Harrop-blown HQ at the Optima Ultimate Street Car Challenge

This blown HQ will be one to watch this Saturday at the Optima Ultimate Street Car Challenge


Brendan Irvine and his blown HQ Holden cleaned up at the Optima Ultimate Street Car Challenge at Calder Park in 2022 and you can bet he is back to defend this title this Saturday.

Getting the rear tyres to stay in contact with the tarmac proved to be a serious issue for Brendan at OSUSC, with the Quey slipping and sliding its way to 220km/h down the main straight, hence some tweaks to the suspension settings and some new rubber since last time.

Even with the traction issues, Brendan pedalled the HQ to a convincing win in the hotly contested Vintage class. “This event was great because you had to perform in all aspects of performance, not just one,” he said.

The bright red Quey has been through a couple of iterations, but its current one is by far the best. “I bought it in 2010 – it was a nice, presentable car with a 308, TH400 and 9in, and I used it for drag racing and skid comps,” he said. 

While the driveline was pretty healthy, the interior and body were in need of some tidying up, so the HQ was blown apart and Brendan slathered it in straight red tinter in his shed, just in time to be his wedding car!

A few years later, with a view to making the car more streetable, Brendan replaced the grumpy 308 and swapped in a VZ-spec LS1 with a Harrop blower, good for 700hp. The grunt heads rearwards through a suitably worked DTM 4L60E trans.

“I wanted it to be a car that I could throw the family in and go for a long drive, but would also stop and steer well,” Brendan said.

To handle the substantial increase in power, the rest of the HQ’s underpinnings were beefed up as well. Brendan braced the body and added Castlemaine Rod Shop upper and lower control arms to the front end, while under the bum, the diff is a shortened XY 9in with 3.5:1 gears. The motion of the ocean is controlled by QA1 shocks at all four corners, with BA Falcon discs and calipers hauling the car up from the crazy speeds Brendan is happy to take it to.

The OUSC competition will be hot this year, so be trackside this Saturday to see how the class plays out.