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JimN
08-07-2012, 06:21 PM
Here's an article that explains some of the tech behind fuel injection.

http://www.fourwheeler.com/techarticles/engine/129_0509_electronic_fuel_injection_tech/viewall.html

wtrskr
08-07-2012, 11:39 PM
I didn't read all of it yet, but read parts. Thanks for posting.

I have a fuel-injection related question that you or someone else may be able to help with. I don't get the whole lean vs. rich concept.

If I understand correctly, rich means that the engine is getting too much gas and doesn't burn all of it before it goes out as exhaust. As I think about it, if the engine is getting more gas, shouldn't it just create a larger explosion in the chamber and make the engine go faster. What creates the scenario where more gas goes to the engine but it just become "rich" and doesn't speed up the engine?

j.mccreight@hotmail.com
08-08-2012, 12:40 AM
I didn't read all of it yet, but read parts. Thanks for posting.

I have a fuel-injection related question that you or someone else may be able to help with. I don't get the whole lean vs. rich concept.

If I understand correctly, rich means that the engine is getting too much gas and doesn't burn all of it before it goes out as exhaust. As I think about it, if the engine is getting more gas, shouldn't it just create a larger explosion in the chamber and make the engine go faster. What creates the scenario where more gas goes to the engine but it just become "rich" and doesn't speed up the engine?

If there’s too much fuel present in the intake and compression stroke, not all the fuel will be burnt efficiently and the un-burnt fuel will be pushed out through the exhaust valve on the exhaust stroke, the stoichiometric air to fuel ratio (14.7:1) must be maintained for a complete burn and using all the air in the combustion or power stroke and this makes the most power, better emissions and fuel consumption.

wtrskr
08-08-2012, 08:42 AM
Ok. I think I am getting it now. My thought was that more gas would speed up the engine and thus create more air flow. I was thinking the engine would always pull enough air to mix with the fuel. I guess, with fuel injection, the computer could force more gas than is appropriate for the given air flow.

CantRepeat
08-08-2012, 09:40 AM
Ok. I think I am getting it now. My thought was that more gas would speed up the engine and thus create more air flow. I was thinking the engine would always pull enough air to mix with the fuel. I guess, with fuel injection, the computer could force more gas than is appropriate for the given air flow.


You can introduce more fuel then air in a carb motor too. It's all about the right mixture of air and fuel.

JimN
08-08-2012, 10:12 AM
Ok. I think I am getting it now. My thought was that more gas would speed up the engine and thus create more air flow. I was thinking the engine would always pull enough air to mix with the fuel. I guess, with fuel injection, the computer could force more gas than is appropriate for the given air flow.

Think of the throttle plate as a controllable vacuum leak. Open the throttle and more air gets in, so the engine can revolve faster and the throttle plate is the only thing keeping an engine from runaway RPM. Close off the intake completely and you would have total vacuum, making the engine stop because A) it's trying to rotate against a vacuum, B) there's no air for combustion and C) the vacuum (with a carb) doesn't cause fuel to be sucked into the intake or cause the ECM to deliver fuel, although I'm pretty sure there's no provision for 100% vacuum on an injected engine.

If the MAP sensor sees low vacuum (like it does when the throttle is open), it will deliver more fuel than needed. If this happens AND the TPS or ECT are telling it that the throttle is open more than it really is (bad TPS, unplugged TPS or bad wiring to the TPS) or the coolant is colder than it really is, the engine will run extremely rich and the throttle response will be very slow/incorrect.

mikeg205
08-08-2012, 10:26 AM
I like the point about the shear on the fuel. I added a filter before the pump on TBI because I found a ton of crud on the intake screen of the fuel pump. Did not notice any performance issues as of yet. Good to know...something to research... thanks JimN

JimN
08-08-2012, 10:46 AM
I like the point about the shear on the fuel. I added a filter before the pump on TBI because I found a ton of crud on the intake screen of the fuel pump. Did not notice any performance issues as of yet. Good to know...something to research... thanks JimN

You didn't already have another filter just after the tank?

wtrskr
08-08-2012, 01:19 PM
Think of the throttle plate as a controllable vacuum leak. Open the throttle and more air gets in, so the engine can revolve faster and the throttle plate is the only thing keeping an engine from runaway RPM. Close off the intake completely and you would have total vacuum, making the engine stop because A) it's trying to rotate against a vacuum, B) there's no air for combustion and C) the vacuum (with a carb) doesn't cause fuel to be sucked into the intake or cause the ECM to deliver fuel, although I'm pretty sure there's no provision for 100% vacuum on an injected engine.

