Good point, I keep forgetting that not everyone builds cars completely from scratch :P
Good point, I keep forgetting that not everyone builds cars completely from scratch :P
frenchyd said:In reply to Pete. (l33t FS) :
I'm sorry Pete.
Too slow a idle speed may mean insufficient oiling or heat extraction due to too slow coolant flow. It may also fail to charge the battery.
Yup. All acceptable tradeoffs. It is somewhat socially unacceptable to drive around idling at 1800rpm. BTDT.
I do have an electric water pump setup I can use so I don't need to run a 3" crank pulley to keep the water pump from cavitating over 6000, a problem when one generally keeps the engine between 5000 and 9000, and a stock pulley will allow the alternator to charge at low speeds... but the current setup is an acceptable tradeoff vs. undesired complexity.
I like carbs. They are imperfect but when they work, they work. They don't care about charging system voltage ripple or if the fuel pump sucks air momentarily or anything, air goes through them and pulls fuel in along with it. Simple, move on to the next problem.
And a good carb works incredibly well! As much as I malign GMs, their Quadrajet equipped engines had some of the best drivability and efficiency ever, their move to TBI was a huge step back, even with the engineering might of one of the largest manufacturers in the world. They had to idle and low load rich of stoich because of the inherent mixture distribution and atomization issues with TBI.
It is telling that TBI systems stopped existing once OBD-II was mandated. Couldn't make the system work well enough.
TBI is gimping yourself. Might as well stick with a well-tuned carb if you are going that route. Yes, its cheaper...but gives up almost all the benefits of EFI for that one feature.
In reply to Pete. (l33t FS) :
This ^
EFI is a lot like certain vehicle marques: where people who had never seen one a year ago, suddenly appear on the concourse judging field the next year as the expert.
EFI is challenging because it is chemistry, physics, electronics, trouble-shooting and mechanical systems/dynamics design that few of us studied. Add on systems analysis ( the bit you do with all the squiggly lines on the computer screen) and you lose the rest of the population.
Not saying "Don't do it" Just saying it is not easy by definition. It is a good education and hobby as long as transportation is not the principle goal.
What I am gathering is:
1. A megasquirt type setup has a tendency to be a long term project
2. TBI has inherent flaws, that are more pronounced at low engine rpms
3. People have a pretty wide variation in experience with both style systems
I picked up a foxbody efi manifold a few days ago to take some measurements. It'll take quite a bit of modification to clear the hood. That, combined with an exhaust setup that is more restrictive than stock (and heads/cam), make me think a stock ford computer will have a hard time running the motor optimally. I am hesitant to spend the money on the next step to improve the carbs consistency (electric fuel pump/return regulator) when the results may still be lacking the efficiency and consistently smooth idle I am after. There is plenty of underhood heat to deal with in this engine bay, and without the feedback loop of the O2 sensor I don't think the carb is going to keep up without a retune every season.
1 and 3 go hand in hand. When I did my MS install in 200...9? I was treating it like a fuel injection system, not an engine management package. I was installing a GSL-SE engine, which was a distributor engine with a very basic form of fuel injection, kind of a licensed copy of L-Jetronic. Coolant temp, air temp, TPS, one wire O2 sensor, two injectors. Distributor already had an MSD ignition so its tach output became the RPM signal. Fan was already controlled by a switch on the dash.
It worked very well for a very long time. Over the years I futzed with fuel pumps and larger injectors and a couple different wideband setups as they came down in price, and when my v1.01 box died I replaced it with a MS2 on a 3.57 board, but it is still basically the same install.
It is as complicated as one wants it to be. I want something that injects fuel that I can tune with a laptop instead of jets, and for that it is awesome. I have had stock port, street port, bridge port, peripheral port, 12A, 13B, all with the same wiring and sensors and injectors, just change the tune as necessary.
In reply to Pete. (l33t FS) :
Brilliant Pete.
That is exactly my thinking. Not so much worried about changing jets but changing anything.
Most 80's 90's EFI's really were fixed lacking the later OBD2 Aftermarket ECM 's aren't really that complicated.
A side benefit is the ability to alter timing. On Jaguars the timing markers are on the bottom of the engine. Where you need extensions on the timing light and mirrors to see the marker.
By getting rid of the whirlygig over $1000 in replacement parts is saved plus all that Tom foolery trying to adjust the distributor. Which on the Jaguar is a massive undertaking requiring disassembly, Allen wrenches, a slight movement ( max 3 degrees) and reassembly followed by restarting Testing only to repeat and repeat and repeat again until correct.
In reply to Pete. (l33t FS) :
So MS can be as simple as one really needs or as complex as they can dream (to a point).
I think one of the more daunting issues to MS to me is building one. But they can be gotten as completed systems, right? Just like most other aftermarket EFI systems.
