High timing for WOT?

[Tarantula]

I have been tuning my car with the SAFC II. The turbo I have is an EVO III 16G and its set at 14psi. I have stock injectors and stock fuel pump with rewire. I have been playing with the settings and the most recent logs has showed 20 degrees by redline. heres one of the logs.
RPM Timing
4392 17
4664 9
4972 11
5280 13
5540 15
5844 16
6084 17
6344 19
6572 19
6808 20
7020 20

I want to know if 20 is too high for a 2G. I have heard that optimum timing would be 15-18 by redline. To get that curve on stock stuff I set the SAFC II at the following
3200 4000 5000 5400 6000 6400 7000
-2 -1 -1 0 +2 +2 +2

I have the Walbro 190 on the way to make that +2 go down (I don't think my injectors are happy at +2) . I want to know if Its safe to turn up the boost to 15-16psi to bring that timing down or if thats good to have timing soo high. I don't have an EGT guage so I feel rich O2's is safe. (Hence why I got the settings on the rich side. I have gone from -7 across to what I have now. That log was the best timing curve I have ever gotten. I did 3 logs and all were at 20 degrees by redline with these settings.

 

[Tarantula]

By the way this was a third gear pull running Pump 91 octane. Air temps were 70 F and coolant was 196-199F (Have the Intercooler project with filter shield. Cold air with SMIC project I designed)

 

[HighPSI TSi Guy]

that's a good timing curve... means your car is running pretty damned good!

 

[Tarantula]

Thank you... I guess that means its probably ok to have high timing. Now I know that turning up the boost won't do me any good because as I have it right now, my SAFC II settings have to be in the positive, which I figured is an indication that my fuel pump and injectors (All stock) cannot keep up. Next mod is injectors. (Hahn 625 or 660's)I was asking this because normally getting bigger injectors means a better timing map because ECU would see less airflow, but in my case right now, I didn't want higher timing than what I see now with the stock stuff. So it made me confused a bit. And the fact that I got this with pump gas was a big shock as well.

 

[jmakado]

the "curve" itself looks good. IMO 18* at redline is optimum on pump 91. you are correct in knowing that going too high is not good as it moves you into a "cruising" map on the ecu. once you get the fuel pump i bet you will be able to turn the boost up to around 16psi and even higher with the new injectors. but it looks like you have a pretty good grasp of what you're doing so i am sure you will figure it out. on race gas, higher timing at redline is good as the higher octaine has a slower burn time. once you have good timing curves go hit the dyno and start at the boost you have been running. then turn it up about 1 psi or so until you lose power (knocking). your car may make more power at 16*@redline or at 21*@redline or anywhere in between....the only way to know for sure is to hit the dyno. the stock ecu/fpr should adjust for the higher boost on it's own so you shouldn't have to change the afc settings much if at all. but all in all, looks pretty damn sweet!!

 

[Blk_99gst]

You say injectors are your next mod, but I hope you meant the fuel pump is going in first (you mentioned the fuel pump in the first post). I would still recommend 660's for a 2g car. They should give you better timing advance then say 550's.

Even though you see 20deg advance now, that could change with more boost, warm air temps, fuel pump. You're on a good track with 20deg advance; at least you aren't getting timing pulled. Keep up the good work.

 

[jmakado]

Thank you... I guess that means its probably ok to have high timing. Now I know that turning up the boost won't do me any good because as I have it right now, my SAFC II settings have to be in the positive, which I figured is an indication that my fuel pump and injectors (All stock) cannot keep up. Next mod is injectors. (Hahn 625 or 660's)I was asking this because normally getting bigger injectors means a better timing map because ECU would see less airflow, but in my case right now, I didn't want higher timing than what I see now with the stock stuff. So it made me confused a bit. And the fact that I got this with pump gas was a big shock as well.

some other thoughts: when you get the larger injectors and pump you will have to take A LOT out of the afc......like around 35-40% or more! just keep turning the boost up and adjusting the afc until you get smooth timing and not absurd advance. that turbo won't really start blowing until you get around 20psi, just so you have an idea of where you want to start.
people have seen as high as 44lb/min (20g power) out of the evo III....but around 40lb/min (18gish) seems to be the norm. so when you are tuning, think of your turbo as an 18g or 20g and not a 16g. just so you know, i have a small 16g and would think of upgrading to an evo 16g over a 20g anyday.....it's like 16g spoolup with 18g top end. can't beat that

 

[Tarantula]

Thanks guys for your responses.
BLK 99GST The first MOD is the pump. I have it on order and should be getting it next week. I want to tune the car first with the 190lph pump than I will get the injectors. The injectors are my next mod but it will be awhile.

