porschesam

Here are my dyno results comparing new Vitesse chips with the older Autothority chips.

Comments welcome...

zoltan944

well, The more power from the autothority chips seem to be because of running a little dangerously lean.
also it difficult to determine much at 'unknown boost'
I think our biggest gain on power results would be deleting the cat tho.

buxton

I think those are decent numbers for a basically stock car with only chips.

IPSC

WOW the Autothority stuff is lean. I would be getting scared of that AFR to be sure.

IPSC

xsboost90

alot of chips will lean the mixture out early in the low rpm range to spool the turbo quicker- ask Russel- thing i dont like is how rich is goes once the rpms come up- this is why the autothority chips make your car smoke under a load- the vitesse chip looks more drivable IIHO.

blown 944

those are nice numbers from a stockish setup.
the old chips were very lean in the top end.

the new chips look to be just about perfect, at least they are a heck of a lot safer.

porschesam

Actually, the car ran well with the Autothority chips and thought everything was great. I decided it have it dyno tuned because I was curious of the HP the car was making and I've heard about the lean issues with Autothority chips. The car runs just as well with the Vitesse chips and actually feels faster with the new set-up. You can see from the graph that the car is making a bit more torque at 4K rpm. This set-up makes for a quick street car that is much happier.

Rogue_Ant

With the cat still in place, the A/F ratio is going to appear to be leaner then it actually is..


Rogue

fast951

Very nice and smooth graph. The AFR with the Vitesse chip looks fine. For a stock car with a cat, these are good numbers. It'll be nice to have a "corrected" garphs to compensate for temps and humidity. A boost curve will be nice to have as well.

In your new setup, is boost dropping around 4200-4300RPM?

Glad you are enjoying your car.

Spidey944

Trying to understand this comment. I can see this being true if the readings are being taken at the tailpipe, but if it through the port for the Wideband, which is located b4 the cat, what would it show up as leaner with a cat vs without one?? The in-the-pipe readings should be the same right??

toddk911

Which proves the point John is always making in that the final numbers do not always dictate the best driveability or "feel" of the car.

And yea, stock set up with just chips and 5 more psi and about 50 hp over stock = NICE!

I'm actually surprised the Autho. did such good numbers, even though they are way lean.

toddk911

Although, you have stock turbo so you get full boost somewhere in the 2,800-3,300 range right?

John's graph is way more lean on the spool up and full boost point than I would have expected, but I guess he knows that is safe. Like at 3,500 which you should definitely be at full boost and your a/f is 13:1 ????

Rogue_Ant

I'm assuming the WBO2 reading came from a tailpipe probe (as pretty much all dyno's do). If I'm correct in this assumption, then the AFRs that are displayed on the dyno read-out will be leaner if measured before the cat...


-Rogue

zoltan944

As stated the dyno more than likely takes a tailpipe reading which will show a touch leaner being out the end. With a cat on there it shows leaner than that.
At that point in the cylender head the car was more likely 12.6ish which is great at that RPM

I too would have liked to see more data, especially a boost graph. Tough to find at many shops with dynos tho

ryanm6100

This makes me feel indifferent about my autothority chips..

Good power, and is that small difference in afr at the end a major issue? (12.2 V vs. 13.8 AA)