Am I running lean?
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Re: Am I running lean?
I’m using the stock fuel line as feed line and a 8mm line as the return back to the pump. I have been playing around and with the engine running (idle) I set the fuel pressure regulator to the highest it could go and I’m only seeing 8 psi of fuel pressure, that’s only going to allow me 7psi of boost and explains why I’m starting to get detonation at around 9 psi
I’m using a Holley blue pump that’s meant to have a 14 psi pressure limit?
Also due to the non return valve I’m using witch goes inline to the pressure regulator ( boost line) it’s taking 1 psi to open it so I’m at 2 psi of boost before the fuel regulator reacts and starts to increase the fuel pressure, do I actually need this ?
Cause I’m thinking with out it the regulator reacts faster and increase 1 psi fuel pressure for 1 psi boost but when I come of boost there will be a vacuum acting on it and will reduce fuel pressure?
Hope this makes sense?
I’m using a Holley blue pump that’s meant to have a 14 psi pressure limit?
Also due to the non return valve I’m using witch goes inline to the pressure regulator ( boost line) it’s taking 1 psi to open it so I’m at 2 psi of boost before the fuel regulator reacts and starts to increase the fuel pressure, do I actually need this ?
Cause I’m thinking with out it the regulator reacts faster and increase 1 psi fuel pressure for 1 psi boost but when I come of boost there will be a vacuum acting on it and will reduce fuel pressure?
Hope this makes sense?
- Dan Dryden
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Re: Am I running lean?
Hey Adam, if you’re not already running 8mm fuel lines, it’s time to install some.
- buguy
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Re: Am I running lean?
I agree that should be done, but I doubt a basically stock 1600 and less than 10psi would require it.
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Re: Am I running lean?
Well I’m going to try something later today. I’m going to use the 8mm return line as a feed and the stock as the return and what happens.
- Dan Dryden
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- Joined: Mon Nov 05, 2007 12:56 am
Re: Am I running lean?
Definitely use the 8mm line as feed.
The fuel pressure regulator is only supposed to keep the fuel pressure at Xpsi above boost pressure. With it set to 8psi, you have set it to run at 8psi above boost pressure. So if you run 10psi boost, your fuel pressure will be around 18psi. Have you plumbed a boost pressure feed to the fpr?
Not sure whether you mean that you’ve plumbed a non return valve to the fuel or boost side of the fpr, but either way, get rid of it. It just acts as a restriction and isn’t needed.
The fuel pressure regulator is only supposed to keep the fuel pressure at Xpsi above boost pressure. With it set to 8psi, you have set it to run at 8psi above boost pressure. So if you run 10psi boost, your fuel pressure will be around 18psi. Have you plumbed a boost pressure feed to the fpr?
Not sure whether you mean that you’ve plumbed a non return valve to the fuel or boost side of the fpr, but either way, get rid of it. It just acts as a restriction and isn’t needed.
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Re: Am I running lean?
You need a boost referenced regulator so you can set your fuel pressure at 1.5-3.0 lbs depending on the carb and let the boost raise the pressure.
The stock fuel pump works really good when you boost reference the bottom of it.
I did it for 2 years with mine. It’s been done many times and the pics are in my build....I copied Mike Thompson and just made it fit my setup.
Doing the pump eliminates a regulator, return line and some headaches too.
It’s cheap, easy and reliable without having to do any plumbing or wiring.
A turbo is a complete system.....you have to follow the steps and do what works or you will fight it all the way as you are finding out.
The stock fuel pump works really good when you boost reference the bottom of it.
I did it for 2 years with mine. It’s been done many times and the pics are in my build....I copied Mike Thompson and just made it fit my setup.
Doing the pump eliminates a regulator, return line and some headaches too.
It’s cheap, easy and reliable without having to do any plumbing or wiring.
A turbo is a complete system.....you have to follow the steps and do what works or you will fight it all the way as you are finding out.
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.
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Re: Am I running lean?
