Monday 6th June 2016

Secrets of Subaru's IoM TT record car

Mark Higgins has smashed the car lap record around the TT; PH goes behind the scenes to find out how

---

Those glued to the action from the Isle of Man TT will likely already know but on Saturday Mark Higgins smashed is own lap record for cars around the 37-mile course by a huge margin, clocking 17min 49.7sec and an average speed of 126.971mph on his first run. How huge? The last time he did it he recorded 19min 15.8sec and a 117.5mph average. From the teaser pics we shared the other week we knew the highly modified Subaru WRX STI he was driving was something special. Now, after a sneak preview at Prodrive, we can reveal exactly how special...

Despite still being cagey on a full specification, those numbers that we do have are extremely exciting. Using a development of the 2.0-litre boxer turbo previously seen in the WRC cars, power is said to be around 600hp. Six hundred. Principally this comes about through revving the engine higher - a WRC car is typically limited to 6,500, this one goes to about 8,500 - but also by fitting a larger turbo and removing the rally restrictor. Weight is "11 something" according to David Lapworth, responsible for every Subaru WRC car and a key figure in this project. Those numbers give it comparable performance to a GT3 car. On the Isle of Man!

As the pictures should make clear, this car is a far more specialist build than the production-derived previous attempts. It's a bespoke build using Prodrive's nous with making swift Subarus and Subaru America's desire to promote the model with this, er, unique publicity stunt. Where they will go from here is anybody's guess...

Underneath this STI is a lot of old WRC stuff; not only does this cut down on costs and development time, but it's also extremely useful for the challenge this car will face. While the Isle of Man has similarities with other tarmac rallies, it's of course much faster than any WRC event. A car going for the record must be fast but also capable of dealing with bumps at high speed plus the odd low speed sections of the TT course as well.

To that end, the car is low but not to the levels of a circuit car - notice the gap between wheelarch and tyre as well as the fresh air between front splitter and tarmac. There is said to be tangible downforce but, with outright speed such a priority, this couldn't be at the expense of aero drag. So the underfloor isn't flat but the big spoiler plonked on the back has a DRS system. Having originally tried a P1-style system - Prodrive helped McLaren develop that - the team used a simple device that uses Prodrive's experience with the Aston GT cars. It's manually deployable but will retract on its own if the speed drops, and aims to help the compromise between aero stability and minimising drag. It's also pneumatic and sounds like an air rife when it's deployed - very cool.

This STI uses Dunlop slicks from a BTCC car and the gearbox from a WRC Impreza, the latter able to change gears in eight milliseconds. Over the previous record holder, this car has a longer fourth, fifth and sixth gear and a theoretical top speed of approximately 180mph.

There was no chance of hitting that around the Bicester Heritage test track, but there is enough space to confirm this is one seriously rapid Subaru. From both inside and out there are familiar (and fantastic) Subaru rallying noises but everything is happening faster. So much faster. The brakes are staggering too, but it's the way this STI handles that's most interesting. It looks like a circuit racer but pitches and moves like a rally car, a result of the softer set-up needed for the TT. At Bicester it's not especially happy, understeering at the slower corners that it simply isn't built for. But when it's out the other side... Wow. The aim for a 120mph average looks extremely pessimistic.

Higgins is aware of the understeer too, but understandably states that it's a worthwhile compromise for the high-speed stability. Inevitably that video comes up in discussion, which he is keen to avoid repeating. "I'm getting older; my hands won't catch up!" he says.

Now while a few commenters have already taken issue with Subaru attempting a record with no competition, the car itself is excellent. We've been clamouring to see a four-door Impreza (allow us one slip of the tongue...) on a rally stage again, and now we have it. Sort of. And with 600hp. The record attempts are due in the following days and we'll be flying out today to catch up with Higgins and the team and find out more. For his part Higgins has already Tweeted "Great first lap ... a bit more to come!" We look forward to seeing it for ourselves!

 

 

[finnie]

I find it notable that this car is not slammed. So many people lower a car to the floor, wheels up in the arches for example. Yet here is a team striving for a fast time on a real road course who actually leave some suspension travel in the car. Surely proves that all the boy racers weren't right at all!

[grumpy52]

Most of the boy racers cars are actually slower than standard ,despite their claims of ridiculous bhp .
The suspension set ups usually end up throwing them in the greenery ,add that to zero talent and you know the rest .

[Monty Python]

A tyre that isn't in contact with the road doesn't achieve much - stiff suspension is fine on a billiard-table smooth track where aerodynamic downforce relies on maintaining a fixed distance between the underside of the car and the road but on anything else it's practically useless.

[shoestring7]

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

SS7

[Guiseley]

shoestring7 said:

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

Maybe, but needs to take another 1 minute off his time to beat them, and then allow a bike build without any restrictions.... still got many more miles in that argument!

Here's hoping for some quality footage of the runs, so we can see what 180mph through the villages and town feels like :O

[vikingaero]

Monty Python said:

A tyre that isn't in contact with the road doesn't achieve much - stiff suspension is fine on a billiard-table smooth track where aerodynamic downforce relies on maintaining a fixed distance between the underside of the car and the road but on anything else it's practically useless.

