Bullet EPROMS Calibration?

[vlad01]

Hi guys,
Just doing a custom tune for an old friend whos got a VR v6 mild engine in a VN wagon (I'll post a bit about this in my built thread at some point, but it was a massive headache) that has crow cam stage 3 and memcal package from Mace.

Just about sorted the new tune, but I was curious to what was on the Mace one, wouldn't really run on this car and wanted to know why. I know the crow cam ones ran crap but at least they ran.

The eeprom is just the standard SST one we all use here, so no probs reading it. I can't ID it and figured it must be a VR based code given it was a 32/32KB stack, I split off the blank half off and it still won't define correctly in any of the factory XDFs nor 12P. The flags and scalars all look fine for $12 but all the tables have just one value throughout, not something I have seen before. So it seems like some custom version of the factory code where all the tables are moved away from the locations normally used where all available XDFs don't see anything , I assume hide the content?

When open in note pad I see the follows where we normally see OSE 12Pro etc. It's got "Bullet EPROMS Calibration (c) 8828 VP67DKO"

I've searched the net for such a company or software etc, zero results. Literally never heard of them, could it be a kalmaker code?

[Gareth]

Pretty sure its from here - https://www.bulletperformanceracing.com.au/

[vlad01]

Interesting, I haven't heard of them before but looks likely its from them.

[VX L67 Getrag]

I should be able to slap something together for you to tune off if you want me to have a look.

[antus]

Try a $FB XDF from here: viewtopic.php?t=5
I have seen this type of bin from Bullet before.... Its a 16Kb image.

[vlad01]

I should be able to slap something together for you to tune off if you want me to have a look.

I've already made a very comprehensive tune in 12P for the car, just some tinkering with the spark map to see if there is anything more to be had, but I doubt it. The starting, warm up, decays, cold offsets, inverse temp and charge temp contribution table as well as the AE and DE stuff all needed to be completely scrapped from 12P and figured out from scratch. It was a pig at the lower end but I got it sounding 90% like a stock car.

I never would have guessed a slightly smaller and more conventional timed cam would be so picky and much worse than my red VP ones which is a bit whacky with 6deg retarded and 109 LSA, I barely had to make changes to mine other than leaning up the idle and warm up slightly, never touched the inverse or contribution tables. But the crow stage 3 does idle nice and stock once all that was sorted out. But my original sims of the stage 3 like cam with Vlad's twist actually was good now that I have been able to drive an actual crow cam stage 3 car and have a direct comparison. I was always questioning if altering the cam timings so unconventionally was a bad idea or not, but I am happy I was right and the sims were pointing in the right direction.

Now I know why the factory had such tight LSA on all the older gen Buicks, wider LSA makes them lazy as hell, they like overlap!

I was just more curious to why the Mace provided memcal wouldn't run, at least not with a new set of plugs each attempt to start it. The owner of the car said it idled extremely high as well, I never got that far.

Spoke to Antus already so hopefully I can read it ok now.

[vlad01]

Thanks Ant! that did the trick.

For those who are wondering, it's just a stock code and as Antus stated, its $FB.

I can see it's actually pretty close results to what I got doing it from scratch in 12P but the VE table looks off, it's different to stock but not like any of the engines I have tuned so far, looks almost generic like those ones you seen on example tunes used on videos to teach tuning.

One interesting thing I noticed is the both AFRs and spark are focused around the 2000-3200 rpm, AFRs are leaned to 13.4 there and spark is boosted a little there as well compared to everywhere else. This is also where the engine seemed lazy as well, so probably a quirk of the cam. Might be something worth playing with before I burn the prom, otherwise my spark map is very similar, max timing on this is 24, mine is about 20, Gareth's is 21-22. I tried 27 because it's got stock vr comp and it hated it, it preferred my and Gareth's Kerrmit maps, which both have similar specs, Kerrmit is a stage 3 in fact but with higher comp. So that is interesting that a larger cam likes less timing over the stock despite comp differences, at least this size rage in cams. I am sure very big cams want more timing again.

I have no idea why it didn't want to run, perhaps it was in limp mode but I never saw any CEL.

[immortality]

Stock cams are lazy for a reason on the Buick engines after what happened with the VN's.

You'll probably find the stock cam never really had good VE where as your Crow cams at higher revs are probably achieving much better cylinder fill and need less timing to make it happy.

[vlad01]

No, I meant the late VN to VR and early Buick before the VN like in the Regal and Grand National etc, they all have narrow LSA compared to most production engines, even within GM. VN series 1 was wider and more typical but did have slightly more duration and lift, overall they were pretty much the same when both have pacemakers and tuned properly, later VN to VR just managed the same with smaller cams due to this extra overlap they like.

VN s1 was an odd one out having a wider LSA, then ecotec went wide again, same range as stock LS, 115 deg or something high like that. Great for emissions ans idle, but sucked for performance.

The crow cams are wide like the Vn s1, some of the more "race spec" cams they list are narrower like 110 deg but is still wider than the cam I had ground, and my FH cam has a LSA of 106 which allows the most to be squeezed from them in a race engine.

What I was saying is the crow cam is lazy even compared to stock, but has ok top end around 4.5-5k. A narrower LSA would help keep compression on pairing with factory pistons, so overall without installing high comp pistons, the crow cams make the engine lazier than they should be for what is suppose to be an upgrade, but a good engine builder should know that a bump in comp is a necessity when installing a bigger cam and also a good builder knows that crows "stages" are basically weak sauce and should be skipped straight to their race cams for a daily commuter. Even their biggest V6 cam barely qualifies as a daily street commuter type upgrade.