Jon Jellison has been an automotive enthusiast for his entire life. He can remember as a child helping his Father in the garage working on Triumph race cars. Both are skilled mechanics so it’s fitting this two man team accomplished the first LSx swap in a TVR.
The project started when the camshaft in Jon’s TVR Chimaera broke. The Chimera 500 is a fast car and Jon loved the Rover V8 but he wanted more power. The horsepower claims made by TVR are exaggerated. TVR reported the 5.0 L RV8 makes 320-340 hp but in reality they make around 250-275 hp. Although they do make great torque due to their long stroke they don’t deliver on the power promise. You can have a Rover built to produce 350+ hp but it gets expensive and very temperamental.
After looking at all options Jon settled on the tried-and-true LSx platform. This would give the car much more power and torque in a package only slightly larger than the Rover V8. Many owners had talked about putting an all-aluminum LSx V8 into a TVR but it seemed no one actually had completed one. So if Jon and his Father were going to attempt this journey it would be without a map. To help their chances the two researched every part of the swap down to the last bolt.
The power plant Jon selected was a new (at the time) 5.7 L LS6 from a 2004 Corvette Z06. Right out of the box it could produce 400 hp and 400 lb-ft of torque or 1.5 times more than the 5.0 L Rover V8. Jon removed and sold the LS6 oil sump and cast headers since they wouldn’t fit in the TVR engine bay. The engine was mounted with a pair of custom LSx engine plates to Chevy small-block mounts and then intermediate custom brackets for the TVR chassis. Jon made a point to not alter the chassis or cut into the fiberglass body to accomplish the swap.
Jon’s good friend who has a background in wiring race and rally cars was brought in to build them a custom wiring harness. The TVR has a lot of anti-theft measures built into the factory harness and Jon estimates there was 30 wires just for security his friend had to work around. Jon wanted to keep the immobilizer and alarm kit so he couldn’t just rip it out.
The factory Tremec T5 transmission was rated for 300 lb-ft of torque so Jon sold it and purchased a Tremec TK0600 which was good for 600 lb-ft of torque. A kit was needed to move the shifter forward and over so it would line up in the factory location. The transmission was modified with a Tilton Engineering hydraulic release (throwout) bearing so there was no need for an external slave cylinder and the system could be bled without lifting the car. A custom length driveshaft was made to hold the bigger TKO600 yoke. All combined the drivetrain gets the TVR to 174.5 mph at 6,500 rpm in fifth gear.
Since Jon was going through all the trouble to increase power he also wanted a suspension to handle it. He decided to use a LEDA single adjustable suspension. These precise coilovers allowed Jon to adjust the bump and rebound with an allen wrench. Jon also played around with spring rates and settled on 400 lb in front and 350 lb in rear.
Jon had already upgraded the brakes before the swap to Tuscan/Cerb AP CP6600 calipers and 300 mm drilled and slotted rotors up front. He felt the rear 273 mm rotors were sufficient but upgraded them to a slotted rotor. New braided lines were installed for better pedal feel.
The first time Jon drove the TVR after the swap it felt faster but not what he was expecting for 400 horsepower. Once the TVR got on the dyno it produced 320 hp and 365 lb-ft of torque. The engine was running very rich because of a bad ECU map. After having a professional tune the TVR put down a more satisfying 390 hp and 380 lb-ft of torque on 95 octane fuel. Now the car felt ridiculously fast.
In the end it cost Jon £13,000 (in 2004) or about $16,200 at the current rate to swap the LS6, transmission, and have a custom stainless steel exhaust fabricated. Of course all of the labor was performed by Jon and his Father. The talented duo completed the entire project in five months; 12-14 weeks on research and 6-8 weeks on actual wrenching. Which goes to show the talent Jon and his Father process to complete a swap no one had attempted in such a short time.
Source: Faster TVR and Jon Jellison