It's been proven quite a few times with 2 identical cars one with phat alloys and one with standard alloys - that the standard car will be faster around a track. Put phat alloys on for looks but don't kid yourself otherwise.

[tbtstt]

grumpy52 said:

Most of the boy racers cars are actually slower than standard ,despite their claims of ridiculous bhp .
The suspension set ups usually end up throwing them in the greenery ,add that to zero talent and you know the rest .

I would say there is a balance. When a mass production car rolls out the factory it's setup will be a compromise of many factors: handling, ride comfort etc.

Reducing the ride height can improve the some aspects of the car, but it will reduce others...

...having said that, there is a limit. Dropping a car as close to the ground as possible will not automatically make it better, especially in the case of a road car.

[DanielSan]

I can't be the only one who thinks this should be a separate event, get other twams/manufacturera involved and it'll be like a bigger version of pikes peak only better, and with less hill.

[200Plus Club]

shoestring7 said:

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

SS7

it doesnt though, does it? the lap record is 133+now. 126mph average will get you nowhere. not even top ten probably.
when a car has actually beaten the bike time, then its worth mentioning. this was a great attempt by a pro driver in a pro car to match the bikes. there are amateur bike racers going faster as we speak.

[dukeboy749r]

200Plus Club said:

shoestring7 said:

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

SS7

it doesnt though, does it? the lap record is 133+now. 126mph average will get you nowhere. not even top ten probably.
when a car has actually beaten the bike time, then its worth mentioning. this was a great attempt by a pro driver in a pro car to match the bikes. there are amateur bike racers going faster as we speak.

Also, I'd venture it takes considerably larger kahunahs to do the TT lap rather on a bike rather than in a car...

[Podie]

dukeboy749r said:

Also, I'd venture it takes considerably larger kahunahs to do the TT lap rather on a bike rather than in a car...

I'm surprised there is enough room on a bike for the size of kahunahs required.

[Elli5]

200Plus Club said:

it doesnt though, does it? the lap record is 133+now. 126mph average will get you nowhere. not even top ten probably.
when a car has actually beaten the bike time, then its worth mentioning. this was a great attempt by a pro driver in a pro car to match the bikes. there are amateur bike racers going faster as we speak.

The car also had a decent rolling start from miles before the start line to get plenty of heat into the tyres and a lot of speed going into bray hill. That 133 bike lap was done from a standing start!!

Both impressive feats but comments like yours SS7 make you look daft.

[J4CKO]

I find the car vs bike thing a bit pointless, motorised transport with different numbers of wheels, not sure why it has to get all us and them ?

Its just interesting to see progress, doesnt matter either way and doesnt make one better than the other.

Would be interesting the see it developed further though, the bikes get faster each year, so no reason the cars cant, not bad going considering how little time they get to develop it.

I wonder what other car could be a starting point to go even faster ?

[xRIEx]

200Plus Club said:

shoestring7 said:

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

SS7

it doesnt though, does it? the lap record is 133+now. 126mph average will get you nowhere. not even top ten probably.
when a car has actually beaten the bike time, then its worth mentioning. this was a great attempt by a pro driver in a pro car to match the bikes. there are amateur bike racers going faster as we speak.

http://www.iomtt.com/~/media/Files/2016/Results/RS...
126.9 would put him 8th in the Superbike TT.

[Cyder]

He'd have been 8th in the first Superbike race out of nearly 50 finishers.

Damn beaten to it.

[Elli5]

xRIEx said:

http://www.iomtt.com/~/media/Files/2016/Results/RS...
126.9 would put him 8th in the Superbike TT.

To be repeated over six laps? On the same tyres without the need to refuel?

Genuine questions btw, I have no idea how much punishment the slicks he used could sustain and what range his fuel tank would provide.

[stuckmojo]

Not interested in the car vs bike debate. Bikers on TT have balls the size of planets.

As for the car, this looks like what a 2016 GR.B car would be like. Love it.

[Gypsum Fantastic]

shoestring7 said:

Kind of ends the bike v car at the TT thing. Just the one lap and a modded saloon is knocking on the door of the fastest bike times.

SS7

For context the supersport (600cc) lap record is 128.666mph. It's also worth remembering that the bike records are set during a race, with the potential of traffic, and setup for 4-6 laps.

[anonymous-user]

PH said:

the gearbox from a WRC Impreza, the latter able to change gears in eight milliseconds

The wrc box is good, but it ain't ^^^^ THAT good.......


(and besides, if you genuinely shifted in 8ms, the cam drive would fail)

[xRIEx]

Elli5 said:

xRIEx said:

http://www.iomtt.com/~/media/Files/2016/Results/RS...
126.9 would put him 8th in the Superbike TT.

To be repeated over six laps? On the same tyres without the need to refuel?

Genuine questions btw, I have no idea how much punishment the slicks he used could sustain and what range his fuel tank would provide.

I was about to say, that is one lap compared to six.