Red Stripe Help

[BoostKillsStres]

I've made the std mods to my chip image(based off the bbkj image) to increase spool, wg dc coeff. and 100% bleed in the low rpm table but now boost comes up so fast I can't seem to get enough fuel to it to keep from pinging off the line or when stabbing the throttle after an easy launch and once into 2nd gear(street fighting ). Once I'm at full boost everythings fine, timing 18 degrees, 02's in the 760-790 range, fp 47 hose off, 340 hot wired pump and 1psi of fp per 1psi of boost at the rail while driving.

I've been adding fuel in the 2400 rpm table, would it be better to get the car into pe a little sooner using the PE tps threshold table, I know I'm basically looking to richen up the pump shot on the car but not sure the best way to get there. It looks as though its going to be a combination of table mods to get there.

TIA,
Mark
87GN

 

[TurboJim]

Just went over this a couple days ago with someone. Dont know the outcome, but try playing with the BKR parameters. Add a couple degrees retard and/or add some time. Stock is 7* retard for .1 sec when you move the TPS 9%. Make it say 13* for .2 sec and see what happens. Or whatever..u get the idea...

 

[BoostKillsStres]

???

Jim, are you talking about the burst knock retard and active values? I see the stock image has .1 for time and 14 degrees. Then there is the TPS threshold for BKR and its 9.8 is this what you mean? I thought this would only be active if there was knock so I'm trying to see if my fueling is the problem. I can email u a small DS file if your interested in taking a look at where its happening 4 me..
Mark

 

[TurboJim]

Well, dont hold me to it, because I may not understand it properly, but I thought BKR was to compensate for possible knock resulting from the "lean gulp" between the pedal moving, and the ECM actually fueling. Anyway, I ASSumed the ECM retarded the timing X degrees for Y time upon Z throttle movement to thwart off this type of knock. I know old carbed cars were VERY prone to this. Maybe I'm wrong. Maybe all you need is some TPS based fuel comp. Or maybe play with TPS delta if you have a larger TB. I dont know, I never had your problem, so never saw trhe need to play with more junk than I do already.

 

[BoostKillsStres]

gotcha

Learn something new every day, I'll give it a shot and let you know. I'll leave the stk 14 degrees in there and change the time to .2 and let u know in a few.
thaks again,
Mark

 

[TurboJim]

Re: gotcha

Originally posted by BoostKillsStres
Learn something new every day, I'll give it a shot and let you know. I'll leave the stk 14 degrees in there and change the time to .2 and let u know in a few.
thaks again,
Mark

Actually, its 14h, but 7 degrees

If I'm doing the conversion right the calc is N=(E*90)/256

14h to dec is 20 *90 is 1800 / 256 is 7.03125 degrees

Try $1A at $317C which is 9.1*, and $0C at $317A for .2 sec and see if anything changes. If it gets better, try more retard, then more time till you get the right balance. Maybe Bruce can chime in here as he's a wonderful tuner and I KNOW has played with this stuff.

 

[BoostKillsStres]

tried it

Well the default for the bbkj image at $317A is 28h instead of 14h in the stk chip before the bbkj. Anyway I left that as is and changed the time value to .3 I think--> 18h instead of 08h from the pre bbkj chip. Not sure what the formula is for time conversion from hex to dec. It seemed to help a bit but I broke the cardinal rule and also changed the pe rpm cell at 2400 rpm from 5 to 12 so not sure which helped the most. My current fuel parameters are as follows: inj size 39.1 a/f from 132-304 degrees 13.5 and rpm trim table from 800-6400 is -6 -8 12 12 18 27 33 50 other pe stuff is basically bbkj stock. I figure tons of fuel above 5600 couldn't hurt as I shouldn't ever be there anyway and if I hit the rev limiter which I have set to 5600 way rich is better than lean.

I'm going to try pulling more timing as it only happens for a split second and see what that gets me.
thx, I really app. u taking the time to reference those hex values 4 me Jim.
Mark

 

[BoostKillsStres]

tried it

Well the default for the bbkj image at $317A is 28h instead of 14h in the stk chip before the bbkj. Anyway I left that as is and changed the time value to .3 I think--> 18h instead of 08h from the pre bbkj chip. Not sure what the formula is for time conversion from hex to dec. It seemed to help a bit but I broke the cardinal rule and also changed the pe rpm cell at 2400 rpm from 5 to 12 so not sure which helped the most. My current fuel parameters are as follows: inj size 39.1 a/f from 132-304 degrees 13.5 and rpm trim table from 800-6400 is -6 -8 12 12 18 27 33 50 other pe stuff is basically bbkj stock. I figure tons of fuel above 5600 couldn't hurt as I shouldn't ever be there anyway and if I hit the rev limiter which I have set to 5600 way rich is better than lean.

I'm going to try .5 for the time value and see what that gets me.
thx, I really app. u taking the time to reference those hex values 4 me Jim.
Mark

 

[TurboJim]

I dont know where you got 28h, unless its the pre recall 87 chip. The recall 87 chip is 08h (.1 sec) and the 86 chip (original from my car) is B6h (2.3 sec) Anyway, it doesnt matter, maybe the TIME is the way to go as GM reduced it for some reason. Now I see where you got your 14*, the pre recall uses a 28h. My bad... so, they have 14* retard for .1 sec, where my 86 has, hmm, this cant be right...60* retard for 2.3 sec? hmmm..maybe my 86 bin is corrupt..that cant be right.... yup, boost tables are fu..dged too....my bin must be bad....

Why is modding the PE/RPM tables breaking a cardinal rule? Thats how you build your fuel curve. Well, if you wanna call it that...10 or whatever cells isnt much resolution

Did you ever download and try the 40# program I uploaded here a few months ago? It ran very well in a few cars and might be a good start for you as well. Just a thought....

Hmm, just downloaded pre/post recall chips and 17A is 08h in both. Sure you're looking at the right address?

 

[BoostKillsStres]

oops

Sorry my bad there, I musta been looking at $317C in the stk bbkj, axca and 89tta images which is 28h and I was getting the 14 decimal from the value in tweakdos but the spreadsheet on the web shows it should be 14h for $317C but that must be the chip before bbkj i guess.
I didn't know you put an image up, I'm guessing its on gnttype? Dave Huniker was nice enough to give me an image some time back and I've been using it and one other that came with my 40's to try to figure and tweak my car but it always seems like just when I get something where I like it something else crops up. And yes, I wish we had a lot more fuel trim values available too.

My testing w/ .3 for time and 20 degrees(i figured take out a bunch, if it all goes away I'd work my way back) didn't net me any better results still 3 degrees of know just when I get to full throttle. These burst knk retard values are interesting in that there doesn't appear to be any way of seeing them take place on direct scan it still reports the expected timing map at 18 degrees and the 3 degrees of retard.
I'll go after your image and see what I can see,
thx,
Mark