I'm presently using six 30/30. The change will be to six 31/31.
Advancement of fuel delivery?
- Thread starter Alky V6
- Start date
Welcome!
By registering with us, you'll be able to discuss, share and private message with other members of our community.
I'm presently using six 30/30. The change will be to six 31/31.
I'm thinking about the 2-step again as I'm waiting for parts. 
What if the 2-step rev limit is set to some rpm value above what the stall speed of the T/C is and the approach rpm setting is set to bring the timing down close to 5 or 0 btdc by the time the engine reaches stall speed? With 5% more fueling too? Wouldn't that be a functional 2-step that would provide extra exhaust energy to heat the exhaust and provide it without the back and forth of the engine rpm like it does when the rev limit is actually reached? Although the rev limit won't be reached because it's set beyond the T/C stall speed.
This could be a nice process to preheat the system in preparation for the ultra cool (meth+n2o) nitrous hit.
What if the 2-step rev limit is set to some rpm value above what the stall speed of the T/C is and the approach rpm setting is set to bring the timing down close to 5 or 0 btdc by the time the engine reaches stall speed? With 5% more fueling too? Wouldn't that be a functional 2-step that would provide extra exhaust energy to heat the exhaust and provide it without the back and forth of the engine rpm like it does when the rev limit is actually reached? Although the rev limit won't be reached because it's set beyond the T/C stall speed.
This could be a nice process to preheat the system in preparation for the ultra cool (meth+n2o) nitrous hit.
Methanol tuning tid bits.
The flame front speed of methanol during normal combustion has been noted to be higher than that of gasoline under the right conditions of a/f mixture and temperature. This would affect the amount of ignition timing advance needed. If this condition could be obtained under a high performance situation, pumping losses would be lowered due to less needed ignition lead time.
The usable a/f ratio tuning range of gasoline has been noted to be 10% rich to lean. The usable a/f ratio tuning range of methanol has been noted to be 30% rich to lean.
The affective compression ratio that can be used with methanol, using the right a/f ratio and conditions, has been noted to be as high as 40.0:1. More commonly found in popular non-intercooled supercharged applications is around 36:1. The affective compression ratio takes into account the static compression ratio and the change in the dynamic compression ratio with the addition of manifold boost pressure above atmospheric level.
mechanical (static) compression ratio x manifold boost pressure (bar) = dynamic CR
12 (12.0:1cr static) x 3.0 bar (29 psi boost) = 36 (36.0:1cr dynamic)
6.0 x 5.44 bar = 32.64
So, a methanol engine with a static CR of 6.0:1 can comfortably operate at a boost pressure of around 80 psi. Wow.
With my intercooled methanol application, I'm presently up to a dynamic CR of 26:1. 2.8 (26-27 psi) bar boost. With my static CR of 9.27:1, I should safely be able to approach a 3.5 (37 psi) bar boost level. That would be a dynamic CR of 32.4:1, not taking into account the affect of other factors that control basic engine VE.
The flame front speed of methanol during normal combustion has been noted to be higher than that of gasoline under the right conditions of a/f mixture and temperature. This would affect the amount of ignition timing advance needed. If this condition could be obtained under a high performance situation, pumping losses would be lowered due to less needed ignition lead time.
The usable a/f ratio tuning range of gasoline has been noted to be 10% rich to lean. The usable a/f ratio tuning range of methanol has been noted to be 30% rich to lean.
The affective compression ratio that can be used with methanol, using the right a/f ratio and conditions, has been noted to be as high as 40.0:1. More commonly found in popular non-intercooled supercharged applications is around 36:1. The affective compression ratio takes into account the static compression ratio and the change in the dynamic compression ratio with the addition of manifold boost pressure above atmospheric level.
mechanical (static) compression ratio x manifold boost pressure (bar) = dynamic CR
12 (12.0:1cr static) x 3.0 bar (29 psi boost) = 36 (36.0:1cr dynamic)
6.0 x 5.44 bar = 32.64
So, a methanol engine with a static CR of 6.0:1 can comfortably operate at a boost pressure of around 80 psi. Wow.
