E85 and boost referenced regulator
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
E85 and boost referenced regulator Car is a 2004 gto cammed sbe with procharger at 9 psi. It has a good tune in it now for pump gas. I’m going to be doing a new fuel system with return and boost referenced regulator. I will do bigger injectors and switch to E85 at the same time.
When I get all the fuel system installed I will change the injector data and stoich for E85. I should then be able to fire it up and set base pressure. After that I should hook up my boost/vacuum source and change my flow rate vs kpa so all columns are the same as zero kpa.
From there i should be able to log and tune my VE. Car is open loop speed density 2 bar and fueling is good currently on pump gas.
Is there anything I’m missing or planned incorrectly? I’m sure my VE will need work, maybe some idle tuning, and hopefully more timing.
When I get all the fuel system installed I will change the injector data and stoich for E85. I should then be able to fire it up and set base pressure. After that I should hook up my boost/vacuum source and change my flow rate vs kpa so all columns are the same as zero kpa.
From there i should be able to log and tune my VE. Car is open loop speed density 2 bar and fueling is good currently on pump gas.
Is there anything I’m missing or planned incorrectly? I’m sure my VE will need work, maybe some idle tuning, and hopefully more timing.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
So the only injector data I need to change in regards to the boost referenced regulator is the flow rate vs kpa? I did some searching and most seem to only mention that while others mess with offsets vs volts and some other things as well.
You should not need to alter the battery voltage offset, those are electro-mechanical characteristics of a given injector and do not change with how much fuel goes through it.
The flow rate vs kPa I usually leave alone since (i think) it only covers 0-100 kPa when the engine is out of boost. Whatever small error is there is made up on the VE table.
The flow rate vs kPa I usually leave alone since (i think) it only covers 0-100 kPa when the engine is out of boost. Whatever small error is there is made up on the VE table.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
You should not need to alter the battery voltage offset, those are electro-mechanical characteristics of a given injector and do not change with how much fuel goes through it.
The flow rate vs kPa I usually leave alone since (i think) it only covers 0-100 kPa when the engine is out of boost. Whatever small error is there is made up on the VE table.
The flow rate vs kPa I usually leave alone since (i think) it only covers 0-100 kPa when the engine is out of boost. Whatever small error is there is made up on the VE table.
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From: Ohio
Flow rate vs KPA isn't highly critical. You can do the math to get the flow rate at different pressures, or make the entire row a single number. It'll just change the shape of your VE chart. Hell, you can leave the flow rates what they are now and you'll just have to scale the fueling tables by the same % you would have changed the flow rates.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
I’m sure my VE is currently jacked up tuning around a large pump with stock regulator in the tank giving me way too high of fuel pressure at idle and fluctuations during wot. On cool days with a full tank it’s not a problem, but on hot days under half a tank the fuel heating is a problem.
My my plan is to gravity feed a magnafuel 4301 which was recommended by them for my 600 rwhp on e85. They said I could send it in to upgrade to 4303 for $100 when I’m ready.
I want to run 43.5 ish base pressure and thinking 88 lbs/hr daetschwerks injectors which are rated at 43.5 psi.
I will set the flow rate all across at the actual actual flow rate for 43.5 psi and I can do some math to get the offset for voltage close. I think you guys are right especially with an OLSD tune the weather will make more difference in low pressure tuning, but I’m going to go ahead and make that stuff as accurate as I can.
My main goal is as simple as possible of a fuel system with enough to support 600-650 on e85 without giving me these fuel heating issues. My long term goal for this car when I have a built short block is 700-750 and definitely don’t expect over 800 through the auto. I would move to the 4303 at that time should do it.
Any other advice knowing my plans would be greatly appreciated as both you guys have a lot more experience than I do.
My my plan is to gravity feed a magnafuel 4301 which was recommended by them for my 600 rwhp on e85. They said I could send it in to upgrade to 4303 for $100 when I’m ready.
I want to run 43.5 ish base pressure and thinking 88 lbs/hr daetschwerks injectors which are rated at 43.5 psi.
