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SVO 30#s tuning

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Old Dec 10, 2007 | 06:57 PM
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Default SVO 30#s tuning

I just got dyno tuned and was running at 113% duty cycle on my stock 2000 (26lb) injectors so I bought some 30lb SVO's from Speed Inc. I plan to just run a script from Chad at GLMS to tune for the new SVO's. The script is attached.

Should I have to touch the VE table after I do this?

Thanks!
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Old Dec 11, 2007 | 01:04 AM
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nobody?
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Old Dec 11, 2007 | 05:53 AM
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Originally Posted by Xtnct00WS6
nobody?
IMO yes, you should re-do VE. At least log it and see how far off it is
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Old Dec 11, 2007 | 07:00 AM
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That script is incomplete. All it is, is an IFR table, doesn't change the offset table, or short pulse tables, and they need to be changed too.
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Old Dec 11, 2007 | 10:37 AM
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Originally Posted by Frost
That script is incomplete. All it is, is an IFR table, doesn't change the offset table, or short pulse tables, and they need to be changed too.
Do you have any resources on how to tune those tables?

Thanks!
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Old Dec 13, 2007 | 02:21 PM
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Originally Posted by Xtnct00WS6
Do you have any resources on how to tune those tables?

Thanks!
That IFR table is 15% too high. The IFR table should start at 30 on the left. If your AFR & LTFT's were correct with the stock injectors, you will now have very high LTFT's. I never had to change the offset table with an injector change. Changing the offset table higher is just compensating for the IFR being too high.

Russ Kemp
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Old Dec 13, 2007 | 03:13 PM
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Originally Posted by Russ K
That IFR table is 15% too high. The IFR table should start at 30 on the left. If your AFR & LTFT's were correct with the stock injectors, you will now have very high LTFT's. I never had to change the offset table with an injector change. Changing the offset table higher is just compensating for the IFR being too high.

Russ Kemp
Hey what's up Russ, nice to see you this way. Most of the OEM (offset) tables seem to really over compensate for voltage drops, which I suppose is better than going the other way. Also (obviously not talking about this setup, but in general) I redo the table for boost referenced setups ie, copying the 0kPa column across like the IFR... as it does change, but that's me

OP, I'm not holding back on you, I just don't have what you are looking for/need. G'luck.
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Old Dec 14, 2007 | 02:59 AM
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Originally Posted by Russ K
That IFR table is 15% too high. The IFR table should start at 30 on the left. If your AFR & LTFT's were correct with the stock injectors, you will now have very high LTFT's. I never had to change the offset table with an injector change. Changing the offset table higher is just compensating for the IFR being too high.

Russ Kemp
Russ, you do realize that the SVO 30# are "rated" at 43.5 PSI, while GM fuel systems operate and are rated at 58 PSI? With the increased fuel pressure, those injectors can will now flow more then 30#, more like 35#, so that table is correct.
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Old Dec 16, 2007 | 03:45 PM
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Injector Scaling write up in my web below, two ways to go about it.
Robert
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Old Dec 16, 2007 | 07:18 PM
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Originally Posted by 12secSS
Russ, you do realize that the SVO 30# are "rated" at 43.5 PSI, while GM fuel systems operate and are rated at 58 PSI? With the increased fuel pressure, those injectors can will now flow more then 30#, more like 35#, so that table is correct.
George,

Setting the IFR table as per the spread sheet causes lean AFR's & postive fuel trims. You would then have to raise the VE/Maf tables to compensate. Setting the IFR table to be 30 starting on the left, the AFR's & fuel trims fall back in line.

Russ Kemp
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Old Dec 17, 2007 | 11:46 PM
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Just to let everyone know...I copied over B4005, B4004, and B4003 from a stock 2002 tune and changed my B4001 (IFR table) to what's in the script above and it seems to work fine. My air to fuel ratios look good.

The only thing that's wierd is that I'm at 91% duty cycle with the new SV0 30# injectors. I thought I'd have more room to grow with them. I guess not?
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Old Dec 18, 2007 | 02:52 PM
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Originally Posted by Xtnct00WS6
Just to let everyone know...I copied over B4005, B4004, and B4003 from a stock 2002 tune and changed my B4001 (IFR table) to what's in the script above and it seems to work fine. My air to fuel ratios look good.

The only thing that's wierd is that I'm at 91% duty cycle with the new SV0 30# injectors. I thought I'd have more room to grow with them. I guess not?
I would think something is not right if you have 30lb injectors running at the LS1 58psi and you are at 91% duty cycle with a 224 cam and heads........
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Old Dec 18, 2007 | 10:46 PM
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I actually have a mid 230's cam, a fast 90/90 and 11.2:1 SCR. I just haven't updated my signature

But still...I wouldn't think it would be 91% either
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Old Dec 19, 2007 | 10:06 AM
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Originally Posted by Xtnct00WS6
I actually have a mid 230's cam, a fast 90/90 and 11.2:1 SCR. I just haven't updated my signature

But still...I wouldn't think it would be 91% either
I see. Still, I wonder if maybe the injectors need to be flushed/cleaned? Is there anything in the tune that will allow more fuel at a lower duty cycle?? Pulse width maybe?? I just can't imagine a heads and 230's cam 346 needs that much fuel......
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Old Dec 19, 2007 | 08:39 PM
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Measure the fuel pressure. Maybe your filter is clogged or your pump isn't putting out. SVO 30s should have more head room than that.
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Old Dec 20, 2007 | 10:40 AM
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Originally Posted by Ragtop 99
Measure the fuel pressure. Maybe your filter is clogged or your pump isn't putting out. SVO 30s should have more head room than that.
Thanks...Will do. I can just hook the gauge onto the factory fuel rail right?
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Old Dec 20, 2007 | 12:10 PM
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AFR will also affect your duty cycle, leaner AFRs will reduce the DC, while richer AFRs will increase the DC. So if you are at 91% DC, but are at 12.5, then that is more understandable.
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Old Dec 20, 2007 | 11:26 PM
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Originally Posted by 12secSS
AFR will also affect your duty cycle, leaner AFRs will reduce the DC, while richer AFRs will increase the DC. So if you are at 91% DC, but are at 12.5, then that is more understandable.
That's actually about right where I'm at. What AFR should I be shooting for at WOT and peak torque?
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