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I decided to try a custom tune for the C55, I know it might be more expensive than a canned-tune; we will see if its worth it or not.
Here are two of the three baseline pulls on the dyno. (The smoke at the end of each run is just from the ECU throwing a bunch of fuel in at throttle lift).
Best pull produced 286hp, so it looks as if these headers alone are good for 20+hp over the stock manifolds.
Car has 100k on it, custom headers, X-Pipe, and deleted resonator and cats, with the stock mufflers.
Don´t give the numbers so much energy.. focus on actual difference before and after.
this is exactly the correct way of using a dyno, to see the difference.
All other is mumbo jumbo dick comparing.
29x is stock C55 numbers. I've seen guys on here WELL beyond 300whp with bolt ons. I myself like to aim for the heart-breaker dynos because you can't be dissapointed in what you run then. But this is a bit extreme.
That aside, 9whp gain after a tune with those mods seems... mediocre. Maybe It's just me.
we don´t know anything about the dyno, about the state of the engine, not anything.
maybe dyno showed totally bogus numbers.
and maybe the car already had a tuningchip inside, we dunno anything.
And 9-10hp increase from an already chipped ecu sounds more correct.
But until we know,,, why don´t we just zip it?
Last edited by swedepat; Sep 29, 2015 at 04:38 PM.
Thats why I was curious about the headers. If they are shorties with the stock downpipes then the gains from any tuning will be very limited. Hopefully the OP can clarify. Otherwise as swedepat said, before and after dyno readings is the only relevant comparison.
A quarter mile would help compare between different cars.
So you were 286whp stock... or with headers, cat/res delete, X-pipe?
Then you went to 295hp after adding all those mods+tune, or just after tune? SAE?
I don't care what kind of dyno, a stock 360hp V8 with almost full, catless exhaust and tune making 295whp is full blown pathetic. That's not an insult, something genuinely might be wrong. For reference a manual 350hp LS1 will consistently put down 290-305 depending on car/dyno. A manual 400hp LS2 will put down 330-345whp.
Not at all. The first post was crystal clear. My follow up post was not meant to be a reiteration of the first post, but only to clarify a point regarding the headers, and that the car had not be "tuned" before. (stock factory tune).
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