Tuning with pure meth injection (Track Results)
03-04-2016, 01:56 AM
#1
Tuning with pure meth injection (Track Results) What do you guys shoot for AFR?
What percentage of the fuel should the meth add?
Assume high boost, 20+ psi.
I tuned a twin turbo 5.3 last weekend. Alky control system with a 10 and 15 nozzle. We started the meth at 9 psi.
I had the fueling at 11.5:1
The meth was 15% of the fueling.
18 deg timing.
We didn't make the power we expected.
So just wondering if we were way off on things.
Ron
What percentage of the fuel should the meth add?
Assume high boost, 20+ psi.
I tuned a twin turbo 5.3 last weekend. Alky control system with a 10 and 15 nozzle. We started the meth at 9 psi.
I had the fueling at 11.5:1
The meth was 15% of the fueling.
18 deg timing.
We didn't make the power we expected.
So just wondering if we were way off on things.
Ron
Last edited by RonSSNova; 03-19-2016 at 08:20 PM.
03-04-2016, 07:32 AM
#2
on my buddies tt383 c5 we run approx 20% of the fuel through meth injection (@45-50gph) target mid to low 10's gas afr since it's also an e85 car. aiming to keep it around 10.2-10.5:1 or so. waiting on the suspension to get finished so I Can finish tuning the car and get it on the dyno to see which afr it likes best.
03-04-2016, 09:25 AM
#3
on my buddies tt383 c5 we run approx 20% of the fuel through meth injection (@45-50gph) target mid to low 10's gas afr since it's also an e85 car. aiming to keep it around 10.2-10.5:1 or so. waiting on the suspension to get finished so I Can finish tuning the car and get it on the dyno to see which afr it likes best.
What do you guys shot for AFR?
What percentage of the fuel should the meth add?
Assume high boost, 20+ psi.
I tuned a twin turbo 5.3 last weekend. Alky control system with a 10 and 15 nozzle. We started the meth at 9 psi.
I had the fueling at 11.5:1
The meth was 15% of the fueling.
18 deg timing.
We didn't make the power we expected.
So just wondering if we were way off on things.
Ron
What percentage of the fuel should the meth add?
Assume high boost, 20+ psi.
I tuned a twin turbo 5.3 last weekend. Alky control system with a 10 and 15 nozzle. We started the meth at 9 psi.
I had the fueling at 11.5:1
The meth was 15% of the fueling.
18 deg timing.
We didn't make the power we expected.
So just wondering if we were way off on things.
Ron
Up to about 18lbs or so I aim for 11.5 A/F then taper it down as boost goes up, about 25lbs I'm right at 10.9-11.1. But that's with stock pistons, if you have forged stuff then I would stick to 11.3'ish at higher boost.
If you're relying on meth that much I would certainly want some safeguards both in the tune and visual to the driver.
03-04-2016, 10:39 AM
#4
It's a forged 5.3.
We started at 11 psi meth off then meth on to establish a baseline for adjusting the VE table.
Essentially tuned every psi from there to 21 psi.
We did exactly that with the timing. Inched it up a degree at a time observing power.
Knock sensors are on and working. We never saw a hint of KR.
The interesting thing was the power curve. Even at low boost, low timing and no meth, the power peak happened at 5200 rpm, then fell off past that.
So we may be up against some other issue. Not sure yet.
Also, the truck has 14" slicks. No doubt they drug the power down.
We started at 11 psi meth off then meth on to establish a baseline for adjusting the VE table.
Essentially tuned every psi from there to 21 psi.
We did exactly that with the timing. Inched it up a degree at a time observing power.
Knock sensors are on and working. We never saw a hint of KR.
The interesting thing was the power curve. Even at low boost, low timing and no meth, the power peak happened at 5200 rpm, then fell off past that.
So we may be up against some other issue. Not sure yet.
Also, the truck has 14" slicks. No doubt they drug the power down.
03-04-2016, 10:43 AM
#5
Sounds like other issues to me if it’s falling off at 5200. What kind of power did it make and at what boost level? What turbos? Intercooled? 5.3 run down? Converter slip calculated? Valve springs? Cam specs?
Tuning window on methanol is huge. I wouldn’t be afraid to richen it up quite a bit, though I don’t think it will make a huge difference in performance at the same boost level, it will just allow more boost. AIS guy suggested 10.8:1 when using a gas scale AFR and tuning with 100% meth injection. I shot for 11.0 on my old pump gas meth inj setup.
