turtlevette
The Turdle
I'm going to mess around with trying to get things running better. It detonates, backfires, and stalls under acceleration.
current setup
74 primary jets (stock is 75)
46 primary rods (stock)
unknown spring (i know its way too light I cut it at one time.)
CH secondary rods (stock i think)
long hanger (service hanger code V ?)
I'm going to go quite a bit richer to be able to switch back and forth between gas and E85
They say rule of thumb is go 10 sizes bigger on primary jets to run E85. If i go half way i might have a good compromise.
The biggest primary jets i can find are 79 which does that.
metering area calcs
metering area = jet area - rod area
existing = pi*(0.074/2)^^2 - pi*(0.046/2)^^2 = 0.00430 - 0.00166 = 0.00264
new = pi*(0.079/2)^^2 - pi*(0.046/2)^^2 = 0.00490 - 0.00166 = 0.00324
percent increase = (0.00324/0.00264)*100 = 22.7
stock = pi*(0.075/2)^^2 - pi*(0.046/2)^^2 = 0.00441 - 0.00166 = 0.00275
percent increase over stock = (0.00324/0.00275)*100 = 17.8
That's pretty rich but i can adjust the aneroid jet all the way closed for gas to minimize the richness. I still don't how much adjustment is there. It's designed to go from sea level to mountain driving. I would guess +/- 5% ?? a little more than one jet size.
I ordered the performance accelerator pump with ethanol rated rubber. The only difference is a stiffer spring behind the plunger.
I ordered a 5 spring set for the power valve and plan on installing something in the middle.
I ordered the shortest hanger and a long tip secondary metering rod code CK. The longer tip rods bring in full richness sooner. I'm wondering if the current long hanger coupled with the short CH rods are even getting to the last step on the rod??? The hangers can be bent to bring in richness sooner or later per air valve angle.
CH =0.0570
CK =0.0530
The secondary jets are non-removable 0.1350 thousands. Gives an area of 0.01431
0.01431 - 0.00255(CH) = 0.01176
0.01431 - 0.00221(CK) = 0.01210
0.01431 - 0.00152(DA) = 0.01279
0.01431 - 0.001320(CE) = 0.01299
0.01210/0.01176 = 1.0289 or 2.9% richer
0.01279/0.01176 = 1.0875 8.6% richer
0.01299/0.01176 = 1.105 10.5% richer
I just realized i messed this one up. I should have gone richer. The CK rod has a longer tip so full rich will come in sooner so there will be some tuning difference that may be noticable. I'll have to buy another set of secondary rods for alcohol that will bring it about 30% richer.
The cool thing about ethanol is that it doesn't detonate under lean conditions so it won't be that dangerous to play. I've actually run E85 with the current setup which should be way way lean but it runs surprisingly well. It takes some work to get it to idle nice. The mix screws need to be backed out 4 or more and idle screw bumped. I don't think it actually gets any richer after 4 turns.
With bigger primary jets the idle circuit should get correspondingly richer.
current setup
74 primary jets (stock is 75)
46 primary rods (stock)
unknown spring (i know its way too light I cut it at one time.)
CH secondary rods (stock i think)
long hanger (service hanger code V ?)
I'm going to go quite a bit richer to be able to switch back and forth between gas and E85
They say rule of thumb is go 10 sizes bigger on primary jets to run E85. If i go half way i might have a good compromise.
The biggest primary jets i can find are 79 which does that.
metering area calcs
metering area = jet area - rod area
existing = pi*(0.074/2)^^2 - pi*(0.046/2)^^2 = 0.00430 - 0.00166 = 0.00264
new = pi*(0.079/2)^^2 - pi*(0.046/2)^^2 = 0.00490 - 0.00166 = 0.00324
percent increase = (0.00324/0.00264)*100 = 22.7
stock = pi*(0.075/2)^^2 - pi*(0.046/2)^^2 = 0.00441 - 0.00166 = 0.00275
percent increase over stock = (0.00324/0.00275)*100 = 17.8
That's pretty rich but i can adjust the aneroid jet all the way closed for gas to minimize the richness. I still don't how much adjustment is there. It's designed to go from sea level to mountain driving. I would guess +/- 5% ?? a little more than one jet size.
I ordered the performance accelerator pump with ethanol rated rubber. The only difference is a stiffer spring behind the plunger.
I ordered a 5 spring set for the power valve and plan on installing something in the middle.
I ordered the shortest hanger and a long tip secondary metering rod code CK. The longer tip rods bring in full richness sooner. I'm wondering if the current long hanger coupled with the short CH rods are even getting to the last step on the rod??? The hangers can be bent to bring in richness sooner or later per air valve angle.
CH =0.0570
CK =0.0530
The secondary jets are non-removable 0.1350 thousands. Gives an area of 0.01431
0.01431 - 0.00255(CH) = 0.01176
0.01431 - 0.00221(CK) = 0.01210
0.01431 - 0.00152(DA) = 0.01279
0.01431 - 0.001320(CE) = 0.01299
0.01210/0.01176 = 1.0289 or 2.9% richer
0.01279/0.01176 = 1.0875 8.6% richer
0.01299/0.01176 = 1.105 10.5% richer
I just realized i messed this one up. I should have gone richer. The CK rod has a longer tip so full rich will come in sooner so there will be some tuning difference that may be noticable. I'll have to buy another set of secondary rods for alcohol that will bring it about 30% richer.
The cool thing about ethanol is that it doesn't detonate under lean conditions so it won't be that dangerous to play. I've actually run E85 with the current setup which should be way way lean but it runs surprisingly well. It takes some work to get it to idle nice. The mix screws need to be backed out 4 or more and idle screw bumped. I don't think it actually gets any richer after 4 turns.
With bigger primary jets the idle circuit should get correspondingly richer.
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