In reply to alfadriver :
What turned me around was a guy in Texas with some old wires twisted onto the contact points and stuffed into the Megasquirt.
The gas tank was an old fire extinguisher And a Chevy fuel injection pump. When he remembered to turn on the fuel pump it fired right off.
Rude, crude, and basic as heck.
alfadriver said:In reply to Pete. (l33t FS) :
So MS can be as simple as one really needs or as complex as they can dream (to a point).
I think one of the more daunting issues to MS to me is building one. But they can be gotten as completed systems, right? Just like most other aftermarket EFI systems.
Yes. The 3.57 is a surface-mount component board only available as an assembled unit, although it does have an area on the board for add on mods.
For "Colin" I went a little fancier, and bought an MS3Pro Evo. Its electronic inputs are a lot more robust. There was an announced price hike so I bought before it went up. (and with a 10% off coupon I got for attending a rallycross)
But that is for something that WILL need a management system: sequential fuel, coil on plug, boost control, antilag, CAN communication with a trans controller (this allows shared sensors, and ignition retard on upshifts). Possibly drive by wire in the future, but if the RX-7 was any indication, if I don't implement something at first, then I won't ever do it. Perfect is the enemy of good enough...
Pete. (l33t FS) said:Perfect is the enemy of good enough...
I was going to point that part out. Better to have a system running now than not.
Pete. (l33t FS) said:Batch fire only works if you have extremely long runners, so reversion pulses can't starve some cylinders and overfuel others.
Note that when Ford and Chevy batch fired V8s, they had those manifolds with 22" long runners. Buick turbo V6s had very short runners and they also had sequential fuel injection, in the 80s. GM went to sequential for the LT1 which had - surprise - very short runners.
I tried running a BGN six batch fire. It ran on four cylinders. Set it up as sequential like I should have and it ran smoothly.
92 and 93 MY LT1s where batch fired. They ran and drove like a modern vehicle.
The advantage of a TBI is simplicity and packaging. If you have a carb it will bolt to your current manifold, and at a glance it will still look carbed. They are easy to put on and most have have a self tuning feature, that's pretty dang good. I've had good luck with stealth and fitech systems. I haven't experienced any of the drivability issues mentioned. All the tbi stuff once dialed in has started up and cold idled like a modern fi car.
You don't have a good OEM MPFI solution for a 5.0. The mustang manifold are tall and flow like E36 M3. I wouldn't consider putting one on without porting the lowe, the ports and runners are all different sizes and shaped. They are also ugly. Plus you have to wire everything up, and run the crappy stock ECM with limited tuning options or run an aftermarket ECM and deal with the same tuning and setup issues of an aftermarket TBI system.
My opinion is too many compromises and added complexity for MPFI. The easy button is a TBI, they are made for your exact situation.
This is coming from someone who likes carbs and MPFI, but in your case it seems like TBI has the clear advantage
Pete. (l33t FS) said:alfadriver said:In reply to Pete. (l33t FS) :
So MS can be as simple as one really needs or as complex as they can dream (to a point).
I think one of the more daunting issues to MS to me is building one. But they can be gotten as completed systems, right? Just like most other aftermarket EFI systems.
Yes. The 3.57 is a surface-mount component board only available as an assembled unit, although it does have an area on the board for add on mods.
For "Colin" I went a little fancier, and bought an MS3Pro Evo. Its electronic inputs are a lot more robust. There was an announced price hike so I bought before it went up. (and with a 10% off coupon I got for attending a rallycross)
But that is for something that WILL need a management system: sequential fuel, coil on plug, boost control, antilag, CAN communication with a trans controller (this allows shared sensors, and ignition retard on upshifts). Possibly drive by wire in the future, but if the RX-7 was any indication, if I don't implement something at first, then I won't ever do it. Perfect is the enemy of good enough...
Annoyingly the 3.57 doesn't have that handy proto area. A very odd design choice tbh.
The microsquirt and ms3 pro units are the easy button for most setups. I only do a few custom ecus per year now with most on those two. The few excirsions are usually cheap asses with audi 5cyls wanting cop and not beinf too spendy.
Wait, the exhaust is more restrictive than what was factory on the Fox 5.0 cars?
It doesn't seem like any of the factory EFI 5.0 intakes were that great, and all but the tubular GT40 seem pretty heavy. EFI conversion of a decent single plane carb intake sounds nice in theory and costly in practice. But it would probably be a method of clearing the stock hood. Stock hood modified with a scoop might be nice though if you want to mess with that.
Paul_VR6 (Forum Supporter) said:Pete. (l33t FS) said:alfadriver said:In reply to Pete. (l33t FS) :
So MS can be as simple as one really needs or as complex as they can dream (to a point).
