic will be hard and depending on what state your in for emissions tests may fail.

Your PCM can be tuned for the (TPI BTW it is MPFI with tuned port runners) you can spend $200. for everything needed to tune or $500 with AutoProm which is an emulator, chip burner and data logger and TunerPro software. Benefit of that is you still have everything needed to tune many more cars. Dynamic is one per car.

toolmantim
02-07-2012, 03:21 AM
So are you suggesting I stay with the original TBI system and tune it? I am looking for torque for a towing vehicle.

toolmantim
02-07-2012, 03:34 AM
Howdy.

TPI or Tuned Port Induction was a marketing name for the long runner port fuel injection system used from 85 to 91 on Camaros and Corvettes. It was designed to make peak power at low rpm and produce high torque numbers. On a 350 it begins to have problems with flow somewhere around 4000 to 4500 rpm depending on the cam. The LT1 uses a short runner port fuel injection manifold designed to make peak power at a higher rpm than the TPI engine. It is also "tuned" but for a different power band. My personal feeling is that the tuned port engines were seome of the greatest truck engines that GM never put in trucks. For a truck that tows or works, the TPI can be a very good addition.

It's really unnecessary work and expense to replace a very capable, very versatile, and completely usable computer with one that is less flexible. Additionally, with two computers you'll have a mongrel system which may scare off even the most adventurous technicians if you have a problem. The stock computer in your truck is able to do the job of controlling the TPI intake just fine. If you're willing to do the work to build or replace the wiring harness for a "dual computer" system, then making a few simple modifications for the tuned port installation shouldn't be an issue. In non-electronic terms the solution recommended by affordable efi might be similar to a hot rod shop telling you they can replace your smallblock Chevy engine with a flathead Ford because they know how to work on the Ford but they just don't know how to make the Chevy do what you want.

The option for support and one-stop shopping to get started is very attractive. If you can get the tools to tune including a laptop, emulator, burner, and datalogging / scantool software for the pcm currently in your truck for $500 then it's probably worth it. If there's no emulator you're going to want one. If there's no tool to burn chips then you're at someone else's mercy each time you want a chip made. If you're getting Tunerpro tuning software in the laptop then it's easily downloadable anywhere and can be used for free if you're just tuning your own vehicle. I'd find out what hardware and software you're getting for the money.

In short I would use the pcm you already have (better, faster, and stronger unit), ditch the idea of mating two computers on one harness (soooo 1988!) and start gathering the tools you'll need for the tuning (laptop, cable, emulator, and software).


So are you suggesting I stay with the original TBI system and tune it? I am looking for torque for a towing vehicle.

toolmantim
02-07-2012, 03:35 AM
Rbob/DynamicEFI has real good stuff, and it would no doubt work fine, but from sounds of it you don't need to go full tilt, unless you have big plans in the future. I would have to agree with most everyone else, stay with GM PCM, it is more than adequate for what you have. GM likely put more man hours into getting EFI right than probably all aftermarket EFI companies put together. And yes TPI really should have been put in trucks as well. The only possible issue I see with putting the TPI on a 383 is airflow, the factory 350's ran out of air by 4500rpm, and even a slightly warmed over 383 will run out of air way before that. So if you don't plan on keeping your foot in it to redline, it should work great. But the torque will be AWESOME!!!!

Is this engine just stroked and cam, or does it have heads and intake as well?

If you can find the correct JY harness for the 'vette TPI(w/ or w/o cold start injector, and speed density or MAF) then it shouldn't be real hard to repin the connectors to plug right into your PCM. Your may have to add a couple of wires, but that should be easy. thirdgen.org should have lots of info on wiring and differences. Once you have the proper schematic it is just a matter of swapping pins.


I have an aftermarket set of aluminum heads that should flow well but are not overkill, RV cam and 10:3/1 compression. I will be using whatever intake works with the system I choose.

toolmantim
02-07-2012, 03:35 AM
You'll never here anything negative about Dynamic EFI products or tech support so put that issue to rest. Road trip mechanic is out of the question and may have emissions test problems.