If the MAP sensor sees low vacuum (like it does when the throttle is open), it will deliver more fuel than needed. If this happens AND the TPS or ECT are telling it that the throttle is open more than it really is (bad TPS, unplugged TPS or bad wiring to the TPS) or the coolant is colder than it really is, the engine will run extremely rich and the throttle response will be very slow/incorrect.

Now I am really learning. I had assumed that giving more throttle just meant giving more gas. So it sounds like, with EFI, punching the throttle allows the engine more air flow and sends the signal to the ECM to give gas. At the same time, the ECM uses the sensors to make sure the gas given properly matches the airflow. Adjusting a carb is then searching for the spot that gives the correct fuel/gas ratio when when the throttle is pushed. Correct me if any of my statements are wrong. Thanks.

JimN
08-08-2012, 06:29 PM
Now I am really learning. I had assumed that giving more throttle just meant giving more gas. So it sounds like, with EFI, punching the throttle allows the engine more air flow and sends the signal to the ECM to give gas. At the same time, the ECM uses the sensors to make sure the gas given properly matches the airflow. Adjusting a carb is then searching for the spot that gives the correct fuel/gas ratio when when the throttle is pushed. Correct me if any of my statements are wrong. Thanks.

That pretty well sums it up.

ahhudgins
08-09-2012, 04:46 PM
Now I am really learning. I had assumed that giving more throttle just meant giving more gas. So it sounds like, with EFI, punching the throttle allows the engine more air flow and sends the signal to the ECM to give gas. At the same time, the ECM uses the sensors to make sure the gas given properly matches the airflow. Adjusting a carb is then searching for the spot that gives the correct fuel/gas ratio when when the throttle is pushed. Correct me if any of my statements are wrong. Thanks.

A guy I know (not a friend thank goodness) thought that “more gas in the engine” meant it would start better. He was having problems getting his carbureted truck to start so he had his wife turn the key while he dumped gas down the carb. He ended up in the hospital with 1st and 2nd degree burns after it backfired.

JimN
08-09-2012, 04:52 PM
A guy I know (not a friend thank goodness) thought that “more gas in the engine” meant it would start better. He was having problems getting his carbureted truck to start so he had his wife turn the key while he dumped gas down the carb. He ended up in the hospital with 1st and 2nd degree burns after it backfired.

How is that going to be better than pumping the pedal a few times before cranking? Back when carbs were common, little kids knew that you could flood an engine by pumping the pedal- how did he not learn this? It's safer, too- I suspect he did learn that.

mikeg205
08-09-2012, 06:18 PM
You didn't already have another filter just after the tank?

no...the hose was connected to the fuel take up and went directly to the fuel pump. 95 TBI

DRRICK
08-14-2012, 06:21 PM
Here's an article that explains some of the tech behind fuel injection.

http://www.fourwheeler.com/techarticles/engine/129_0509_electronic_fuel_injection_tech/viewall.html

Nice article. I am casting about for someone with the knowledge to help with my EFI. Specifically does anyone have experience with recalibrating The Mastercraft LT-1, and if so how did you do it? I have a '94 Prostar 190

see my other posts for further information. ROller rockers 1:6, etc.
I have been in contact with Bob At MEFIBurn, but I was hoping someone here would have already been down the road less traveled..................which I am on.


for example, how to make an O2 sensor work in a marine environment and the difference between closed and open loops as they relate to the marine engine. and that stuff

or.............do I really need the O2 adaptor from Howell or something like it, in addition to the O2 sensor and separate gauge, since the ECM doesn't listen to an O2 sensor...

1. ADAPTOR, O2 SENSOR for Marine use
Part # HM206 O2 sensor adaptor designed to install heated Oxygen sensor in water cooled marine exhaust manifolds. Oxygen Sensor is priced separately.
http://howellefi.com/?subcats=Y&type=extended&status=A&pshort=Y&pfull=Y&pname=Y&pkeywords=Y&search_performed=Y&q=marine&dispatch=search.results


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I will continue my search. When (not if) I get it settled I will post results here.

