Are you adding any fuel to the front cylinders? It doesn't look like you are using a power plate with the spacer and GN1 cast intake, is this true? Thanks
Datar
WOT correction OFF with Alky?
- Thread starter TurboBuRick
- Start date
Are you adding any fuel to the front cylinders? It doesn't look like you are using a power plate with the spacer and GN1 cast intake, is this true? Thanks
Datar
Robert Wilson
Member
- Joined
- May 26, 2001
Not adding fuel to the front cylinders and no power plate, just an open spacer. I have had an EGT probe in #6 and now have the same probe in #2 with 25 degrees C difference between the two cylinders.
Which cylinder is the hotter one? I'm assuming the front one.
With any turbo regal that has heads and cam I never target leaner than 10.5:1. The more power and lower the rpm the more I lower the target. 10.3:1 has been good up to 700whp so far.
That's interesting. Even with the 100% methanol I run, my wideband targets (with gasoline readouts) are 11.3-11.7:1 at light boost, ramping to 10.3-10.7:1 at around 30 psi boost, I'm guessing around 800 rwhp. I would guess, needing to ramp even richer as boost is increased beyond 30 psi.
Exactly.. Kudos..
My issue is all this talk of 11.0:1 afr on a twin nozzle then "stuff" happens.
Wow.. run it richer and no problems.. Interesting
And it runs in the low 9's on a 3700 lb Buick on pump gas.. Without adding jack to cylinder 1.. Amazing I should add that with the wrong spark plug, the above target (10.7:1) at 30 psi would be on the dangerous edge. The spark plug design I presently use has virtually eliminated any concern that a hot ground strap might cause a catastrophic 'issue'.
Some of you may be needing to run richer just to keep a ground strap happy.
Robert Wilson
Member
- Joined
- May 26, 2001
Yes, #2 is hotter in my case.
when tuning using alky and a aftermarket ECU's i generally set the correction limits to never be able to pull fuel. but add fuel as a safety. just in case something happens.
Also i think the best way for the alky to be injected is using the smallest nozzle with the highest amount of pump pressure you can make. Doing this will make the droplets way smaller and then alky will be far more efficient.
Somthing i have been thinking about lately is the the amount of time the progressive kits take to reach full voltage. It's in that dead time that the pump pressure is low and the alky is not being atomized very well it any at all. It's very possible that it could be entering as a small stream.
I presonally think there should be a poppet valve on alky line the don't allow any alky to flow untill the pressure reaches x to over come the valve. This might would take care to the low pressure low atomaztion area i'm referring too.
Bison i also agree that for the very short time in first gear one can get away with a tad more boost or delaying the alky coming on as there are other tables adding fuel and having the extra fuel being added makes it hell to tune.
Also i think the best way for the alky to be injected is using the smallest nozzle with the highest amount of pump pressure you can make. Doing this will make the droplets way smaller and then alky will be far more efficient.
Somthing i have been thinking about lately is the the amount of time the progressive kits take to reach full voltage. It's in that dead time that the pump pressure is low and the alky is not being atomized very well it any at all. It's very possible that it could be entering as a small stream.
I presonally think there should be a poppet valve on alky line the don't allow any alky to flow untill the pressure reaches x to over come the valve. This might would take care to the low pressure low atomaztion area i'm referring too.
Bison i also agree that for the very short time in first gear one can get away with a tad more boost or delaying the alky coming on as there are other tables adding fuel and having the extra fuel being added makes it hell to tune.
I was referring to the full boost situation. Not the ramp in on my post.
That's what I figured. You don't normally see people explaining their ramp-in a/f ratios.
- Joined
- May 28, 2001
Robert Wilson said: ↑
And it runs in the low 9's on a 3700 lb Buick on pump gas.. Without adding jack to cylinder 1.. Amazing
Twin nozzle in up pipe, 10:1 AFR, 27 PSI, 18.5 timing on my set up. Been as rich as 9.7:1 AFR but car slows down. Haven't tried to lean it down.
I have seen IAT's down in the 50's to start the pass and end in the low 70's. I do have the GN1 intake with a .800" spacer versus a stock intake which may be a factor
Wow.. run it richer and no problems.. Interesting I have seen IAT's down in the 50's to start the pass and end in the low 70's. I do have the GN1 intake with a .800" spacer versus a stock intake which may be a factor
And it runs in the low 9's on a 3700 lb Buick on pump gas.. Without adding jack to cylinder 1.. Amazing At what point does the methanol become the dominant fuel to tune with? What most do with the alky is use it to lower EGTs so as not to blow head gaskets and to increase the octane rating of the fuel to run the boost necessary to make the power.
If you are using a dual nozzle set up and tuning for 9.5 to 1 you are on a methanol tune. The datalog posted up by the OP is not very much different from mine. Have we gone so far as to have a street tune with a single nozzle and a track tune with a dual nozzle?
Robert Wilson
Member
- Joined
- May 26, 2001
NGK 5671-9 gapped at .025" with stock ignition. Got a suggestion for something else I should try?
Ohhh YES. Is this the same plug most everyone else is using?
I've used NGK plugs for a long time. By far, they are the recommended plug to use with alcohol. The main reason for that is how easily one can learn to read the plug for mixture and timing settings when running alcohol as the primary fuel. I used the same part number as Robert. I'm not sure about the heat range I used. With alcohol, you don't have to worry about fouling and can run as cold as you want. The 5671 is a very popular part number for racing.
It is true that the NGK can be read easily to judge fueling and timing on a pure alcohol engine. What I've learned over the years is that if you're on the wrong end of the tune, the length of the ground electrode is not forgiving. It will get too hot and set off a preignition condition. I am talking about combustion temps that are related to running pure alcohol. That would be less than what you fellas are doing with gasoline and a small portion of alcohol.
