The baseline tune did not really lean the AFRs out. The AFRs were still around 10.2 to 10.6 depending on weather conditions. Stock I was mostly hovering around 10.2. I leaned them out to 11.2 with my tune and didn't see much in terms of a higher peak HP but I did widen the powerband.

My own software - it takes into account air density, frontal area, drag coefficient, car mass (+ occupant and fuel), gear ratios, wheel/tire size. It uses a moving average to smooth the input data.

The program uses the time it takes for the car to increase RPMs in a given gear, which directly translates to speed (given no slippage). From this it calculates the power required to accelerate the car in this time. It's not a replacement for a real dyno, but it's useful to monitor a trend (and it has worked fairly well for a friend's Evo as well as my old VIII).

With regard to the low gains, I think I need to do some pulls in other gears. Perhaps the transmission is slipping thru some RPM range in 3rd. I feel the car is almost about the break traction in 1st gear with my winter tires with WOT.

 

I ran my logs through DLL (Data Log Lab), and the trends are identical but the software gives higher power/torque values. Perhaps it is correcting for drivetrain loss and thus calculating power at the crank and not wheels. I don't know - it didn't mention it in the documentation, but it does ask for drivetrain losses in each gear.

 

Any advice what is going on here? This boost dip (easier to see on a linear plot) occurs every time in 3rd and 4th, even when stock with no MBC.

 

Its the stock WGA being too weak and opens briefly.

 

Even with stock boost at this altitude? Hmm. I'll look into a replacement.

 

Increased preload or Forge Adjustable units. We have the Forge units in stock with special deals for our ZChip customers.

 

I'd be interested in seeing some other people's boost graphs from this altitude to get a better idea of the problem. This seems pretty strange to be that a stock car would behave like this - my VIII (although obviously different turbo, wastegate, etc) tapered linearly with no weird dips.

 

Every Evo X we've dynoed and tuned does the same thing. It has nothing to do with altitude. Its the WGA spring rate.

 

On the +107hp car you had good success with, did you adjust the stock WG actuator at all, or anything related to the WG (aside from boost controller)?

 

Pulls in 3rd and 4th are virtually identical in terms of the curve and peak power (270whp in both cases), except that the car loses a lot of top end with the pulls in 4th (power is 240whp at 7000rpm in 3rd but only 200whp in 4th). In 4th, the power peaks at 5500rpm and tapers from there. In 3rd, the power peaks at 6100rpm.

Not really sure what is going wrong here - I have tried making the AFRs richer after 5500rpms in case the ECU was pulling timing (now tapering from 11.2 at 4500rpm to 10.7 at 7000rpm), but this doesn't seem to help. It looks like it could be the boost taper. However, I'm really interested in what others are doing with the ZChip at this altitude.

Edit: added crappy graph, which is hopefully good enough to see a comparison (left: 3rd, right: 4th):

 

Problems with mile high altitude and thin air can be alleviated with a larger turbo.

 

That's a bit drastic.

Let's ask this instead. I bought the WORKS drop-in, ZChip and MBC to increase my power at this altitude, and so far I have gained about 40whp in total, which is good. Do you have other customers at a similar altitude who are making more power with the ZChip and MBC? If so, what are they doing? I don't think I could go wrong getting more air into my stock turbo, so perhaps the wastegate mod, different air filter, intercooler piping or larger intercooler might be in order?

I would be happy with just 20whp more and that's all. I don't need a new turbo to achieve that target, so I just need to know if a better tune could do that, or if I need something else.