JimN
08-14-2012, 07:33 PM
Nice article. I am casting about for someone with the knowledge to help with my EFI. Specifically does anyone have experience with recalibrating The Mastercraft LT-1, and if so how did you do it? I have a '94 Prostar 190

see my other posts for further information. ROller rockers 1:6, etc.
I have been in contact with Bob At MEFIBurn, but I was hoping someone here would have already been down the road less traveled..................which I am on.


for example, how to make an O2 sensor work in a marine environment and the difference between closed and open loops as they relate to the marine engine. and that stuff

or.............do I really need the O2 adaptor from Howell or something like it, in addition to the O2 sensor and separate gauge, since the ECM doesn't listen to an O2 sensor...

1. ADAPTOR, O2 SENSOR for Marine use
Part # HM206 O2 sensor adaptor designed to install heated Oxygen sensor in water cooled marine exhaust manifolds. Oxygen Sensor is priced separately.
http://howellefi.com/?subcats=Y&type=extended&status=A&pshort=Y&pfull=Y&pname=Y&pkeywords=Y&search_performed=Y&q=marine&dispatch=search.results


--------------------------------------------------------------------------------
I will continue my search. When (not if) I get it settled I will post results here.

If you want to go closed-loop, I would suggest putting the engine on a dyno, like the person who was interviewed for that article. He did the original setup for your engine and when MC was working on O2 and catalytic converters, it was done at his shop, too. That's where we went for MC testing before they changed to their current location. It takes a lot of testing to get it right- the emissions & in-cylinder temperature measurements are needed and his dyno labs are equipped to do this. If you try to do this on the fly, it's pretty easy to set it up too lean or too rich, neither of which works well and if it's too lean, you can cook your engine. One main thing you would need to do for the O2 sensor is keep it dry and if it gets wet, it's toast. Unless you're a manufacturer, you really don't need an O2 sensor and open-loop will work fine for performance. Besides, it's not like you're driving a light-weight car that hooks up to the road really well- a prop turning in water isn't the most efficient way to propel something, although it is more efficient than doing it in air. I have talked with Bob and I would say he should be able to get you where you want to go.

CantRepeat
08-15-2012, 08:42 AM
If you're going to do any type of tuning you will need to data log what's happening in the motor. The O2 sensor is going to be needed to map the VE tables. Without out the O2 sensor you wont know what's being burned.

The only software I have looked at for marine use is DIACOM and it's some what costly. I think it's right around $700 bucks for the software and one or two cables that go from the laptop to the DLC. With that software and the stock tune you'd have a starting point.

I've never seen that O2 sensor adapter and I never new they made them. The only issue I see with it is if the current EFI isn't using an O2 sensor then you'd have to do some pretty major work to get the EFI to use it. If I was going to try this I'd be looking for a MEFI that is wired and programmed for an O2.

The neat thing about that O2 adapter is it gives a method to get an O2 in to an older carb motor if someone was looking to do an EFI conversion.

DRRICK
08-15-2012, 01:08 PM
If you're going to do any type of tuning you will need to data log what's happening in the motor. The O2 sensor is going to be needed to map the VE tables. Without out the O2 sensor you wont know what's being burned.

The only software I have looked at for marine use is DIACOM and it's some what costly. I think it's right around $700 bucks for the software and one or two cables that go from the laptop to the DLC. With that software and the stock tune you'd have a starting point.

I've never seen that O2 sensor adapter and I never knew they made them. The only issue I see with it is if the current EFI isn't using an O2 sensor then you'd have to do some pretty major work to get the EFI to use it. If I was going to try this I'd be looking for a MEFI that is wired and programmed for an O2.

The neat thing about that O2 adapter is it gives a method to get an O2 in to an older carb motor if someone was looking to do an EFI conversion.

The way I understand it, the MEFIBurn setup is used to remap the delphi computer already in the boat=MEFI I, in my boat. The O2 sensor is only used to monitor the a/f mixture, and as a such becomes a gauge that one would mount either on the dash or "under the hood". The O2 sensor does NOT interact with the ECM. It is just used for tuning, although according to Bob, the heated O2 sensors can operate in a wet environment, but this is the part I do not understand. I am going to talk to Bob again today.

The other option would be to replace the ECM with an external ECM like Holly or Accel make, but I have yet to find someone who has done that in this particular boat/engine combination.

DRRICK
08-15-2012, 05:20 PM
although according to Bob, the heated O2 sensors can operate in a wet environment, but this is the part I do not understand. I am going to talk to Bob again today.



