I'm very pleased to introduce the Shutter intake manifold upgrade for the LS4 platform, available from Overkill Motorsport.
I am very pleased to be offering this for the LS4 Grand Prix GXP crowd, this is a first of its kind, a true bolt on intake manifold upgrade for the LS4 platform. The Shutter name is tribute to Nathan Shutt, who first did this manifold swap, and whom has partnered with Overkill to bring you these kits.
For those who are unaware, the LS4 is severely restricted in the intake manifold setup. Basically the LS4 has its intake manifold bolted on backwards, compared to a traditional rwd LS application. To make this work, to route around the existing oil pressure sensor location on the LS engine, GM simply pinched off the inlet of the LS4 manifold, cutting about a third of the 75mm port off on one side. Trying to adapt a regular LS car manifold in the LS4`s place is not a straight forward job, requiring fabrication to get around the oil pressure sensor, and the DoD valley plate in general.
Our kits are based on extensively modified GM truck manifolds, which improve horsepower and also torque significantly. They are extensively modified to fit the LS4 which give them a great cosmetic look, and come completely assembled with new billet fuel logs and all required connections, new fuel injectors, throttle body solutions, and intake vacuum connections for the PCV, EVAP and MAP sensor. The kits do not require removing or modifying the oil pressure sensor or the DoD valley plate, they are completely bolt on in a couple hours. Gains are anticipated at 30-50 horsepower, depending which manifold you choose and your other modifications. Tuning is required and of course available from Overkill Motorsport!
First kit is a 75mm manifold. This has the same inlet size as the LS1.LS6 and reuses the LS4 75mm throttle body with an aluminum adapter plate. Optional is a MAF sensor upgrade with a 4 inch inlet with matching intake tubing and cone filter to complete the intake system upgrade. This 75mm manifold kit comes in at $999 and we anticipate it being very popular due to its pricepoint versus power gains.
Second kit steps up to a 90mm inlet size, same as the LS2.LS3, which we match with a 90mm LS3 throttle body. The larger inlet will obviously flow more air, and is great to have if you have a camshaft upgrade for example, or if you just want to ensure you buy the best for your vehicle. Optional is a MAF sensor upgrade, this time a 4 inch LS7 card MAF upgrade, with wiring adapter, matching intake tube and cone filter. Pricing is $1549 for the 90mm manifold kit.
90mm kits are available now, 75mm kits are available Monday Aug 17 and will be posted on my website.
Go to www.ls4manifold.com to go right to the Shutter manifold page
Go to www.ls4tune.com to go to my LS4 tuning and product page, or www.overkilltune.com for my main website page.