Baseline Timing and AFR for Flex Setup on TermX
How does one get around the 3/8 inlet size at the fuel rail? I would think that'd be a restriction regardless of the feed line size (smallest orifice in the path of the fuel). I see folks all the time making way more power than I am on stock car/truck rails.
Also, given the fact that the factory rails are deadheaded (only 1 inlet), how much am I giving up mounting the regulator before the rails rather than after?
Also, given the fact that the factory rails are deadheaded (only 1 inlet), how much am I giving up mounting the regulator before the rails rather than after?
Also i had terrible luck keeping those aem style pumps working. I went through 10s of them, they would be fine then start losing pressure under boost. I even went to dual aem pumps thinking 1 wasn't enough and it eventually did the same.
The fix for me was intank walbro 450/525 pumps, been flawless so far. My buddy has had good luck with his magnafuel 4303 which is external. I believe the aem style pumps would overheat while street driving.
Revised the fuel system slightly. Headed in the right direction I think. I removed the C5 FPR and cut it open to see what was going on inside and if there was a restriction.
The smallest orifice is the supply hole in the end cap. My calipers measured it at about .200", and a 3/16" drill bit fits freely. So the all the fuel was being shoved through a hole smaller than 1/4"...combine that with no boost reference it's no wonder my fuel pressure was dropping before.
Anyhow, the new adjustable FPR was easy to install, I didn't even have to modify the lines. Everything is still a -6AN throughout. The regulator is mounted inline with the feed in the trunk, and there is still the flex sensor mounted inline with the feed right by the fuel rail, so there is technically still room for improvement in removing restrictions. 58psi with engine running and no vacuum applied. Gauge pressure matches rail pressure.
Given how cheap these adjustable regulators are they really need to become the golden standard for the LS swap. I'll never use another C5 FPR again...they might have their place on stock motor swaps but for anything with any semblance of performance would benefit from one of these.
Took the car out and made some pulls rolling into it, slowly increasing the boost to make sure fuel pressure and AFR was in check. It was safe at 8, 10.5, and 12.5 psi, so I turned it up some more. During a sustained 30-70mph pull in 2nd the boost peaked at 14.7psi and settled at 14.5psi. I only revved it out to a hair under 5000 so once I throw some new plugs in it I plan on making some longer pulls and reading plugs #5 and #7.
30-70 Roll
Interestingly enough I stabbed it hard from a dig on the way home and it boils the tires easily, this is the result I have been dreaming of - even with the 2.88 gears! Within 1 second of 100% TPS applied the rear wheels are doing 26mph and 2 seconds later they're at 120mph in 3rd gear (with a little pedaling in the middle). Real vehicle speed probably never exceeded 35mph - cheap thrills for sure.
What an absolute riot of a car.
The smallest orifice is the supply hole in the end cap. My calipers measured it at about .200", and a 3/16" drill bit fits freely. So the all the fuel was being shoved through a hole smaller than 1/4"...combine that with no boost reference it's no wonder my fuel pressure was dropping before.
Anyhow, the new adjustable FPR was easy to install, I didn't even have to modify the lines. Everything is still a -6AN throughout. The regulator is mounted inline with the feed in the trunk, and there is still the flex sensor mounted inline with the feed right by the fuel rail, so there is technically still room for improvement in removing restrictions. 58psi with engine running and no vacuum applied. Gauge pressure matches rail pressure.
Given how cheap these adjustable regulators are they really need to become the golden standard for the LS swap. I'll never use another C5 FPR again...they might have their place on stock motor swaps but for anything with any semblance of performance would benefit from one of these.
Took the car out and made some pulls rolling into it, slowly increasing the boost to make sure fuel pressure and AFR was in check. It was safe at 8, 10.5, and 12.5 psi, so I turned it up some more. During a sustained 30-70mph pull in 2nd the boost peaked at 14.7psi and settled at 14.5psi. I only revved it out to a hair under 5000 so once I throw some new plugs in it I plan on making some longer pulls and reading plugs #5 and #7.
30-70 Roll
Interestingly enough I stabbed it hard from a dig on the way home and it boils the tires easily, this is the result I have been dreaming of - even with the 2.88 gears! Within 1 second of 100% TPS applied the rear wheels are doing 26mph and 2 seconds later they're at 120mph in 3rd gear (with a little pedaling in the middle). Real vehicle speed probably never exceeded 35mph - cheap thrills for sure.
What an absolute riot of a car.
Revised the fuel system slightly. Headed in the right direction I think. I removed the C5 FPR and cut it open to see what was going on inside and if there was a restriction.
The smallest orifice is the supply hole in the end cap. My calipers measured it at about .200", and a 3/16" drill bit fits freely. So the all the fuel was being shoved through a hole smaller than 1/4"...combine that with no boost reference it's no wonder my fuel pressure was dropping before.
Anyhow, the new adjustable FPR was easy to install, I didn't even have to modify the lines. Everything is still a -6AN throughout. The regulator is mounted inline with the feed in the trunk, and there is still the flex sensor mounted inline with the feed right by the fuel rail, so there is technically still room for improvement in removing restrictions. 58psi with engine running and no vacuum applied. Gauge pressure matches rail pressure.
Given how cheap these adjustable regulators are they really need to become the golden standard for the LS swap. I'll never use another C5 FPR again...they might have their place on stock motor swaps but for anything with any semblance of performance would benefit from one of these.
Took the car out and made some pulls rolling into it, slowly increasing the boost to make sure fuel pressure and AFR was in check. It was safe at 8, 10.5, and 12.5 psi, so I turned it up some more. During a sustained 30-70mph pull in 2nd the boost peaked at 14.7psi and settled at 14.5psi. I only revved it out to a hair under 5000 so once I throw some new plugs in it I plan on making some longer pulls and reading plugs #5 and #7.