But you have everything you need right now, just tune it and it will be more then you need with TBI. You'll never feel difference in going TPI unless you get dyno numbers. road trip mechanic readily available and emissions should pass.

Now if you want to go to the TPI intake you still have everything you need except wiring in MPFI injectors and changing the fuel pump in tank to TPI pump needed for TPI/MPFI pressure. Then are going to probably loose some top end power WOT high RPM... road trip mechanic will be hard and depending on what state your in for emissions tests may fail.

Your PCM can be tuned for the (TPI BTW it is MPFI with tuned port runners) you can spend $200. for everything needed to tune or $500 with AutoProm which is an emulator, chip burner and data logger and TunerPro software. Benefit of that is you still have everything needed to tune many more cars. Dynamic is one per car.


I am not afraid of the tuning learning curve as long as I don't have to spend 40 hours to accomplish it. Time is not my ally. Are you suggesting I tune the TBI system? I have the original wiring for that. And the ECM/PCM. Would it be better to spend the money on a better throttle body or is that even necessary with good tuning? What are you suggesting I spend $200 on. I searched for AutoProm and didn't see anything right off the bat. I downloaded Tuner Pro but have done no more than install it and run it. I will have to study the help screens.

1project2many
02-07-2012, 05:15 AM
I wasn't suggesting one type of fuel injection over another. I was suggesting that you use your stock computer for whatever efi you choose to install. It's one of the best ones GM made before OBDII.

If you don't want to invest as much time in getting the truck running, keep the vehicle as close to stock as possible. Keep the TBI and factory intake, invest in slightly larger injectors, get an emulator and laptop, and start making changes. My feeling is that you'll end up with well over 40 hrs into a learning curve no matter what method you choose. The stock intake will make the truck easier to get up and running but you'll end up looking for a better induction system and then you'll have the time to swap it out plus the time to retune the engine. But, and this is a big one, you will already have some practice tuning and you'll have driven and used the truck so it won't seem like a huge amount of downtime.

Deciding whether or not to use the tuned port is easy. Look at the weight of the vehicle, stall speed of the computer, rear gear ratio and tire size, power band of the cam, and the type of driving you'll be doing. If you're crossing the Rockies every day pulling a trailer your truck's going to be working it's rear off with the trans downshifted and the rpm as high as it will get. A restrictive low end intake won't help that situation. If you're mostly cruising highways and engine rpm at 65-75 mph will be in the neighborhood of 2800-3500 the tpi might be a nice option. If you're going to be carrying a full load through town with a lot of stops and starts and you've got 3.42 or 3.73 gears with a 30" tire the TPI could be a good choice.

383, aluminum heads, right cam should be a tire burner but airflow demands can easily exceed what a stock smallblock TBI or TPI wants to provide unless you choose a low end cam. But low end cam might not be right for vehicle or expected use. The best approach imo to choosing components is to look at what you want the truck to do, pick the cam to match, then pick the induction system that best fits the engine as a package. Once the components are selected the job is to invest the time in making them work together to get the result you want. If you choose parts based on how easy it will be to make them work you're likely to have compromises you didn't want to make.

toolmantim
02-07-2012, 05:57 AM
My biggest concern is to be able to tune whatever I put on the engine. If I could invest in a system that will tune both the TBI and TPI I would stick with the TBI until I learn to tune. I can make a quick modification to the crossover bolts on the aftermarket heads so the the bolts will match and use my original computer and wiring harness. You mentioned investing in slightly larger injectors for the TBI. Wouldn't I have to purchase a complete throttle body to do that?
Where do I purchase the emulator?

EagleMark
02-07-2012, 10:03 AM
pick the cam to matchHe alrady has a RV cam I think was posted.

Injectors can be changed from TBI to TBI. With your cam your injectors will be fine, may need more pressure to tune WOT high RPM properly. So an adjsutable regulater and gauge is still cheaper then new injectors. Since you just rebuilt your engine you should have had injectors serviced, if there is no one in town and you need to mail them look at Mr Injector. He is in my town and does lkots by mail, but I get to watch before and after and you get report on how much differnce if they were slightly clogged. Everyone I have done shows an improvement.

