If I wasn't so far down the rabbit hole of multi-port injection already, the fitech system would be appealing to me. But at this point, I'm sticking with the multi port.
If I wasn't so far down the rabbit hole of multi-port injection already, the fitech system would be appealing to me. But at this point, I'm sticking with the multi port.
Shielding is dead easy in low-power circuits like sensors.
Shielded wire has a central wire for the conductor, and then foil wrapped around that, or metal braid. Foil right on top of the conductor is the weakest version; metal braid with foam insulator between it and the conductor is stronger. Sometimes there is both foil and braid, etc. But, the "better" the shield, the stiffer the package, so there are trade-offs. In truth, in some applications, just using a pair of wires (one for the circuit voltage and one for a separate ground), twisted tightly together, will be adequate if that wiring is run close to the grounded sheet metal of the car.
If you use something with a foil or braid shield, the main thing you need to do is drain the shield. That means, at one end of the cable and one end only, you need to connect a wire to the shield (just the shield, not the internal conductor) and ground that wire. The shield is kind of an antenna and it will pick up adjacent electrical interference, and the ground gives it a place to drain.
Dusterbd13 wrote: If I wasn't so far down the rabbit hole of multi-port injection already, the fitech system would be appealing to me. But at this point, I'm sticking with the multi port.
Once you have an intake and fuel rail that puts a separate injector adjacent to each cylinder, replacing it with a carb-style intake with distant injectors just seems like a step backwards to me. If I'm using that carb-style intake, I want the carb! More Powerrrr . . .. .
Best wording to put the Fitech in perspective. (Not my words):
Here is the thing about Throttle Body injected EFI systems. They are a quick and dirty EFI retro fit. That's it......Fuel is still injected above the throttle blades of the throttle body, just like a carb. You are at the mercy of air flow through the throttle body and distribution of the intake manifold, to distribute everything as it should. Better than a carb?....sure......as good as port injection?.....not even close. So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car or milder race car. GREAT for off road stuff, like Jeeps, where terrain changes wreak havoc on a carb.
From a system requirements standpoint, this clinched the deal:
So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car
JBasham wrote: Shielding is dead easy in low-power circuits like sensors. Shielded wire has a central wire for the conductor, and then foil wrapped around that, or metal braid. Foil right on top of the conductor is the weakest version; metal braid with foam insulator between it and the conductor is stronger. Sometimes there is both foil and braid, etc. But, the "better" the shield, the stiffer the package, so there are trade-offs. In truth, in some applications, just using a pair of wires (one for the circuit voltage and one for a separate ground), twisted tightly together, will be adequate if that wiring is run close to the grounded sheet metal of the car. If you use something with a foil or braid shield, the main thing you need to do is drain the shield. That means, at one end of the cable and one end only, you need to connect a wire to the shield (just the shield, not the internal conductor) and ground that wire. The shield is kind of an antenna and it will pick up adjacent electrical interference, and the ground gives it a place to drain.
Can you direct me to a guide with all these helpful tips?
Matt I sent you an email let me know if you got it and I look forward hearing back from you.
Jbasham thanks for the education. What is a good source of the good shielded wire?
Dusterbd13 wrote:Burrito wrote:Please....Javelin wrote: I have an MS for sale...Go on...
NOHOME wrote: Best wording to put the Fitech in perspective. (Not my words):Here is the thing about Throttle Body injected EFI systems. They are a quick and dirty EFI retro fit. That's it......Fuel is still injected above the throttle blades of the throttle body, just like a carb. You are at the mercy of air flow through the throttle body and distribution of the intake manifold, to distribute everything as it should. Better than a carb?....sure......as good as port injection?.....not even close. So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car or milder race car. GREAT for off road stuff, like Jeeps, where terrain changes wreak havoc on a carb.From a system requirements standpoint, this clinched the deal:So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car
So a MS2, a GM TBI unit, sensors, etc. and you're there. MegaSquirt was originally developed from reverse engineering the GM TBI system and "fixing" it.
https://www.diyautotune.com/product/carb-to-efi-diyer-kit-package-2/ $546
and here's the article that goes alone with it:
https://www.diyautotune.com/support/tech/carb-to-efi/
The car I'm looking at for FiTech is a good fit. Existing good manifold that I don't want to deal with removing and adding bungs to for port injectors. No desire for fiddling with the laptop. Not looking for ultimate performance but curing the same things NOHOME mentioned.
Hope this works. Not so good with the linky things here.
http://www.jegs.com/rebates/fitech/rebate.pdf
Only good through the end of this month.
In reply to wawazat:
because their dumbed down "touchscreen" solution is somehow better?
I guess its better than Holley's early attempts that required you to fiddle with tiny knobs on the side of the case to adjust various settings. What a joke that was.
I wish you luck and please post pictures and results once you get going on it as many of us are curious and enjoy seeing other people's projects and results.
