"Stephen said he wanted to engineer us, which is really cool because he is obviously super experienced," Harker told The Herald.
"I am looking forward to working with him.
"I get on really well with Stephen so we will see what we can do."
Having the steadying influence of Giles alongside him will be invaluable for the category rookie, who is making the step up from the Toyota 86 class this summer.
"I am feeling pretty comfortable and confident at the moment," the 21-year-old said. "I think the closer it gets to the time the realism will probably kick in a little bit more.
"At the end of the day it is a learning year for us. I am still going to go out there and give it my best and see how far up we can race. Hopefully we can be on the podium and even fight for race wins – that is the ultimate goal – but whatever comes out of this series is going to be positive."
Harker got a taste of driving a Toyota Racing Series car at Hampton Downs a fortnight ago in a shakedown of the cars.
The test session was designed to make sure the cars were ready for the first round and drivers were made to keep at less than 90 percent attack.
"It was nice to get back into the seat," Harker said of the experience. "We did a seat fitting a couple of weeks ago so just testing it out and feeling comfortable in the car.
"I'm ready to go 100 percent now."
The series begins at Ruapuna in Christchurch on January 10-14. Rookies like Harker will get extra time on track in the lead-up to the first round to get up to speed with the car.