Do 650's and higher injectors always idle like crap at start up?

[Rice Over Wheat]

I think this is why the tech at FP recommended that I stick with 550s on the SAFC. He said my setup would run smoother as a daily driver that way. But I went with 650s anyway. As of now, idle is always rough for the first minute after starting the car when it's been sitting for a few hours. I have to give it a few extra 100 rpms until it gets settled. It's not a huge pain or anything because the car is running great otherwise, but it's kind of annoying for my impatient ass. What gives? It's like it needs time to get some fuel up in there or something.

 

[Eclipsethis90]

I run a MAFT Translator, SAFC II, and 670's. It idles just fine for me. Now mind you it took some time to tune it and let the ecu relearn after I reset it.

 

[eclipsegst3131]

780's, safc2, keydiver chip. perfect

 

[spyderturbo007]

650's & a SAFC-II with no problems.

You problem sounds like it could be with your settings, or a mechanical problem. Post up your SAFC settings and maybe we can help you out.

 

[silvah_gsx]

AFC can't properly compensate for the deadtime of a 650. Even if your corrections are perfect, it'll still run like crap because they're firing way too late.

$250 for a socketed EPROM @ ffwdconnection
$125 for Stage 3 chip @ dsmchips to deal with deadtime

 

[spyderturbo007]

Even if your corrections are perfect, it'll still run like crap because they're firing way too late.

So I guess you are calling me a liar? I know for a fact, that myself and CanadianTsi both run 650's and have no problem.

 

[Quasimondo]

650's is about the limit of what a SAFC can run without running into timing issues from having to lean them out excessively.

I want to see the SAFC settings and I'm curious to know what the LTFT's are as well.

 

[CanadianTSi]

My 650's Idle like stock with only an S-AFC to control them.

Use your logger and get your STFT to 0 (+/- 2%) and your car will be fine.

 

[pneumo]

There's an easier way to adjust the idle. The next time you start you car adjust the 1k rpm/ lo throttle point up and down until you find the setting that has the smoothest idle.

 

[Rice Over Wheat]

I'm currently untuned, -25% across the board HI/LO. Friday I go in to a shop to have my car tuned to 11:1 on the dyno. Since I am just now starting to learn about tuning, I wanted to start from a good tune and play from there (that way I can always put the settings back, ).

I guess being untuned is my problem then. Phew, I was worried about my fuel pump for a bit there...

There's an easier way to adjust the idle. The next time you start you car adjust the 1k rpm/ lo throttle point up and down until you find the setting that has the smoothest idle.

Hm...doing that would seem to require lowering the LO throttle point from 30% down to 5% or something. I thought that parameter was only for the AFC to change which settings table to use for correction depending on throttle opening. At idle my throttle is 0%, 40 karman, 600 rpms.

 

[CanadianTSi]

In my experience with 2G's, generally on the low throttle setting you don't need to take out very much air down low.

My low settings for my 650's are -8 at 800 and 1400rpm's.

So trying giving it some more fuel, you've probably taken out to much and your past the range that the car can adjust for.

 

[pneumo]

Hm...doing that would seem to require lowering the LO throttle point from 30% down to 5% or something. I thought that parameter was only for the AFC to change which settings table to use for correction depending on throttle opening. At idle my throttle is 0%, 40 karman, 600 rpms.

Leave the lo throttle point at 30%. The way the throttle points work is that anytime TPS is below the lo thr point you'll be on the lo thr map. Anytime you're above the hi thro point puts you on the hi thr map. Anytime TPS is between the lo and hi thr points, the SAFC extrapolates, between the two maps.

Like I said, just put the safc on the 1k lo map and adjust the fuel % correction up and down until it's smooth. BTW for 680 injectors you should start with -30%.

 

[Rice Over Wheat]

In my experience with 2G's, generally on the low throttle setting you don't need to take out very much air down low.

My low settings for my 650's are -8 at 800 and 1400rpm's.

So trying giving it some more fuel, you've probably taken out to much and your past the range that the car can adjust for.

I should be running quite rich. -30.77 is the stock-like baseline for 650s. I'm at -25 right now until Friday's tune. That's roughly 23% richer than when I was on the 450s, all other factors being the same.

I'm only at 17psi off my actuator as my mbc is disconnected until I tune on Friday. I'm guessing you're running 25+ lbs on your 50 trim? I'm looking for a safe 22-23 lbs when I tune. Trying to break 300 whp. Last dyno was 242 whp / 268 wtq @ 15 psi on stock smic and 450s.

