2000 Pontiac Firebird MMS 421 Concept
Morgan Motorsports put together this 2001 Trans Am MMS 421.
The parameters set down were that the power would have to 1) come from natural aspiration – no turbocharger, supercharger or nitrous oxide in use here, and 2) be in the output range of 600 horsepower. No small feat, indeed.
Starting with a sleeved block resulting in a 4.125 bore the MMS team installed a SCAT billet crankshaft. ROSS 2618 alloy pistons sit atop Callies forged I-beam 6.125 rods.
In Detail
submitted by | Richard Owen |
displacement | 6899 cc / 421.0 in³ |
bore | 104.77 mm / 4.12 in |
compression | 11.7:1 |
power | 466.1 kw / 625.0 bhp |
specific output | 90.59 bhp per litre |
bhp/weight | bhp per tonne |
torque | 745.7 nm / 550.0 ft lbs |
front tires | 295/35-ZR18 |
rear tires | 295/35-ZR18 |
f brake size | x 356 mm / x 14.0 in |
r brake size | x 356 mm / x 14.0 in |
front wheels | F 45.7 x 25.4 cm / 18.0 x 10.0 in |
rear wheels | R 45.7 x 25.4 cm / 18.0 x 10.0 in |
gear ratios | :1 |