getting bummed...help somethings wrong

[blksn955.o]

Background--- on my stock factory shortblock with unported gt40 heads, TFS 1 cam, and ported stock lower I ran a 13.5 @102 with a 2.2 60ft. And before that running with the factory long block (stock heads, intake, cam) I ran a 14.3 @ 98.

I had to replace the shortblock due to wear and tear.

I have a D.S.S. 306, forged pistons, ball, ect... the gt40 heads were ported and done by a perfessional, the intake is a ported gt40 intake, and still running the tfs1 cam, The only thing I re-used was the stock lifters (they looked good with not too bad wear) and rockers with the stock length pushrods. The heads are shaved .065 and I should have about 10.5:1 - 11:1 comp. depending on how much matt. makes a diff. when polishing the chambers (removed the casting flash to smooth no re-shaping).

I ran a 14.5 @98 at a local shootout back in April or March...preaty pissed but looked into some things, the #6 and 7 cyl. were not getting fuel. at all, the pass. side bank was rich bad from this.

I found a poor connection (used a noid to test the harness an it got juice) and put some di-elec. grease on the conn. After driving it about 250-300 miles all the plugs have even wear...I fig. there getting fuel...everything should be sorted out.

Tonight I ran 14.1 @99 2.29 60ft ... 14.3 @ 98 2.3 60ft... 15.7 @78 2.2 60ft (missed 4th bigtime)... and 14.3 @98 with a 2.01 60ft.

No matter what I did with the tune changed from 30*total at wot to 32* at wot, from mid 12 a/F to 13.0 a/f.

other than alittle idle issue it drives and gets around perfect, no bucking, stalling, surging, overheating, good mileage, all my datalogs show things are fine in the eec.

 

[final5-0]

Are you running 19lb inj's and stock fuel pump?

I can see how just 2 degrees of spark change might not make much difference.

How quick do you have the spark at full advance?

Are those af ratios correct? I would think a 1/2 of a point would make a difference in your times more so than the spark change above.

Grady

 

[bimmertech]

when your heads were ported, did you put new springs in? dunno if your datalogger shows sensor readings, but maybe you got a sensor spiking.

 

[blksn955.o]

Are you running 19lb inj's and stock fuel pump?

I can see how just 2 degrees of spark change might not make much difference.

How quick do you have the spark at full advance?

Are those af ratios correct? I would think a 1/2 of a point would make a difference in your times more so than the spark change above.

Grady

24#inj. and a 190lph walbro

I thought 2* would show something least of all a loss in 1/4?

I had 31 in at the cell after the 2000rpm collum in the top collum, in base and alt. tables in the next to top table I just had 1* removed (from the 31, to make 30) for the next two rows.

then upped that to 32-33 in those top tables In the next two row's I upped them the same amount.

Yes started at 12.6- and went to 13.0. Even on the dyno along time ago (last march). When I went from 11.2 (stock) to 13.1 I gained 1-2hp only. Thats when I started messing with stuff (the motor not the tune). At the dyno the A/F went right were I commanded it to, and every time I load a file into EA it says the MAF is perfect. I am thinking of running it in the off possition and see if there is a large diff. However, with the stock eec and my mods I had drivability issues, with the tweecer tune I have now other than a slight idle issue it is like stock, damn near perfect.

 

[blksn955.o]

when your heads were ported, did you put new springs in? dunno if your datalogger shows sensor readings, but maybe you got a sensor spiking.

had comp cams springs installed right before the port work, they were specd' out at safely running up to .550 lift. In the datalogs the sensors are all reading fine, thats why I think its a mech. issue. not sensor.

 

[blksn955.o]

One of the local guys sug. that I take out the spout and set my timing to 30-34 and run it fixed or locked. Makes sense... another guy sug. turning off the tweecer and run the stock eec, to see if the tweecer is working correctly.

My thought are this, how could it change the A/F so perfectly, and have the drivability it has and not be working, could it only not be working in some areas and not others??? If the tweecer is bad...what do I do???

BTW-thanks guys for your replies.

 

[final5-0]

One of the local guys sug. that I take out the spout and set my timing to 30-34 and run it fixed or locked. Makes sense... another guy sug. turning off the tweecer and run the stock eec, to see if the tweecer is working correctly.

They don't have a clue

Why would you want to do that when you can do the same thing and more?

Have all of your spark in by no later than 2500. As you have done, the top load row is fine as it is used for wot conditions. I know you got iron heads but see if you can get 36 or more. SBF's have made the most power at about 36 since before lots of you guys were born, lol. At the track run good gas and all the spark you can ........ right to the point of ping and then back off a couple.

When you look at your wot dlogs, does the spark show up like you expect in respect to load & rpm?

You know your Tweecer is working OK or the improvments you have made with drivability would not have been evident.

My thought are this, how could it change the A/F so perfectly, and have the drivability it has and not be working, could it only not be working in some areas and not others??? If the tweecer is bad...what do I do???

BTW-thanks guys for your replies.

I think the af ratio is more of the prob than spark.

In your other post you said you gained only 1 to 2 hp when going from a fat 11 to 1 to a much leaner 13 to 1 ............... there ain't no way that is right.

I know you don't wanna hear this but ..............................

You need your own wb so you can know for sure how your fuel looks at different load and rpm conditions.

Grady

 

[blksn955.o]

I should have made it clearer that they wanted me to lock the dizzy out/turn it off to see if the tweecer is working fully. Not a perm. fix more like a test. They totaly agree with the benfits of the tweecer/pms type stuff when needed.

