The "70" badge was made using...
The "70" badge was made using the "7" from the 2004 "5.7" badge and the "0" from the 2005-2006 "6.0" badge.
Offering the controller will help ensure that the swap will be as hassle-free as possible and will eliminate the need to go to a third-party vendor for a fuel and ignition management system. "By working all of the details out on this GTO, we now have solutions to any issue that a customer might have with an LS7 engine conversion," Dr. Meyer says. "That experience will help us serve them better."
This swap also necessitated a custom exhaust system. The stock LS7 exhaust manifolds were retained and mated with custom intermediate pipes and a Stainless Works 3-inch dual exhaust system.
Upgraded Drivetrain
With the engine successfully installed and calibrated, attention could now be focused on the driveline. Due to the substantial increase in output, the GTO needed some beefing up to get the power to the ground reliably. This particular car was built with a Tremec T56 six-speed transmission, and it was retained, though upgraded with a Z06 Corvette clutch and pressure plate.
Moving downstream, the weak points of the GTO drivetrain were addressed with a variety of components developed in conjunction with BMR. As BMR has considerable experience with putting massive amounts of power through the GTO's IRS system, the company was uniquely qualified for the task.
In order to beef up the GTO's unibody structure, a set of BMR subframe connectors were added. Additionally, the stock strut tower brace was replaced with a much more powerful BMR unit.
Moving to the rear, considerable attention was paid to the differential and suspension. Knowing that GTOs are susceptible to wheelhop, which can destroy differentials, a set of Harrop polyurethane cradle bushings was added, as were BMR Drag Bags. A BMR aluminum driveshaft was enlisted to replace the stock 2-piece unit, and is safely retained with a BMR driveshaft loop. The differential itself was also upgraded with a Harrop differential cover and KAAZ limited-slip unit.
The LS7 engine is accented...
The LS7 engine is accented with custom body-colored engine covers and a beefy BMR strut tower brace was added to the bay. The air intake tube is a custom aluminum unit. Also custom is the oil reservoir for dry sump (not shown), which fits where the battery originally went.
From there, the stock axles were replaced with BMR billet CV shafts, stub axles and wheel studs. The added strength in these critical areas really helped with the success of the project, as the GTO has spent very little time in the shop for repairs.
On The Road
When Dr. Meyer flipped me the keys to the GTO, it was obvious that this was going to be a ride to remember. Having spent a considerable amount of time in the new GTOs, including track time at the Bob Bondurant School in Phoenix, I can say that I'm pretty familiar with how they feel and react.
Dr. Meyer cautioned me that the stock GTO gauge cluster was not operational, so a cluster of analog gauges was pressed into service. Aside from that and the Chevy steering wheel, I felt as though I was in familiar territory.
Once underway and off to a test track to get an idea of its performance, I was very surprised to see how docile the car was. In fact, driving around town, it felt just like a stock GTO, civilized and refined, yet firmer than Grandma's Buick. Happily, there was no additional harshness from the beefed up rear suspension. Likewise, the cornering and braking were essentially unchanged. Aside from a throatier exhaust note, nothing seemed out of the ordinary.
Stainless Works' 3-inch dual...
Stainless Works' 3-inch dual exhaust peeks out from under the factory rear fascia. A trailer hitch receiver is used for hooking up test equipment.
During my drive through some residential areas, the GTO really turned heads, mostly because of the GMPP decals, the Roush Racing hood scoop and, of course, that nasty exhaust note. We received several thumbs-up from a Corvette owner and others "in the know."
Once at the track, I really found out what it was all about. All I could say was, "Yikes, this thing's a beast!" Not wanting to hurt the car, I eased out the clutch and then nailed it. The LS7 reacted violently, emitting a roar seldom heard outside a dragstrip. No wheelhop, no drama, just extremely rapid forward motion in the blink of an eye. With the redline coming near, I slammed the shifter into second, the GTO squatted down and continued the surge toward the century mark. I repeated this ritual several times and thought I would need to have the smile surgically removed from my face. I commented to Dr. Meyer that if I owned this car, it would have to come with bail bonds!
Since no clocks were available that day, an estimated 0-60 time comes in under 4 seconds, and the quarter-mile e.t. is said to be in the low 12s. Mind you, this is with street tires and through the mufflers. Realistically, I don't think that the GTO is quite as quick as a stock Z06, which is blessed with more rubber, better front-to-rear balance and a several-hundred-pound weight advantage. Still, it's not that far off. Plus, the GTO has a backseat and is a much more practical daily driver.