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So I have a set of "Python" injectors that came with one of the TPI setups I acquired at some point and I have no clue what rate they are. Did a google search and didn't have any luck. The only writing I can find on them is "python" and that's it. Anyone want to chime in?
If they're worth keeping and using they would be squirting into a stock '97 Vortec 350 with a TPI intake.
Pythons were Venom injectors iirc. So I googled venoms, found orange topped ones on ebay. Listed as 30lb per hr. https://www.ebay.com/p/1640298488
Are they any good? Don't know, I'd have to search that out. I'd suggest having them cleaned or flow checked before using them anyway.
Pythons were Venom injectors iirc. So I googled venoms, found orange topped ones on ebay. Listed as 30lb per hr. https://www.ebay.com/p/1640298488
Are they any good? Don't know, I'd have to search that out. I'd suggest having them cleaned or flow checked before using them anyway.
And this is why I love this group. I learn something new every day! Yeah I forgot to mention that I was going to reach out to a local shop and have them tested and cleaned.
Without proper offset data they are useless. Also old. They should go directly in the trash.
GD
Yeah I got the same reply from the guy that was going to test them lol!
Sooooo the next question is what should I go with? Like I stated before the engine is a stock '97 Vortec 350 out of a tahoe and the intake is a SD3816 vortec TPI base with stock plennum and runners.
Yeah I got the same reply from the guy that was going to test them lol!
Sooooo the next question is what should I go with? Like I stated before the engine is a stock '97 Vortec 350 out of a tahoe and the intake is a SD3816 vortec TPI base with stock plennum and runners.
Given you will be tuning anyway, I would go with these Holley injectors:
Don't bother with the cheap refurbished Bosch III's. Poor data on them so makes them very difficult to tune. Don't fall into the trap of cheap injectors - you get what you pay for and cheap injectors will make tuning unreasonably difficult - you will regret trying to save $200 on the injectors when you are days or weeks into tuning and are frustrated that things don't work as expected.
Don't bother with the cheap refurbished Bosch III's. Poor data on them so makes them very difficult to tune. Don't fall into the trap of cheap injectors - you get what you pay for and cheap injectors will make tuning unreasonably difficult - you will regret trying to save $200 on the injectors when you are days or weeks into tuning and are frustrated that things don't work as expected.
GD
The Fast system I installed is self learning, so tuning shouldn't be an issue. Southbay was closed so I sent them an e mail and will check in on Monday if I don't hear from them by then.
The Fast system I installed is self learning, so tuning shouldn't be an issue. Southbay was closed so I sent them an e mail and will check in on Monday if I don't hear from them by then.
The system can't "learn" injector voltage offsets. That is information that must be input into the system - just like displacement, fuel type, fuel pressure, etc.
Regardless of what type of system you use, you cannot entirely rely on the "self learning" to fix poorly selected parts for you. My recommendation stands. I've used plenty of injectors from half a dozen different suppliers including SouthBay. I own a DynoJet AWD Chassis dyno and tune regularly at my performance shop. Don't use cheap Bosch III's.
Regardless of what type of system you use, you cannot entirely rely on the "self learning" to fix poorly selected parts for you.
Exactly, EBL is "Self Learning" too. JI just hate hearing people say that. It has a self learning tool for the VE tables.
Originally Posted by GeneralDisorder
Don't use cheap Bosch III's.
I have B3's and wouldn't do it again. Usually when I tell people this all they see is the price and others say they run "fine".... none of those people ever seem to talk about data logging
I would use Delphis if I were replacing a set today. Unfortunately, my car had the B3s in it when I got it. Now that I am starting into my own tuning, I wish I had Delphis.
"Self Learning" EFI is only as good as the data that the algorithm has available to it. And it has further limitations depending on how integrated it is. Take for example the FiTech or the Holley Sniper systems - they are essentially throttle body injection systems designed to bolt to carb manifolds. As such the injector is integrated into the system and the self learning algorithm already knows it's flow rate, voltage offsets, low pulse width linearity, and so forth.
