More (Horse) Power!

by James Walker, Jr. of scR motorsports (2000)

More Power!  More Power!  More Power!

Exactly one hundred and twenty-four horsepower just doesn’t cut it, does it?  After racing our 124-horsepower 1997 SC2 in Showroom Stock for two years, we were ready for the switch to ITA – and “more power” was one of the biggest reasons for the change.  The draw of big power, monster acceleration, and tire-spinning torque was just too much for us to pass up.

At the onset of the 1999 ITA season we teamed up with pro engine guy Mark Womack who, utilizing his lessons learned from his days supporting the ICY racing efforts, worked with us to develop a top-shelf Saturn ITA-spec motor.  As you will shortly discover, there is not a small-block Chevy trapped inside of the Saturn 1.9-liter motor, but – with the right combination of parts and patience – there IS power to be unleashed.

Before you read any further, we should warn you that there are no “speed secrets” here – sorry!  Instead, what you will find are the results of hours of dyno testing and tuning on an ITA-spec motor.  Since your requirements, rules, and/or budget may be significantly different from ours, your results will certainly vary…so with that said, let’s go find “more power!”

ITA Rules and Regulations

Before we began our engine project, we sat with Mark and developed an engine strategy.  On one hand, we wanted power, and lots of it, but the rules and regulations in ITA were very clear cut – and quite restrictive.  For this reason, several of the modifications listed herein might not seem ‘sexy’ or ‘cool’ but given the constraints of the rules at hand, those big cams and turbo kits were off-limits.

Essentially, we were allowed to experiment only in the following areas:

  • Intake system up to (but not including) the throttle body
  • Spark plugs and plug wires
  • Head and intake manifold (port matching only)
  • Compression ratio (increase of 0.5)
  • Cam timing
  • Exhaust manifold and tubing
  • Emissions equipment removal (catalytic converted included)

Note that the list did not mention camshafts, intake manifolds, ported heads, computer chips, or big-bore throttle bodies…these parts, by the rules, were required to remain stock.  D’oh!  How were we going to make ANY power?

The Parts List

With our requirements in hand, we were ready to start the project.  Since engine balancing, blueprinting, and a slight compression increase were allowed, Mark attacked the engine internals while we went shopping for parts.  Armed with our MasterCard, the basket filled with the following goodies:

  • Ceramic-coated Powerstack from SPS with conical filter
  • AC Rapidfire spark plugs
  • Magnecor spark plug wires
  • Stainless steel, mandrel bent exhaust tubing (although we used the 1992 stock Saturn header)
  • Borla straight-through 3” race muffler
  • Plenty of RedLine 30-weight racing oil

Every single other part that went into the engine was direct from our local Saturn of Ann Arbor Retailer.

Machine Work

We definitely had the easy part, as Mark toiled away with the stock Saturn engine internals.  Although stock parts were used throughout, Mark sorted, matched, and machined (where allowed) to optimize the fit, finish, and performance of our motor.  His list of modifications ended up looking like this:

  • Shaved the cylinder head to achieve a 10.0:1 compression ratio (up from 9.5:1 in stock form)
  • Bored the block to accept Saturn pistons 0.4mm larger than stock (now it’s a 1.92-liter motor)
  • Port-matched the intake manifold to the cylinder head
  • Port-matched the exhaust manifold to the cylinder head

Again, not a very long or glamorous list, but we took advantage of every modification permitted by the rules.

Assembly

As the parts came together, we quickly learned just how many emissions devices are strapped to the poor Saturn motor – the pile on the floor after final assembly was pretty sizeable. Canister purge solenoids, EGR valves, PCV lines, and other miscellaneous switches and sensors seemed to be everywhere.  Nothing against the environment, but good riddance!

Finally, we were getting close.  We buttoned up the baffled oil pan and front cover as Mark readied the dyno for the motor’s maiden run.  Just how much power could there be with all those stock parts!?!  The answer was getting close.

It’s Alive!

Oil, air, gas, water, power, go!  The motor fired on the very first try (after first checking for oil pressure during cranking).  Yahoo!  The smell of our green engine filled the control room as the sound of the open Saturn race exhaust certainly caught the attention of anyone in earshot of the dyno.  Mark carefully ran the motor through its paces for the first few hours, delicately breaking in the critical components.  We were counting on this motor to last through the ITA Championship…and the following few hours were to be among the most important!

Once the break-in was complete, we drained the dyno oil and filled the crankcase with RedLine’s finest 30-weight race oil.  Firing the dyno back up and running heat into the oil lasted all of 15 minutes…the power pulls were about to begin!

Tire-shredding Torque?

Well, not quite.  Our initial dyno pulls certainly showed that our changes had netted a significant power gain – approximately 20 horsepower more than stock – but we knew there was room for improvement.  After all, this was in our “out of the box” configuration.  Still, 145 horsepower was impressive given the stock cams, intake manifold, etc.

After hours of tuning, Mark managed to find another peak 5 horsepower from cam timing, air filter, and exhaust configurations.  Of course, these changes had consequences on low-speed torque and power, but since this was a race motor designed to run above 5,000 RPM, those trade-offs were readily accepted.  150 horsepower was the target at the outset of the project, so we walked away from the dyno satisfied with our results – a 21% horsepower gain using mostly stock parts was something to be proud of!

Of course, just as important was the fact that our ITA car weighed in at 2170 pounds – compared to 2395 for our Showroom Stock car.  When coupled with the power gains, our horsepower-to-weight ratio went from a portly 19.3 pounds-per-HP in SSC trim to an Integra Type-R like 14.4.  That’s a difference you can feel!

And, Well, That’s It!

So, now all of our secrets have been laid on the table.  No magic parts, no silver bullets, just the correct mix of parts and attention to detail during the assembly.  Of course, in a few years when we move up to E-Production we will be searching for even more power, but for now we’ll take what we have.  Besides, it’s time to go racing…

JWJr
teamscR.com