Yes I noticed my mistake with the pressure regulator silly me
Yes set it to xpsi than I added a calibrated pump to it and as I increase the pressure into the regulator it increased the fuel pressure and with 10 psi pressure added to the regulator (boost pressure) the regulator increased the fuel pressure to 14psi and no matter how much more boost pressure I added the regulator topped out at 14 psi fuel pressure witch is what the pumps max is.
The non return valve I’ve fitted goes in the boost pressure line that goes to the fuel regulator, now I need to be at 2psi before the valve opens so the regulator doesn’t increase fuel pressure till I hit 2 psi boost pressure if that makes sense?
Now if I remove the non return valve the second I hit 1 psi boost pressure the regulator increases fuel pressure by 1 psi but when I come of the throttle or I’m at a cruise and causing a high vacuum that vacuum is acting on the regulator and trying to close it off, is this ok to run like that?
Yes set it to xpsi than I added a calibrated pump to it and as I increase the pressure into the regulator it increased the fuel pressure and with 10 psi pressure added to the regulator (boost pressure) the regulator increased the fuel pressure to 14psi and no matter how much more boost pressure I added the regulator topped out at 14 psi fuel pressure witch is what the pumps max is.
The non return valve I’ve fitted goes in the boost pressure line that goes to the fuel regulator, now I need to be at 2psi before the valve opens so the regulator doesn’t increase fuel pressure till I hit 2 psi boost pressure if that makes sense?
Now if I remove the non return valve the second I hit 1 psi boost pressure the regulator increases fuel pressure by 1 psi but when I come of the throttle or I’m at a cruise and causing a high vacuum that vacuum is acting on the regulator and trying to close it off, is this ok to run like that?
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Re: Am I running lean?
Why do you have a check valve in it???
Hook the boost source for the regulator out of the turbo and not off the intake manifold.....the regulator does not need to see vacuum.
I put a Tee into the line that feeds the wastegate and run it to the regulator.
Hook the boost source for the regulator out of the turbo and not off the intake manifold.....the regulator does not need to see vacuum.
I put a Tee into the line that feeds the wastegate and run it to the regulator.
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.
- buguy
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Re: Am I running lean?
I have my boost gauge located in my waste gate line and it reads vacuum.
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Re: Am I running lean?
Oh yeah.......the draw through.....I keep forgetting........
That also explains the check valve in the line.......which could be a problem since the boost has no way to get out once you let off the throttle and could be keeping the fuel pressure up once off boost......
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.
- buguy
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Re: Am I running lean?
Damn draw through guys!
- Chip Birks
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Re: Am I running lean?
The check valve thing works fine. It needs to be there.Clonebug wrote: ↑Sun Feb 18, 2018 3:47 pmOh yeah.......the draw through.....I keep forgetting........
That also explains the check valve in the line.......which could be a problem since the boost has no way to get out once you let off the throttle and could be keeping the fuel pressure up once off boost......
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Re: Am I running lean?
Well a result today, went and got a new fuel pressure gauge and found out the old one under reads by 2psi. So I had it set to 3psi fuel pressure witch was in real life only giving me 1 psi. Anyway that’s all sorted now and she drives much better and it looks like I can stay on boost for ever now where as before after going through all the gears on boost to red line she would start lean popping towards the end of fourth gear
The last issue I have to sort out is why after a good thrashing she stalls out when the clutch is dipped, she’s fine if you just driving her normal and in town traffic it’s only after you have done a all four gear thrash or been at high rpm for a while that when the clutch is depressed the engine drops down to idle ( 1000 rpm) and then slowly drops further till she stalls out
The last issue I have to sort out is why after a good thrashing she stalls out when the clutch is dipped, she’s fine if you just driving her normal and in town traffic it’s only after you have done a all four gear thrash or been at high rpm for a while that when the clutch is depressed the engine drops down to idle ( 1000 rpm) and then slowly drops further till she stalls out
- buguy
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Re: Am I running lean?
I wonder if that is a draw through issue? I would think that if you were in it hard and then get out of the gas your intake is still full of fuel and drowning it out?
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Re: Am I running lean?
Good point it may be.
I’ve learnt to dip the clutch and control the throttle and brake all at the same time
I’ve learnt to dip the clutch and control the throttle and brake all at the same time