Stefan (Not Bruce) wrote:NOHOME wrote: Best wording to put the Fitech in perspective. (Not my words):So a MS2, a GM TBI unit, sensors, etc. and you're there. MegaSquirt was originally developed from reverse engineering the GM TBI system and "fixing" it. https://www.diyautotune.com/product/carb-to-efi-diyer-kit-package-2/ $546 and here's the article that goes alone with it: https://www.diyautotune.com/support/tech/carb-to-efi/Here is the thing about Throttle Body injected EFI systems. They are a quick and dirty EFI retro fit. That's it......Fuel is still injected above the throttle blades of the throttle body, just like a carb. You are at the mercy of air flow through the throttle body and distribution of the intake manifold, to distribute everything as it should. Better than a carb?....sure......as good as port injection?.....not even close. So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car or milder race car. GREAT for off road stuff, like Jeeps, where terrain changes wreak havoc on a carb.From a system requirements standpoint, this clinched the deal:So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car
You are missing the point here. Pretend I really don't know or care to know anything about fuel injection, I am just some guy who can read a quick-start document and I just want it to work out of the box; about the same level of commitment I would give to a cell phone.
I have a healthy dose of skepticism myself as to how well the Fitech product matches their claims. However a year in, Fitech gets rave reviews from anybody who uses it for its intended purpose and did not opt for the Fuel Command center as a way to obtain EFI conditioned fuel supply.
I am a year away from wanting to fire the engine, so I will continue to monitor the feedback on both the Fitech and the Holley "Sniper" that should be released in June.
I get it. I just think its a bit silly and short-sighted since you DO have to understand a bit about engine tuning to understand what either system is doing.
To each their own and I wish you luck.
So, jimstim: Matt said useful for trouble shooting. Can we teach me more?
Also, a previous post about always seeing megasquirt guys on their laptops has made me nervous. I'm looking for a set it and forget it system. Assuming no changes to the engine, and no failures of injection hardware, how reliable is this stuff over the long run?
Fuel system : currently have it set up with a vacuum reference fuel pressure regulator. What does megasquirt like?
In reply to Dusterbd13:
As a guy who calibrates for a living- it's going to take a while to actually make the calibration perfect.
But all that means is having a laptop take data for every unique situation and processing it. And it sounds like the DIYAutotune system does a good job at that.
That's true for any system out there, the level of "goodness" is directly related to how much time is taken for data and processing. If the system doesn't need to make changes, then I would suggest it's not nearly as robust as one can claim it to be.
But it's also pretty easy to make a car run very well with not much time.
It all depends on how far you want to take it, and how good that has to be.
Like -20 to +120 F range or not, below sea level to 15,000 feet or not, humidity, etc. What range of that is good enough?
This isn't to scare you off- it's the reality of calibrations.
I'd love to hear more about the robustness of the hardware.
We've been running MS on a TR6 for three seasons now. We've had a few issues like a bad set of injectors, but the tuning hasn't been touched for two years. That's hundreds of autocross runs in various conditions. I didn't get too aggressive with the ignition map, and the fuel map is setup slightly rich. Drivability is much better than with the triple Webers. We spent much more time fiddling with jets on the Webers than I have messing with the Megasquirt.
I've also had a MSPnP-Pro on a MSM for 2 years. It's taken more fiddling, but is almost perfect now and a huge improvement over the stock MSM ECU.
Dusterbd13 wrote: ill be using the small cap HEI and coil. as well as the diyautotune premade 8 foot harness, which I believe is pre-shielded. so this will solve the problem?
Yes, our harness has the RPM input wire (in this case, it would be the HEI tach signal) shielded. The shield is grounded to the ECU and should not be grounded to the other end.
While I generally prefer high impedance injectors - they put out less voltage spikes - the flyback board is a leftover from the V2.2 board days. The same circuit is standard equipment on V3.0 and V3.57 boards.
Stefan (Not Bruce) wrote:NOHOME wrote: Best wording to put the Fitech in perspective. (Not my words):So a MS2, a GM TBI unit, sensors, etc. and you're there. MegaSquirt was originally developed from reverse engineering the GM TBI system and "fixing" it. https://www.diyautotune.com/product/carb-to-efi-diyer-kit-package-2/ $546 and here's the article that goes alone with it: https://www.diyautotune.com/support/tech/carb-to-efi/Here is the thing about Throttle Body injected EFI systems. They are a quick and dirty EFI retro fit. That's it......Fuel is still injected above the throttle blades of the throttle body, just like a carb. You are at the mercy of air flow through the throttle body and distribution of the intake manifold, to distribute everything as it should. Better than a carb?....sure......as good as port injection?.....not even close. So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car or milder race car. GREAT for off road stuff, like Jeeps, where terrain changes wreak havoc on a carb.From a system requirements standpoint, this clinched the deal:So if you are pretty happy with the carb, but want better starting, better idle and better fuel control, these are a decent deal for a street car
The big negative here is the TBI electrically noisy low impedance injectors and then the wetted walls and fuel pudding that causes fuel distribution and tuning issues. There is no good way to fix a TBI other than chucking it in the recycle bin.
