M-Theory

I'm here asking about what a FBO decatted M156 should make power wise, everything I've read tells me:

470-490rwhp

But after my baseline which you will find in my other thread: (Super flow dyno, some claims it reads low).

https://mbworld.org/forums/w211-amg/...ture-tune.html

(Came here cause the C63 section offers much more knowledge and experience with the M156)

I put down a max of 421rwhp on stock Ecu software running rich 10.46 A/F.

After contacting tuners they are telling me to only expect a 25-35rwhp gain!?!?

That would only net me around 450-60rwhp total with my set up, which I'm not really happy with after seeing countless C guys put down 470-480+rwhp.

Anyone have any advice?

Thanks
Marcus

mthis

Enjoy your car and dont go after dyno numbers. my car put down 465-470 on race gas with Full exhaust intakes ectttt...
car runs low 11s high 10s and does 60-130 in 7.9-8.3 in that set up. if i had another 20-30 rw who knows what it will run.

Kriston

Most FBO C63's are doing 460-470ish wheel HP.

Perhaps your dyno is reading low. Who knows. Like Mthis said, don't stress about it. Enjoy the car.

m a x i m u s

.

HoozyerdaddyC63

My C63 with tune, ROW airboxes, MBH headers, mids, and x-pipe only showed 300 whp on a Mustang dyno. Needless to say I was heartbroken.

I took it to the track and it ran an 11.9 @ 119 mph and I didn't feel as bad. I found out later I also had a air leak in the intake manifold.

While I may have had awful dyno numbers and several possible reasons why, I could still feel a huge difference between stock and after mods.

Good luck with your ride!

Merc63

Who cares about dyno numbers??


Bench racers maybe at cars and coffee, see Ya at the drag strip I always say.

And if you're wondering why you're down on power with a 10.4 AFR, you need to read up, cause that is pig rich for an NA car.

BLKROKT

Exactly this ^

Do we really need 2 concurrent threads about the same guys issue?

M-Theory

The last two post have clearly missed the point im making in reaching out to the forum for information.

I understand I'm down on power big time because the car is running extremely rich on a stock tune, which will be resolved with a tune coming soon.

My concern is that tuners are only telling me I'll only see another 25-35rwhp gain, which seems really modest from the results I've read about.

I just wanted to know if that was typical, I'm not one to get caught up in number but when I'm spending cash on this stuff I just want to make sure I'm spending it with the right company.

Even now over stock running rich the car feels like a monster in comparison so I can't imagine what a tune would make it feel like, can't wait.

Thanks for all the words and help.

BLKROKT

No, I think everyone gets it just fine. You are complaining about a problem that doesn't even exist. Your car is down on power stock because it's running fat. Then you want to take tuner claims for their hp gains - which for good reason are on the modest side of things - add it all up, and you wonder why the math seems off.

Have you even re-read what you posted?

Do your research, make some calls and actually TALK to people. Form a RELATIONSHIP with the tuner you like. And then get the tune and don't look back.

All this hand-wringing over imaginary numbers is so silly. When you have a real problem, that's the time to make a post like this. Not over faulty math.

M-Theory

Faulty math is what you chalk my thread up to.... Thanks and no thanks for your input. (Not being a ***).

To put it in simple terms for you, I was just wondering why I was only be quoted a total of 450-460rwhp when I've seen an average of 470-490rwhp with my same mods (through the search feature btw).

I have learned a few things from you and the others that have posted, that dynos differ and the track will really tell you where a car is performance wise.

As for building a relationship and talking to tuners that's exactly what I've done (5 of them over a period of 6 months) and I've gone with the one that actually put forth the effort in understanding and educating me on what I'm trying to do instead of just looking at my money.

Seriously though I appreciate all the input on my question, I never said it was a issue, just wanted clarification.

That's what the forums are for, someone will search and see this one day and learn something haha.

QWKSNKE

Have you determined why you are running so rich? That needs to be addressed before putting a tune on the car

M-Theory

From what I've spoken to tuners about, its likely the car over compensating for the mods, (long tubes, row air box, cat delete etc..).

After the first dyno pull we realized the cat deletes weren't the only codes it was throwing, cleared the codes and the car started to adapt more and gained power ever dyno pull, The shop I used was sure if we kept at it the stock software would possibly be around 430-40rwhp (assumption on power of course).

QWKSNKE

Didn't realize you had these items, however row air boxes and cat delete shouldn't have any impact on a/f ratios. Actually I wouldn't have thought headers would either but I suppose it is possible as they now allow higher velocity of air to pass over the O2 sensors which 'may' not allow for a proper reading.

But I don't have the experience with this engine as I do others and these mods that are mentioned do not impact the air/fuel in other cars in this fashion.

Typically cars running to rich are a result of a faulty MAF, O2 sensors, or fuel press regulator.

M-Theory

I've been thinking about taking those three into consideration, it wouldn't hurt to replace those items for preventative maintenance either way. The car just rolled 70k miles so it might be a good idea.

Thanks.

QWKSNKE

I wouldn't randomly replace them. 70k miles is nothing on those parts

Find someone that can datalog the car on the dyno and see what those items are telling the car eec

Merc63

10.4 AFR stock????


That can't be correct, have your confirmed that? Throw a AFR monitor in your secondary O2 sensor port... That's wayyyy too rich.