Other less integrated systems (such as the FAST you are using), are limited by the available information you input. They need to know as much accurate information as possible to get usable results - note I say "usable" because self-learning is not really a substitute for a real quality dyno tune by an experienced tuner. These systems are just not capable of creating a perfect calibration at WOT. They can do a pretty decent job of idling and steady-state cruise conditions, etc. But the AFR is based on an AFR target map that is very general and not customized to the needs of any particular engine. They have trouble with transient areas of the map where the engine moves rapidly through fueling cells during quick throttle openings, and they really can't do squat about timing - they rely on timing maps based on the user data such as displacement and cylinder head type, or many systems use old school carb distributors with vacuum and centrifugal advance - this is decidedly not ideal for best performance.
It's a bit like throwing on a new out-of-the-box carb and just driving it. Some do fairly well with this - mostly this works on relatively stock engines, but even then is typically not ideal.
Just because it's "Self Learning!" doesn't mean it can know what your engine displacement is, or what your injector characteristics are.
Again - just don't bother with injectors that don't come with data IN THE BOX.
"Self Learning" EFI is only as good as the data that the algorithm has available to it. And it has further limitations depending on how integrated it is. Take for example the FiTech or the Holley Sniper systems - they are essentially throttle body injection systems designed to bolt to carb manifolds. As such the injector is integrated into the system and the self learning algorithm already knows it's flow rate, voltage offsets, low pulse width linearity, and so forth.
Other less integrated systems (such as the FAST you are using), are limited by the available information you input. They need to know as much accurate information as possible to get usable results - note I say "usable" because self-learning is not really a substitute for a real quality dyno tune by an experienced tuner. These systems are just not capable of creating a perfect calibration at WOT. They can do a pretty decent job of idling and steady-state cruise conditions, etc. But the AFR is based on an AFR target map that is very general and not customized to the needs of any particular engine. They have trouble with transient areas of the map where the engine moves rapidly through fueling cells during quick throttle openings, and they really can't do squat about timing - they rely on timing maps based on the user data such as displacement and cylinder head type, or many systems use old school carb distributors with vacuum and centrifugal advance - this is decidedly not ideal for best performance.
It's a bit like throwing on a new out-of-the-box carb and just driving it. Some do fairly well with this - mostly this works on relatively stock engines, but even then is typically not ideal.
Just because it's "Self Learning!" doesn't mean it can know what your engine displacement is, or what your injector characteristics are.
Again - just don't bother with injectors that don't come with data IN THE BOX.
GD
The reason I went with the system I did is that the cost to tune the 1987 ecu to the current engine was going to be a lot more then the cost of a "self learning" setup. I simply couldn't find a shop that could, or was willing, to burn proms to get it sorted out. I did a lot of research into what exactly I was going to need to get the jobs done and in the end this is what I have to work with. All of the selected components are from the same company and are designed to work together. Hopefully once I get into the initial setup all of the documentation I have can be input into the system to get me a good general tune.
This car isn't going racing or to the strip and I was never looking to pull every ounce of HP out of the engine. That's the task of the next build that will see a lot of dyno time
If the general consensus is that the lower cost injectors are not up to par then I will buy a more costly set.
You are buying injectors that are not from the same company as the rest of the parts so "designed to work together" doesn't really apply as regards this discussion..... also that's really a misleading statement. Sure - they are EV1 bosch injectors and the FAST system is capable of "running" them in the sense that they are the correct impedance, etc. Tuning them efficiently is possible IF AND ONLY IF you have the proper data re: flow rate, offsets, and low PW linearity, etc. Which the cheap B3's don't come with.
It's not even a matter of "every last HP". It's a matter of driveability, repeatability, and stability. The "Self Learning" algorithm can't know that it's running the wrong injector offsets and will end up fighting itself trying to learn the fuel under varying conditions which it has no ability to compensate for due to a lack of proper data having been input by the user. And you can't input what you don't have...... make sense?
I fully understand what you're saying, but you're not listening to what I am saying. Have you read my build thread and seen where I have had to rewire the entire engine compartment due to rodent damage? It's not like I can just call up Painless and get an entirely new 1987 c110 block harness made up. This car has never run since i've owned it.