I will set the flow rate all across at the actual actual flow rate for 43.5 psi and I can do some math to get the offset for voltage close. I think you guys are right especially with an OLSD tune the weather will make more difference in low pressure tuning, but I’m going to go ahead and make that stuff as accurate as I can.
My main goal is as simple as possible of a fuel system with enough to support 600-650 on e85 without giving me these fuel heating issues. My long term goal for this car when I have a built short block is 700-750 and definitely don’t expect over 800 through the auto. I would move to the 4303 at that time should do it.
Any other advice knowing my plans would be greatly appreciated as both you guys have a lot more experience than I do.
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That sounds like a pretty legit plan.
But again, just use the voltage offsets supplied by the injector maker, no need to scale them for pressure/flow. Theyjust tell the computer how the injector will behave as the supplied voltage changes from nominal. Nothing to do with flow/pressure
One benefit to having the flow vs kPa scaled right is the your calculated injector duty cycle % will be more accurate.
It also makes tuning transient fueling much easier.
But again, just use the voltage offsets supplied by the injector maker, no need to scale them for pressure/flow. Theyjust tell the computer how the injector will behave as the supplied voltage changes from nominal. Nothing to do with flow/pressure
One benefit to having the flow vs kPa scaled right is the your calculated injector duty cycle % will be more accurate.
It also makes tuning transient fueling much easier.
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Verdad Gallardo Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
That sounds like a pretty legit plan.
But again, just use the voltage offsets supplied by the injector maker, no need to scale them for pressure/flow. Theyjust tell the computer how the injector will behave as the supplied voltage changes from nominal. Nothing to do with flow/pressure
One benefit to having the flow vs kPa scaled right is the your calculated injector duty cycle % will be more accurate.
It also makes tuning transient fueling much easier.
But again, just use the voltage offsets supplied by the injector maker, no need to scale them for pressure/flow. Theyjust tell the computer how the injector will behave as the supplied voltage changes from nominal. Nothing to do with flow/pressure
One benefit to having the flow vs kPa scaled right is the your calculated injector duty cycle % will be more accurate.
It also makes tuning transient fueling much easier.
With a referenced regulator that sees both vacuum and boost you want to run a "flat" injector AND offset table. Meaning the 0 manifold vacuum column of both tables are populated across to 80 kpa the same and make sure it is accurate for your selected base fuel pressure. As for the calculated injector duty cycle % in the scan tool that will always be accurate regardless if the tune is scaled or not since it's literally just the result of the actual final injector pulsewidth and RPM.
Thread Starter
Joined: Jun 2005
Posts: 2,265
Likes: 671
From: Oskaloosa, Iowa
With a referenced regulator that sees both vacuum and boost you want to run a "flat" injector AND offset table. Meaning the 0 manifold vacuum column of both tables are populated across to 80 kpa the same and make sure it is accurate for your selected base fuel pressure. As for the calculated injector duty cycle % in the scan tool that will always be accurate regardless if the tune is scaled or not since it's literally just the result of the actual final injector pulsewidth and RPM.
If I understand correctly with base at 43.5 and 15 inches vacuum at idle my pressure at idle will be around 36 and pressure at 10 pounds boost will be 53.5. The regulator is doing the work accounting changes in flow due to vacuum/boost rather than the tune compensating that’s why in the tune the flow rate vs kpa must be flatlined.
Launching!
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if you're running 88lb/hr injectors on E40 you'll likely have to halve the IVT AFR term values and leave stoich at 14.7 when using E85. that way you'll be able to flat line the IFR table at 60lb/hr and have "normal" data in the VE tables. and you wont have to deal with reduced spark resolution that way.
if you're running 88lb/hr injectors on E40 you'll likely have to halve the IVT AFR term values and leave stoich at 14.7 when using E85. that way you'll be able to flat line the IFR table at 60lb/hr and have "normal" data in the VE tables. and you wont have to deal with reduced spark resolution that way.
Thread Starter
Joined: Jun 2005
Posts: 2,265
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From: Oskaloosa, Iowa
Deatschwerks also sent me the offset vs volts vs kpa for a base pressure of 43.5 at 0 kpa for the injectors so I don't have to try and figure that out. Just copy and paste it in.