With my intercooled methanol application, I'm presently up to a dynamic CR of 26:1. 2.8 (26-27 psi) bar boost. With my static CR of 9.27:1, I should safely be able to approach a 3.5 (37 psi) bar boost level. That would be a dynamic CR of 32.4:1, not taking into account the affect of other factors that control basic engine VE.
Old was 11. New is a lot more than 11.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
Interesting.
Post some pics when you get itI'm betting you have a 11 blade stator, this new one will possibly be a 12 or he just pulled some angle out if it.
Just as I called it. So now he's adding many more blades rather than using pump angle.........Who has been doing this for years:biggrin:
Still he's only calling for 300 more stall rpm?? If so, and he's added many more blades, the angle of them has to be quite a bit different as well.
Actually, he didn't call the 300 rpm increase. I asked if this would get me 300 rpm, and his answer was, at least, if not more. I can't remember his exact words, but I had the impression by the way he said it that I might see quite a bit more. That's alright with me. I need 300 to 500 more.
The angle is different. It's moved in the direction that would result in more stall speed and torque multiplication.
There's also more open space between the fins of the stator and the impeller. Stator fins are shorter than the previous stator design.
What do you think Dusty? Does it sound like a good move?
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
You'll most likely see 100rpm more from the spacing alone. You will see much more than 300 total, depending on how much he moved the angle. If the angle is in fact moved in the direction to increase stall speed, you will see a huge difference.
You have well over 1000 rpm of stall change possible from your 11 blade design.
I needed the stator change anyway. I had too much rpm drop on the shifts. Had 1100-1200. Looking for 550-800. Any added tq multiplication won't hurt either. Those bigger tires are a biatch to wrinkle.
You bring up the fact that you might have helped with the stall with the 11 fin stator I already had, now, because...?
I was thinking the same thing. Thanks for the input. I'm going to be focusing in on adjusting the stall speed now. It is time. The tuneup has peaked out, as far as the launch goes.
Judging by how the boost is rising at the launch with the present configuration, a stall speed of 4300 to 4600 would be sweet. That would definitely challenge the boost controller. Even the drag sim likes it. That would be a needed increase in the stall of 400 to 800 rpm.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
Not sure what your asking here? Are you wanting to know if I could have taken the 11 blade and restalled it?
I would never use an 11 blade stator to begin with. I know he likes them and is familiar with what makes them work. I have taken numerous NC converters in on trade and they have all been 11 blade stators with various angles and pump configs. IMO, it's not the best way to build a converter for a small engine. A big block loves it but the small motors do not. Just not enough grunt down low.
What I was saying was, you have well over 1000 rpm of adjustment from where you were at. Of course the exact number depends on what angle he was at. I can move the stall rpm 2-300 either way with just the angle or as much as 500 if it starts on the extreme of high or low.
When you originally told me it would be 300 rpm, I already had in my mind what blade count and angle he sent you. If he indeed moved the angle towards looser and added several blades. You could see 600-800 rpm looser. If it only changes 300 rpm or so, then he actually moved the angle towards tighter and offset this with the blade count.
You are doing the right thing. The looser converter would have drastically helped your situation months ago.
Nigel’s key to keeping Spinal Tap among England’s loudest bands.
Nigel: "You see, most blokes will be playing at 10. You’re on 10, all the way up, all the way up...Where can you go from there? Nowhere. What we do, is if we need that extra push over the cliff...Eleven. One louder."
DiBergi: "Why don’t you just make 10 louder and make 10 be the top number, and make that a little louder?"
Nigel (after taking a moment to let this sink in): "These go to 11."
TGIF!Yeah. That's the impression I got from your earlier statement. I didn't think that was do-able. Thanks for clearing that up.
After studying the angles, the entry angle on the 11 fin is low, then sweeps (bent) to high (high stall/multiplication) at the exit. They're long blades that end tight to the impeller fins. You've seen them before.
The new stator has shorter fins, almost half the length of the old stator fins, that end with about that difference of clearance to the impeller fins. The angle of these fins are at the same angle as the exit angle of the old stator. The new fins are flat, not bent, with the same angle at entry and exit.
I get it, Todd. If there isn't an eleven, make the eleven.
Or, the eleven is there. You just have to look for it, and be willing to step up.
Less? You're silly. :tongue:
Well, it's on the car so I'll keep using it. :tongue:
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
- Messages
- 5,802
Similar threads
