alright, finally in a place where i can start tuning and gaining some driveability & power. 4 things i'd like to take care of right now: 1. i'm leaning at 2000-2500rpm (verified by my buddy who is a professional diagnostic specialist and has all sorts of gismos) 2. i'd like to advance my timing some (currently, base timing on the dizzy is set to 10*) 3. bucking/backfire at low load, first gear (usually after a cold start) 4. injector timing -- do i need the cam specs to calculate this? for # 2: i've taken a look on your site, Grady, and have seen how you talk about the Spark Table--Base. i assume the #'s in the table are in degrees? how should i go about incriment the numbers--adding, say, 2 degrees to each one till i get to a certain #? should i do so in all three (low, middle, top) load rows and all across the columns? very informative tuning section, Grady--though, a lot for *me to digest (not savvy at all when it comes to this stuff).
For #4 you will need the cam specs, which should be on the cam card. Are you using EA? The other stuff I will stay out of, as I am not that knowledgable on the sn95 EEC's. (I am curious though...) Good Luck, and welcome to the Nightmare of Tuning... Er, I mean the Dream of Tuning. jason
thanks. i figured i would need the cam specs for optimal injector timing. i'll post those up asap. side note: what's EA?
Until you get the upgrade to the R/T model EA will be really pointless. You can download it for now though as the help files are still worth gold and work without a reg. code (at least the used to, I am several upgrades behind the newest version). 1. Leaning...what direction are you leaning too . Guessing one of the gizmos was a wideband...what was it reading? 2. If you are lean (like more than 13.2 WOT...then I would get that sorted out FIRST. Most N/A seem to target 12.8 and see best WOT perf. there. 3. With the stock maf and inj. keep the values as the stock gt tune. If your running a cobra base file, transfer the t4m0 breakpoint, slopes, and batt. offsets to the cobra base file. From what I have seen they kinda all need to be in the same format as running a cobra slope setup and t4m0 breakpoint or vise versa messed things up alittle. 4. Inj. timing really is far down the list as far as power and stuff goes. For the bucking also list all the changes you have made to the program so far...EVERY change or tweec make. For your #2 question, the numbers are the total timing the eec will be giving. there are a few diff. ways to skin that timing cat...one killing the MBT, boarderline tables and making the Alt. and base table match*. The other is to kill the MBT, boarderline, and Alt. table and ONLY use the base table. The changes you need to make would be in the top 2 or so rows (across) that are the high load area of the table (WOT = high load). * by match I mean, match the total timing you want to see in the top 2 rows (across) in both the alt. and base table.
hmm, wait a tick--i hadn't thought about running the cobra tune! i'm running a cobra engine, basically, with a different cam so maybe that would help out! guess i'll set it to the 4th unused setting and see what it's like. hang on... don't know if that would work... although the engine is a gt40p setup, my eec is still a t4m0... thoughts? by "leaning" i meant going lean on fuel from 2000-2500rpm. looking for a way to add a little more there. also, wanna see what can be done about the cold start bucking in 1st gear under light load (like when i'm taking off from my house in the mornings, usually, even after having warmed the car up). timing: is there a quick, simple way to raise the timing (like one single scalar i can change from 0 to 6 to add 6* to the base 10*)? i wanna make a couple passes at the strip this weekend and want to try a little higher timing other than 10* where i have it set now and using the tweecer to do it rather than twisting the dizzy.
Under tables "Spark_base_table" You'll see rpm and load, adjust it accordingly For the fuel, another table "fuel_table_stabilized_OL" You'll See rpm and load agian, adjust where u leaned out, adjust the AFR number lower, now since you dont have a wideband and have no way to see your actual AFR, i would normally suggest not to mess with this but since your adding fuel not taking away you may be able to get away with it, but you'll have no way of seeing the effects. Really you need a wideband and the R/T model to use the tweecer to self tune with good sucess. Also, read the tuning manual up top and read gradys site, it talks about all of this that I just listed.