Jmakado, I have heard that about timing and you confirmed my doubts. Now the only thing is how to get 18 by redline without going over or getting Flat spots during the rise in RPM's. I have gotten 16-17 degrees but only if I hit a flatline (Not a dip) which seems to be popular from 4000 to 5000 rpms. Its always dips to 9-10 at start of boost, than rises, hits a flat line starting around 4000 stays there until 5000 than rises aggresively. I didn't want that flat line there so I richened 4000-5000 ONE notch towards the positive (In which case it was -2 and I changed it to -1) And I have logged airflow as well (Always do ) and the highest on 14psi was 28lbs/min. so anywhere from 27.8 to 28.2 lbs/min and that the corrected value, not the value that the logger showed. (Because I am at +2 so the ECU sees more airflow) My highest Karman value can be anywhere from 1550 to 1570Hz at this MBC setting of 14psi.

And I figured I'd share one thing that has helped me while tuning. I have created a chart/table type to write my WOT pull details and corrections. I keep a file of these with changes so that I can actually see the differences in my changes with each pull. I put current SAFC II values on the top boxes. These are the values I used for the WOT pull Details below it. After the pull I write all the details in the WOT Pull Detail area. I look at the run at each rpm point logged and decide what NE point I want to change from what I see in the deatils. Than I write that correction in the second set of boxes under CORRECTIONS. When I am ready for my nect pull, I put in the new figures into the SAFC II and start all over. And as for the O2 output, I don't tune with those values. I generally ignore them. But as you can see its still in my Table. Well I use it as reference to let me know that the engine is never running lean. (Below .94V) Since its not accurate like a Wideband. As long as my engine is getting fuel above .94V I know I am in no danger of blowing the engine.

 

[jmakado]

Thanks guys for your responses.
Jmakado, I have heard that about timing and you confirmed my doubts. Now the only thing is how to get 18 by redline without going over or getting Flat spots during the rise in RPM's. I have gotten 16-17 degrees but only if I hit a flatline (Not a dip) which seems to be popular from 4000 to 5000 rpms. Its always dips to 9-10 at start of boost, than rises, hits a flat line starting around 4000 stays there until 5000 than rises aggresively. I didn't want that flat line there so I richened 4000-5000 ONE notch towards the positive (In which case it was -2 and I changed it to -1) And I have logged airflow as well (Always do ) and the highest on 14psi was 28lbs/min. so anywhere from 27.8 to 28.2 lbs/min and that the corrected value, not the value that the logger showed. (Because I am at +2 so the ECU sees more airflow) My highest Karman value can be anywhere from 1550 to 1570Hz at this MBC setting of 14psi.

do you by any chance have your mas hacked or backed the screw out at all? i have been fighting a sudden lean condition at around 4200-4500rpms which results in timing being pulled and mass fuel being dumped from 4600-5200rpms. check out this link:http://www.rmdsm.org/forums/showthread.php?s=&threadid=3254&perpage=15&pagenumber=1
look about halfway down and you'll see my dyno chart with race gas. look at the A/F graph and you'll see what i'm talking about. after much searching, i found that hacking the mass can cause this sudden lean condition. i then put 2+2 together and figured that i am having the same problem by backing the screw out. i won't be able to test the theory until early july though. as far as getting *exactly* 18*, i wouldn't worry much about it until you can get to a dyno. the numbers you posted earlier look almost perfect for now. once you put the pump in you will be able to start working the turbo and then you're in for some real tuning fun!!
by the way, i think that chart is kick ass!! mind if i steal your idea to make my tuning easier?

 

[Tarantula]

By all means steal away!!!!! I posted it for anyone who wanted it. I felt it helped me alot and might help others. Now with my setup.... I have an untouched Mas. I don't like the idea of messing with that, nor taking out honey combs. Its exactly as it came from the factory. (I've had the car since it was 38,000 miles old with everything original, now is at 122,500 miles)
With my table and all the runs I have done I have found that theres 2 areas where I would lose timing or get flat spots. It is the area between 4000 to 5000 rpms (Can go as high as 5300rpms) and 6000 to 6600 rpms. I figured that the area of 6000 rpms is where right where my torque peak is. That was one explanation and the second explanation (Which I figured when I added more fuel) is that my pump was not supplying. Now with the 4000-5000 flat lines, I don't know why it always happen. I just added fuel and that solved it.
All my other runs I have always fought with those 2 areas. Maybe its the design. Maybe 2G's run that way. So for me it was always WOT at around 3100, timing dips to 9 than starts rising to about 4100 than timing stays still. Rpms still rising (Timing still flatline) and timing starts going up again when I pass 5000 rpms. Rpms still rising along with timing once again till I hit 6050 rpms where timing would either dip or flatline than one or two more degree rise after 6500 to redline (7000-7100)

 

