Advancement of fuel delivery?
- Thread starter Alky V6
- Start date
New nitrous tuning strategy
The best 60 foot when on the nitrous resulted from the 22G tuneup. At the boost transition point (3800 rpm) with the 22G cal, the fuel was about 20% leaner than where I presently have it (bin file 25h). I would not dare go any leaner than the 22G tuneup with the nitrous. The latest 25h cal was setup for good O2 readings off the nitrous.
The new plan is to start tracking the a/f mixture, 60 foots and nitrous bottle pressures through the boost transition point and slowly lean the mixture in steps. After each step change, I'll perform a run while off the nitrous, and then another run with the nitrous, recording changes in the O2 readings and the 60 foots.
It has become clear that the best mixture through the boost transition point and while on the nitrous will not give me a clear O2 reading. What I can expect with a perfect nitrous tune will be a flat line 14.64:1 readout while on the nitrous. Since I now have a known lean limit and a target 60 foot of 1.5x, I can start working the mixture leaner from where I presently have it. I know the n/f mixture is on the rich side, so it makes perfect sense that the fuel table would need to be leaned from an 'off the nitrous' tune. It will be interesting to see how lean the mixture starts to move with the 'off the nitrous' runs. If the 'off the nitrous' a/f readout starts to move towards scary lean I may decrease the size of the nitrous system fuel jets, then go back to the 25h cal and start over with the leaning process, if necessary, to get the target 60 foot of 1.5x using .45 seconds of pre-spool time on the nitrous.
I will be using the spool valve with these tests.
The best 60 foot when on the nitrous resulted from the 22G tuneup. At the boost transition point (3800 rpm) with the 22G cal, the fuel was about 20% leaner than where I presently have it (bin file 25h). I would not dare go any leaner than the 22G tuneup with the nitrous. The latest 25h cal was setup for good O2 readings off the nitrous.
The new plan is to start tracking the a/f mixture, 60 foots and nitrous bottle pressures through the boost transition point and slowly lean the mixture in steps. After each step change, I'll perform a run while off the nitrous, and then another run with the nitrous, recording changes in the O2 readings and the 60 foots.
It has become clear that the best mixture through the boost transition point and while on the nitrous will not give me a clear O2 reading. What I can expect with a perfect nitrous tune will be a flat line 14.64:1 readout while on the nitrous. Since I now have a known lean limit and a target 60 foot of 1.5x, I can start working the mixture leaner from where I presently have it. I know the n/f mixture is on the rich side, so it makes perfect sense that the fuel table would need to be leaned from an 'off the nitrous' tune. It will be interesting to see how lean the mixture starts to move with the 'off the nitrous' runs. If the 'off the nitrous' a/f readout starts to move towards scary lean I may decrease the size of the nitrous system fuel jets, then go back to the 25h cal and start over with the leaning process, if necessary, to get the target 60 foot of 1.5x using .45 seconds of pre-spool time on the nitrous.
I will be using the spool valve with these tests.
It's a B/W wheel. I don't think they deal with B/W.
The new T/C stator is 'in the mail'. Can't wait. :biggrin: The promise is at least 300 rpm more stall speed. That would put the new stall speed, on the nitrous, at 4100 rpm, at least. The boost transition point, on the nitrous is 3800 rpm. The turbo, with the nitrous assist, is generally building 1-2 psi of boost at this point. If the stall happens to increase to 4500 rpm,... hold onto your hats!
There's a promise of higher T/C efficiency on the top end also. I wonder what this thing looks like.
There's a promise of higher T/C efficiency on the top end also. I wonder what this thing looks like.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
Post some pics when you get it
I'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.Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
So this isn't a stator from Chance?
It won't be very far different than what you have if your not having to change other internals around to compliment the new stator.
The old stator that is in the T/C now is a simple fabricated steel stator. It is a stage V stator. This was as far as I could go with this stator design and the other components to get the highest stall out of this turbine/impeller combination. The fins are flat and bent to shape.
From what I gathered in talking with Marty, the new stator that's coming is new technology for them. Don't know when they started supplying these, but I think it's been pretty recent. They are steel or aluminum CNC machined stators. I would imagine that being CNC machined they have much more control over the whole shape of the foil. I'm sure it's not just a flat shape as what I've been using.
He was very confident that I would see a difference, and was very hesitant to change the turbine/impeller combination. We'll have to wait and see.
Marty understands the difficulty with my combination. As he put it, you're either a hero, or a zero with this turbo V6 stuff. He's not totally sure himself what I'm going to end up with. We're experimenting. Just my style. At least, he seems excited about this new technology and is willing to work with it. We'll find out next week.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
You don't have to take a pic, I understand that. Just share with us how many blades are on it vs what you had in the car. I'm curious if this "new" tech is what other manufacturers have been doing for years.
Ok Don, speaking of flapper valves (sortof VNT'ish thinking), think this would be a cool next project
Garrett PowerMax Stage 1 AVNT GT3794VA Turbocharger Upgrade
2 of these. About 130 lb/min total flow at 3-3.5 pressure ratio. VNT, which should allow you to spool them easily, even with no hose. And likely no wg needed either.
Wish we could find info on a bigger single VNT that would support 120-140 lb/min on the compressor side. That would be the shiznit. Think they're out there, just hard to find online info.
Surprised that PTE hasn't jumped on the VNT thing and provided us some choices!
TurboTR
Edit- hmm... Maybe some Holset technology
maybe something like 2 x HE431V:
Garrett PowerMax Stage 1 AVNT GT3794VA Turbocharger Upgrade
2 of these. About 130 lb/min total flow at 3-3.5 pressure ratio. VNT, which should allow you to spool them easily, even with no hose. And likely no wg needed either.
Wish we could find info on a bigger single VNT that would support 120-140 lb/min on the compressor side. That would be the shiznit. Think they're out there, just hard to find online info.
Surprised that PTE hasn't jumped on the VNT thing and provided us some choices!
TurboTR
Edit- hmm... Maybe some Holset technology
maybe something like 2 x HE431V:
Don't get me started.
While I'm sitting around waiting for a turbine wheel and posting on TB.com, I'll be upping the nitrous shot to the 346hp rating.
N/F jetting X 6: 32(950 psi)/31(45 psi)
Going to lean the system a little, and watching bottle pressure more carefully. 950 to 1,000 psi bottle pressure should be a good target still.
While I'm sitting around waiting for a turbine wheel and posting on TB.com, I'll be upping the nitrous shot to the 346hp rating.
N/F jetting X 6: 32(950 psi)/31(45 psi)
Going to lean the system a little, and watching bottle pressure more carefully. 950 to 1,000 psi bottle pressure should be a good target still.
I found a link to the very hard to find compressor map and some information on the Airwerks S510 (FI91X).
With the hp that I've figured I'm at with the car so far, I'm sitting right at the tip of the 78% efficiency island. Yes!!!
Build Your Own Turbo Kit
With the hp that I've figured I'm at with the car so far, I'm sitting right at the tip of the 78% efficiency island. Yes!!!
Build Your Own Turbo Kit
The target is 1.8-1.9:1. I've thought more about it and I think I'll start off with 31/31 jets first, see how it works, and then lean it to 32/31 if things look right for it.
I'm still using the nitrous to spool only. It shuts off at 16 psi or sooner if I program the timer to cut it off before the 16 psi pressure switch can.
Dusty Bradford
Well-Known Member
- Joined
- May 24, 2001
Your using six 31 jets in the nitrous system?
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