I misunderstood Bob. Apparently one can drill through both jackets on the riser and braze (not weld-cast iron) an O2 bung, or ??a plate between the log and riser?? Either way, the O2 sensor has to be removed after the new ".bin" is uploaded to the ECM.

After all this, I am going to send my ECM to Bob. He will re-program it with a program from a similar project he has helped fix (one of many). And send it back to me.

CantRepeat
08-15-2012, 07:17 PM
I know of NO O2 sensor that will work in a wet environment. If there was one then no one would be building dry exhaust for boats. Clearly they could not get a reading of A/F ratio when the air is combined with water. After all its not air/fuel/water ratio that engines are tuned to.

The entire purpose of the O2 sensor is to provide real-time feedback of A/F to the ECM so it can make real-time adjustments to the tune. What good is a an O2 sensor if the ECM does not use the data that it provides?

Why would the O2 sensor have to be removed to reprogram the ECM? That would NEVER be the case. I had my ECM flashed and the sensor was not removed. There's no reason to remove it.

If Bob reprograms your ECM to a "similar project" without any data logs you are just taking a very big swing at it. Sure this would be an ok place to start but you really need to log data and then make corrections to the tune. The only way to correct VE and spark tables without a dyno is to get data logs from the ECM while the boat is on the water.

DRRICK
08-17-2012, 07:25 PM
The entire purpose of the O2 sensor is to provide real-time feedback of A/F to the ECM so it can make real-time adjustments to the tune. What good is a an O2 sensor if the ECM does not use the data that it provides?

The MEFI I ECM is not capable of using the O2 sensor. Weren't built that way. Cannot be made to use an O2 Sensor.

The new boats have O2 sensors and ECM's that are capable of responding to the A/F.

The point is, I realize that the BEST way would be installing and O2 sensor, but in this case the only use It would have is using the number on the external gauge in combination with the data you have referred to and tune the boat that way. Again, the ECM in my boat does not have the capability to be attached to an O2 sensor, that I know of. I sure wish I were wrong.


Why would the O2 sensor have to be removed to reprogram the ECM?

Bob said that the O2 sensor would eventually get contaminated and be ruined. Suggested that during the tuning phase one would not perform any maneuvers that would possibly get moisture on the O2 sensor? If I should be brave enough to make further changes to the motor, I would be able to reinstall it for the next tune episode.

Thanks for your input!

JimN
08-17-2012, 11:09 PM
The MEFI I ECM is not capable of using the O2 sensor. Weren't built that way. Cannot be made to use an O2 Sensor.

The new boats have O2 sensors and ECM's that are capable of responding to the A/F.

The point is, I realize that the BEST way would be installing and O2 sensor, but in this case the only use It would have is using the number on the external gauge in combination with the data you have referred to and tune the boat that way. Again, the ECM in my boat does not have the capability to be attached to an O2 sensor, that I know of. I sure wish I were wrong.


Bob said that the O2 sensor would eventually get contaminated and be ruined. Suggested that during the tuning phase one would not perform any maneuvers that would possibly get moisture on the O2 sensor? If I should be brave enough to make further changes to the motor, I would be able to reinstall it for the next tune episode.

Thanks for your input!

What is the real reason you were trying to use an 02 sensor- to have a more accurate A/F ratio? See if he can work with an IAT (Intake Air Temperature) sensor. That's another way to be more accurate and it doesn't require placing a sensor in the cooling water flow. Also, it DOES make a difference. The last time I went fro MC tech training, one of the others from the dealership wanted to cut down on gas consumption, so Alan, who was interviewed for the EFI article, gave us an IAT to install, using his machine shop and tools. Once it was in, they took the boat out and ran diagnostics, making the appropriate changes to the program. IIRC, it had a better hole shot, better mid-range and used a lot less fuel.

Changing the ECM to a more recent version will require changing the wiring harness fairly extensively. The relays are now triggered with negative signal (not that hard to change, really), some pin locations are different and the Knock Sensor module is now internal.

Youp might want to re-read the article for the comments about making changes to an engine that uses these controllers and programs. I'm not sure a change from 1.5 to 1.6 ratio rockers will require major adjustments to the A/F ratio. The air will rush in faster, but the volume will be the same. If the cylinders were bored out a lot larger, I could see the need to make a change but since the MAP sensor will see the vacuum with the new or the OEM rockers, it should be close. Even if the rockers are changed, I don't know how much they'll add to the engine's performance unless the heads are ported and polished. That would reduce turbulence and allow the intake AND exhaust to flow more easily.

