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Forum nameEngine Management Systems & Controllers
Topic subjectDyno success
Topic URLhttp://forums.2gnt.com/dcboard.php?az=show_topic&forum=54&topic_id=958
958, Dyno success
Posted by ner947, Dec-31-69 06:00 PM


Is what I was able to get. 012 is what I started with, and 015 is what I ended up with after a few runs to tune the spark table. I only tweaked it by +3 or +4 degrees here and there, I concentrated on the top end and in the "spool-up" area mostly.

The runs were made with only spark being changed. I did not touch the VE table or the boost controller at all between 015 and 012. The boost pressure was about 15 PSI at peak torque, then it slowly goes down to around 13 by redline. The MS is able to hit the AFR targets very well, the AFR is about 11.5:1 at peak torque and slowly goes to 12.0:1 by redline. I am using a set 415 cc/min fuel injectors which are pretty much maxed out. My duty cycles are around 83-85%, I could probably increace the static fuel pressure which would allow me to increace the boost pressure a bit, but I don't think it's really worth it. It's probably time to put the 780's in.

The thing I like the most about these stock cams is that torque peaks right around 3500-4000 RPM's, which is about 70-80 MPH in 5th gear. Heh, I never have to downshift, just put your foot down and bam, 273 foot pounds at the wheels.

006 is an old run that I made with my Crower 3's and the 8 injector setup with similar boost pressure. Those cams suck with a turbo. Just thought I'd throw that graph in there.

Here is my spark and VE tables that I used.



959, RE: Dyno success
Posted by dougie2, Dec-31-69 06:00 PM
Why do your VE numbers at idle and low load look very high to me?
960, RE: Dyno success
Posted by ner947, Dec-31-69 06:00 PM
I don't know. Idle AFR is around 12.5:1. Low load is around 14.0-14.7:1. I noticed that thay are kind of high too but that's what seems to make the car run best.
961, RE: Dyno success
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Very nice nate. The high numbers have been discussed on MSefi and many others have the same including lance.

Terry
962, RE: Dyno success
Posted by dougie2, Dec-31-69 06:00 PM
Originally posted by ner947
I don't know. Idle AFR is around 12.5:1. Low load is around 14.0-14.7:1. I noticed that thay are kind of high too but that's what seems to make the car run best.


That's a little rich for an idle AFR. Engines like to run rich at idle, but you should be able to lean it out a little (like 13.5:1 AFR). Also, are you seeing a lot of EGO Correction at idle? Are you using Target AFR at idle? I'm thinking that it may be pulling back a lot from the VE table. Either that, or your injectors really do make that much of a difference in the way the VE table needs tuned.

BTW- great job on the VE table... the curves and transitions are feathered very well. Looks like you started from the MrSlick MSQ and tuned the hell out of it.


Originally posted by Star Turbo Talon
Very nice nate. The high numbers have been discussed on MSefi and many others have the same including lance. Terry


Terry, that discussion at MSEFI was regarding Chevy small block engines. The idle VE of a 2.0L 4 banger is going to be very different. I'm not saying that there's anything wrong with using the high VE numbers... it's just that I haven't known of any other 420A VE table using such high VE values at idle and still not be too rich to start the engine. The rest of Nate's VE table is very similar to mine, but my idle VE values are closer to 22-25 percent using Delphi 780cc injectors. I did notice that I was able to increase my idle VE values to almost 30 percent when I installed a set of Denso/Greddy 720cc injectors.

...Which brings me to my next point.... these damn Delphi injectors I've been experimenting with seem to be way off. I've noticed that I can nail a stable injector pulsewidth at idle when using stock 235cc, DSM 450cc, and Denso 780cc injectors, but the Delphi injectors seem to walk all over the place. The stock, DSM, and Denso injectors are also very smooth under load, and the Delphi injectors result in a very eratic AFR. I really don't like the Delphi injectors and I've also noticed there are a lot of bad reviews of them over at DSMtuners.com as well. The 4G63 guys are having to adjust their dead-time setting a lot to get them working decent and then they're still getting unexplained knock. I have a set of Accel 72 lb.(756cc) injectors on the way and I'm willing to bet they'll work better than anything I've tested thus far. And the nice thing about them (and the primary reason I'm going to use them) is that they are the standard Bosch style injector... which means they have the exact same dimensions as our stock injectors and will have an OEM fit using the stock o-rings. Accel also uses a pintel design with a wide conical spray pattern.
963, RE: Dyno success
Posted by XtremeRS, Dec-31-69 06:00 PM
Good work Nate! Glad to see a MS dyno run!

