I cannot fathom how any chip can affect a mechanically injected engine's HP or torque... Above idle...
The 98/99 still uses a mechanically injected engine...

Did the guy do anything to the injectors or pump timing?

It must be playing with the response curve of the IP rack actuator, inhibiting the operation of the EGR, and delaying opening the waste gate.

These are the only points that can influence the operation of this engine. The 606 turbo engine vacuum system is very simple, with two vacuum transducers, one for the EGR and one for the waste gate. No vacuum shutoff (it's electrical), and no transmission vacuum control (this is done by CAN bus to the electronic transmission controller).

No...all he did was replace two chips.

that makes sense.
so likely he shifted around the HP and Torque numbers by changing the defuel map and turbo wastegate dump... I can see that affecting the seat of pants meter...

I don't doubt HP gains which are relatively easily achieved by overriding the conservative boost management. The ECU must be able to influence the full load stop because otherwise swapping a pressure wastegate actuator for the devil's own vacuum actuator is half the battle.

Until there's better information, I'll assume the mpg projections are for their chips in general, not specific to this application.

Sixto
MB-less

Yes - that is basically correct. Also, the ECU can override the "full load stop" on the electronically-governed mechanical pumps. The chip simply maxes out the fuel delivery available from the 6mm elements on the 98-99 E300 / 606.962 IP. And it probably increases boost as well... this would have been easy to measure before/after, bummer I didn't think to ask David to check, oops. Photos of the 606.962 pump internals are here... skip down to photo numbers 15-20, notice the back half is pretty empty.



Now THAT would make sense. Chips on newer gasser cars can modify fuel delivery and ignition timing (amongst other things), and I could understand a potential for a small gain in economy for certain models/engines. But not on an MB diesel with M-type inline pump. I think you nailed it, Sixto, those are boilerplate claims made for all their chips, even including chips that can't do what they claim. Lousy, misleading, inaccurate marketing. At least there's a good power gain.

:chinese2:

EXCEPT that I was given the 3-4 mpg increase in an email responding to an inquiry I made about MY PARTICULAR CAR. So the guy at Rocketchip was not holding that out to me as a generic figure.

I am going to continue to monitor mileage for a couple of months, filling up at the same station. Then I will give him a call to ask some questions.

He was giving a sales pitch with the intent to make a sale, not necessarily provide accurate information about realistic gains. I'd be willing to bet they never actually put a 210.025 on a dyno to measure the actual change, or at best they took info provided by an early customer and used that info.

I went through this discussion with a different chip maker (or two) years ago when they were claiming steep power gains on a 500E. I eventually got a guy who admitted their charts are based on "average gains for that type of motor" and that it was not accurate for the 500E specifically. I was shocked at the honesty, but also don't think they removed their listing/info for the 500E chip (can't remember - they may have).



I'd expect a tap dance about how you are using the power more and that is affecting the MPG numbers, varying fuel quality, AC usage in summer, winter blend fuel with lower BTU, etc, etc. Hope I'm wrong. It will be interesting to see what they response is after you have more data to share.


:stuart:

There's undoubtedly a lot of plausible deniability baked into the whole arrangement. But, if it every occurs to me to be disappointed about no gains in fuel economy, I'll simply stomp the accelerator, feel that smooooooth power, and keep driving. :D

BTW if a customer is dissatisfied for any reason they'll do the next stage up for free.

Ooooo. Is there another stage you can move up to?

:w00t:

Why yes, in fact. There are Stages 1, 2, 3, 4, and 5! But, in order to benefit from higher stages, there would have to be hardware modifications (e.g. exhaust). So, I don't think I could realize any benefit from a Stage 3 tune. Rocketchip did make the point that Stage 2 is what most people typically do and what they would recommend if I didn't plan on other mods (which I don't).

Eh.... do you have a link to their Stage 3/4/5 claims? All I could find on their website was Stage 2 at +30ps.

That is about the limit of what the stock 6mm elements can deliver. Exhaust, intercooler, and other mods will not increase power unless you have the IP modified at considerable expense (like, $2k plus the 5-6 hours labor to R&R the pump). If they are claiming bigger gains with just a chip and the stock pump, that is definitely out of line.

:blink:

No, I don't. And it may be that, on certain cars, you can only do so many stages. While Rocketchip has apparently done quite a few MB's, their main stock 'n' trade is VW. Do a search and you'll find all sorts of VW owners ranting and raving (and being purely objective, of course ;)).

BTW, those folks on VW boards are FANATICS....not normal folks like us MB owners. haha

FYI here's a thread that claims a fuel economy improvement:

http://www.peachparts.com/shopforum/diesel-discussion/269087-99-e300-chipped-yee-hah.html

How many data points could he have collected in a month?

Sixto
MB-less