STOCK-bottom-end (SBE) racing is producing some amazing results from LS and Barra motors in particular, but how about the old Holden V8? Its age doesn’t make it a likely candidate for SBE action, but Jay Jeffreys’s Holden-powered VR ute has something to say about that.
Perth local Jay has owned a bunch of tough aspirated combos over the years, including his current VK Commodore with an LS that runs in the 9.40s in Super Sedan. He also teamed up with his brother Blake on last year’s Street Machine Drag Challenge in Blake’s LS-powered streeter, and came away with the Longest Distance Travelled award.
Jay’s mates have been onto him for years about getting on the turbo train, and after a recent session on the cans, he agreed to do it if his mates helped him.
“I had a heap of junk kicking about the shed, including an old 308 that had been under the bench for seven years,” Jay recalls. “We bought a VK for my youngest brother Blake to get into Super Street and pulled the top off it to find it was 60-over, so we pushed it under the shelf, until now.”
While it’s not 100 per cent SBE-legal, being 60thou-over in the bore, it’s all stock, factorystyle stuff with a set of stock VN heads that have had LSA valve springs and aftermarket collets and retainers added. The cam is a baby hydraulic with 216 and 222 degrees at 50thou lift.
“The whole car is literally a collection of all our bits and pieces from over the years, from the Harrop intake manifold to the 6AL ignition and MSD dizzy,” Jay says.
The exhaust manifolds are steam pipe, done by one of Jay’s mates at Lundy Race Fab, and everyone chipped in $100 towards materials.
The only thing they did have to buy was the 45mm wastegate. The carby is a total bitsa, with a Demon main body, Holley base plate and standard metering blocks, all built and converted to E85 by Jay’s buddy Wayne Smith.
The turbo is a BorgWarner S366 (66mm) with a 0.8 rear wheel, currently pushing 16psi of boost. Backing up the small-block is a twospeed ’Glide with a pretty loose 4800rpm converter, driving 28x9in slicks through a 3.45:1 rear end and a 6400rpm maximum on the motor.
“We dyno-tuned the car at Streetbuilt Racing and it made 560hp on 16psi, and so far we have run a best of 9.81@142mph,” Jay says.
“It definitely surprised me; my VK Super Sedan runs 9.4-9.5 at 142mph with a built motor, and this busted-arse 308 has gone 9.80 with a crap 60-foot time!
“From here we will look at rear suspension and pinion angle, so we should go 9.60 or better. In second gear compared to my VK, it just keeps pulling. I guess I’ve seen the light, but I don’t want to admit it to my mates!” s