APR B8 Stage 3 S4 versus GIAC B8 Stage 2 S4

[euroswagr]

JHM just needs to put a centrifugal kit on one of these bitches…use a 3.2l manifold and BAM.

[sakimano]

Interesting, I’m just bringing this up trying to understand the precedent set for the platform regarding tuning development.

Since I’ve been following, one of the more interesting periods was between the 2013/2014 cars. We saw many people with 2014’s going to the strip and running very poor times. APR/GIAC etc. Some tuners came out and claimed it was due to the lower redline. Jim and myself did some simulations and hypothesized that the lower redline was only costing maybe .2 sec and 1-2 mph trap. Nothing like the near stock numbers we were seeing. Skywagon’s logs were awful as his ignition timing curve was stock-ish and this was with IAT’s well in check.

My point is that there are a lot of revisions of the ECU software, and it might not be the case that APR is able to write the correct software for everyone’s cars without writing some new files, having some back and forths with customers. APR doesn’t have factory source code so they can’t simply recompile to different ECM build targets. This is beyond my understanding, but basically, they reverse engineered the ECU by logging the car with extremely high resolution hardware/software tools and extracted where the tables/parameters exist within non-volatile memory. Ability to change fueling tables/cam phasing/timing tables (revo said the ECM interpolates between 3 tables based on measurements and calculations)/boost control. They then have a database of all ECU revisions, and overwrite the reverse engineered correction/calibration onto similar locations in memory for the other ECU revs.

The issue with that is OEM’s change software builds very frequently (even in-between MY’s), there are new standards in emissions, new DTC’s that need to be identified, other features that get introduced which require different ECM software. So basically, APR assumes the different ECU revision will react similarly to their software. Which it probably doesn’t.

So aside from Richi’s hardware issues with the CPS, there could also be something wrong with his tune? This is why we need a guy like Ron to run this kit (not saying that Richi isn’t working with APR to solve issues, but Ron clearly has access to the red phone). If it flops and doesn’t deliver the performance advertised, Ron will be pissed I’m sure, but also will understand that he was going with an unproven product. And the community will beit.

I don;'t think anyone is being fooled by the ‘the cooling just needs bled’ line. That’s just a cover for the failure to perform. Richi can think that’s what it was all he likes, but when the other stage 3 cars are also getting crushed by stage 2 cars, a lightbulb should be going off.

There are probably 3 or 4 variables that are holding the kit back from its full potential…and then again, it’s full potential may not be all that great on pump gas on a small V6. Chevy sized it for 6 litre V8 in the Z06 and the CTS-V. Not the small V6 in the malibu.

[sakimano]

JHM just needs to put a centrifugal kit on one of these bitches…use a 3.2l manifold and BAM.

I’m not sure if that would make more sense than sticking with a TVSr1320. Don’t forget a small V6 doesn’t generate much torque on its own, and when you’ve got a Vortech that is better at top end, you’re going to have a bit of a dog on your hands down low. It works well on the 4.2 cars but that’s thanks to 40% more displacement for down low torque production.

[drob23]

Looks like GM’s engineers also don’t know how to bleed a 1740

http://jalopnik.com/why-the-corvette-z06-flunked-motor-trends-big-performan-1736976325