From Bone Stock Street Car to E85 Track Machine - A Performance Driving Saga

Posted on 01. Jul, 2009 by jeffz in Features

Words by Carl M. Tootle
Photos by Dito Milian/gotbluemilk.com, Tom Sanders and Carl Tootle

Dennis and Peggy Hale made it clear you shouldn’t drive your convertible at the Thunderhill Miata event unless it had a roll bar. So in went the Boss Frog dual hoop. I hardly knew what that was. While the other guys were in auto shop in high school, I was practicing piano. Any teenager is interested in driving, but I was lucky to figure out which pedal made the car go and which stopped it.

Then, thirty-plus years later, my lady Charlee, light of my life and one of the original founders of Tucson’s Old Pueblo Miata Club, suggested we attend Thunderhill with a bone stock 1990 Miata while visiting my family in Sacramento. On the first day I burned out the original clutch, which had lasted well over 140,000 miles. I found that one can overdo high revs while excessively and amateurishly feathering the clutch during autocross exercises!

Dave DeNuzzo (the “Crazy Red Italian”) installed an upgraded clutch for the trip home. But by then I knew for sure I wanted to do more of this track stuff. I told my friend Robert M. Powers of Pro Per Racing about the Thunderhill adventure. He gave me a copy of the Mazda Miata Performance Handbook by Norman Garrett. Bob has a long history of racing, including setting Maxton, El Mirage and Bonneville land speed records in his class F gas-modified roadster. He asked a seemingly innocent but extremely devious question: “Would you like us to put in a turbo?” I replied, “Well, I guess so.”

He and Ryal Greenwood installed the Greddy kit, which produced about 6 pounds of boost. I was thrilled with the difference. A dyno run at Addictive Racing in Tucson showed that the 90+ factory wheel horsepower was now over 125, and I could see no reason why I shouldn’t add more and more and more and more!

Powers and Greenwood then did me a favor for which I will be forever grateful: they told me that horsepower is lower down the list of important racing car attributes. The suspension, the wheels and tires, the brakes and the driver’s ability are all more important.

A balanced car with all systems brought to the same level is almost always faster. With great effort, I resisted the temptation to immediately add lots of power. I learned a little about unsprung weight and bought some Volk Racing wheels that weighed about 10 pounds each, with some Falken Azenis RT-615 tires. I still use them on both street and track. I replaced the factory shocks with Tein SS+ adjustable coilovers.

Powers recommended I read Paul Frere’s Sports Car and Competition Driving. I did, and I’m still trying to digest its finer points. Ditto for Bondurant on High Performance Driving, Carl Lopez’ Going Faster!, Ross Bentley’s Speed Secrets and George Anderson’s Winning. I joined the Old Pueblo Miata Club and started attending ProAutoSports events at Firebird International Raceway in Chandler, Arizona.

In addition to OPMC members Richard Olsen and Geoff Pangrac, my mentors included Saguaro Miata Club members Lyle Schall and Rod DiMarco. We were part of the “Miata Contingent” for one event after another. My skill and understanding increased with instruction from Larry Pond, John Devine, Andrew Waltenburg and others. Eventually, I spent a day seeing just how late I could brake at the end of the mile straight on the Firebird Main Track.

Then I bought Brian Goodwin’s Miata Big Brake Kit. When he says you will never exceed its thermal capacity, he means it. No fade. Your braking point is later than almost everyone, and a later braking point is the equivalent of more horsepower.

By now, I was thoroughly obsessed with improving both the car and my driving, I signed up for a Speed Ventures event at Willow Springs. My instructor was none other than Emilio Cervantes of 949 Racing. I noticed that when he was driving my car, only a few higher powered cars with really experienced drivers were faster  but when I was driving, only a few lower powered cars with really new drivers were slower.

I still remember trying to make a quick steering over-correction at high speed going from the 900-foot radius turn into the 450-foot radius turn which leads to the main straight. Emilio instantly preempted, saying, “No! If you do that, you’ll go off track. Drive like your hands are in syrup.” I had spinouts from time to time, as well as polite crashes into hay bales and tire barriers. Jim Holmes always kept a supply of Miata red in stock at his body shop so repairs could be completed before the next track event. He and Dennis also did a great fender flare job to make room for larger tires. Mike and Ann of Mike’s Miata Place, Ebay’s azmiata_man and Flyin’ Miata kept us supplied with used door, fender and other miscellaneous parts.

Over time my driving continued to improve, and so did the car with 949 Racing’s 6UL wheels and Nitto NT01’s or Hoosier R6’s. Then, for the second time in my life, I lost an engine. When the original 1.6 liter finally gave up, it had over 150,000 miles and many track days on it. You may never have heard of “Tootle, the Little Engine that Could”  but it’s been popular in my family for several generations. That little Mazda engine kept running in spite of repeated flogging on track at revs of 7,500 and more, and increases in turbo boost to eight or more pounds with dyno readings in the 160+ horsepower range.