[FASTFWD]

i used to run the evo III 16g turbo.. at the top of 3rd at 7500 rpms, the highest timing degree reached, averaged 23.. the most i hit was 24.. this was at 20 lbs of boost, in the hot and humid south florida weather.. also, the inital dip (lowest timing) was 9 degrees upon the start of the 3rd gear pull (starting out from a steady 3k rpms).. w/ this turbo, on the dyno, it put down 307.6 whp..

in any case, i was doing some street tuning w/ the logger on the new 50 trim set up.. i currently have the turbo running 15.5-16 lbs of boost.. w/ tonight's current tune (still running somewhat rich), at the top of 3rd (between 7000-7300 rpms), i hit 26.5 degrees.. i was shocked to see that value, especially on a 2g... timing curve was excellent.. lowest inital dip was 14 degrees..

 

[Blk_99gst]

I have many things to say, I hope I don't forget them all. First:

Tarantula - It's good to see that you're being very diligent about tuning and keeping track of things. But go overboard and say that you must acheive 18deg's timing advance, any less is bad and any more is bad. That's not the case. I think 20deg advance is still O.K (I'll talk about this more in a minute). Also, I would recommend not logging air flow. From your first log, you go quite a long time between samples which isn't good. Logging air flow really doesn't help you at all, and it's "corrected" airflow that the ecu is seeing. You can't compare it between log runs because as you change safc values, you're chaning how much air flow the ecu is seeing. So I would say don't log that, so that you can get more samples of timing, which really matters. Also, there is nothing wrong with timing to be flat for a while, as long as it doesn't dip. And I don't know how much I would try to tune on stock injectors. I would say get the 660's as soon as your wallet will let you, throw those bad boys in, and then really start to tune. That's when it gets fun and interesting. Tuning 450's is good practice, but you really aren't changing much. I commend you for not hacking your maf; just leave that guy alone, or get a gm maft!

Now about the whole timing advance getting into a "crusing" map statements. I don't know, I just don't buy it. For one, the ecu's crusing maps are for closed loop mode, which is below 4000 rpm and below like 30% throttle. During times like this, the o2's are cycling and you get reallyhigh timing; like 30degs or something. When calculating what fuel map to use, the ecu takes a LOT of variables into account. Airflow, rpm, throttle position, coolant temps. So if you're doing a 3rd gear pull, the ecu is going to see 100%tps, high rpm's (above 4000), it's going to be in open loop mode, and it's going to be very big air flow compared to cruise. The ecu is going to do it's thing; it will drop timing down to about 9degs, and then it's will conservatively(sp) start advancing it as long as no knock occurs. It will use it's "high" maps all the way through the run. It's not going to get up to 6000rpm and then say, "oh I think I'll use a crusing map at this high of rpm, this high of airflow, and 100% throttle". No way, I don't buy it. I'm not arguing with you jmakado, but from all I've read over the years, I have never heard of the ecu using crusing maps at the top of wot runs. If you could come up with some other threads about this, I would be more than interested to read them. If you have high timing at the top of a run (20-23degs), all that says to me is that you have plenty of room to run more boost. Running more boost, then the ecu will max timing out at a lower number.

 

[jmakado]

http://www.dsmtalk.com/forums/showthread.php?s=&threadid=115192&highlight=timing+optimum+fuel
this is just the first one that i found. it deals more with the damage that can be done with too much timing. it also *dips* into super high timing (above 30*) moving into "other fuel maps". others can be found where more info is given on fuel map switch over points....i'll see if i can find them. vern (VAN), also sent me an e-mail about what some of the "big guys" see with timing on the top end. i don't want to copy and paste it with out his permission so you'll just have to take my word that he REALLY sent it to me it basically says that some of them only see 15* peak timing. now this is all second hand.....but second hand from people that know much more than me (not sure on your dsm knowledge so i won't comment on that) and maybe you?
i have no hard proof on switching maps as i'm sure that most don't on either side of the debate. however, their is a reason that too much timing makes less power with piggyback management systems and more power on stand alone types. using my own (sometimes wrong) logic, that tells me that the ecu is changing something (fuel maps IMO) when it gets a low (fake) airflow signal (piggyback) and not changing the fuel maps when it gets the real signal and the timing is just *added* in after the fact as it is with a standalone (aem) or emmbeded (dsmlink) system.

 

[Tarantula]

Now that was some good info! (Thanks for the link Jmakado) Reading that made me realize that I'm going to increase boost by 1 to 15psi and leave my SAFC II settings alone and see what happens. This should lower my timing at redline.
With regards to airflow logging, I log it out of curiousity. I'll omit that parameter like you advised (Blk 99GST) to get more samples of timing. The highest sample rate I get is 10. Any higher and I'll get errors.