On the after pdf, why the dips at 15 and 30 seconds? Did he fall asleep at the wheels?

Winmutt, have you tried to extract any extra power from your 91? I'm happy with mine as is...but would be glad to pursue gains if any are to be had.

At the wheels vs at the crank/adjusted hp is probably the difference


Sent from my iPhone using Tapatalk

That makes sense.

The 91 is staying stock. The only mod might be P2 flap replacement.

Those are the most confusing dyno graphs I have ever seen. I think it is due a software setup issue by the dyno shop. Crazy. RPM should be on the bottom (X-axis), power/torque should be the Y-axis.

Anyway, it went from 126 to 147, +21hp at the wheels.

At the crank, this should be roughly 168 to 196, or about +28 at the crank, estimating 25% loss from the funky Mustang dyno (with DynoJets, it's usually around an 18% loss).

The gain is definitely less than claimed, but still respectable. Remember, chip tuner advertised gains are ALWAYS crank numbers, because they are higher. Sure beats having to take an IP apart and twiddle screws inside!

:zorro:

It's been a couple of months and I now have a bit of fuel economy data. I'm not sure I see much improvement. I did recently have a highway run of 31.5 mpg, which is the best I've seen....but I doubt that's statistically significant. Last leg of journey (85-90% highway) was 532 miles and I got 29 mpg.

Part of my problem is that I didn't own the car long enough prior to the chip tune to have solid mpg data. But, as I mentioned before, I think I was getting 27 mixed, 30 highway.

My hope was that I would see 33-34 mpg highway, but I doubt I'll see that.

I will say, though, that I'm thrilled with the performance of the car irrespective of any fuel economy gains. I would do it again in a New York minute even without any mpg improvement. I now have the stock 99 to compare the 98 to and there's a very noticeable difference in smoothness, responsiveness, and power.

Contrary to their claims, I did not expect any increase in economy... your MPG absolutely would remain the same. You may get an economy increase with larger pump elements but that is a TOTALLY different scenario. I get annoyed with chip mfr's making claims that are pure BS, it's all marketing, no substance.

Overall, it sounds like the power gain was worth the expense, and it was painless compared to the OM603 procedure!!

:stuart:

It would be interesting to see if any others who've gotten chip tunes have seen improved fuel economy or not.

FWIW here is the explanation from Evolution Chips in the UK as to why there is/should be an increase:

Q. What about my fuel consumption?
A. With same driving style, improvements in fuel consumption of up to 20% are possible, especially in turbo diesel powered engines. Take a look at our fuel savings calculator to see how fast a remap could pay for itself.

Q. How is extra fuel economy achieved on Turbo Diesels?
A. Normally, when the same driving style is adopted after remapping, the mere fact that you now have more torque output at the flywheel for any given throttle angle will mean that you can make the same physical progress as before whilst using less throttle to do so. You will normally find you can also shift up a gear that little bit earlier, again due to the extra torque, so you are also limiting the overall engine speed that is being used on every journey. For those overtaking manouvers we all occasionally have to make, you will now be more relaxed and confident so again will tend not to be flat to the floor and panicking during such manouvers, thus, using less fuel due to more available power.

When these factors are then allied to the various tweaks we make to pump timing, boost pressure and injection calibration fuel tables you end up with an overall improvement in fuel consumption of up to 20%. Take a look at our fuel savings calculator to see how fast a remap could pay for itself.

Dont forget, we guarantee you will make savings... or your money back.

Another explanation: Chip Tuning advantages for gas mileage and power | MpgEnhance.com

Did he use a hot air gun to unsolder the chip and mount the socket?

From Rocketchip FAQ:

Also to note we use professional hot air soldering, and not messy flux-soaked clamps like our competition. It’s difficult to determine if the chip has been disturbed after we are done soldering. There are also no cold solder joints. It’s very clean and neat. If you’re getting re-chipped and the last chip tuner added gobs of solder, I’ll clean up the board and install a brand new chip. (Note: we only use industrial grade 70ns quality chips, not commercial 120’s.)

More torque or power on a diesel comes from more fuel, not less. Cruising down the road you are using the same amount of power as previously. It's marketing malarky.

:shutup:

Back in 2001 I had a Wettenauer (sp?) chip installed in my 2000 Beetle TDI. They installed a socket into which their chip and the stock chip could be inserted (plug and play). So, you could switch back to stock if you wanted. I never wanted to, but it was comforting to swap back to stock if a trip to the Stealership was required.

I kept and drove that car until earlier this year when I got my 77 300D NA. :D

x2. That reasoning makes sense for gassers and maybe DI but not IDI. It sounds like the chip delivers more fuel for less pedal travel. 20% improvement in mpg has to come from ~20% leaner fuel mixture. How do you achieve that with a chip when the business end of the pump is purely mechanical? Does that chip affect transmission programming? Even so it wouldn't improve highway mpg.

Sixto
MB-less