What we've been telling you is you already hace a PCM that will tune everything!

Moates has all you need. For tuning I have an AutoProm which is all in one unit. Or you can buy seperate emulater (ostrich) burner (Burn 2) and cable ('ALDU1CABL1'). That will all be left over to retune 100/s of other cars. For the PCM need a G1 adapter and chip. AutoProm also comes with software needed TunerPro license.

toolmantim
02-07-2012, 10:12 AM
Thanks, I'll give it a shot!

historystamp
02-07-2012, 12:36 PM
I will have to study the help screens.

The help is being reworked.

See...
http://www.gearhead-efi.com/Fuel-Injection/showthread.php?466-TunerPro-starter-Tutorial!-New-users-this-is-a-must-read!-)

and

http://www.gearhead-efi.com/Fuel-Injection/showthread.php?420-Micro-mini-startup-Guide-for-Beginners

Robert

toolmantim
02-07-2012, 02:16 PM
Thanks!

bybyc5
02-10-2013, 04:36 AM
Interesting project you have going. It matches mine almost completely.
I have a 93 K1500 4X4 that I also built a 383 and used an RV type cam (actually a Comp Cam high torque and improved fuel mileage ).

I have had it running now for about 2 years with the 16168625 ECM, and Craig Moates hardware so I could use flash chips and get it running a bit better. I use TunerCat to modify the bin.
I too want to change my intake manifold set up to a TPI system, and have rebuilt one and am ready to make the swap.
I have a few thoughts for you to consider.
There are a lot of people putting the TPI system in trucks because of the low rpm torque it offers, and it is also a good looking system when you open the hood!!
The stock swirl port heads also enhance low rpm torque and better mileage. My thoughts are what a good tow motor this would make with those two put together, in a 383. Stroking the 350 to 383 gives a lot more torque all by itself.

Down side to the TPI is high rpm HP is not possible, as the port flow velocity runs out at about 4500 rpm.
The up side is, Low rpm port velocity is increased. This brings HP and torque peaks down in the lower rpm range desirable for towing, and improved mileage.
But for a TOW vehicle this is ideal (IMO).

You will have to upgrade your fuel pump to a higher pressure capable system. As mentioned earlier.

You mentioned having aluminum hi flow heads. Depending on what their flow characteristics are and port / valve size is, these may or may not work with a TBI or TPI system. Some aftermarket heads have large ports and require high rpm to get the port velocity up. Not sure which heads you have.

I look forward to hearing how it goes for you! I will be "tuned in" to this thread and others like it!!

Keith

gregs78cam
02-10-2013, 07:17 PM
Don't forget that using a rock stock factory TPI on a 383 will run into the brick wall even sooner because you will using more air at lower RPM. Might not be by a lot, but I would bet that it would be noticable.

bybyc5
02-11-2013, 08:41 AM
I agree there will be an rpm limit with this TPI on my 383. Not wanting a race truck.
I am hoping it will enhance the engines off idle and normal driving torque.
If not I'll swap the TPI out for something else!

The factory 193 swirl port heads don't flow much past 4500 due to the ramps built into the intake valve pockets. Put there to increase the mixing of the low rpm intake charge. Factory max rpm range for this motor shows red on the stock tachometer at 4500. I may be wrong here, but I am guessing it is due to these heads not making usable power above that?
I can't imagine any factory SBC not being able to spin past 4500 safely?

I have purpose built this combo for low rpm torque. The cams rpm range I selected(Comp Cam 08-464-8) is 1000-5000. And for "increased torque and economy". Actually for a 305 or 350, but without having a custom cam made this one is working great for me.

I am running this motor now, but with the stock TBI intake. The 383 and this cam has given me noticeable torque increase just off idle and normal driving rpm. Fuel mileage seems better as well. Living in the Hills of NE Tennessee I drive up and down quite a bit, and with less throttle for sure!
The motor does spin past 4500 if I want it to, but guessing the HP starts tapering off. I have no way to measure this?

HTH
Keith