Rebuilding the Prodrive PPP Development Hawkeye Impreza Part 3

D​emo rally car bought back from the dead thanks to Richard Clews. This time... suspension and brakes

32w ago


Wow, time flies! Here we are again discussing some updates on the Subaru project that’s coming together rather nicely.

In the last installement, we talked about the car having had its new Owen Developments turbo and being mapped by Bob Rawle amongst a few other key little modifications to improve both power and driveability. This time, it’s all about wheels, tyres and suspension.


\With the Chevron (Motorsport) boys working flat out on my tarmac spec Impreza rally car ahead of the Down rally in Norther Ireland, we hadn't quite had time to do everything we wanted on CHL, but we are still cooking on gas.

On the rally car we always use Revolution wheels which are strong and reliable, there was always a price to pay for this strength with the weight but the new CR10 wheel is a game-changer. It’s a race or tarmac rally wheel coming in at 9.5kg. It's not the lightest out there, but there’s no compromises in quality which we’re really keen on.

So what tyres are we going to use, Ben at Nankang is a friend of mine but I’ve never had the opportunity to use the latest AR-1 semi slick, road-legal, trackday rubber before. This isn’t just a fantastic looking tyre but a great performer on both track days and within several national race championships around the globe.

The AR-1 arrived on the scene in 2017 but it has gone through some changes since then, the latest 2019 tyre has a Kevlar lining to reduce weight and increase consistency. According to Ben, the latest spec tyre was created through development at the Nurburgring, where tyre stresses are higher than other circuits alongside Apex and others who are based there.

From the homework I’ve done and at that price point they seem the perfect option, they also appear as a 1B” tyre for both sprinters and hill climbers alike, great stuff.

So, what about the bouncey stuff? On to the suspension, well there is only one choice for me and it's EXE-TC, problem is these are a serious top end rally damper and whilst they represent good value in professional motorsport they are somewhat over kill for a ‘fun’ car. Doing the man maths and chatting to a few our existing sponsors, we opted for a new set for the real rally car and the old ones from there to go on CHL. It’s a win-win situation as we’ve always been impressed with the road holding and compliance of the EXE setup.

EXE-TC are a UK based suspension business who’s products can be found not only on winning Subaru WRC cars and the famous Prodrive Isle of Mann lap record car, but also on the Citroen WRC cars that Sebastian Loeb drove to some whooping world driver titles.

In my opinion, too many people spend too much money on power and not enough on suspension and decent brakes. Power isn’t always the greatest gain, on track typically 80% of the time is spent entering or exiting corners. That’s where EXE-TC’s deep knowledge and experience of vehicle dynamics allows them to produce chassis and suspension components to maximise mechanical grip – which in many cases is more greater lap time improvements than adding 100 extra horsepower.

When we started fitting the dampers it became pretty apparent that all the rubber bushes on the car had seen a bit too much action to be ignored! A call to Whiteline resulted with them supplying a full kit of parts to tighten the whole chassis up. Whiteline’s experience with Subaru is extensive and the collective knowledge of how to improve over the standard design is second to none.

It’s a good job John at Chevron was on hand to fit some of these as they aren’t all a five-minute job to press out and replace, thankfully they have all the kit and more at the Stafford based Subaru tuners and that job is now complete.

In between this month and next we will have the car on the set-up bed to dial in all the data, we have conducted smooth tarmac testing in the past so we are going to start with that information and go from there. This car is heavier than the rally car but we should be ok to get started.

Simon has a few “Chevron” specific tweeks he wants to put into this car so I’m really looking forward to testing it all out. Hopefully, next time you read about CHL, it will be all dialled in and awaiting a little bit of a shakedown, stay tuned for more soon.

I​f you missed the second part of the updates, here a direct link to them. I'll be back with another update real soon. -

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