CantRepeat
08-19-2012, 12:19 PM
The MEFI I ECM is not capable of using the O2 sensor. Weren't built that way. Cannot be made to use an O2 Sensor.

The new boats have O2 sensors and ECM's that are capable of responding to the A/F.

The point is, I realize that the BEST way would be installing and O2 sensor, but in this case the only use It would have is using the number on the external gauge in combination with the data you have referred to and tune the boat that way. Again, the ECM in my boat does not have the capability to be attached to an O2 sensor, that I know of. I sure wish I were wrong.


Bob said that the O2 sensor would eventually get contaminated and be ruined. Suggested that during the tuning phase one would not perform any maneuvers that would possibly get moisture on the O2 sensor? If I should be brave enough to make further changes to the motor, I would be able to reinstall it for the next tune episode.

Thanks for your input!

I wasn't speaking of MEFI 1 ECMs.

JimN
08-19-2012, 12:32 PM
I wasn't speaking of MEFI 1 ECMs.

Pretty sure that the cost of changing the ECM, doing data acquisition/new program AND harness would be a deal-breaker for this.

CantRepeat
08-19-2012, 04:41 PM
Pretty sure that the cost of changing the ECM, doing data acquisition/new program AND harness would be a deal-breaker for this.

I would agree.

I was thinking more along the lines, with that O2 adapter it would be a great way to get an MEFI4 into an older boat.

JimN
08-19-2012, 07:20 PM
I would agree.

I was thinking more along the lines, with that O2 adapter it would be a great way to get an MEFI4 into an older boat.

I wouldn't be surprised if the MEFI controllers are all able to accept additional inputs- the harnesses don't use all of the pins, so....

CantRepeat
08-19-2012, 08:01 PM
I wouldn't be surprised if the MEFI controllers are all able to accept additional inputs- the harnesses don't use all of the pins, so....

So its just a matter of writing a new .CAL file use HEX code to accept the inputs. But, after that it would be a major rewrite to get the code to use the inputs.

I think we'd(I) be better off going with a .CAL file that uses the all the sensors and then just data logging and working on the VE and spark tables from there. I don't write code so it would be completely out of my league to even suggest it.

The biggest issue is having the MASK file to decode the .CAL file so you can even see what you are trying to adjust.

JimN
08-19-2012, 08:19 PM
So its just a matter of writing a new .CAL file use HEX code to accept the inputs. But, after that it would be a major rewrite to get the code to use the inputs.

I think we'd(I) be better off going with a .CAL file that uses the all the sensors and then just data logging and working on the VE and spark tables from there. I don't write code so it would be completely out of my league to even suggest it.

The biggest issue is having the MASK file to decode the .CAL file so you can even see what you are trying to adjust.

Or, just pay someone who has the capability. Too bad Delphi closed here- I'd talk to a friend who worked in the prototype lab.

I'll see if Alan has time to discuss this question.

wtrskr
08-19-2012, 11:28 PM
I wonder how many owners of the older EFI boats would be interested in making modifications if it weren't for the problems with updating the computer to match the mods? I've got a '94, and while I have no desires for an upgrade right now, I could envision wanting add a little HP at some point down the road since I don't have the upgraded LT1 engine.

It seems like a solution could be figured out with some cooperation. If one person with the knowledge and technology was able to find the appropriate computer settings to match the best bang-for-the-buck mods for the LT1 and the best-bang-for-the-buck mods for the TBI engine, they could charge a certain fee to upgrade computers for those wanting to make the modifications. Of course, this assumes that the hull doesn't make a difference, which I'm not sure of.

JimN
08-19-2012, 11:45 PM
I wonder how many owners of the older EFI boats would be interested in making modifications if it weren't for the problems with updating the computer to match the mods? I've got a '94, and while I have no desires for an upgrade right now, I could envision wanting add a little HP at some point down the road since I don't have the upgraded LT1 engine.

It seems like a solution could be figured out with some cooperation. If one person with the knowledge and technology was able to find the appropriate computer settings to match the best bang-for-the-buck mods for the LT1 and the best-bang-for-the-buck mods for the TBI engine, they could charge a certain fee to upgrade computers for those wanting to make the modifications. Of course, this assumes that the hull doesn't make a difference, which I'm not sure of.

