- Joined
- May 27, 2001
Fastest v6
- Thread starter casper
- Start date
turbodragster
New Member
- Joined
- Sep 23, 2004
yes still messing with alky . got some new injectors this time around and useing a new fast xfi so we are exspecting to have allot more data so we can dial it in better. alky seems to be the way to go i got allot of buddies running in there 10.5 cars so im hoping to see some big gains when we get testing next week.
I have to agree with you. From the racing I've seen, anyone going for the max limit is burning methanol. I have to believe that the person that ends up squeezing the most out of a Buick V6 will be the person burning methanol. What other fuel is there where you can run 12 to one CR with 50 psi boost and run so rich that its spitting out the exhaust without fouling spark plugs. Methanol is the fuel that's going to do it.
From what I have seen thus far , compression just kills parts in these things.
I have tried 9.5 , 10.5 , 11.5 and killed connecting rods as the comp went up,
so then dropped to 7.51 made 137 passes then went to 8.12 and made 12 passes before shortening up a rod. Im working on putting in rods .125" shorter than I had to lower the compression into the 6.70 range. That way I can put more boost to it. My problem could easily be in the tune because Im way outside the box on timing. It ETs quickest with 36-38 degrees timing
I know that just rediculas!!! But that is what works!!!
Im putting an A/F system on my racepak computer and Im going to install a 3 stage retard system on timers for this year. With the A/F info I hope to be able to move back towards a normal tuning window. I will be Looking for tuning advice on this project!!!! Mike
I have tried 9.5 , 10.5 , 11.5 and killed connecting rods as the comp went up,
so then dropped to 7.51 made 137 passes then went to 8.12 and made 12 passes before shortening up a rod. Im working on putting in rods .125" shorter than I had to lower the compression into the 6.70 range. That way I can put more boost to it. My problem could easily be in the tune because Im way outside the box on timing. It ETs quickest with 36-38 degrees timing
I know that just rediculas!!! But that is what works!!!Im putting an A/F system on my racepak computer and Im going to install a 3 stage retard system on timers for this year. With the A/F info I hope to be able to move back towards a normal tuning window. I will be Looking for tuning advice on this project!!!! Mike
Dusty, Went back into 3 runs from last year and came up with an average to give you an idea. Powerglide trans. Shift at 7700 / dsr 1.85 , right after shift 6600 / dsr 1.46 , 660" finish line 6900 / dsr 1.15. Probably should throw out the finishline because the car is not pulling at that point.
Id love to try one of the aluminum blocks if the deal was right. I think when people see what we're coming out with, we might get a "right deal"
Things are about to get REAL interesting in more ways than one.
Jay, the suspense is killing me. What do you have going on? Shoot me a PM!!!
turbodragster
New Member
- Joined
- Sep 23, 2004
9 to1 bent rods
8 to 1 bent rods
7.2 to 1 we will see
8 to 1 bent rods
7.2 to 1 we will see
I'm running 9.21 to one at 32 psi so far and I'm calculating I should be able to do 45 psi with an efficient turbo. The ignition timing should be conservative. That is not where your attention should be. Don't get me wrong. It's important, but not the most important thing. The important thing is controlling mixture temp throughout the first three cycles. Too cool, you lose power. Too hot? It sounds like you guys know about that one pretty well. There is one condition with methanol where you can be so rich that the engine actually burns lean because of lack of vaporization at the right time in the process and pow.
There are a few ways to control mixture temp in a high blown application. Blower or turbo efficiency. Aftercooler, and air/fuel mixture. If you're not running an aftercooler, then it's all going to need to be done with mixture. You're going to need to control the rate of vaporization through the intake, compression AND power strokes. When it's right, most likely some will still be vaporizing on the exhaust stroke. The correct tune will be down on power a bit, but will be safe. If you tune for absolute peak power with methanol and don't back it down a bit, you'd better have a lot more of those rods handy.
There are a few ways to control mixture temp in a high blown application. Blower or turbo efficiency. Aftercooler, and air/fuel mixture. If you're not running an aftercooler, then it's all going to need to be done with mixture. You're going to need to control the rate of vaporization through the intake, compression AND power strokes. When it's right, most likely some will still be vaporizing on the exhaust stroke. The correct tune will be down on power a bit, but will be safe. If you tune for absolute peak power with methanol and don't back it down a bit, you'd better have a lot more of those rods handy.
turbodragster
New Member
- Joined
- Sep 23, 2004
we run about 22 to 23 degrees of timing and have run 45 lbs of boost. we have no intercooler. we did try spraying the fuel in the intake tubs to cool the charge but saw no difference. we have played with blower motors in the past and starting line temp means allot about how the car will run.