Any of the cbaza family of eecs can run any other cbaza family program, you can run a gt tune, a cobra tune, or the only factory 351 tune with the cobra R tune. You will have to make the inj. stuff match the gt(t4m0) program to drive the 19's vs the 24's the cobra is setup with. The cobra computer basicly got rid of the bucking I had...dunno if it would help yours but it did mine. To change/add timing quick and easy like if you were wanting to turn the dizzy, its in the spark adder global or spark global (something like this) scalar. It adds that value across the WHOLE rpm range just like turning the dizzy. Not as precise as what you CAN do with the tweecer but if you want fast and easy that is the one your wanting.
thanks a lot for the replies, guys, exactly what i was looking for. i'll try the global spark adder for a quick fix for tomorrow night's passes, as well as the cobra comp tune w/ changes to the injector stuff. what do i do about the maf stuff, though? i know the cobra tune compensates the maf stuff with the tune itself, but if i have to change the injector stuff, shouldn't i have to change the maf stuff, too? tj: i've been to grady's site and he's got lots of useful info--unfortunately i'm not up to speed with understanding it all. hoping to get there one day, though, so i can help others out rather than bugging you guys all the time, hehehe.
The cobra maf and gt maf are the exact same part...I mean exact down to the part number. You may try running these thing from the t4m0 tune to the cobra j4j1. t4m0 breakpoint t4m0 slopes (high and low) t4m0 offsets t4m0 maftransfer, the gt maf has alittle more airflow IIRC (been awhile since I looked but one has more flow than the other despite them being the same meter). I would maybe make one with the j4j1 and one with the t4m0 and see what one works best for you.
yeah, i thought i read about the maf's being exactly the same between the cobra and gt. my question, though, is if i'm transfering t4m0 injector scalar stuff to the j4j1 injector scalar stuff, should i do so with the maf data, too, since the calibration for my t4m0 is for 19# injectors, whereas w/ the j4j1 the maf is calibrated for 24#ers (and i'm transfering 19# stuff to a tune w/ a maf calibrated for 24#)?
i wish our local track was open.... this new charger is itchin for a few passes. Edited: The MAF curve isnt calibrated for the injectors, its a totally different thing, the injector calibration is done in the computer with the injector high/low slopes. The curve is stricly the Airflow vs volts of the meter, nothing at all to do with injectors. Your thinking about those MAF's that you buy that are cal'ed for certain injectors, what they do is "Trick" the computer into thinking its getting different air amounts that it actually is thefore allow for the use of different injectors.
like said above it has nothing to do with inj. just value of air coming in. You may see an improvement with the transfer that flows alittle more...its free and worth a shot.
sweet, ok, thanks for clarifying that, gentlemen--i was, in fact, thinking about those mafs that trick the computer. gonna give the j4j1 tune (w/ t4m0 injector scalars) and a little more timing a shot and see if it'll work well. thanks!
ok, just loaded two j4j1 tunes (slightly modified to my needs as discussed above--19# injector stuff to both and 5* of spark added to one of them) and have two t4m0 tunes to compare to (one w/ 5* of spark added). don't have a chance to test them out tonight, but will let you fellas know how it goes. i took a look at the fuel tables but was too chicken to mess with it right now. i will, though, when i have more time and have done a bit more research.