Looking back on the problems I experienced that were associated to the NGK spark plugs, I'm very happy I got away from that plug. Compared to what I've been able to get away with since switching to the plugs I use now, it is clear to me now that I was balancing the tuneup to not necessarily keep the fuel from preignition, but I was trying to keep the ground electrode happy so that it wouldn't trigger the preignition.
It is true that the NGK can be read easily to judge fueling and timing on a pure alcohol engine. What I've learned over the years is that if you're on the wrong end of the tune, the length of the ground electrode is not forgiving. It will get too hot and set off a preignition condition. I am talking about combustion temps that are related to running pure alcohol. That would be less than what you fellas are doing with gasoline and a small portion of alcohol.
Looking back on the problems I experienced that were associated to the NGK spark plugs, I'm very happy I got away from that plug. Compared to what I've been able to get away with since switching to the plugs I use now, it is clear to me now that I was balancing the tuneup to not necessarily keep the fuel from preignition, but I was trying to keep the ground electrode happy so that it wouldn't trigger the preignition.
I'm running Autolite Racing AR 3934 plugs (non projected tip, pre-gapped at .028).
One thing to add to all this. Once I stated logging alky pressure last year, I noticed a large variation in alky pressure when the tank wasn't filled to the top. I now top off the tank before each run. I'm moving my battery to the trunk soon and plan on putting the alky reservoir in the stock battery location like Pacecarta did with the it turned 90 degrees counterclockwise so that the outlet is at the rear of the tank. I also prime the alky before a pass and watch the pressure on the laptop to make sure it is coming up normally.
As far as #1 leaning out...... it seems that its hard to say whether it is due to running too lean of an A/F ratio on alky and the weakest link in the chain (#1) is the first to go or its due to alky richening up the rear cylinders. After taking out #1 cylinder I dual fed my Champion fuel rails and switched to an external fuel pressure regulator. And after reading up I've lowered my timing a little, richened up my A/F ratio and switched over to the non-projected tip spark plugs in order to be on the safe side as I've turned up the boost and gone faster. I've been keeping my eye out for a stand alone mulitple EGT setup as that will ultimately tell the tale.
Here are some PowerLogger screengrabs from my last time out. 10.28@134mph. I spun on the launch so only a 1.63 60ft. Analog input 4 is alky pressure. EGT was 1469. MSBC boost controller in wastegate mode with CO2. Running 28" tires on this run, slippage around 5-6% on a PTC converter. This is on a TT 5.7 chip, non-correcting.
One thing to add to all this. Once I stated logging alky pressure last year, I noticed a large variation in alky pressure when the tank wasn't filled to the top. I now top off the tank before each run. I'm moving my battery to the trunk soon and plan on putting the alky reservoir in the stock battery location like Pacecarta did with the it turned 90 degrees counterclockwise so that the outlet is at the rear of the tank. I also prime the alky before a pass and watch the pressure on the laptop to make sure it is coming up normally.
As far as #1 leaning out...... it seems that its hard to say whether it is due to running too lean of an A/F ratio on alky and the weakest link in the chain (#1) is the first to go or its due to alky richening up the rear cylinders. After taking out #1 cylinder I dual fed my Champion fuel rails and switched to an external fuel pressure regulator. And after reading up I've lowered my timing a little, richened up my A/F ratio and switched over to the non-projected tip spark plugs in order to be on the safe side as I've turned up the boost and gone faster. I've been keeping my eye out for a stand alone mulitple EGT setup as that will ultimately tell the tale.
Here are some PowerLogger screengrabs from my last time out. 10.28@134mph. I spun on the launch so only a 1.63 60ft. Analog input 4 is alky pressure. EGT was 1469. MSBC boost controller in wastegate mode with CO2. Running 28" tires on this run, slippage around 5-6% on a PTC converter. This is on a TT 5.7 chip, non-correcting.
The main thing to look at with the plugs is the length of the ground strap. Of course, a projected nose spark plug is going to have a very long ground strap and has absolutely no business being used in a serious hp engine.
Even a non-projected nose (regular gap) spark plug will have varying lengths and thicknesses of ground straps from one spark plug model to the next. The NGK 5671 has a slightly cut back ground electrode. It is not cut back far enough. If one plans to keep using the NGK 5671, the ground strap needs to be cut back further by hand. Cut it back so that you have a side gap plug. .022-.028" gap. I use .022".
I now use a Champion plug that is very cold, has a fat, and short ground electrode. It is cut back so far that I can barely get the side gap to close down enough to get my .022" target gap. The nice thing is, the plug comes with the ground electrode already cut back as short as possible. No manual work on my part to modify the ground strap. Since using this Champion plug, I have been in situations where I know if I had still been using the NGK plug, I would most likely have had serious engine damage.
Even a non-projected nose (regular gap) spark plug will have varying lengths and thicknesses of ground straps from one spark plug model to the next. The NGK 5671 has a slightly cut back ground electrode. It is not cut back far enough. If one plans to keep using the NGK 5671, the ground strap needs to be cut back further by hand. Cut it back so that you have a side gap plug. .022-.028" gap. I use .022".
I now use a Champion plug that is very cold, has a fat, and short ground electrode. It is cut back so far that I can barely get the side gap to close down enough to get my .022" target gap. The nice thing is, the plug comes with the ground electrode already cut back as short as possible. No manual work on my part to modify the ground strap. Since using this Champion plug, I have been in situations where I know if I had still been using the NGK plug, I would most likely have had serious engine damage.
