Whats the latest on the SVO 42# Injectors
Whats the latest on the SVO 42# Injectors Searched most of this site and it seems that there is still some uncertainty if the injectors are rated at 39 or 43.5psi. Has anyone received a definitive answer?
Also, I've seen people plug in values for the IFR table ranging anywhere from 15x% to 193%... That’s a pretty large spread. Right now, I'm experimenting with a few different values 183, 175, and 170 so far. The thing is that the Lterms jump around so much its hard to determine if its really making much of a difference. Any tips on what fuel cells to watch and which to eliminate from observation for tuning purposes?
Thanks,
Also, I've seen people plug in values for the IFR table ranging anywhere from 15x% to 193%... That’s a pretty large spread. Right now, I'm experimenting with a few different values 183, 175, and 170 so far. The thing is that the Lterms jump around so much its hard to determine if its really making much of a difference. Any tips on what fuel cells to watch and which to eliminate from observation for tuning purposes?
Thanks,
TECH Resident
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Re: Whats the latest on the SVO 42# Injectors I don't know what % it is, but my ifr table is in the upper 4's, and around -8ish most of the time, idle is like -12 though. Just remember when you log map, you have to subtract the map value from 105 to get the right cell. Work-in-progress man, work-in-progress. 
Re: Whats the latest on the SVO 42# Injectors Upper 4's??? Wow, that seems low. I plugged in some values in the low fives at 0kpa and it seemed like it ran pretty rich. LTerms were in the -11 to -3 at idle, part-throttle and cruise. I changed back to stock *183 and it seems to be a little on the lean side, so I guess I'll drop it back down to 175% or so and give it some time to learn. If I can get 0 to -5% LTerms everywhere but deceleration, I'll be happy.
This sucks not feeling safe to go WOT yet
Anyone know if a bad BOV could cause problems with large fluctuations in LTerms and occasional surging at around 2000 rpms? Its a Bosch unit and I swear I can never hear the thing releasing.
This sucks not feeling safe to go WOT yet
Anyone know if a bad BOV could cause problems with large fluctuations in LTerms and occasional surging at around 2000 rpms? Its a Bosch unit and I swear I can never hear the thing releasing.
Re: Whats the latest on the SVO 42# Injectors i really dont see where it matters as long as you arent over -25% and get 0 at wide open.
i have a referenced regulator and have my ifr at 5.51 all the way across.. no problems..
if you have your stock regulator in, just start with the stock ifr table and lean it out until you can get 0's consistently at wot and thats it.
i have a referenced regulator and have my ifr at 5.51 all the way across.. no problems..
if you have your stock regulator in, just start with the stock ifr table and lean it out until you can get 0's consistently at wot and thats it.
Re: Whats the latest on the SVO 42# Injectors I always thought you were to shoot for a couple degrees negative, with O% at WOT and then tune the PE vs RPM for WOT.
If it doesnt really matter as long as you dont go over -25, then these things will not be hard to tune at all... not counting surging and idle stability when soming off the throttle. I havent started to play with that yet.
If it doesnt matter so long as you dont exceed -25, then I'm assuming:
1. Part-throttle fuel economy/performance will not matter if LTerms are -20 or -2, as the PCM will adjust the fuel to obtain the same results.
2. The Tune with the lower negative Lterms(-20) will result in a richer condition at WOT than the tune with the higher negative Lterms(-2), and will require a larger adjustement in PE vs RPM to lean the AFR out, provided that both are richer than the desired AFR.
3. Once PE vs RPM is dialed in to the obtain the same AFR for both tunes, WOT performance for both will be the same, regardless of how much adjustment the PCM needs to do at part-throttle based on differing IFR values.
Did I get it right?
If it doesnt really matter as long as you dont go over -25, then these things will not be hard to tune at all... not counting surging and idle stability when soming off the throttle. I havent started to play with that yet.
If it doesnt matter so long as you dont exceed -25, then I'm assuming:
1. Part-throttle fuel economy/performance will not matter if LTerms are -20 or -2, as the PCM will adjust the fuel to obtain the same results.
2. The Tune with the lower negative Lterms(-20) will result in a richer condition at WOT than the tune with the higher negative Lterms(-2), and will require a larger adjustement in PE vs RPM to lean the AFR out, provided that both are richer than the desired AFR.
3. Once PE vs RPM is dialed in to the obtain the same AFR for both tunes, WOT performance for both will be the same, regardless of how much adjustment the PCM needs to do at part-throttle based on differing IFR values.
Did I get it right?
Staging Lane
Joined: Jul 2002
Posts: 90
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From: Mechanicsville, VA
Re: Whats the latest on the SVO 42# Injectors Mike,
I'm dealing with the same stuff on my 02 Z06 and have a decent handle on things now. I recently swapped to the SV0 42# injectors as I had no luck with the MSD 50# injectors.I have my IFR's at 5.30 in the first cell and the L-trims are in the -3 to -11 range and the L-trims always go to 0 at WOT. Before with my 50lb injectors I could never get the L-trims negative no matter what I did with the IFR table. I never screwed with the MAF table though. I believe that your assumptions 1,2, and 3 are correct as far as I have determined with my tuning. I have an in car wideband for air/fuel ratio tuning so it has been much easier to get things right with my setup. The only thing has been to try to get the lower rpm's a little leaner as the upper rpm's are easy to adjust. My air/fuel always seems to be 10:1 or so at 2000rpm and leans to 12.8:1 or so at redline. If I change the PE vs RPM in the lower rpm cells it really doesn't change anything in this respect and I have no idea why. My Z06 has basically the same setup as yours with a D-1SC, a 4.10 pulley and 214/224 cam.