You got several options available to you here Paul However, like Greg said, you can only go so far with out datalogging EA does a fine job of explaining things and gives you excellent methods for obtaining a stable Open Loop tune The main focus around all that Open Loop tuning is using dlogging for a baseline and EA can even make recommendations for some of your changes based upon those dlogs I would advise you to stay away from fuel stuff until you really know what is what with a wb. You can pick up a good bit of power with spark optimization and You can do that with your current non RT Unit with these two methods 1) Look at my site for info on how to kill the tip in retard 2) Work with the greatest load row (top row) in the base spark table just as Greg said above. You basically want it all in by 2500 and you will need to start with a conservative value for the total advance amount. I'd go no higher than 30 to start with and listen for ping then Creep up on the spark value 2 degrees at a time until ... ping occurs or you notice a power loss then Back down 2 degrees for a final value which will be based upon your particular combo's needs ... OR ... Custom Specifications You want to kinda feather the values for a smooth curve and you can look at my table for an idea of what I mean here IMHO ... You are now at OR beyond those tiny 19# inj's limit Remember ... You no longer work them at elevated pressure I'd be putting a plan in place to move up to 24's :Word: The j4j1 is a good plan but honestly ... moving a bunch of stuff over from the t4m0 is not all that beneficial if you ask me I mean ... You're just gonna change a lot of that stuff to what your particular combo likes anyway btw ... if you wanna try the j4j1 Don't forget to load in 19# offsets as they are VERY different from offsets for 24's Grady
thanks, grady =) an upgrade to the r/t is definately in the future, so is an upgrade to 24's, if not 30's. didn't forget to move the injector stuff from the t4m0 tune to the j4j1 one =). also added 5* global spark, but would like to do it the better way using the Spark Table--Base. how many degrees should i add to each, though? should i just add it on the top 2 or 3 rows so it'll only add under wot? and all the way to the end of the row from 2500 to 4000? stock cbaza setting: so lowering the first number in the a/f ration (the 14.7 in 14.7:1) adds more fuel? should i just lower it to, say, a conservative 1 unit in the highlighted columns in the top 3 rows since i can't really tell what my a/r ratio is? stock cbaza fuel table w/ where i lean out highlighted:
well you see how it says 12.128 in the first highlighted block, lower that number down to say 11.7 for now and it will richen that part up, you really need only be concerend about the top row as that is the WOT row, maybe the top 3 for part throttle blasts, but once you go so low it goes into closed loop. but agian you really have no idea whats going on, a wideband and R/T is a must, I know ive said it and other have said it to you alot, but you have no way of really telling at all what is going on.
Here is what I would do Paul since you have no way of seeing ............. 1) Things as they now are ... or a baseline of reference and 2) Things after tweecs which verify you did either ...... Right or Wrong For now ... I'd only work with the top load row in the spark table You don't wanna go down 3 rows as That will be hosing around with your mid range stuff and ... About that fuel table ............ For a stocker ........ The default values are OK ... I guess Although ... everybody knows ... the GT could use a bit more fuel however I don't feel those fatter values as the rpm's climb is optimum for maximum NA performance. Now I wanna be very clear with this next part here That statement has to be followed up with ....... Provided one has two things in place 1) a wb to ensure accurate wot readings 2) knowledge of how the fuel table, maf curve, and high speed enrichment if using the j4j1 file, all work together to determine your final wot ratio. anyway ... the fuel stuff can be a later thing and I guess we should say this very basic fact ... at this time A tune is based upon two parts 1) Closed Loop or easy drive around town type of conditions 2) Open Loop or WOT You want to obtain STABLE CL tune :Word: before You even think about WOT tuning Here is the deal and I know this is not gonna be received too well but The smartest thing any noob Tweecer user could do is ...... 1) get CalEdit & Calcon up and functioning correctly 2) make no changes other than simple scalar changes 3) do a GOOD BIT of datalogging while capturing to hard drive Make each file around 30 seconds long and Each file should be different with GOOD documentation Examples should include the following idle during normal ect steady cruise acceleration from stop ... say 2nd gear (no gear change) with ...... 10% maximum throttle 30 - 40% 60 - 70% 100% I know ... I know ... Everybody wants to get in there and start doing all kinds of cool stuff but hey ... You do the above ... and you will quickly start to see ...... how that little silver box works with load, adaptive, spark and all the rest That simple method worked for me and That is exactly how I started to approach the whole deal Grady
Paul For a conservative first time spark effort you could try top load row only ... btw 2000@22 2500 and above@26 I'd be willing to bet the other three tables and possibly some other scalars or functions could be adding a bit more spark as well Soooo Just take is easy and listen for ping DO NOT use this table method and Global Adder together Grady