May look into what the system is actually flowing. Most nozzle flow numbers are calculated at 100psi. Most pumps are putting out 200-300psi these days. At 200psi “25gph” worth of nozzle is actually flowing about 35gph.
At 200psi even the big alky inj pumps are only rated at about 30gph. Less in real world testing I’ve done, and MUCH less at 250-300 psi. As the pressure drops the flow goes down fast. Then you also need to factor in boost pressure the pump has to overcome. So trying to tune these things accurately is a pain with the flow jumping all over the board. Ideally you’d want a set pressure. Meaning multiple pumps that can support your nozzle size without dropping pressure.
How did you calculate that you were replacing 15% of the fueling with methanol?
.087gph per 1 HP is a conservative general rule for pump gas.
So 25gph worth of nozzle is enough to fuel roughly 290hp on gas. It takes roughly twice the fuel to make 290hp with straight methanol. So your 25gph is enough to supplement roughly 145hp. If you were supplementing 15%, that would mean your engine is making 967 crank HP? I’m guessing you were spraying quite a bit more than 15%.
Lastly distribution issues become a real problem when you spray large volumes. You want to run excessively rich because spraying the fluid at the TB isn’t going to distribute equally to all cyls. This obviously gets worse the more you use the methanol to supplement. So targeting 11.5 at 20lbs and 18* timing seems a little risky IMO. I wouldn't feel safe turning it up from there at least without backing down the timing again.
Tuning window on methanol is huge. I wouldn’t be afraid to richen it up quite a bit, though I don’t think it will make a huge difference in performance at the same boost level, it will just allow more boost. AIS guy suggested 10.8:1 when using a gas scale AFR and tuning with 100% meth injection. I shot for 11.0 on my old pump gas meth inj setup.
May look into what the system is actually flowing. Most nozzle flow numbers are calculated at 100psi. Most pumps are putting out 200-300psi these days. At 200psi “25gph” worth of nozzle is actually flowing about 35gph.
At 200psi even the big alky inj pumps are only rated at about 30gph. Less in real world testing I’ve done, and MUCH less at 250-300 psi. As the pressure drops the flow goes down fast. Then you also need to factor in boost pressure the pump has to overcome. So trying to tune these things accurately is a pain with the flow jumping all over the board. Ideally you’d want a set pressure. Meaning multiple pumps that can support your nozzle size without dropping pressure.
How did you calculate that you were replacing 15% of the fueling with methanol?
.087gph per 1 HP is a conservative general rule for pump gas.
So 25gph worth of nozzle is enough to fuel roughly 290hp on gas. It takes roughly twice the fuel to make 290hp with straight methanol. So your 25gph is enough to supplement roughly 145hp. If you were supplementing 15%, that would mean your engine is making 967 crank HP? I’m guessing you were spraying quite a bit more than 15%.
Lastly distribution issues become a real problem when you spray large volumes. You want to run excessively rich because spraying the fluid at the TB isn’t going to distribute equally to all cyls. This obviously gets worse the more you use the methanol to supplement. So targeting 11.5 at 20lbs and 18* timing seems a little risky IMO. I wouldn't feel safe turning it up from there at least without backing down the timing again.
03-04-2016, 11:15 AM
#6
TECH Apprentice
I get thing right without the meth, then spray enough to drop afr about a point, and take some fuel out to bring it back to where I want.
I run 15 degrees of timing and about 11 AFR... or .75 lambda which I tune in.
I run 15 degrees of timing and about 11 AFR... or .75 lambda which I tune in.
03-04-2016, 12:55 PM
#7
22psi on twin agp zeta 3.2's.
car pulls clean, thinking of having him drop a meth nozzle out to lean it out a tad. (3x15gph)
also methanol does run a sh*t ton richer then e85
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03-04-2016, 01:48 PM
#8
It's a forged 5.3.
We started at 11 psi meth off then meth on to establish a baseline for adjusting the VE table.
Essentially tuned every psi from there to 21 psi.
We did exactly that with the timing. Inched it up a degree at a time observing power.
Knock sensors are on and working. We never saw a hint of KR.
The interesting thing was the power curve. Even at low boost, low timing and no meth, the power peak happened at 5200 rpm, then fell off past that.
So we may be up against some other issue. Not sure yet.
