Faelflora breaks his promise, time to part out car. GIT THE SAWZALL!
08-16-2012, 06:39 AM
#3422
Yes, that's me. FM's dyno is pretty accurate, I believe, but the debate lies in whether the SAE correction should be applied to a turbo car to account for the mile-high altitude (my take is that there should be some correction, but not that much). My uncorrected chart from those runs were about 325 whp, which jibes with a local Dynojet run here at 2,000 feet.
Both the FM and local dyno sessions were less than optimal. At FM, we were chasing a fueling issue (ultimately caused by a failing fuel pump) and ignition woes (originally attributed to dwell settings but ultimately fixed by changing out to NGK race plugs). Here at home, I was running with sub-optimal fuel numbers, finally traced to an incorrectly-calibrated WB sensor. In other words, there's more in my system than I can prove with existing dyno charts. Given that, Fae should be making far better numbers than he has (so far). Summary: The Hydra is not the problem.
Both the FM and local dyno sessions were less than optimal. At FM, we were chasing a fueling issue (ultimately caused by a failing fuel pump) and ignition woes (originally attributed to dwell settings but ultimately fixed by changing out to NGK race plugs). Here at home, I was running with sub-optimal fuel numbers, finally traced to an incorrectly-calibrated WB sensor. In other words, there's more in my system than I can prove with existing dyno charts. Given that, Fae should be making far better numbers than he has (so far). Summary: The Hydra is not the problem.
I put down 245whp on FM's dyno, and this is probably the slowest 245whp car i've ever driven in my life. Feels more like 150whp at best.
I don't think that Hydra is the problem here, even though i HATE my Hydra, and it seems that FM couldn't even get my car running correctly. (Driveability is downright awful.) The issue here is clearly the dyno. The dyno was so messed up that you can't even accurately say that FaeFae's car is making 350whp.
Judging from videos (because, you know... this is accurate) i'd say he's well into the 400whp range, likely over 450whp.
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08-16-2012, 08:19 AM
#3424
What does it show at idle?
What does it show at idle when you pop off the vac line?
Do your IPW increase when you lean out now vs before when it didn't? Or are they the same.
Talked to my buddy with the crapped out regulator yesterday, and his diaphram started leaking inside the regulator when this started happening.
What does it show at idle when you pop off the vac line?
Do your IPW increase when you lean out now vs before when it didn't? Or are they the same.
Talked to my buddy with the crapped out regulator yesterday, and his diaphram started leaking inside the regulator when this started happening.
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08-16-2012, 01:38 PM
#3425
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What does it show at idle?
What does it show at idle when you pop off the vac line?
Do your IPW increase when you lean out now vs before when it didn't? Or are they the same.
Talked to my buddy with the crapped out regulator yesterday, and his diaphram started leaking inside the regulator when this started happening.
What does it show at idle when you pop off the vac line?
Do your IPW increase when you lean out now vs before when it didn't? Or are they the same.
Talked to my buddy with the crapped out regulator yesterday, and his diaphram started leaking inside the regulator when this started happening.
When I pop off vac line I forget what it is at.
IPW did NOT increase when I leaned out. Stay the same.
BTW. I just popped off my fuel rail lines. Both fuel pumps are flowing just fine. Massive, massive, amounts of fuel all over my garage floor.
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08-16-2012, 01:48 PM
#3430
Ooorrrrrrrr... maybe i just learned an important lesson?
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08-16-2012, 01:49 PM
#3431
Yup. You want your fpr to reference manifold pressure any and all manifold pressure. Its so hard to tune an engine in right when the pressure doesnt vary 1:1 in vac never mind boost. You want to keep the same differential pressure across the injectors no matter the conditions in the manifold.
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08-16-2012, 01:54 PM
#3432
Yup. You want your fpr to reference manifold pressure any and all manifold pressure. Its so hard to tune an engine in right when the pressure doesnt vary 1:1 in vac never mind boost. You want to keep the same differential pressure across the injectors no matter the conditions in the manifold.
45psi base w/ check valve hitting around 65psi at full boost yielded good AFRs and an idle that worked.
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08-16-2012, 01:55 PM
#3433
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I guess the injectors are probably the difference. On one of my other Mazdas i had to run a one-way check valve to keep the vacuum from killing the motor, and that was with 45psi base fuel pressure. (higher than stock.)
Ooorrrrrrrr... maybe i just learned an important lesson?
Ooorrrrrrrr... maybe i just learned an important lesson?
And your check valve would hold boost inside the regulator signal... i.e. once you reach your xx psi, that's what the regulator would stay at until it leaks down which, depending on the check valve quality and volume inside the regulator/line, might take a while.
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08-16-2012, 02:06 PM
#3435
1. Disconnect vacuum line to pressure regulator.
2. Set pressure to 45PSI.
3. Connect vacuum line back.
4. Re-tune the fuel map as it will be too lean
5. Give us a good dyno run on a good dyno!
Remember typically regulators are 1:1. So if your idle is 70psi, your open air is 80ish which means with 35psi of boost you will be at 115PSI. Most pumps will have a hard time getting that high or if they do, the volume flow drops dramatically. You have no reason to run 70psi fuel pressure at idle.
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08-16-2012, 02:19 PM
#3438
Yeah, like leafy said. 1:1 regulators are the norm, the pressure differential is always the same across the injector. Makes life easier.
And your check valve would hold boost inside the regulator signal... i.e. once you reach your xx psi, that's what the regulator would stay at until it leaks down which, depending on the check valve quality and volume inside the regulator/line, might take a while.
And your check valve would hold boost inside the regulator signal... i.e. once you reach your xx psi, that's what the regulator would stay at until it leaks down which, depending on the check valve quality and volume inside the regulator/line, might take a while.
It is a 1:1 regulator, though. Aeromotive 13109.
I have research to do i see, on the subject of figuring out how to make the car not run at like 8:1 under full boost with 85psi of fuel pressure.
/threadjack
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08-16-2012, 02:39 PM
#3439
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I don't think your problem is fuel flow. Even though you're apparently running the pump beyond what is usually considered advisable or sensible, a single 044 should provide enough flow for the current setup at 35psi. Two of them are super-massive overkill.
I was not able to quickly find published data for flow of the 044 above 100psi, but at 100psi it still flows a massive 390lbs/hr. And the characteristic curve is still almost flat/horizontal in that area. So at 115psi we should still see considerably more than 300lbs/hr.
Fuel Pump Comparison
Still: Lower your fuel-pressure, re-tune and see what's happening!
Leafy: What do you mean "Fuel flow typically tapers off exponentially as pressure increases"? Characteristic curves of fuel pumps are usually pretty well approximated by two or three straight lines. Looks more like something logarithmic to me, if any. Please elaborate what an exponential taper-off is.
I was not able to quickly find published data for flow of the 044 above 100psi, but at 100psi it still flows a massive 390lbs/hr. And the characteristic curve is still almost flat/horizontal in that area. So at 115psi we should still see considerably more than 300lbs/hr.
Fuel Pump Comparison
Still: Lower your fuel-pressure, re-tune and see what's happening!
Leafy: What do you mean "Fuel flow typically tapers off exponentially as pressure increases"? Characteristic curves of fuel pumps are usually pretty well approximated by two or three straight lines. Looks more like something logarithmic to me, if any. Please elaborate what an exponential taper-off is.
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08-16-2012, 02:48 PM
#3440
Leafy: What do you mean "Fuel flow typically tapers off exponentially as pressure increases"? Characteristic curves of fuel pumps are usually pretty well approximated by two or three straight lines. Looks more like something logarithmic to me, if any. Please elaborate what an exponential taper-off is.
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