Mike Mann's Hot Rod Corsa
The highly modified, flat black, Corsa pictured below is owned by Mike Mann of Salt Lake City, Utah. Mike has had the car in storage for the past few years, but when it appeared at the 1990 CORSA convention, it turned a few heads, to say the least.
Starting with a 1965 140 horsepower engine equipped with an Otto's oil pan, baffle spacer, oil pump and TB-30 camshaft, Mike added a Dale's distributor, advance/retard canister, bolted flywheel and Seth's spark plug wires. The cylinder heads were reworked to open up the combustion chambers much like turbo heads. The top 1/3 of each piston was milled off as described in an article written by Bob Helt for the CORSA Communique. Oversized valve seats were installed and Otto bored the cylinder barrels to .060 over. TRW pistons and pro Total Seal rings were installed.
Fuel injection was added, using an Air Sensors aftermarket unit intended for the 305/350 cu. in. small-block Chevy V-8, with a few resistors changed out in the "black box" to yield the correct fuel flow for the Corvair, as measured by an exhaust gas analyzer. The unit, which is no longer on the market, can be adjusted to any of 5 different modes.
A hot wire air mass sensor is used so that when the turbo spools up and increases the air flow past the hot wire, the flow rate of fuel is increased to maintain the correct mixture ratio. A compressor by-pass valve from a Porsche 911 Turbo is housed in the tube between the sensor and the turbo unit to keep the turbo spinning when you take your foot off the gas between gears, reducing turbo lag. It also promotes longer life of the turbo vanes. The same tube is used for the water injection system.
Mike uses an E-flow turbocharger with a B-flow exhaust housing and exhaust manifolds from a 110 horsepower Corvair engine to encourage high exhaust gas velocity and to reduce turbo lag. A small sacrifice in total horsepower is made in the interest of crisp, instant horsepower on demand.
The intercooler uses a plate type oil cooler for a high capacity core. It and the electronic fuel injection are flow rated at 1,000 CFM, which is needed at full boost. A Hobbs switch turns on the water injection at 7 pounds of boost.
Keeping it cool
Mike had to do a little scratch building to accommodate some of the on-board systems on this radical Corvair. The trunk was sub-divided into two sections, with a sub-trunk to house a pair of oil and water radiators, an electric water pump, A/C condenser and electric fan.
Slots cut into the lower valance panel allow air to enter, and it then exits through louvers on the sub-trunk floor.
The oil radiator is opened by an Oil-stat thermostat in order to maintain correct oil temperature.
The car's suspension is also heavily modified. 1" sway bars are used front and rear, and the rear one is adjustable. The heavy duty coil springs have been cut one turn and Clark's HD adjustable shocks were used, along with a Crown lowering bracket, a quick steering box and telescopic steering column with an adapted Momo steering wheel.
Mike also installed power front disc brakes to make sure the car stops as well as it goes.
Power is transmitted via a 4-speed transaxle with a 3.27:1 final drive ratio. Front tires are 205x60x14. Rears are 225x60x14. Both are mounted on 7" wide Chevy rims.
Here's a shot of the engine compartment, showing the extent of the top-side modifications. We'll take a closer look at the engine later.
Mike estimates the Corsa's top speed to be in the area of 130 to 135 MPH, although he won't admit to having it up there. Must like to be on the right side of the law!
He did mention it would lead an early '90s 911 Turbo to 100 MPH and once walked away from a modified 215 cu. in. V-8 'vair with 3.55:1 gears (although the V-8 got the jump on him in 1st gear).
Click the road sign to see Mike's latest project!
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