BlackBirdDriver

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.

Car is being tuned at HG Motorsports, in San Diego.

I'll post up the results when I get the car back.

swedepat

keep us updated.. really interesting.
Might be going for a custom tune myself.

BlackBirdDriver

So, I got the car back today.
The three stock/baseline runs produced 282.8, 285.5, and 286.2hp respectively.

10 different tunes were built and installed in the car, with the best one producing 294.9hp


The Dyno time was free (as quoted), and the tuning cost $1000.00 So, that translates to a performance increase of 8.7hp, or $114.94 per Horse.

The Staff were very polite, and pleasant; and I can only assume they did their best.

swedepat

Nice!

do you know if he adjusted the ignition anyhing?

loungn14

wow that is expensive

tw2

If I understand correctly, the stock/baseline run had the exhaust and header work already installed?

Which/what type of headers did you use?

///AchMeinGott

I'm confused as well.
A custom header(I assume mid to full length?), X pipe, cats/resonator delete, dyno tune C55 makes 294whp? SAE or STD?

100k miles or not, bone stock a C55 should be able to put down 290+whp on any given dyno.

swedepat

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.

ez53436

$1000 for less than 9 horsepower?!

///AchMeinGott

That's true to an extent but a poor excuse.

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.

swedepat

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?

tw2

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.

swedepat

yes... make an 1/4 pass then we can see direct if dyno is bad.

mbguy949

every motor is different but that seems way low...My c55 dynoed 302rwhp 310wtq bone stock

BlackBirdDriver

Forgive the delay,

Car was bone stock with exception of long tube headers built by RPM/Richards performance muffler, in Oceanside California.

///AchMeinGott

That... contradicts your 1st post.

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.

swedepat

60-80hp loss is actually normal on an automatic car.
I would question every else that got above 300hp at the wheels with stock c55´s

BlackBirdDriver

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).

tw2

If the car feels faster and has more top end with good 0-60/0-100 then I wouldn't worry too much about the numbers.