When we first heard of the Mercedes SLR Mclaren 722, we all licked our lips at the prospect of a 722 horsepower engine, but when the final figure of 650hp was released it left a sour taste in our mouth. Renntech soon put that sweet taste back with their own tuning package which boosted the supercar's power up to where it should be at 722 horses, and now by popular demand the tuning house has pumped yet more ponies out of the 5.4-liter supercharged engine bringing total power up to 740hp
For the upgraded tuning package Renntech have re-worked the ECU software and added a less restrictive motorsports-style exhaust system to get the extra ponies to the new Renntech Signature 10-spoke, 3 piece performance wheels.
For an extra bit of added spice the tuner has also provided a nice little video in which you can hear the engine.



Press Release

When Mercedes-Benz introduced its SLR McLaren 722, there was a bit of confusion about the special-edition's name. Many believed the car would offer a fire-breathing, 722 hp supercharged V8, but it doesn't (it makes 650 hp). Some believed that "722" meant there would be 722 of the cars made ... but that was wrong, too. In the end, the 722 badge actually referred to 7:22AM - the starting time of Sterling Moss' epic 1955 Mille Miglia run in a then-new Mercedes SLR.

SO, 722 = 7:22AM, not 722 hp.

While the automotive enthusiasts of the world uttered a collective (and skeptical) "um ... OK", Hartmut Feyhl took one look and announced: "this car should have 722 hp". When most enthusiasts say things like that, they can be easily ignored - but when Feyhl says something like this - it happens.

Hartmut is the owner and chief engineer of RENNTECH, the South Florida-based tuning firm best known for producing incredibly powerful Mercedes-Benz automobiles that often redefine what highly-tuned exotic cars should and should not be capable of.

Last year, RENNTECH introduced their own "722" option: RENNTECH SLR Performance PKG1. RENNTECH's PKG1 upgrades included upgraded intercoolers, a larger crankshaft pulley, and custom ECU software that delivered the full 722 hp SLR customers expected (along with more than 700 lb-ft of torque!). RENNTECH announced the package in an April '07 press release titled "Here in Florida, 722 Means What You Think it Means", and SLR customers responded by sending their cars to Feyhl's Florida garage from across the Western hemisphere ...

... of course, after driving their new 722 hp rocketship for a few months, some of Feyhl's customers started asking for more, which brings us to RENNTECH's latest batch of SLR tuning options: SLR Performance PKG2 and new RENNTECH Signature 10-spoke, 3 pc. performance wheels.

Available for both the "standard" SLR and 722 models, PKG2 builds on RENNTECH's previous upgrades by adding a less restrictive, motorsports-style exhaust system and re-mapped ECU software to boost the already powerful SLR engine to over 740 hp at 6400 rpm.

To give the SLR more visual impact, RENNTECH now offers its Signature 10 spoke wheels in SLR offsets and 3 finishes (chrome, satin-ceramic, and sniper gray). Pricing for RENNTECH's SLR performance upgrades are set at 12990US for PKG1 and 26990US for PKG2. RENNTECH 20" wheels are 1950US (ea.). Big Brake upgrades also available - contact RENNTECH for more.
Video:worldcarfans

Nice,if i had a SLR i'd take it straight to BRABUS or Rennech to get the full potential

I think it's pretty useless. 650 hp is moooore than enough.