Donnie, Turbo dragster switched from gas with intercoolers to alchy without intercoolers last year. His control system measured in stoch?? Sorry im an idiot reguarding these things. His new system will be capable of reading in A/F ratio and Im sure he will share his setup with us. He has ties to the Titan toyota group and thus knows some of what they are doing and should help him with his tuneup!! HOPE I STATED THIS CORRECTLY correct me if im wrong.
Being super charged with a roots blower I am not intercooled either. My intake temps on an 75 degree day will be 80-90 degrees at 60' and continuiously rise to around 140-150 degrees at 660'. I have mechanical
fuel injection and a locked timing system. Increasing the timing makes huge gains in ET but doesnt help much with MPH. Im quite sure the timing is killing
some of the speed. My racepak is on its way back to me with A/F system installed and I have a timer controlled retard system on the way also. If I get my connecting rod issue straightened out and get some new rods built
in time I will get to play again this year. Right now Im rodless!!! My boost is basically 40# at 10' and goes up to 50# at 7800 rpm Mike
Being super charged with a roots blower I am not intercooled either. My intake temps on an 75 degree day will be 80-90 degrees at 60' and continuiously rise to around 140-150 degrees at 660'. I have mechanical
fuel injection and a locked timing system. Increasing the timing makes huge gains in ET but doesnt help much with MPH. Im quite sure the timing is killing
some of the speed. My racepak is on its way back to me with A/F system installed and I have a timer controlled retard system on the way also. If I get my connecting rod issue straightened out and get some new rods built
in time I will get to play again this year. Right now Im rodless!!! My boost is basically 40# at 10' and goes up to 50# at 7800 rpm Mike
Your timing looks good for peak level cylinder pressures (peak torque). If you have to go any less than that, you have a mixture problem. Of course, as the engine runs through its rpm band cylinder pressure levels will vary. Fixed timing is an elephant from the past (lazy mans tuning). If a timing curve system is available to you, you should be taking advantage of it. Fixed timing is a compromise. It is usually set to take care of the timing needs for a particular rpm range (a very narrow one). All other areas will be less than optimum.
Idle will be much happier with a little more timing.
A/F will usually be leaned out and timing will slightly increase after peak torque is past. This may or may not be true in your case. Every methanol engine is its own animal. Be careful taking advice from the Toyota camp. What works on their engines may not transfer over to yours.
I'm going to say this again. And its very important that it sinks in. 'Every methanol engine configuration is its own animal.' What works for one, may be totally wrong for another.
Spraying the extra fuel may not have increased power, but it may be, at least, moving your mixture from being dangerously close to an auto-ignition state. Keep in mind. Methanol fueled engines always go the fastest, right before they go boom! You should have increased your fuel until you started seeing a drop in performance or you noticed raw fuel out the exhaust. That will establish your tuning window.
Your correct about starting temps at the line. This is very important with a methanol engine. If your tuneup is less than safe, you don't want to be hot at the line. If your tuneup has a safe cushion, you will want to be hotter at the start. My best times are usually done when I get caught in the water box waiting for the person from the previous pass to pickup his chute and get off the track. This would be a coolant temp of 180F. Of course, at this point, my tuneup is relatively safe. The difference in power from having a hotter engine at the start of the run is because I've changed the vaporization synchronization or curve that the fuel will go through as it passes through the 4 cycles in the engine.
It all comes down to controlling the intake charge temp (starting temp), rate and amount of vaporization throughout the 4 cycles of the engine.
The rate of vaporization throughout the 4 cycles of the engine, along with the amount of fuel available for vaporization and the quality of vaporization from the start of the process will change with differing tuneups, and engine, and fuel system layouts. Just the fact that someone decided to use heat barrier coatings on just their pistons can change this very important synchronization of vaporization with the 4 engine cycles.
As the mixture is compressed, the mixture is heated.
The heat from compression helps to vaporize the mixture. How quickly and how much of the mixture that vaporizes is important.
As the mixture vaporizes, it absorbs heat and helps control the temperature of the mixture. It's important that the mixture never rises to auto-ignition temperatures during this phase. If more fuel is needed to provide more vaporization and hence temperature control, then more is added. And yes, sometimes at the expense of power. Aftercooling will help lessen the level of extra fuel that would otherwise be used for mixture cooling purposes alone.