Leave the lo throttle point at 30%. The way the throttle points work is that anytime TPS is below the lo thr point you'll be on the lo thr map. Anytime you're above the hi thro point puts you on the hi thr map. Anytime TPS is between the lo and hi thr points, the SAFC extrapolates, between the two maps.

Yeah, I misunderstood your previous post. I thought you were talking about something else.

 

[steve]

I should be running quite rich. -30.77 is the stock-like baseline for 650s. I'm at -25 right now until Friday's tune. That's roughly 23% richer than when I was on the 450s, all other factors being the same.

Your not accounting for the fact that those injectors take 300+ uS longer to open than the stock injectors. At idle where your IPW might be 1.7mS thats about 17% right off the top. The percentage changed as the IPW increases but you have to take this into account when tuning with an SAFC.

Steve

 

[Rice Over Wheat]

Oh yeah, I keep forgetting about that. That has to be part of why I'm idling rough on start up...it's almost like my car is waiting for fuel to squirt out, like a lawn sprinkler turning on. Once it gets going it's fine.

What does "uS" and "mS" stand for?

 

[Quasimondo]

Because of character limitations, the uS is really µS or micro seconds, .001 second.
mS is milli seconds, or .1 second.

 

[kronus]

I think uS is supposed to be Microseconds, because the symbol for the prefix micro- looks like a 'u' with a long tail. And I'm also assuming mS is milliseconds. But I could be wrong. Someone please correct me if I am.

 

[CanadianTSi]

Do you not have a Logger?

You can't dyno tune your low throttle settings...

And I run 24psi.

 

[Rice Over Wheat]

Thanks for the info on the greek symbols guys. That threw me off.

CanadianTSi, no I don't have a logger. That was the next thing I was going to buy. I'm so new at tuning that I really don't want to OJT it and risk making mistakes. I'd rather get a good tune by a pro at Central Florida Turbo, and then learn from there so I can always go back to safe settings.

What do you mean I can't tune LO settings on the dyno? I had Garry Marsh tune my car last year on a dyno, LO and HI.

My appt is for Friday and I have to confirm it tomorrow. I have two options here: I can get a pro to tune my car to get things running smooth, then buy a logger next month. Or I can cancel my appt and buy the logger, and probably run like shit for a long time until I learn for myself. I kind of think my first option is best since I can only choose one for now...just blew $3000 on all these upgrades and really need to chill things out until January when I get the 50 trim.

Btw...the tuner guy told me he can tune for any a/f ratio I want, 11:1 or 11.5:1. What's the advantage of the latter? Lean isn't it?

 

[CanadianTSi]

Well your Low throttle settings need to be tuned by watching your STFT on your datalogger.

I would try lowering your settings around 1000 rpms to -10 or -15 and see if it Idles any better.

 

[GPTourer]

Hmm, good info here. I was having some idle trouble with my Denso 660s and S-AFC2. Now that I have a DSMchip we'll see how things work out.

 

[Rice Over Wheat]

I decided to cancel my tune on Friday and get a datalogger from obdlogger.com since it is cheaper and I might as well start learning how to tune on my own. I'm not convinced these guys at the tuning shop will be able to watch counts of knock since they won't have a logger hooked up...most probably they will tune by O2 bung and experience. I don't have a wideband though so I hope the logger is enough to do some decent tuning until then.

Besides, I went from being DSM-retarded to installing my fmic, injectors, and every other mod lately myself and saved a lot of money while learning a ton. This site is invaluable, thanks everyone.

 

[Rice Over Wheat]

AFC can't properly compensate for the deadtime of a 650. Even if your corrections are perfect, it'll still run like crap because they're firing way too late.

$250 for a socketed EPROM @ ffwdconnection
$125 for Stage 3 chip @ dsmchips to deal with deadtime

I can't really justify $375 for that when DSMlink is only $200 more. Looks like a decent product though.

 

[larsrya8]

I can't really justify $375 for that when DSMlink is only $200 more. Looks like a decent product though.

Don't forget that DSMLink doesn't include an EPROM ECU. So add that $250 back in. I'd still go with DSMLink though.

 

[steve]

I'm not convinced these guys at the tuning shop will be able to watch counts of knock since they won't have a logger hooked up.

You won't either since your a 2G and don't get knock counts from the datalogger.

Steve