As a car enthusiast with over a decade of experience, I’m always drawn to unique challenges and exhilarating drives. So, naturally, when the opportunity arose to turn a 1977 Saab 99 into a rally car, I was hooked. This article chronicles the second phase of our rally car build, focusing on squeezing more power out of our Saab 99’s engine.
The Need for Speed: Addressing the Saab 99’s Power Deficit
Our initial foray into the rally world with the Saab 99, while successful, exposed a glaring issue: a lack of power. The car felt sluggish, especially in a straight line. Dyno tests confirmed our suspicions, revealing a meager 82 horsepower at the wheels – a far cry from the engine’s original 115 crank horsepower rating. A compression test indicated a tired engine, leading us down the path of a full rebuild.
Unleashing the B-Series: Engine Rebuild and Performance Enhancements
Our goal was clear: enhance the Saab’s performance without compromising reliability. We envisioned competing in the M2 class, which allows for significant modifications. However, we opted for period-correct tweaks to maintain eligibility for potential Historic class events.
Engine Rebuild: A Blend of OEM and Performance Parts
Collaborating with Jack Lawrence of Motor Sport Service (MSS), we sourced high-quality bearings, gaskets, and pistons. We chose cast flat-top pistons from a 2.0-liter Ford Pinto, a cost-effective way to increase compression. These pistons required some machining to fit the Saab’s engine, but at around $90 each, they provided an excellent value proposition.
Head Work: Porting and Precision
The Saab B-series engine boasts a robust intake but a somewhat restricted exhaust. We focused our efforts on improving exhaust flow. Using a die grinder and a Dremel, we meticulously cleaned up the exhaust ports, smoothing out transitions and matching them to the exhaust manifold gasket. The head was then professionally decked, fitted with new valve guides, and treated to a three-angle valve job.
Camshaft Upgrade and Other Goodies
To complement the improved breathing, we installed a street performance camshaft from MSS. This camshaft, designed for a strong powerband between 3000 and 7500 rpm, was paired with dual valve springs to prevent valve float at higher revs. Additionally, we opted for a lightened MSS flywheel, sacrificing five pounds to improve throttle response and acceleration.
The Results: A Healthier Heart for our Rally Beast
The engine rebuild, including parts and machine work, cost approximately $1800 – a reasonable investment considering the performance gains. While we haven’t dyno-tested the rebuilt engine yet, we anticipate a significant boost in power and torque across the rev range.
Beyond the Engine: Enhancing Grip and Handling
Our first rally highlighted the desperate need for a limited-slip differential. Thankfully, SaabRally.com organized a group buy for Gripper differentials. This 1.5-way clutch-type LSD, designed for rally use, provides excellent traction on corner exit while allowing for smoother deceleration.
Transmission Swap and Suspension Tuning
We paired the Gripper differential with a used five-speed transmission from a mid-80s Saab 900 for more comfortable transit stages. To dial in the handling for tarmac rallies, we added Addco anti-roll bars. These bars effectively reduce body roll without sacrificing adjustability for gravel events.
The Finishing Touches: Attention to Detail
With the major components in place, we focused on refining the car’s reliability and usability. This included:
- Cleaning up the wiring harness
- Applying flocking to the dashboard for reduced glare
- Reinforcing the fuel cell mounting straps
- Installing hood tie-down straps
Conclusion: Prepped and Ready for the Next Challenge
With weeks to spare before our next event, Rally Tennessee, we’ve transformed our Saab 99 into a more potent and reliable rally machine. We eagerly anticipate putting the car through its paces and sharing our experiences in future updates.