The issue is the pump flows less and less as pressure rises. Most GM applications start at 50psi so as long as the pump can keep up you should be ok.
V3 no longer virgin
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Another thought. I’m not sure if my Kirban adjustable regulator is a boost reference one. If it’s not, then 54psi is the max the pump would have to put up with, unless I’m misunderstanding something else.
I’m not running an fmu. Everything other than my tinkering with pressure is in the chip tune.
I’m not running an fmu. Everything other than my tinkering with pressure is in the chip tune.
Here's my pump. According to the info here, it's made to handle what I'm doing with it.
http://walbrofuelpumps.com/255lph-walbro-gss340-intank-fuel-pump.html
http://walbrofuelpumps.com/255lph-walbro-gss340-intank-fuel-pump.html
I admit I'm cheating, and getting away with it so far. Gonna do dyno pulls hopefully this September.
Dyno pulls scheduled for Friday Sept 7at 9am. Considering I can fine tune my mixture on the spot, what is the best AFR for max power? Consider 10psi. I don't mind getting on the edge for the dyno pulls. Is 12 a good target? 12.5 maybe? I'll richen it back up for street driving. This is my first time doing dyno pulls. Anything I need to do for preparation? I'm paying $125 for three pulls.
11.5AFR
You wont see any appreciable gain by leaning it out.
How are you dealing with timing? What total are you running now?
93octane
24* max without meth
You wont see any appreciable gain by leaning it out.
How are you dealing with timing? What total are you running now?
93octane
24* max without meth
I’m running 10 degree base timing. I have no idea what the total is. It’s whatever All Out programmed into the chip.
I’m probably at 9:1 compression. I made effort to keep it down. I’ve never experienced detonation with this setup so far
I’m probably at 9:1 compression. I made effort to keep it down. I’ve never experienced detonation with this setup so far
Yes.
Do initial pull at your current timing.
Then bump it 2*
Look at the difference in HP on the curve of it is not significant DO NOT ADD MORE.
Without knowing total timing I can give no further useful advice for keeping it safe.
Do initial pull at your current timing.
Then bump it 2*
Look at the difference in HP on the curve of it is not significant DO NOT ADD MORE.
Without knowing total timing I can give no further useful advice for keeping it safe.
I did some timing and AFR adjustments tonight. I now know what detonation sounds like. Coulda swore I heard the sound of a hammer hitting the block! Not just a tap either, a good knock from a big hammer. Yikes!!!!
Initially I though my base timing was at 10. But when I checked it was actually at 8. So I bumped it to 10. I also leaned up 3/4 turn and it spiked at 12.3 AFR. at those settings, BANG!!! Pulled over and richened up 1/2 turn on the regulator. 11.5ish now and no detonation. I think I've got it right in the sweet spot now. No way in hell am I going to 12 base timing. Might even drop back to 8 after dyno pulls.
Feels really strong. 4th gear from a 60mph roll to the redline is pretty fun. Need alot of room in front because 70mph traffic comes up really quick. Im doing about 115mph at redline 4th gear.
Initially I though my base timing was at 10. But when I checked it was actually at 8. So I bumped it to 10. I also leaned up 3/4 turn and it spiked at 12.3 AFR. at those settings, BANG!!! Pulled over and richened up 1/2 turn on the regulator. 11.5ish now and no detonation. I think I've got it right in the sweet spot now. No way in hell am I going to 12 base timing. Might even drop back to 8 after dyno pulls.
Feels really strong. 4th gear from a 60mph roll to the redline is pretty fun. Need alot of room in front because 70mph traffic comes up really quick. Im doing about 115mph at redline 4th gear.
I remember someone tellin ya to keep the AFR around 11.5..... 
Be glad you lifted, usually you dont get a second chance the engine usually just comes apart on ya.
Be glad you lifted, usually you dont get a second chance the engine usually just comes apart on ya.
I remember someone tellin ya to keep the AFR around 11.5.....
Be glad you lifted, usually you dont get a second chance the engine usually just comes apart on ya.
Werd.
Luckily the engine is a fresh balanced build. And it only knocked once, right at redline. So i was in the process of letting off anyway. Call it luck I suppose.
All set for dyno tomorrow morning. I’m not gonna make adjustments while there. I’m at 9 degrees initial timing and running 11.1-11.6 in the ARR flat out.
Interesting thing though. I noticed my idle AFR recently go lean. Like 16-17. Then I noticed an exhaust leak at the x pipe clamp. Fixed the leak with a new heavy duty clamp and immediately the idle AFR is back to 14.5ish.
Interesting thing though. I noticed my idle AFR recently go lean. Like 16-17. Then I noticed an exhaust leak at the x pipe clamp. Fixed the leak with a new heavy duty clamp and immediately the idle AFR is back to 14.5ish.
starts to lean at 5700... I would shift at 5500
That curve looks really strong, must pull like a train
That curve looks really strong, must pull like a train
My shift light is currently st at 5800. I'll Change it to 5500. 5600 is about max power anyway on this setup.
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