Although in stock trim the Saturn powerplant makes a respectable amount of horsepower and torque, you can never have enough of either. It sure is disappointing to watch that 140+ horse Nissan walk you at the start of the race time and time again…
In E-Stock, SSC, and ITA, you really can’t do much with the engine – legally, anyhow. We have found through dyno testing that a fresh rebuild with a K+N air filter, Red Line Racing Oil, and a 2" open exhaust (no muffler) from the cat-back will net about 130 horsepower at the crank, up 6 hp from the advertised ‘stock’ rating. It may not seem like much, but that’s about a 5% power increase. Further testing with aftermarket spark plugs and plug wires made no difference – evidently the stock ignition system is pretty robust at these power levels. Finally, for ITA, SPS offers a great tri-Y ceramic-coated header (be sure to scrap the cat while you’re down there).
For those of you not limited by preparation rules, take heart that in addition to the modifications listed above, the Saturn powerplant will respond quite well to basic hot-rodding techniques. Keep in mind, however, that you should not expect small block power from the little 1.9l…
1. Compression, compression, compression. With the Saturn 1994-1997 DOHC, there are two simple ways to raise the compression ratio:
- Shave the head – taking off 0.50mm will bump the ratio from 9.5 to about 10.2
- Install the flat faced intake and exhaust valves from a 1991-1993 DOHC – this alone will bump the ratio +0.3
2. Get air in, get air out. A quick list of what has worked for us on our project car:
- Extrude Honed intake and exhaust manifolds
- SPS enlarged throttle body (52mm, up from 50mm)
- SPS powerstack intake with K+N filter
With all these modifications and an otherwise stock exhaust system, our project car runs consistent 15.8’s in the quarter mile (stock 2’s run about 16.5 seconds). More extensive exhaust work planned for next year should bring that down into the mid-15’s, or so we hope.
Sorry, but there are no big secrets here. In both E-Stock and SSC you can legally change your transaxle fluid - that’s it. We happen to use Red Line D4, and after one season of abuse - and without changing the fluid even once - the transaxle internals looked as good as new (crew chief note: that included a few too many 8000 RPM downshifts). The transaxle appears to be bulletproof at these power levels.
The ITA crowd and street car folks have a few more options. Although very hard to come by, a limited slip or torque-biasing differential makes a world of difference. Our project street car is equipped with a Torsen torque-biasing differential, and exiting corners on the throttle is no longer a waiting game (if only it were SSC legal…). Final drive gears are also ITA legal, and with the incredibly low 0.73:1 fifth gear ratio you will probably want to ‘super size’ your final drive, but we do not know of anybody with parts on the shelf today.
When shopping for a spare transaxle, be aware that - even though the internal ratios are different - both the 1-series transaxle and the 2-series transaxle are mechanically interchangeable! We know of at least one competitor who purchased a 1-series transaxle and found out the hard way that the ratio change is not favorable. I bet he would have managed to get great fuel economy, though.
Warning - do not go into this section thinking that you will learn how to magically shorten your Saturn’s stopping distance! As with any other automotive application, making changes to your Saturn’s braking system will not have a significant impact on stopping distance. If you want to stop in a shorter distance, go buy stickier tires! However, in order to compete on a regular basis, changes to your stock braking system are absolutely necessary to increase fade resistance, improve pedal feel, and reduce wear.
Rotor heat storage and dissipation is the number one brake system concern of any Saturn competitor. Stock Saturn rotors perform adequately for autocrossing because the brakes are allowed to cool between each lap, but for road racing the rotors are not large enough to store the heat generated by lap after lap of 100 mph stops. Unfortunately, Club Racing rules prohibit the use of larger rotors, so the heat must be dealt with in other ways. (Note that ITA drivers can – and should! – use brake cooling ducts, but the rest of us are not so lucky.)
The first line of defense is a quality brake fluid. Several are on the market, and if you stick with one of the ‘brand names’, you should be safe. Don’t cut a corner here, or you will find out going into turn 5 at Road America that your fluid isn’t up to the task! For street and autocross duty, changing your fluid once per year is probably overkill, but for the road racers, bleeding the fluid between every race is mandatory. In fact, we bleed our fluid between every track session (4 times per race weekend). It might sound unnecessary, but the first time you forget, it will come back to bite you. Want to see our battle scars?
The next upgrade should be brake pads. In this area, autocrossers and road racers have very different needs, and a great autocross pad should never be used on a road race car. If your Saturn sees both autocrossing and road racing duty, you need to consider separate pads for each type of event.
Autocross-specific brake pads will typically generate peak output at lower temperatures than road racing pads, and do not need to get hot before they start to ‘come on’. A good autocross pad will also have great initial bite and allow the driver to modulate the pedal throughout the stop. SPS’ Kelate Metallic autocross pads meet all of these criteria, but like most autocross-specific pads, they will fade quickly at higher temperatures, so they are not suitable for road racing applications.
Road racers will require a pad which operates at higher temperatures without a loss in performance. During one of our test days, we used thermal paint to determine our rotor operating temperatures and found peak temperatures as high as 1100° F! Because of the high temperatures seen on our SC2, an insulating liner between the friction material and the backing plate was deemed to be mandatory for our application. Expansion grooves were also necessary to prevent the friction material from cracking as heat built up – and we found through experimentation that 1 expansion groove is not enough for a Saturn. We use two grooves exclusively to prevent premature pad disintegration.
The only brake pads we have found which meet all of our road racing requirements are manufactured by PowrPad. Other materials we have tested in our application have debonded, cracked excessively, or transferred excessive heat to the brake fluid. And although the PowrPads have the ceramic liner and twin expansion grooves, they only last about 2-3 race weekends before they need replacing. You can’t have everything, I guess…
The only other ‘tuning’ you can do to the braking system is to vary front and rear friction materials to change the braking balance of the car. We think of it as using the brake pads as a bias bar. In 1998, we chose to use a slightly more aggressive rear compound to help the car turn-in under trailbraking conditions, but in the rain, one could use a less aggressive rear material keep the back end in line! In either case, this parameter is best evaluated by each individual driver.
Finally, unless your Saturn came equipped with ABS, you are stuck with rear drum brakes; however, you can easily convert it to rear disc brakes using factory parts. The rear knuckle and bearing are the same for the disc and drum cars, so you can complete the entire job without even having to reset your alignment. Best of all, SPS has recently assembled a kit which includes all of the hardware necessary (even fasteners) to complete the job in your driveway in a few hour’s time. The serious competitor will not hesitate to make the switch – and it’s SSC and ITA legal to boot.