30-70 Roll
Interestingly enough I stabbed it hard from a dig on the way home and it boils the tires easily, this is the result I have been dreaming of - even with the 2.88 gears! Within 1 second of 100% TPS applied the rear wheels are doing 26mph and 2 seconds later they're at 120mph in 3rd gear (with a little pedaling in the middle). Real vehicle speed probably never exceeded 35mph - cheap thrills for sure.
What an absolute riot of a car.
The smallest orifice is the supply hole in the end cap. My calipers measured it at about .200", and a 3/16" drill bit fits freely. So the all the fuel was being shoved through a hole smaller than 1/4"...combine that with no boost reference it's no wonder my fuel pressure was dropping before.
Anyhow, the new adjustable FPR was easy to install, I didn't even have to modify the lines. Everything is still a -6AN throughout. The regulator is mounted inline with the feed in the trunk, and there is still the flex sensor mounted inline with the feed right by the fuel rail, so there is technically still room for improvement in removing restrictions. 58psi with engine running and no vacuum applied. Gauge pressure matches rail pressure.
Given how cheap these adjustable regulators are they really need to become the golden standard for the LS swap. I'll never use another C5 FPR again...they might have their place on stock motor swaps but for anything with any semblance of performance would benefit from one of these.
Took the car out and made some pulls rolling into it, slowly increasing the boost to make sure fuel pressure and AFR was in check. It was safe at 8, 10.5, and 12.5 psi, so I turned it up some more. During a sustained 30-70mph pull in 2nd the boost peaked at 14.7psi and settled at 14.5psi. I only revved it out to a hair under 5000 so once I throw some new plugs in it I plan on making some longer pulls and reading plugs #5 and #7.
30-70 Roll
Interestingly enough I stabbed it hard from a dig on the way home and it boils the tires easily, this is the result I have been dreaming of - even with the 2.88 gears! Within 1 second of 100% TPS applied the rear wheels are doing 26mph and 2 seconds later they're at 120mph in 3rd gear (with a little pedaling in the middle). Real vehicle speed probably never exceeded 35mph - cheap thrills for sure.
What an absolute riot of a car.
It shows 60 psi in picture and then pic of log shows 14.4 lbs boost and 62 psi. If 60 was base pressure then it should have 74 fuel psi with 14 lbs boost is what I was going by,
I agree the pressure should be higher but atleast it's not dropping now. Look at the id of your 6an hose, most of the ptfe hose is about 1 size smaller than regular hose. So 8an ptfe has an id the size of regular 6an. So your hose may have an id of 4an. You're going the right way now tho
I am diagnosing another issue at this point, a pretty solid misfire at any RPM. Ordered an IR gun to check exhaust runner temps but before that came in I did the simple test of spraying water on each exhaust runner. #4 seemed to be running a lot cooler. No discernible change in how the engine runs with #4 injector unplugged, so I had them cleaned and flowed by Eric Derr, and he said #4 was actually one of the better ones with no major issues on the rest. Need to make sure I still have good spark on all cylinders.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever
Verdad Gallardo Weird, maybe the base pressure moved on me at some point. I will have to reset it and make some more pulls to see if it changed. The other possibility could be that the gauge is inaccurate, or the regulator isn't rising 1:1. I did compare the gauge against the rail pressure when I initially set it and they matched, so that seems unlikely. Definitely a gamble with any offshore product, but I read of some issues with Aeromotive products as well.
I am diagnosing another issue at this point, a pretty solid misfire at any RPM. Ordered an IR gun to check exhaust runner temps but before that came in I did the simple test of spraying water on each exhaust runner. #4 seemed to be running a lot cooler. No discernible change in how the engine runs with #4 injector unplugged, so I had them cleaned and flowed by Eric Derr, and he said #4 was actually one of the better ones with no major issues on the rest. Need to make sure I still have good spark on all cylinders.
I am diagnosing another issue at this point, a pretty solid misfire at any RPM. Ordered an IR gun to check exhaust runner temps but before that came in I did the simple test of spraying water on each exhaust runner. #4 seemed to be running a lot cooler. No discernible change in how the engine runs with #4 injector unplugged, so I had them cleaned and flowed by Eric Derr, and he said #4 was actually one of the better ones with no major issues on the rest. Need to make sure I still have good spark on all cylinders.
Andrew
You can use a Mityvac MV8500 (or something similar) that can do pressure and just add 1 PSI at a time and see if fuel PSI goes up with pressure vs using vacuum and doing conversions,
I do have a boost leak tester I build a few years ago I built that has a high resolution, low pressure gauge. Could add pressure to the regulator using that thing with the pump running on a long prime. My money is on it not rising 1:1.
On The Tree
Joined: Jul 2013
Posts: 196
Likes: 55
As a quick sanity check you might want to make sure your fuel pressure sensor is scaled correctly in the software. I managed to make a little fold in the graph on mine and chased a fuel pressure issue for quite a while. Most likely because of an errant mouse click.
I am diagnosing another issue at this point, a pretty solid misfire at any RPM. Ordered an IR gun to check exhaust runner temps but before that came in I did the simple test of spraying water on each exhaust runner. #4 seemed to be running a lot cooler. No discernible change in how the engine runs with #4 injector unplugged, so I had them cleaned and flowed by Eric Derr, and he said #4 was actually one of the better ones with no major issues on the rest. Need to make sure I still have good spark on all cylinders.