I think one of the more daunting issues to MS to me is building one. But they can be gotten as completed systems, right? Just like most other aftermarket EFI systems.
Yes. The 3.57 is a surface-mount component board only available as an assembled unit, although it does have an area on the board for add on mods.
For "Colin" I went a little fancier, and bought an MS3Pro Evo. Its electronic inputs are a lot more robust. There was an announced price hike so I bought before it went up. (and with a 10% off coupon I got for attending a rallycross)
But that is for something that WILL need a management system: sequential fuel, coil on plug, boost control, antilag, CAN communication with a trans controller (this allows shared sensors, and ignition retard on upshifts). Possibly drive by wire in the future, but if the RX-7 was any indication, if I don't implement something at first, then I won't ever do it. Perfect is the enemy of good enough...
Annoyingly the 3.57 doesn't have that handy proto area. A very odd design choice tbh.
The microsquirt and ms3 pro units are the easy button for most setups. I only do a few custom ecus per year now with most on those two. The few excirsions are usually cheap asses with audi 5cyls wanting cop and not beinf too spendy.
Huh. I bought my MS2 from DIYAutotune and originally wanted a 3.0 board, modded for four COPs, and they recommended a 3.57 because it was more easily modifiable. And they only charged me something like fifty bucks to add the ignition outputs. That I ended up never using...
Part of the reason "Colin" has a MS3Pro (on the shelf, waiting to go in) instead of a WRX MSPnP is that I bought the computer well before I knew if I could actually shove a WRX drivetrain and suspension into a Mini Cooper, because of aforementioned time constraint. I actually bought the computer before I had a WRX parts car.
If it didn't work, I have an Audi 5cyl long term project sitting here that could use it. (MC2 engine bored to 83mm, with 7:1 pistons, heavily ported NG cylinder head with 034 valves, short runner intake manifold, two-piece exhaust manifold, K24-7400 turbo...)
If it DID work, I was planning on using a Link for various reasons, mostly centered around connecting the accelerator pedal to the throttle body, which requires either a 5000 Turbo automatic throttle linkage, some other weird combination of parts that have not been sold on this continent and have been discontinued for 30 years, or drive by wire.
Looks like I am buying a Link 
Well, after my credit cards get un-dilated, anyway
Shavarsh said:What I am gathering is:
1. A megasquirt type setup has a tendency to be a long term project
2. TBI has inherent flaws, that are more pronounced at low engine rpms
3. People have a pretty wide variation in experience with both style systems
I picked up a foxbody efi manifold a few days ago to take some measurements. It'll take quite a bit of modification to clear the hood. That, combined with an exhaust setup that is more restrictive than stock (and heads/cam), make me think a stock ford computer will have a hard time running the motor optimally. I am hesitant to spend the money on the next step to improve the carbs consistency (electric fuel pump/return regulator) when the results may still be lacking the efficiency and consistently smooth idle I am after. There is plenty of underhood heat to deal with in this engine bay, and without the feedback loop of the O2 sensor I don't think the carb is going to keep up without a retune every season.
I have used MegaSquirt since MS1 first came out...installing it was a weekend project, I was driving the following Monday with a basic street tune. Keep in mind, I knew nothing at all about EFI when I installed that first MegaSquirt(to be fair though, that first tune I just downloaded a basic tune others had made as a starting point...its far more tricky to build a tune from scratch). It did take me months to dial in that tune for higher boost levels and I continually tweaked the tune for years, but the basic tuning was pretty quick and easy. For my next MS2 and MS3 installs on other vehicles, I built the ECU from a kit instead of ordering a pre-built one like I did for the first. Its really only intimidating until you actually do it.
In reply to Wicked93gs :
This is good feedback. I am not intimidated by the setup, just looking for a solution that I can reach a stopping point and stop looking at the gauges all the time. Another factor is that I drive this car long distances. If I have problems on the road a carb (or even a mpfi made of oem parts) can be repaired while the aftermarket TBI ecu cannot be repaired on the road. I am tempted to use a microsquirt to just set up fueling and save some $, but in the future I'll definitely want to control timing as well. Cost and reliability become my major hurdles to ditch the carb and move to mpfi. I'll have to sit on it a bit. I really appreciate all of the discussion in this thread.
I run and like megasquirt on two project vehicles. Agree that it can be as complicated or simple as the user desires, but even a simple setup can deliver great performance and driveability. It's all about the information you make available to the ECU and how the tuner uses it. Yes, you can buy them pre-assembled.
I also run and like carbs (Holley 4150s and Q-jets) on other projects. Lots of time spent tuning creates great-running vehicles that return EFI-like economy and driveability. It really boils down to the same approach, just different hardware.