Doug, in your injector testing, did you notice the idle A/F get richer as the car was driven? Thats my issue really with the idle..
965, RE: Dyno success
Posted by dougie2, Dec-31-69 06:00 PM
Originally posted by XtremeRS
Doug, in your injector testing, did you notice the idle A/F get richer as the car was driven? Thats my issue really with the idle..


Only with the Delphi injectors. I really don't know what the deal is. Maybe the injector open time and voltage correction need tweaked significantly. I don't know, I'm done with them.
964, RE: Dyno success
Posted by ner947, Dec-31-69 06:00 PM
Originally posted by dougie2
BTW- great job on the VE table... the curves and transitions are feathered very well. Looks like you started from the MrSlick MSQ and tuned the hell out of it.


Yep, that's what I did. For the spark table, however, I started from scratch and really had to play around with it. I probably should acquire some type of knock detection system, for I have no way of monitoring knock right now other than my ears. The knock system in the newer extra code is pretty neat, I'd like to play around with it.
966, RE: Dyno success
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Dont the 4g guys have a hard time with the Delphi injectors Doug? I could be thinking of a diffent injector though. I would expect the larger the injector the more difficult to tune idle, .1 PW in either direction is a greater change obviously.

My 550's stay pretty much 13.9-14.6, they may move a bit morewhen sitting at a light but thats because i have to adjust my 46kpa bins at idle.

In regards to your getting richer Matt (this i have wanted to discuss with you just havent had a chance) I ahve noticed with mine that once it has been driven to a period of time i have a rich condition. Its in the VE table. I noticed that our cars may idle at 37kpa but after being driven may idle at 41kpa.

When i pull to a light and stop my rich condition is also at a higher KPA value. my 46kps bins are a tad high. I have been slowly dropping them down and improving. here are my lower 9 bins:

38 39 41
34 33 31
31 31 31

they were

42 41 42
34 33 31
31 31 31

This has helped me, look at yours and see where your at. I also noticed it seems a bit easier to work with the KPA values like this:

46
38 <~~~~~~1-2 above where I idle
20
600 900 1100

Terry
968, RE: Dyno success
Posted by XtremeRS, Dec-31-69 06:00 PM
Well I have the bins from 20 kpa to 50 kpa, and from 600 rpm to 1200 rpm, all at the same VE percentage...so it can't be that. I'm really thinking it's the Delphi's, since Doug's findings have sort of proved it. I'm more thinking that the injector's electrical characteristics, and how the pintle is actually injecting fuel, is changing with the heating of the injector coil. They do seem to like more PWM though, as I can get it to lean out at idle by lowering the PWM threshold time(which gives less full open current, and more PWM current). I wish I had the money to get different injectors :(
970, RE: Dyno success
Posted by XtremeRS, Dec-31-69 06:00 PM
Hey Doug, where did you get your Accel injectors from? I'm also thinking of using some injector resistors with my Delphi's, so that I won't have to run any PWM at all..Maybe these injectors just don't like that type of software current limiting control..
971, RE: Dyno success
Posted by dougie2, Dec-31-69 06:00 PM
Holy shit... these Accel 72 lb. injectors are awesome! The engine idles smoother/consistant and my AFR is more consistant throughout the entire range... the engine is much more responsive too (didn't expect that from an injector swap!). I just can't describe how much better these injectors are from every other injector I've tested. Every aspect is better. And the cool thing is, they fit like stock, because they have the same stock dimensions, and come with o-rings! (sorry if I sound "giddy", but I'm really excited about the results I'm getting from these injectors!)

I got them from SummitRacing.com, they were about $89/ea. Unlike the 625cc and lower injectors from Accel, these are actually re-packaged Siemens Deka injectors. If you don't know, they make about the best injector around and they normally retail at over $500 for a set of 4.

Here's some pics I took when they arrived yesterday:









Recessed pintle & precision machining to create a nice conical spray pattern:


972, RE: Dyno success
Posted by Star Turbo Talon, Dec-31-69 06:00 PM
Yeah those are the make i have and they seem fine. I havent really had to work with a bad injector though so i cant compare them. Nice to see your happy with them.

Matt had a good point, have you tried using a resistor pack and running them with 100% PWM doug?
973, RE: Dyno success
Posted by XtremeRS, Dec-31-69 06:00 PM
Doug, what can you get your idle A/F ratio to with those injects? What is your idle PW? What PWM and constants settings are you using? If I can scrape the money together, I may have to pick these up :)
992, RE: Dyno success
Posted by Brandon005, Dec-31-69 06:00 PM
LOL I really wish i knew what you guys are talking about all the MS this and AFR lol guess I'm more into minitrucks I will learn one day
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