Depending on the engine (different animals again), it may be necessary to have enough un-vaporized fuel available during early stages of the power stroke (early and critical phase of ignition) to control mixture temperature and combustion flame speed.
Fuel injector location is just one of the many variables that will have much to do with the required bsfc of the engine.
Fuel injector location will have much to do with the initial state of vaporization of the fuel before it passes the intake valve.
Fuel injector location will have much to do with the density value of the air as it passes through the intake port.
Intake port volume will have much to do with the air velocity through the intake port, which will have much to do with the vaporization level of the mixture before the intake valve.
With methanol its vaporization cycle and synchronization, vaporization cycle and synchronization, vaporization cycle of the fuel and synchronization to the 4 cycles of the engine. And everything has an effect on it. Even the smallest tuning change.
Theoretically, it's possible to tune a methanol engine to the point that the fuel is detonating at just the right point to achieve maximum pressure rise at just the right point in crankshaft rotation. This is something that is normally stumbled upon and not tuned for. The engine components would have to be able to withstand the quick pressure rise also.
There really is so much more to this. I hope I did a good job of summarizing it for you. Good food for thought?
Happy methanol tuning to all!
BlownV6,
I hope the last post gave you some food for thought. Especially about the timing. Where are you measuring the intake air temp? Before fuel is added or after? Between?
Those temps sound too good for 50 psi with a blower. Is some fuel injected before blower and some after? If so, what's the ratio of fuel before and after? Where is the fuel being injected after blower? Valve pocket? Port entry?
A target a/f ratio for you guys with high boost and without aftercoolers should be in the low to mid 3 to ones at full load to start with. Then work toward leaner to find your lean limit. That will usually be where the power increases start to level off or you break parts. Once you've found that limit, hopefully before you've broke any parts, go back to the ratio you started with (low to mid 3s) and work rich, until the engine becomes sluggish or raw fuel is blowing out the exhaust. That will be your rich limit. You should end up with a 30% tuning window. Go to the middle and leave it alone. Timing is going to have a small part to play in the overall scheme. don't go crazy with it. I know the old school guys are going to tell you stories about how they locked out their timing at 50 degrees. Don't listen to that junk. It doesn't work with our engines.
I hope the last post gave you some food for thought. Especially about the timing. Where are you measuring the intake air temp? Before fuel is added or after? Between?
Those temps sound too good for 50 psi with a blower. Is some fuel injected before blower and some after? If so, what's the ratio of fuel before and after? Where is the fuel being injected after blower? Valve pocket? Port entry?
A target a/f ratio for you guys with high boost and without aftercoolers should be in the low to mid 3 to ones at full load to start with. Then work toward leaner to find your lean limit. That will usually be where the power increases start to level off or you break parts. Once you've found that limit, hopefully before you've broke any parts, go back to the ratio you started with (low to mid 3s) and work rich, until the engine becomes sluggish or raw fuel is blowing out the exhaust. That will be your rich limit. You should end up with a 30% tuning window. Go to the middle and leave it alone. Timing is going to have a small part to play in the overall scheme. don't go crazy with it. I know the old school guys are going to tell you stories about how they locked out their timing at 50 degrees. Don't listen to that junk. It doesn't work with our engines.
turbodragster
New Member
- Joined
- Sep 23, 2004
we are looking for 3.8 a/f to start but have seen 4.0 as ok on allot of combinations of course the plug is the ultimate gage of cylinder temp so we are going to start soft then see what the plugs look like .
My computer blew up about a month ago and I lost all my pics (sorry) But here is a couple I just took of the hat, blower & manifold. This will give you idea how the fuel system is plumbed up. About 60% of the total amount of fuel going into the engine is in the hat which helps cool and lubricate the blower. The port nozzles suppy the remaining 40% and help balance the EGT's . I measure the intake temp in the plenium of the manifold. Mike
Attachments
How many threads do you look for on the plug reading.
What a/f seems to get you in trouble on the lean side.
What's your target EGT?
Blown V6. Wow. Too pretty.
For comparison, I'm seeing 149F in the up pipe after the intercooler, at the 660 before any fuel is added. 29-31 psi boost. I'll have to get you the EGT later.
Are you doing any lean out on the top end? High speed bypass?
For comparison, I'm seeing 149F in the up pipe after the intercooler, at the 660 before any fuel is added. 29-31 psi boost. I'll have to get you the EGT later.
Are you doing any lean out on the top end? High speed bypass?