Sounds like the OP is considering all of this due to heat soak/hot weather/hot start issues. Been there, done that. An electric pump with return-style regulator will help, but the hot fuel issues are always going to be tough to eliminate with a carb, especially in a tight engine compartment. Putting a phenolic spacer under the carb and ditching the presumed open-element round air cleaner for a remote air filter with ducting to pull air from the coldest corner of the engine bay will work nicely with the fuel system upgrade.
The choice of TBI vs MPFI may very well come down to what you can fit if you're not willing to install a taller hood.
Shavarsh said:In reply to Wicked93gs :
This is good feedback. I am not intimidated by the setup, just looking for a solution that I can reach a stopping point and stop looking at the gauges all the time. Another factor is that I drive this car long distances. If I have problems on the road a carb (or even a mpfi made of oem parts) can be repaired while the aftermarket TBI ecu cannot be repaired on the road. I am tempted to use a microsquirt to just set up fueling and save some $, but in the future I'll definitely want to control timing as well. Cost and reliability become my major hurdles to ditch the carb and move to mpfi. I'll have to sit on it a bit. I really appreciate all of the discussion in this thread.
About the only thing at risk is the non-oem ecu, if you are really that concerned a spare microsquirt is relatively inexpensive. Also able to get the next day from a local supplier .. I have loaned out a unit once for a customer that managed to pop one with a reversed battery charger. Other than that no failures in quite a few units on the .. track 
In reply to Paul_VR6 (Forum Supporter) :
I was going to say that most of them seem fairly robust. And like you say a spare one isn't that heavy or bulky . The only hard part is the initial connection to the plug. After that I'll bet you could change one out in a few minutes.
Honestly the hardware is really good.
I damaged my 1.01 twice. First by running two peak and hold injectors off of one driver, which required the "hold" PWM to be 70%, and was running near 100% duty cycle for extended periods of time. This eventually fried the flyback transistor, or whatever it was. Borrowed a laptop, set the tune to "no PWM", limped the car 170mi home, installed a resistor block from a low-z RX-7. Fixed.
The second time, the positive terminal came off the battery while I was driving. Applied the brakes, voltage spike fried something else. That was the reason for the MS2.
It should be noted that the 1.01 was the original Bowling & Grippo "hey DIY-EFI mailing list, let's do something cool" group buy circuit board. It was nowhere near as robust as the newer boards. Still, I got many years of use and abuse from it.
I've done Megasquirts on several 4 cylinder cars that had factory EFI and a Microsquirt with a throttle body on my classic Mini. As this thread shows, there is a lot of experience here with Megaquirt and options from very low buck to more pricey.
I've now done two Holley Sniper setups on Ford 302s--one NA, one blow through supercharged. We're planning several more installations at Eclectic. A friend at another shop installs a lot of them successfully, and my dyno shop installs them on a lot of cars, some with more than 1500WHP. There can be issues, usually grounding or EMI, but Holley's tech support is pretty good.
In my experience, they have been almost as advertised. Install the throttle body, wire it up, update your fuel system, and the self-tuning works very well. I've touched up my installs on a dyno to get the last bit of HP and driveability, but my friend at the other shop just sends them after the self-tune is good.
I like to install the Sniper, a new, locked distributor, CDI box, and a new fuel pump/return setup. That's around a $2000 spend but it will grow with your engine if you want more power later.
People have mentioned the theoretical drawbacks of TBI vs port injection, but in practice I find the Sniper giving better drivability and easier tuning than a carb. Here are some of my reasons:
My main frustration with the Sniper (and probably other TBI kits) is the wiring--it's all too long and you have to either loop it up or reterminate it. Holley doesn't sell kits to reterminate it, so you either have to figure out all the connectors and source them, or shorten and splice wires.
I don't want to make this a Sniper commercial, but thought I'd share there are positive experiences with it.
In reply to Carl Heideman :
Carl, do you know if there is a source for spare ecus? I haven't been able to find them. That is my major concern with the sniper unit. It might be unreasonable, but the heat and vibration at the throttlebody make me want a spare to avoid getting stranded far from home.
In reply to Shavarsh :
I'm afraid the answer is buy a whole spare Sniper. I've had little luck finding individual components as well. I've been planning to call Holley tech support and try to chase down how to put together a spares kit. That's how I've slowly been figuring out how to source connectors to reterminate the wiring.
This makes me think of my other concern with Snipers or aftermarket EFIs. I imagine they have a life of around 10 years and if they last that long, parts and tech support will be no longer available. and it will be time to buy a new EFI with whatever is current.
In reply to Shavarsh :
The ECU isn't mounted at the throttle body. Are you concerned about the throttle body unit or the ECU? The sniper uses mostly standard serviceable sensors you can get at the parts store
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