I just bought an assembled MS3X (I wanted to run sequential) and have been reading up for my project. I have the benefit of not having anything but the engine decided on, so everything else is going to be set up around MS.
I've been reading manuals and forums for quite a while. My biggest issue is I need to have it in front of me to figure it out. All the reading isn't really helping much, I hope I got the right stuff.
I hope you get it figured out, this stuff can sure be frustrating.
In reply to bentwrench:
yes, and? So why pay MORE for that opportunity? Which is what happens with the FITech stuff.
THAT was the point of that post you quoted. Just saying that if you're going to saddle yourself with a programmable carburetor, then might as well not spend a bunch on it.
To each their own and if it gets more people out there enjoying their rides because they are able to start and drive them more easily, then that's a good thing no matter how you accomplish that.
bentwrench wrote: The big negative here is the TBI electrically noisy low impedance injectors and then the wetted walls and fuel pudding that causes fuel distribution and tuning issues. There is no good way to fix a TBI other than chucking it in the recycle bin.
After quite a few port injected installs/tunes with various EFI systems, I got to do a TBI system.
TBI... sucks. There were some interesting "learning experiences" that I had with that. I eventually got great drivability with it, the client/customer was ecstatic with the finished product, but I'm enough of a perfectionist that I was still not happy with it. Sure it drove okay, but I knew where it was imperfect and how it could have been better.
One of the biggest drawbacks is the fuel gets injected above the throttle plate. At idle, most of the air is coming through the IAC port. If you have a large throttle body, the main throttle plates may be passing so little air that the injected fuel seals the airflow off rather than going through, and of course any atomization you may have gotten is now gone... I banged my head against that particular wall for a long time, going so far as to go ape-S on the PCV system and going with a special low-flow PCV valve, all so I could get the throttle open enough so fuel could reliably flow through it at cold start and idle without having a 1500rpm hot idle. And acceleration enrichments... ugh.
I now fully respect Cadillac's decision to go with a throttle kicking idle control on the 4.1/4.5/4.9 engines, rather than an IAC valve.
Knurled wrote:bentwrench wrote: The big negative here is the TBI electrically noisy low impedance injectors and then the wetted walls and fuel pudding that causes fuel distribution and tuning issues. There is no good way to fix a TBI other than chucking it in the recycle bin.After quite a few port injected installs/tunes with various EFI systems, I got to do a TBI system. TBI... sucks. There were some interesting "learning experiences" that I had with that. I eventually got great drivability with it, the client/customer was ecstatic with the finished product, but I'm enough of a perfectionist that I was still not happy with it. Sure it drove okay, but I knew where it was imperfect and how it could have been better. One of the biggest drawbacks is the fuel gets injected above the throttle plate. At idle, most of the air is coming through the IAC port. If you have a large throttle body, the main throttle plates may be passing so little air that the injected fuel seals the airflow off rather than going through, and of course any atomization you may have gotten is now gone... I banged my head against that particular wall for a long time, going so far as to go ape-S on the PCV system and going with a special low-flow PCV valve, all so I could get the throttle open enough so fuel could reliably flow through it at cold start and idle without having a 1500rpm hot idle. And acceleration enrichments... ugh. I now fully respect Cadillac's decision to go with a throttle kicking idle control on the 4.1/4.5/4.9 engines, rather than an IAC valve.
What throttle body was it that you got around to install? If it was a Fitech or a Holley I would be very interested in specifics.
To clear up one of the misconceptions about the MS: While the first engine run on an MS1 was a small block Chevy with a TPI, and it was set up for GM sensors, the MS1 was not a reverse engineered GM ECM. Bowling & Grippo had previously designed another system, the EFI332, that didn't really catch on due to a really steep learning curve. The MS1 was intended as a simple, bare-bones system where their goal was to make sure they could put a good support structure in place behind it.
Designing a system and making it run is only part of the process - the bigger challenge is putting a support system in place for others who are looking to use your system.
Flight Service wrote: Can you direct me to a guide with all these helpful tips?
Sorry, that's off the top of my head. If you have any other questions, I'd be glad to try and help out. PM me any time.
AS FOR a source for shielded cable -- there is a ton of it out there but much goes by the spool, which is crazy expensive.
Good quality plug and coil wires are the first thing to think about, because they will keep a lot of EFI from getting loose in the first place.
Then we're worried primarily about sensor connections back to the MS, which are small signal devices. I don't see any reason why you couldn't use shielded microphone cable (flexible) or shielded guitar cable (less flexible) for these. www.partsexpres.com sells it by the foot.
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123456789 wrote: this is what i think of when i hear megasquirt
bit of warning please...daughter was sitting on couch next to me.
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