You won't get a lot more HP or torque from these engines without doing more than changing the program. An engine needs to breathe better if it's going to perform better and these just don't have enough displacement to develop a ton of power without shoving more air down the intake. The problem with that is the size of the throttle body orifice- it's too small to pass a lot more air without major turbulence. The other part of the equation is the hull- they're not designed to be go-fast boats, they're designed to provide a good wake and get the skier or 'boarder out of the hole quickly. They're not hot rods and the hull makes a big difference. The fact that it's in water and not on land is a huge factor.

If you have an LT-1, you have the best bang for the buck without running dangerously lean in the event that the fuel supply isn't optimal and the operating conditions don't cause problems. These engines were tested extensively on dynomometers, installed in various boats and tested again. Data was read & analyzed, settings were changed and tested in different parts of the country, in all kinds of weather. It's great to make it work in one place, but a manufacturer has to make sure it will work all over. That's why they don't allow major changes to be made to the program- it's likely that the boat will be used where the custom program isn't going to work.

wtrskr
08-20-2012, 11:31 AM
I see all these threads about people putting GT40 heads on the ford carb motors and it doesn't seem right that those with 15+ year old EFI technology couldn't do something similar. I get why, but it seems like a solution could be figured out if enough people had interest.

If there was a certain head/intake manifold/internal modification combination that made sense, if one person was able to do those changes and do the work to get the appropriate computer settings to match, others could theoretically just copy that work. I realize that getting the appropriate MEFI settings would probably be very difficult to obtain for that first person.

As I think about it more, I doubt I'd personally make any changes even down the road because I am more than happy with the power I have (have powerslot) but I could see how others may be interested in a little more juice. To your point, there is no way in heck I would make changes to anything unless I thought the data was analyzed and tested in a similar manner to the original calibrations.

JimN
08-20-2012, 04:00 PM
I see all these threads about people putting GT40 heads on the ford carb motors and it doesn't seem right that those with 15+ year old EFI technology couldn't do something similar. I get why, but it seems like a solution could be figured out if enough people had interest.

If there was a certain head/intake manifold/internal modification combination that made sense, if one person was able to do those changes and do the work to get the appropriate computer settings to match, others could theoretically just copy that work. I realize that getting the appropriate MEFI settings would probably be very difficult to obtain for that first person.

As I think about it more, I doubt I'd personally make any changes even down the road because I am more than happy with the power I have (have powerslot) but I could see how others may be interested in a little more juice. To your point, there is no way in heck I would make changes to anything unless I thought the data was analyzed and tested in a similar manner to the original calibrations.

LT-1 is a freaking Corvette engine- how much more performance do you want in a boat that's made to drag people around a body of water?

wtrskr
08-20-2012, 05:13 PM
Good point. I don't disagree with that at all. I used t ski behind a 97 maristar with the LT1 and it was rock solid pulling through the wakes despite it being a heavier boat than the Prostars.

I know that some people can never get enough horsepower though. I have the TBI with powerslot and have absolutely no complaints about the power. I was thinking more along the lines of those who have boats they love but have the standard TBI without powerslot.

You can tell differences in power while skiing. I skied the course behing a 197 with the MCX engine then shortly after skied behind a 197 with the Vortec engine. It could have been the speed control but the Vortec felt easier because you could slow down the boat a little on the cuts. Both were plenty fine for my purposes but I could see how some might care.

JimN
08-20-2012, 05:20 PM
Good point. I don't disagree with that at all. I used t ski behind a 97 maristar with the LT1 and it was rock solid pulling through the wakes despite it being a heavier boat than the Prostars.

I know that some people can never get enough horsepower though. I have the TBI with powerslot and have absolutely no complaints about the power. I was thinking more along the lines of those who have boats they love but have the standard TBI without powerslot.

You can tell differences in power while skiing. I skied the course behing a 197 with the MCX engine then shortly after skied behind a 197 with the Vortec engine. It could have been the speed control but the Vortec felt easier because you could slow down the boat a little on the cuts. Both were plenty fine for my purposes but I could see how some might care.