We put it out to pasture with a couple of lawnmower engines to chase. With help from friends Andy Aragon and Ray Niemi of Tucson’s Revolvstore, we found a used 1.8 in a salvage yard with only about 50k miles on it. Ryal and British Car Service of Tucson did the engine conversion using the Flyin’ Miata kit, which made it considerably simpler and easier, not to mention less expensive.

Ryal also championed the use of E85 ethanol. Not only is it friendly to the environment, but it also has a high octane equivalent and cool burn, allowing additional boost. Again British Car Service helped, with owner Bob Schlanger showing great patience with Ryal’s efforts to do a good job in somewhat uncharted territory.

Do we have an alcohol problem? Hell no. The fuel hoses were changed to flexfuel-compatible 5/16 Goodyear 300psi FI hose with the blue inner liner from Auto Zone. The engine requires approximately 1.62 times as much E85 as gasoline. Even 550cc injectors proved too small above eight pounds of boost, so we installed 1000cc RC injectors from Eric Woon at Apex Motorsports, along with a larger fuel pump.

Currently, the engine’s idle is a bit fussy. The typical injector pulse is 1.1ms (1.0ms to open the injector and 0.1ms squirt). To go leaner the next step is 1.0ms (no fuel!) and to go richer the next step is 1.2ms (twice the fuel!). The best compromise was to adjust fuel pressure to give a slightly rich mix at idle with a 1.1ms pulse.

Ryal also installed a Garrett GT28R60 water cooled, ball bearing turbo with a custom, jet-hot coated manifold from Rusty’s Total Performance. In our experience, even E70 Ethanol (the winter blend) has a higher knock resistance than 100 octane or 108 octane unleaded racing fuel, allowing more aggressive spark timing under boost. The cooler burning ethanol blend allows high boost on a high compression engine and creates less heat to remove through the cooling system.

Our next step is to add 949 Racing’s M-Tuned Coolant Reroute to improve general engine cooling. That kit is on order right now. Completing the picture for now is a custom exhaust with Innovate LC-1 wide band O2 sensor (required for proper tuning) and a DIYautotune Megasquirt PNP engine management system, tunable via laptop computer for either ethanol or gasoline; 91 octane premium gasoline or 100 octane unleaded racing fuel.  We also have an Auto Meter Boost Gauge and AEM A/F Meter running off a second O2 sensor.

The Megasquirt’s ability to instantly change maps from ethanol to gasoline and back eases the problem of E85 stations being somewhat few and far between. Oh yeah, we also added the KnocksenseMS from Boris Mohar to keep better track of engine-crippling detonation. Perhaps there is more boost in my future. Or another blown engine.

Ryal wondered if there was a better alternative than carting gallons of ethanol to every track event, so he called Don at Torco Fuels. They now supply us with ethanol at Firebird and we hope that others will consider the benefits of this fuel. If the demand is there, Torco may prepare and deliver E95 for an even cooler burn with even more power.

Meanwhile, my performance driving saga has continued with Hooked on Driving events, memberships in NASA and SCCA and the 20th Year Anniversary of the Miata at Mazda Raceway Laguna Seca.

I still remember grumbling at Ryal last year when the $900 “junkyard” engine was first installed and he limited me to 4800 revs, but cooler minds prevail! Again, it’s not just about horsepower. Since then, we’ve replaced the drive shaft and rear end with later model, beefier parts including a Torsen Type II diff. Boost is up to 15 pounds, revs back to 6500 (with a hard limit of 6800) and wheel horsepower to about 300.

After the latest tuneup by Jerimiah Taylor of Jumbo Motorsports using the steady state dyno at IA Performance, we have about 200 pound-feet of torque at 3,000 RPM, rising to 235 pound-feet at 3,500, rising again to 241 at 4,500, and then slowly tapering back towards 200 at 6,000 RPM. In other words, 200 or more pound-feet over a 3,000 RPM range. Such a wide band is far more useful on track than a higher but narrower one that would produce “peaky” power.

We do have to replace brake pads and gear boxes regularly. I’m checking into the Quaiffe transmission, but Ryal’s words still ring in my ears: “A lot of performance mods are to correct problems with the car. When you start with a Miata, there are no problems with the car. The mods just make the good performance even better.”

Related websites:

www.torcoracefuel.net/news.html
www.miatasatmrls.com
www.949racing.com
www.flyinmiata.com
www.oldpueblomiataclub.com
www.good-win-racing.com
www.mikes-place.biz