I will add some spark to one of the files and make a short street run.

Yes in the datalog the spark has been were is should be with what load it is in. AT .9-1 wOT it has been showing me the amount I have bumped it.

I know I need my own WB, just not in the cards right now, I do want to get bac to the dyno and at least check it again though.

I agree 11.x:1 to 13.1:1 and only gaining that little something is deff. wrong. but I have no idea what it could be at this point. NONE...no idea at all. grasping at straws and building a plan to check tomarrow.

 

[mytight95]

have you checked your valvetrain geometry, proper length pushrods etc....?

you shaved the heads a lot to have stock push rods. I assume they are still pedestal mount since you didn't list hardened pushrods with guideplates for stud mount rockers...


jason

 

[urban96]

have you checked your valvetrain geometry, proper length pushrods etc....?

you shaved the heads a lot to have stock push rods. I assume they are still pedestal mount since you didn't list hardened pushrods with guideplates for stud mount rockers...


jason

ya are the rockers shimmed properly?

 

[blksn955.o]

I do need to do it proper and get a solid lifter and check, I am running .090 worth of shims now and it seems to be just a tad loose or too much shim but .060 is not enough as I had that and the valve seemed to float (the first thing I looked at when it dynod' 160ish hp on the dyno) as soon as the lifters pumped up as power came on fast at the dyno, but stoped at 2000rpm. Maybe a messed up some of the lifters but they look OK.

It does run better from putting a larger shim in, but something else is amiss. I realy realy hope the tweecer is working 100%. I know I am getting good drivability but perf. is deff. sucking.

 

[blksn955.o]

Just ran a 20 or so min. loop that I like to run as it has a few stop lights, good amount of hwy driving, and some off/on ramps to test all around drivability/power.

The first half I ran the 12.8 A/F and 34* tune, the second I ran the tweecer in the off position.

IF I had to say what tune felt stronger it would be hands down with the tweecer off, it was damn near out of controle in comparison to the tune (any tune).

With the tweecer off though the eec threw a CEL, and would need assistance to idle, and ran a little bit hotter (a tic above the line between 180 and 210 on the autometer guage).

when I switched the tweecer back on (the car died at a light, so I switched back to the tune) the idle was not stable and almost stalled, the rest of the way home. The CEL went away and temps cooled off back to were they were at before. (a tic below the line between 180 and 210 on my autometer guage)

 

[WhiteDevil]

This is a puzzling thing. I wouldnt trust the old but dyno to say that its stronger without the tweecer. I thought when i got the tweecer and bumped the timing to 33 degrees it felt like a beast, but it didnt really gain much at the track or dyno. I would put it up on a dyno and see what kinda power ur making.

 

[blksn955.o]

It went from excellerating(sp?) ok with the tweecer on

to

pulling like it has never done before it got that I am going from side to side movement going on, it even sounded meaner....

Both excells were in the same gear (3rd) and punching it from the same rpm. on level roads.

 

[blksn955.o]

***IDEA***

OK I have been using the stock GT MAF transfer loaded into the J4J1 bin, I have been getting commanded to go exactly were I want it to go and EA showes it is perfect as far as what it sug. So I have been against changing it as it seems to be correct.

COULD changing to the stock j4j1 MAF transfer fix this? could it be not jive'n with the the j4j1 bin causing it to into some kind of limp-ish mode??? could the GT transfer be correct but not work with the fine points of the j4j1 someplace else?

 

[final5-0]

OK

If I understand correctly, you have been using the following:

j4j1 cal file
stock oem 94-95 maf
24lb inj's
t4m0 maf curve

If I got all of that right, then I would use the j4j1 maf transfer curve and the j4j1 inj offsets, slopes, breakpoint, & min pulse width.

btw...what is the most airflow you have seen in your dlogs?

Af for running your car with the Tweecer off for a test .........................

Seems to me that if you went to the default switch position, you would be using 24lb inj's that the pcm did not know about and that should put you in a rich condition.

A bit more about running the different maf curves with the different cal files.

I ran both curves with the j4j1 and could not tell much of a difference except for wot at the higher rpm range.

My combo would not work with the j4j1 curve as it only went to 875 kg/hr@5v and that was not enough for what airflow I produced.

The t4m0 curve shows 925kg/hr@5v and I was right at the verge of pegging that GT curve.

Grady

 

[blksn955.o]

Yes I was using the things you had listed, and was already using the j4j1 stock slopes and breakpoint along with batt. v. offset just useing the GT curve.

I just got the j4j1 call file but the MAF will not stay the way I input it it will change ever so slightly if I do it by hand? and I cannot for the life of me fine one to export.

 

[final5-0]

Yes I was using the things you had listed, and was already using the j4j1 stock slopes and breakpoint along with batt. v. offset just useing the GT curve.

Glad I understand things correctly

I just got the j4j1 call file but the MAF will not stay the way I input it it will change ever so slightly if I do it by hand? and I cannot for the life of me fine one to export.

That is normal for the values to change a tiny bit. Are you talking about a change of 1% or less? If so, then don't worry about it.

Grady

 

[blksn955.o]

things would go from like 1.3001 to like 1.2998v on just a few.


I am going to try and load this up and go on a ride quick, its going to rain and rain the next 2-3 days.

 

[mytight95]

aside from the tweecer stuff, i would buy some correct length pushrods, after i got it checked, and mocked up correct length without shims......


just my opinion


jason