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Old 02-08-2012, 11:09 AM
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eschaider eschaider is offline
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Join Date: Feb 2006
Location: Gilroy, CA
Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
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If you are going to put a ModMotor into a Cobra you will probably want to go supercharged. The naturally aspirated versions of the motor including the Coyote produce impressive power but at elevated rpms, because of their displacement. The only replacement for displacement is a blower.

A blown version of the engine would be better off not to use the Coyote as the starting point. The very same thing that gives the Coyote the great n/a performance - the variable valve timing - does nothing for the blown version of the engine and adds a level of unneeded complexity to the platform. The blown versions of the Coyote are using aftermarket toys to impede or eliminate the TiVCT feature of the Coyote.

Once you do not use the TiVCT cam phasing feature the earlier version of the engine has a more attractive profile for supercharging - including very importantly, in the supercharged blocks, thicker cylinder walls.

The blown version of the engine has about 90% of its peak torque right off idle. The torque curve tends to be table flat from about 1800 rpm all the way to redline! The blower puts a vast amount of power down extremely low in the rpm range which makes for a very nice cockpit driving experience.

A relatively mild form of the engine on 91 octane will produce a little over 600 rear wheel HP and about 580 ftlbs of torque at the tire. You can get flywheel figures by dividing by .85 which means the flywheel numbers would look like 700 hp and about 680 ft/lbs of torque. this comes pretty close to lightening in a bottle in one of these cars.

The other nice feature is light weight. You can get a fully dressed version of the engine less flywheel and transmission in at about 450 lbs which produces a very nimble package, especially when you consider the torque curve.

As with any of the higher powered versions of the Cobra your ability to get into trouble fast has been enhanced with this engine choice. In terms of reliability and performance it is an impressive kick in the pants.

The engine as I have just described it will cost between $12,000 and $15,000 depending on how crazy you want to get.


Ed


p.s. While it is not a traditional choice by any means it does come from the right gene pool in as much as it was the engine platform for the 2003/2004 Cobra's. The other attractive aspect is with polished valve covers the visual impact when you open the "bonnet" is stunning. The engine is actually the same size or a whisker bigger than the 427 SOHC. The visual WOW is pretty good.
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Last edited by eschaider; 02-08-2012 at 11:15 AM..
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