I'm dealing with the same stuff on my 02 Z06 and have a decent handle on things now. I recently swapped to the SV0 42# injectors as I had no luck with the MSD 50# injectors.I have my IFR's at 5.30 in the first cell and the L-trims are in the -3 to -11 range and the L-trims always go to 0 at WOT. Before with my 50lb injectors I could never get the L-trims negative no matter what I did with the IFR table. I never screwed with the MAF table though. I believe that your assumptions 1,2, and 3 are correct as far as I have determined with my tuning. I have an in car wideband for air/fuel ratio tuning so it has been much easier to get things right with my setup. The only thing has been to try to get the lower rpm's a little leaner as the upper rpm's are easy to adjust. My air/fuel always seems to be 10:1 or so at 2000rpm and leans to 12.8:1 or so at redline. If I change the PE vs RPM in the lower rpm cells it really doesn't change anything in this respect and I have no idea why. My Z06 has basically the same setup as yours with a D-1SC, a 4.10 pulley and 214/224 cam.
Re: Whats the latest on the SVO 42# Injectors mike, to #1, the -20 and -2 numbers ARE the pcm adjusting back to perfect fueling... so correct no mileage driveability problems
to #2 when they go to zero that means that it will NOT affect power enrichment tuning. any other number and yes it does... thats why we want 0
to #2 when they go to zero that means that it will NOT affect power enrichment tuning. any other number and yes it does... thats why we want 0
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Re: Whats the latest on the SVO 42# Injectors Ok. I understand that with negative LTerms the PCM will add nothing at WOT.
What I'm getting at, and I'll use 01Tahoe's ZO6 as an example. Lets assume that his tuning is as follows:
IFR~ scaled flat percentage with 5.30 in the first block.
PE v. RPM~ Stock Settings
With those settings, he is seeing 10:1 at 2000rpms and 12.8:1 at 6000rpms. As he stated he is having trouble leaning it out in the lower rpms.
Here is the question. If he reflashes the PCM with a higher percentage in the IFR tables, say 5.70, and is still able to obtain 0 LTerms at WOT, would his AFR at WOT be leaner than had the IFR table been scaled at a lower percentage?
I may be way off, but I think it would be. At WOT the PCM uses the PE values to richen the AFR up. These tables are a modifier, not the base. I'm assuming that the base table would be the IFR values, and that if these tables are raised to a numerically higher number(leaner), then the resulting AFR after PE values are taken into account should also be leaner as the base table has also been leaned out.
I would think that by obtaining an IFR scaling factor closest to 0 LTerms, while maintaining 0 LTerms at WOT, it would make tuning at WOT easier... if it really is difficult raising AFR in the lower RPM area. I dont know, as I have not put this thing on a wideband yet to play with the PE table.
What do you think?
What I'm getting at, and I'll use 01Tahoe's ZO6 as an example. Lets assume that his tuning is as follows:
IFR~ scaled flat percentage with 5.30 in the first block.
PE v. RPM~ Stock Settings
With those settings, he is seeing 10:1 at 2000rpms and 12.8:1 at 6000rpms. As he stated he is having trouble leaning it out in the lower rpms.
Here is the question. If he reflashes the PCM with a higher percentage in the IFR tables, say 5.70, and is still able to obtain 0 LTerms at WOT, would his AFR at WOT be leaner than had the IFR table been scaled at a lower percentage?
I may be way off, but I think it would be. At WOT the PCM uses the PE values to richen the AFR up. These tables are a modifier, not the base. I'm assuming that the base table would be the IFR values, and that if these tables are raised to a numerically higher number(leaner), then the resulting AFR after PE values are taken into account should also be leaner as the base table has also been leaned out.
I would think that by obtaining an IFR scaling factor closest to 0 LTerms, while maintaining 0 LTerms at WOT, it would make tuning at WOT easier... if it really is difficult raising AFR in the lower RPM area. I dont know, as I have not put this thing on a wideband yet to play with the PE table.
What do you think?
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Verdad Gallardo Staging Lane
Joined: Jul 2002
Posts: 90
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From: Mechanicsville, VA
Re: Whats the latest on the SVO 42# Injectors Mike,
That is exactly what I was thinking would be a good thing to try. I may put a higher value in the first cell by multiplying the entire table by another 2-3% and see what happens. I haven't had time to mess with it the last few days but the l-trims are still in the negative range after a few days of driving. Your theory seems to have merit and I think that would help my low rpm rich condition with the higher IFR value in the first cell. Then, as you said the PE vs RPM would be easier to "dial in". Hopefully I'll get a chance at the track in the next couple weeks to test this theory. BTW, the car feels much stronger with the 42# injectors than it ever did with the 50#'s. I really didn't say anything new here just agreeing with what you have said.
That is exactly what I was thinking would be a good thing to try. I may put a higher value in the first cell by multiplying the entire table by another 2-3% and see what happens. I haven't had time to mess with it the last few days but the l-trims are still in the negative range after a few days of driving. Your theory seems to have merit and I think that would help my low rpm rich condition with the higher IFR value in the first cell. Then, as you said the PE vs RPM would be easier to "dial in". Hopefully I'll get a chance at the track in the next couple weeks to test this theory. BTW, the car feels much stronger with the 42# injectors than it ever did with the 50#'s. I really didn't say anything new here just agreeing with what you have said.
Re: Whats the latest on the SVO 42# Injectors
Your theory seems to have merit...
I dont want to see anyone break anything, because of something I posted.