Also, the truck has 14" slicks. No doubt they drug the power down.
We started at 11 psi meth off then meth on to establish a baseline for adjusting the VE table.
Essentially tuned every psi from there to 21 psi.
We did exactly that with the timing. Inched it up a degree at a time observing power.
Knock sensors are on and working. We never saw a hint of KR.
The interesting thing was the power curve. Even at low boost, low timing and no meth, the power peak happened at 5200 rpm, then fell off past that.
So we may be up against some other issue. Not sure yet.
Also, the truck has 14" slicks. No doubt they drug the power down.
Tires ate some up for sure. I've seen 60-70hp gain switching from 10" DR's to street tires. 14's are prolly hogging some good power.
03-04-2016, 01:55 PM
#9
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What spark plugs? Any chance you are blowing out the spark at high rpm? Were you able to get a look at the plugs?
Valve float sounds like it needs to be ruled out too.
Valve float sounds like it needs to be ruled out too.
03-04-2016, 02:03 PM
#10
Gotcha. Ya the car would probably be just fine on straight E85. Is it not intercooled or just playing it really safe? I've run 20lbs on pump and M1 before switching to E85 and I still didn't run it that rich. But I have no idea what the AGP turbo's dish out, they use smaller T3/T4 guys aren't they?
intercoolers are pretty small being in a c5 and limited space. Iat's weren't too bad on straight e85.
03-04-2016, 08:25 PM
#12
Hey guys.
Was working and couldn't break away to respond.
5.3 has flat tops, small valve heads. Not 706 but similar. Truck intake. TSP cam, I think it's 218 .600 114. Installed dot to dot. Springs are supposed to be Comp duals. But I haven't seen under the covers.
I determined approx 15% based on how much I had to remove from the VE to get back to my commanded AF with the meth on. It might be closer to 20%.
We put a new plug in #1 to monitor the timing mark and any detonation. With forward swept headers, the rest are tough to get to. Gap was .025. BR7EF, everyone's favorite.
All looked excellent when removed after the dyno.
The curves looked odd to be honest. I'll post the sheet.
On our 21 psi run, AF was 11.2-11.4
14" bias ply slicks. With 4.30 gears, we couldn't bolt on some some short DR's.
Was working and couldn't break away to respond.
5.3 has flat tops, small valve heads. Not 706 but similar. Truck intake. TSP cam, I think it's 218 .600 114. Installed dot to dot. Springs are supposed to be Comp duals. But I haven't seen under the covers.
I determined approx 15% based on how much I had to remove from the VE to get back to my commanded AF with the meth on. It might be closer to 20%.
We put a new plug in #1 to monitor the timing mark and any detonation. With forward swept headers, the rest are tough to get to. Gap was .025. BR7EF, everyone's favorite.
All looked excellent when removed after the dyno.
The curves looked odd to be honest. I'll post the sheet.
On our 21 psi run, AF was 11.2-11.4
14" bias ply slicks. With 4.30 gears, we couldn't bolt on some some short DR's.
03-04-2016, 09:41 PM
#15
Restricted User
Falling off at 5200 RPM?
What does the mid range look like?
My 5.3 at 20 PSI makes 660 ft lbs on a DynoTech at 3500 RPM and holds it until almost 5000 RPM. I'm on my phone so I can't see the numbers on the graph you posted, but the setup seems lazy. Any chance cam timing is off?
What does the mid range look like?
My 5.3 at 20 PSI makes 660 ft lbs on a DynoTech at 3500 RPM and holds it until almost 5000 RPM. I'm on my phone so I can't see the numbers on the graph you posted, but the setup seems lazy. Any chance cam timing is off?
03-04-2016, 09:49 PM
#17
Falling off at 5200 RPM?
What does the mid range look like?
My 5.3 at 20 PSI makes 660 ft lbs on a DynoTech at 3500 RPM and holds it until almost 5000 RPM. I'm on my phone so I can't see the numbers on the graph you posted, but the setup seems lazy. Any chance cam timing is off?
What does the mid range look like?
My 5.3 at 20 PSI makes 660 ft lbs on a DynoTech at 3500 RPM and holds it until almost 5000 RPM. I'm on my phone so I can't see the numbers on the graph you posted, but the setup seems lazy. Any chance cam timing is off?
There was no midrange. Tq fell off past 4800.
Last edited by RonSSNova; 03-04-2016 at 10:02 PM.
