Ohlins TTX/TPX rally adapted for BRZ

[grumpysnapper]

I've finally (today) completed my full BRZ build, and thought you might be interested in the specially built Öhlins TTX/TPX rally dampers I have had built to fit the BRZ...replacing an existing set of Ohlins SUS MP21 R&T.

(I've tried to build my perfect interpretation of a useable daily driver tarmac/dirt rally car, that is still comfortable, reliable and can cover large distances.
It is producing around 350 HP and a touch over 400Nm at the rear wheels via a Harrop supercharger controlled via a Motec. I had a priority to keep weight down, and with a full tank of fuel, it sits at about 1260kg. But with aircon and an OK sound system.)

Fronts are a twin piston strut with a 44 mm piston (TPX 44) and 3-way adjusted with 1-way rebound and 2-way compression. The rear damper is a twin tube damper (TTX 44) with a 44 mm piston and 3-way adjusted.

I couldn't find anyone here in Australia, or the USA, who wanted to take on the challenge...and eventually found an amazing Ohlins rally suspension specialist in Holland (Leo at Madeno Racing) who has produced the most incredible dampers....after many emails, cad drawings, photographs, measurements etc etc.

My stipulation was that they had to be a direct "bolt in" to a standard BRZ/86 suspension set up...but then have enough flexibility of adjustment to be able to cope with a number of different possible set ups.

The TPX and TTX had to be completely re-engineered....including being shortened to a huge degree (Rally dampers have a huge amount of travel...and our cars have a very small amount of travel...sadly..).

The dampers come from the factory with no front mounts, and incompatible rear mounts, so every thing had to be custom made from scratch.

On advice from the builder I have fitted softer spring rates (40N/40N compared to my existing SUS MP21 rate of 60N/60N). He ended up fitting Eibach springs with helpers.

These are the finished beasts....

If there is any interest, I can post comparison pictures and development pictures.

Cheers, Lyndon

[new2subaru]

Interested and subbed!

[Racecomp Engineering]

Absolutely brilliant. Well done!

How much travel did you end up with? What kind of tires? Stock swaybars?

- Andrew


BuT tWiNtUbEs ArE nO gOoD

[churchx]

If you intend to use for rally, haven't considered ohlin's strut hole camber inserts for reliable under abuse/hits/jumps camber offset? (page #9)
No clue how these performs, but purely from aesthetic viewpoint, looks & finish of these look like porn.

[venturaII]

Hell - I'd just hang those in the living room and stare at them all day..

[grumpysnapper]

I know this will all seem strange...

I run 16" wheels with 225/55 Pirelli P7 and P1's on two sets of Rays CE28's.
Front sway bar is standard, and rear is a hollow 23mm.
Bushes are all standard...but replaced regularly. All arms and links are standard too. (Brakes are AP Racing)
Ride height is set about 5mm above standard.

I've fitted a different rear top mount to release an extra ~25mm of travel.
However, aside from that, the front has the standard length of travel.

I might be wrong, but I've always felt that controlled compliance is your friend for speed on real world roads, and that too much mechanical grip can take a lot of fun out of driving.

This is the comparison of a standard SUS MP21 strut with the TPX as it came out of the box before any modifications!

[grumpysnapper]

Rears: comparison of a standard SUS MP21 with the TTX as it came out of the box before any modifications.

[venturaII]

Originally Posted by grumpysnapper

I know this will all seem strange...

I run 16" wheels with 225/55 Pirelli P7 and P1's on two sets of Rays CN28's.
Front sway bar is standard, and rear is a hollow 23mm.
Bushes are all standard...but replaced regularly. All arms and links are standard too. (Brakes are AP Racing)
Ride height is set about 5mm above standard.

I've fitted a different rear top mount to release an extra ~25mm of travel.
However, aside from that, the front has the standard length of travel.

I might be wrong, but I've always felt that controlled compliance is your friend for speed on real world roads, and that too much mechanical grip can take a lot of fun out of driving.

This is the comparison of a standard SUS MP21 strut with the TPX as it came out of the box before any modifications!

225/55-16?? Or 225/50? Or 205/55?

And compliance is indeed the way to go fast on real roads.

[grumpysnapper]

Originally Posted by venturaII

225/55-16?? Or 225/50? Or 205/55?

And compliance is indeed the way to go fast on real roads.

225/55 r16 Pirelli P7's & P1's. (P1's have a touch less grip, but can cope with road surface abuse a little better)

[grumpysnapper]

Originally Posted by churchx

If you intend to use for rally, haven't considered ohlin's strut hole camber inserts for reliable under abuse/hits/jumps camber offset?

Yeah, it has the camber 'shim' inserts system, and came with a set of inserts from 0 to -3.5 deg.
Its a great system, very quick to change and very accurate.
Having said that I only run about -1.5 deg on the road, and the car is still intended as a road car, I won't be rallying it.

You can see the cutout for the camber inserts under the top bolt in this shot.

[venturaII]

Originally Posted by grumpysnapper

225/55 r16 Pirelli P7's & P1's. (P1's have a touch less grip, but can cope with road surface abuse a little better)

Weird...I can only find the Centurato P7 all season in that size on TireRack, and nothing in the P1. The P7 has a TWR of 700, which seems to put it in a very different performance category than what the rest of your suspension setup is capable of delivering. Maybe you have a different selection of Pirelli products down under?

EDIT: Just went to Pirelli Australia, and indeed it does seem that way...

[Lincoln Logs]

This is a cool project, props! Those photos showing the standard Ohlins vs Motorsports Ohlins says it all, travel is king.

[CSG Mike]

Carn porn!

[asdf]

Beautiful! Would love to see more photos!