The TBI actually has a bump in the low end of the torque curve that the LT-1 doesn't, but loses some power at the top end because of turbulence, The LT-1 just has a wide, flat torque curve, so the low end bump isn't as noticeable.

daniel44
03-19-2014, 05:14 AM
STAY AWAY FROM AFFORDABLE FUEL INJECTION, the guy norman, i paid $1400 ,it doesnt work ,it backfires , the wiring was incorrect ,norman told my mechanic , used junk yard parts, used ECM, not programmed, i returned everything ,they refund only half of my money ,i called my bank disputed the charges ,i called BBB next i am calling the attorney general , next small claims court, biggest SCAM, BIGGEST FRAUD OUT THERE , if you can make it work fine , if you cant i, they keep half of the money $700 , plus mechanic bill , fuel line hose $120 muffler shop $60 so much damage done the truck ,cutting ,drilling ,removing all the smog vacuum hoses , affordable fuel injection is garbage junk yard pars ,it never works ,, SCAM SCAM ,BEWARE ,YOU ARE WARNED ,FRAUD ,keep your carburetor ,or rebuild it, AFI would waste more gas , affordable fuel injection burnt $45 gas while idling ,running ,trying to adjust it , i am honestly wasted 2 weeks to install this junk , no installation help diagram , if 35 years experience mechanic cant do this , who can ? stay clear from NORMAN WITTE guy , NEVER AFFORDABLE FUEL INJECTION ,DONT BUY IT ,

Hammer
03-19-2014, 08:15 AM
STAY AWAY FROM AFFORDABLE FUEL INJECTION, the guy norman, i paid $1400 ,it doesnt work ,it backfires , the wiring was incorrect ,norman told my mechanic , used junk yard parts, used ECM, not programmed, i returned everything ,they refund only half of my money ,i called my bank disputed the charges ,i called BBB next i am calling the attorney general , next small claims court, biggest SCAM, BIGGEST FRAUD OUT THERE , if you can make it work fine , if you cant i, they keep half of the money $700 , plus mechanic bill , fuel line hose $120 muffler shop $60 so much damage done the truck ,cutting ,drilling ,removing all the smog vacuum hoses , affordable fuel injection is garbage junk yard pars ,it never works ,, SCAM SCAM ,BEWARE ,YOU ARE WARNED ,FRAUD ,keep your carburetor ,or rebuild it, AFI would waste more gas , affordable fuel injection burnt $45 gas while idling ,running ,trying to adjust it , i am honestly wasted 2 weeks to install this junk , no installation help diagram , if 35 years experience mechanic cant do this , who can ? stay clear from NORMAN WITTE guy , NEVER AFFORDABLE FUEL INJECTION ,DONT BUY IT ,

Wow. Guess we know how you feel.
Honestly, that ***. There are some good people in the world and then there is everyone else.

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CantRepeat
03-19-2014, 10:04 AM
Sounds like operator error to me.

+10 on first post rant, thanks.

Roman
03-19-2014, 12:22 PM
I skimmed over this.

You can tune without an WB02, but youll always be running rich of stoic to be safe.

Is there really a market for people converting there boats over to EFI? I think the price of a properly engineered kit would be $2000-$3000. Lots of stuff to modify so its actually a robust system

JimN
03-19-2014, 12:28 PM
I skimmed over this.

You can tune without an WB02, but youll always be running rich of stoic to be safe.

Is there really a market for people converting there boats over to EFI? I think the price of a properly engineered kit would be $2000-$3000. Lots of stuff to modify so its actually a robust system

If it was as easy as changing over in a car- going to a shop with a chassis dyno-, it would be a different story. Lacking real-time data acquisition and prior testing to find a good baseline WRT detonation, in-cylinder gas temperatures and cam specs, this is very much a BandAid solution. The variables alone makes it difficult to reach workable solutions without the knowledge and tools.

The sensors, intake, distributor and injectors are cheap enough, but the ECM/harness/tuning is where the money comes in.

Dreamline
05-07-2014, 12:55 AM
On my 94 Indmar 350 TBI HP, there are a couple of easy things to do to get more power. On my 225VRS, the exhaust is routed forward and under the engine and back out...I think the exhaust manifolds could be turned around and the exhaust shortened a few feet for better flow. Also, a pair of 165cc Vortec or DART heads would also improve breathing quite a bit.

CantRepeat
05-07-2014, 03:49 AM
On my 94 Indmar 350 TBI HP, there are a couple of easy things to do to get more power. On my 225VRS, the exhaust is routed forward and under the engine and back out...I think the exhaust manifolds could be turned around and the exhaust shortened a few feet for better flow. Also, a pair of 165cc Vortec or DART heads would also improve breathing quite a bit.

If you change the heads you're going to need to retune the ECM. Without data logging there is no way to know what needs to be done.