Tucson Course Layout - Day 1

2 years and 2000 miles away from the East Coast, who would have thought that I would find myself on dirt with the Evo again. This time I find myself in the Southwest at the "sunniest city" in North America: Tucson Arizona! Lots of dirt, lots of land, lots of motorheads make a great recipe for off-road venue potential.

In the past couple of months, I've been helping a group of rally enthusiasts with breaking new grounds at a potential new location for a rally racing venue in the South East side of town. Long and short of it is there was a lot of blood/sweat/tears poured into clearing up trees, fences, brushes, cactus's, etc, and with 90% of most obstacles cleared, it has now come time to actually lay down a course. With my background in organizing three years of my own rallycross events (many of you have most likely attended) and 7 years in being a stage commander with Rally New York, I went ahead and laid in a tentative course using aerial photos and a little photochop skillz.



~~~~~~~~End of the Day Report ~~~~~~~~

Today the planning went better than expected. Originally we were only planning to get half of the course laid out due to the lack of cones, shortage of day-light, but ended up laying out the entire course with plenty of time to take the Evo for a few spins to test the course for safety, speed, and the surface.

The first part of the course is more technical, with a switch-back and tight slaloms, I was only able to get the Evo up to about 30mph. We went back and adjusted it so that the switch-back wasn't so difficult; Evo was able to hit about 35 after adjustment. The second half of the course is much more opened up, and we realized we hit almost 45 mph on a straight section on the first time around. We had to make a few adjustments, and were able to slow the course down to about 35.

The crazy thing that confused both Lee and myself was the last section; gravel. We both thought the speeds would be much higher on the gravel surface but ended up causing the Evo to hang its tail out in a drift throughout almost every turn...quite frustrating as a driver, but as far as course design it works because the surface naturally forces the driver to slow down toward the finish.



The surface held up really well for the 6 runs we did, but visibly some areas started to loosen up. Contrary to what I'm used to (mud, grass), there was still plenty of traction in the loose dirt. Unfortunately we have to be careful about loose surface because it causes too much dirt to be kicked in the air (a big no-no for the land owner and its surrounding customers).

Next step: the land owner has gratefully offered to water our track couple times each week to see if that will cause the earth underneath to solidify. Worst case we will need to throw mulch down in areas prone to loosening up and dump water frequently in those areas so the moist can stay in the dirt longer. We will be running a few more times to check out logistics and finalize the course before officially opening up the venue for a registered and sanctioned motorsports event.

Project Evo Tuning (Let's add a sprinkle of Subaru)

Dare I say this?

Many have asked, and YES I am bringing Subaru's into the Project Evo Tuning Series! There I said it. I figure why not?

For the longest time Evo's and STI's have been compared in every aspect from the AWD performance to their chick magnet rating, and it is now time for me to compare their OBD-II data!

I realize they're vastly different in engine design, and thus I'm expecting the data collected from these Factory Tuned vehicles to be very revealing about their performance advantages.

Predictions
Following my datalogging traditions, I will be carefully monitoring Airflow, Timing Advance, and Knock Sum.

• The 6- Speed Gearbox that came on the STI and the MR are distinctly different . I'm not a transmission expert so I wouldn't know how to interpret it, but I know these ratios will affect the values I will be seeing. Look at how the STI is consistently lower-geared throughout.
• 2.5 versus 2.0 Liter: Displacement difference is going to contribute to the airflow values greatly. Would I see a higher spike in Airflow in the STI, with the MR catching up midway through the RPM?
• Turbocharger Size: Need I say more?
  

Become Part of Gus' Tuning Story

If you have $1 for me, I will take it!

The money will go toward purchasing a Wideband O2, Evo Scan, and a Digital Boost Gauge.



I will think of good ways to reward you when it's all said and done.

~ Look out Subaru's here I come!

Project Evo Tuning (EvoIXMR versus EvoIXRS)

The Battle is ON. Head to Head, my MR against Rich's RS.

Both cars are Stock, Factory Tuned, and strangely the RS out performs any and all other Stock Evo's I know. It out ran Doug's IX MR and Henry's GSR. Is it just a well built EVO, or are the cars different from the factory? Let's dissect it.

