Motor Swaps

niall · Joined: 06 Sep 2007 Posts: 153

When thinking of doing a motor swap to increase your cars power output, Powe to weight is something that should be considered. Installing a sr20 or rb20 into a bmw 5 series or holden commodore, the engine will work very hard and provide poor performance because you have put a small engine in a big car.

Putting a big engine in a small car is a sure way to make it fast but more attention must be then paid to issues like traction,driveability and cornering.

V8 engines and some big sixes have massive amounts of low rpm torque. this is great for off roading,towing and usually performance. Alot of V8 engines were designed for cars weighing 1600-2000kgs with big solid rear ends and alot of traction. Taking that same engine and installing it in a bmw 3 series or mk2 escort will give the vehicle a great power to weight ratio but all that low rpm torque in a vehicle weighing 950-1150kgs will probably mean poor traction and tyre smoking action through the first 3 gears, Great fun for a week, but not so great when grandma in her 200kw Aurion leaves you behind while you are fishtailing and tyresmoking up the road!

Personally for light weight vehicles with standard rear ends and for street use i recommend using a motor where peak torque is delivered much higher in the rev range. this will make the vehicle much more driveable in the wet at low rpms and improved traction under hard acceleration.

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