So what is your recommendation for moving forward since you've basically told me the FAST system I've installed is complete garbage and will not do what it was designed to do? I have no idea if I can input the proper injector data since I kind of need the motor together in order to run the initial tune. All I wanted to know in this thread was to identify what I had and if they were garbage what should I go with. That info was given and now I will buy a different set of injectors then what I was thinking and pay a little more then I was planning.
Thanks for the recommendations and hopefully this system will do what I need it to do.
I'm not saying the FAST system is garbage - not at all. I have no direct experience with it other than I know what it's listed capabilities are and have used many systems that are virtually identical or very similar. I think it can absolutely do what you need (self-tuning aside - that really should just be to get you to the dyno safely - the system certainly has the capability to be manually tuned as well). But for it to perform correctly you will need to give it as much information as possible. What FAST system did you buy? Does it not have a controller that you can input data with? It should have some method of hooking it to a laptop or have a hand-held unit that you can configure it with. You WILL have to configure it - it's not just plug it in and turn the key. It needs to know what size engine you have, what fuel you are running, camshaft specs, injector data, and a LOT more to even begin to self tune. In that respect it is the same as all other aftermarket fuel injection systems. None of them will run without basic information loaded into them by the user.
I would still recommend the Holley 36lb injectors. They will easily run your engine and have plenty of room for growth and going smaller will not save any money as the 19-36lb injectors are all the same price. I have used the Holley 36's and found them to have accurate data.
GD
Last edited by GeneralDisorder; 07-02-2020 at 05:36 PM.
I'm running the ez-efi 2.0 retro kit which did come with a handheld unit, but other them being turned on to see if it would power up, has never been used. The ecu and handheld are pretty much universal and the addition or subtraction of a section of the harness and a module will determine what injection system it manages. There is an "advanced" section in the handheld that I'm guessing is where the specific data for the injectors and other specialized parameters needed for the optimal tune will need to be input.
The issue I ran into was that when the intake was installed two years ago I didn't think twice about python the injectors being an issue, they were already in the rail and I just foolishly installed them with out giving it a second thought. Fast forward two years and I've had back surgery, new position at work, a new home, and I'm back working on the iroc. I buttoned up all the engine wiring and filled the coolant system up just to find out the rear driver's side of the intake was leaking. Tore it all apart to fix the leak and found out one of the bolts is slightly bent and was giving me a false torque reading. figured I'd take the time to go over everything one more time for good measure which brought me to making sure the fuel rail O rings were good, they weren't, and it dawned on me that I knew nothing about the python injectors.
Now I know which injectors to stay away from and which ones to buy. I just want to hear the engine run in this car since the last time I heard it was almost six years ago when I pulled it out of the tahoe lol!
Ah yes - you should be able to find where to input the data in the hand-held and then you will be fine for startup and basic self-tuning of the fuel table. Should work fine. You will need a carb style or dual-sync FAST distributor for timing control according to the specs I saw. The stock TPI distributor will not work as the FAST system likely can't control it due to harness limitations (it almost certainly can't supply the 5v timing unlock signal to the stock module) and it will be locked at 6 degrees (or whatever base timing was set at).
As I stated before I went with an entire FAST system made up of the ez-efi 2.0 multi port retro kit (#30404-kit), E6 CD Digital ignition box and E92 coil (#306401) , Dual Sync Distributor (#305005). This setup was engineered to work together and was literally plug and play. The only wiring that was required was running the obvious stuff like 12v constant, 12v keyed, ground, and then plugging in the sensors. The part that took the longest was decoding the C100 block so I could determine what wires were needed for the new system and then routing of the new harness for a clean fit.
An example was lengthening the power wire out of the alternator so it flowed with the rest of the harness since the alternator is now on the driver's side vs the passenger because I switched to a serpentine setup. I had to figure out what gauge of wire would be needed to carry the power the new length (10ft vs the old 2ft). So yeah I am trying to put as much thought into the placement and quality of the parts selected so I don't have issues down the road.
06-30-2020, 07:34 PM