The Meeting
The sky was raining, dark, and abnormally warm (50~60F). I heard a rumbling exhaust approaching from the distance; Rich arrived.

The Goal
We wanted to do enough pulls until we are completely satisfied that we have everything needed to find out the real differences between the MR and the RS. Since I've read that on the IX, the MR 6-speed advantage doesn't kick in until 4th gear, we had limited the agenda to 2nd and 3rd gear pulls from 2500rpm until redline. (We did do a 4th gear pull which I have eliminated from discussion)

The Prediction
I've been told that the IX RS and the MR should have no ECU or mechanical difference. I have not confirmed it, but I will in my next blog. Regardless, here's my original prediction cut and pasted:

Stock to stock comparison, I'm going to expect the RS's timing to be a little more aggressive, the AirFlow value to hike at a sooner RPM and to hold steadily higher AirFlow value all the way to redline.

The Test (2nd Gear Pull)

Initially as 100% throttle is applied, you can see the timing dips really low (MR to 3 and RS to 2) and climbs steadily upward until they both end up at 17 degrees. It is clear that after 5500 rpm, the RS starts to close in on the timing advance numbers but nevertheless reaches 17 deg later than the MR.

I was totally wrong about the Timing Advance Prediction! As you can tell, the MR wins most of the race, and with its more aggressive timing, it should be giving the engine a little more advantage.

Note: The MR showed knock count of 1 between 2700-2900rpm while the RS showed knock from 3000-4500rpm (between 1 and 2 counts). Bad gas? More Aggressive tune? I don't know.


The Airflow comparison is where the RS shined and walked away from the MR. From the very beginning, the RS has a slight advantage on the Airflow and around 3700-4250rpm, it really puts the beating on the MR. Strangely, at around 4300rpm both cars showed a decline of Airflow value! Air restriction, back pressure, resonance frequency, AFR, and critical speed of motor may all have something to do with it.

There after the RS wins the race entirely until the end the MR makes an attempt to catch up (never does).

In this case I was totally right about the prediction of Airflow values. Because the RS steadily flows more air through the intake, with a good tune, it would undoubtedly product more horsepower than the MR.

The Test (3rd Gear Pull)
More of the same, but this time in 3rd gear pull fashion. Ignoring the first portion where the timing advance dips very low, the MR out advances the RS by far (largest gap of 4 degrees at 4400rpm) and continues to hold a steady lead until redline; MR finishing at 17 deg while the RS finishes 1 deg lower at 16.

How much advantage does this help the MR in producing more horsepower than the RS? Since the MR didn't register any knock in its pull while the RS had between 1 and 2 degrees of knock between 4200-4800rpm, the MR presumably has more potential in timing advance tuning than the RS.


Airflow comparison: Again, the RS out performs the MR by light years. Regardless of its knock count and the less aggressive timing advance characteristics, after the turbo spooled completely, the RS pulled an instant 50 Hz advantage, grew the gap significantly between 4600-5700 rpm, and held on for a steady win.

Having a better airflow flow characteristics in both 2nd and 3rd gear pull, I'm not surprised to see Rich's RS pull away from cars like mine. With a lighter car and more horsepower potential due to higher volume intake of air at all rpms, I'm expecting his car to respond to mods better than mine. Who knows?

My Comments
The RS had consistent knock present right at the meat of the power band (3000-5000rpm) even though it has a lower overall timing advance values which is a terrible situation because if further timing needs to be pulled from the map in order to reduce knock, the RS may suffer more horsepower loss. Tuning the timing advance may be where the MR can gain some ground back.

As far as the airflow characteristics goes, did anyone notice that on both 2nd and 3rd gear pulls, the MR has a little bit of a jump right before 3300rpm? It seems like the MR had better response to throttle? Perhaps there's not enough data to make any solid statement or claim here.

Next Steps

• ECU: To bust the myth about RS vs MR, I'm going to break into the ROM and compare chart to chart the differences between the AFR, Boost, and MIVEC maps. I'm not going to be surprised if I find them all to be the same, but at least I have satisfied the itch.
• Boost Leak Test: To cover any mechanical difference the cars may have, I'm going to conduct a boost leak test on both cars to make sure the car is boosting healthily.

Stay Tuned...