Ohlins TTX/TPX rally adapted for BRZ

[soundman98]

what rear brake calipers are you running? did the bias noticeably change from stock?

[Tokay444]

Originally Posted by grumpysnapper

You know what, after I commissioned them about 6 months ago, I spent most of the time worrying that they might be good...but not sooo good that I could actually tell the difference in any meaningful way across a broad spectrum.

Suspension is a bit of a 'black art' that very very few people fully understand...and I'm that classic numpty who has some idea and no idea all at the same time.

Luckily I have some very talented professional driving friends that I can bounce dumb ideas off, or seek assurances that I'm not stark raving mad.

Its important to remember that I'm primarily talking about hard road use, back roads, dirt roads, rough roads....( I have zero track based experience, I grew up in the world of rally)

To me, WRC rally suspension (generally) is the best real world point 'A to point B' suspension there is. Everything I have ever read about anyone who has experienced it first hand are simply in awe at its capabilities...

I wanted as many of those capabilities as I could realistically get squeezed into the huge compromises of our BRZ/86 underlying fundamentals. Basically that means having to work with very limited travel.

But, it is possible to have amazing control over that short travel...and that control then allows you to be able to use all of that available travel to its best advantage.

To cut a long story short.... they are truly phenomenal. Mid corner vicious bumps, dips, ridges, undulations, are now simply driven over with almost zero effect on what you want the car to do. Suddenly you can actually feel that the tyres are able to do more of what they are supposed to do. To me, thats where (beautifully controlled) compliance comes in.

A vastly experienced driving friend once told me that the definition of good suspension...is simply that you shouldn't have to actually think about it at all while you are driving. I finally understand this.

But the dampers should be phenomenal, they were hideously expensive and took a huge amount of development time, by world experts. Valving was carefully chosen and testing was critical. Leo at Madeno Racing understood completely what I wanted, and could interpret that. (But being in Holland, I had to send him photos of the sorts of back roads that are common in Australia).

As an interesting aside, when I first spoke to Leo about the dampers he obviously asked me about the rest of the suspension components, I explained to him that it was fundamentally standard (save for an adjustable stiffer rear anti roll bar) but refreshed often, and I then explained my reasoning ...so I was prepared for a lecture about bushes, rose joints, arms, links, pick up points, etc etc! But, no... instead he said that actually sounded perfectly fine for the cars intended use, and would in fact offer some real benefits. He also said that world wide among the serious damper manufacturers there is a concerted move back to softer spring rates.

None of this is intended as a criticism of people who do things differently to me, and I stress this set up works for me and my uses... I am sure that it would not be ideal for others and their particular uses.

Schumacher was telling his team "Softer spring. More damping" for years while he was still winning world championships.

[Captain Snooze]

I have come back to this thread a few times just to look at the pics. And will probably come back some more.

[solidONE]

Originally Posted by Tokay444

Schumacher was telling his team "Softer spring. More damping" for years while he was still winning world championships.

Valentino Rossi has a preference for soft spring as well. He is a master on the brakes and in the wet. And a master on the brakes in the wet. He is a master, period.

[Tokay444]

Originally Posted by solidONE

Valentino Rossi has a preference for soft spring as well. He is a master on the brakes and in the wet. And a master on the brakes in the wet. He is a master, period.

But a billion fuckin' ricers on BCs can't be wrong. "They're great!"

[solidONE]

Originally Posted by Tokay444

But a billion fuckin' ricers on BCs can't be wrong. "They're great!"

Everything is relative, my friend. Great compared to ____. (fill n the blank. eg. block of wood, loaf of bread, etc.)

[Tokay444]

Sure. $1000 coils are relative to $1000 coils, but they're literally not even as good as the factory dampers. So comparing garbage to garbage still leaves you with garbage.

[grumpysnapper]

Originally Posted by soundman98

what rear brake calipers are you running? did the bias noticeably change from stock?

The rears are 08-12 STI (gold, re-coated black), with slotted DBA T3 4000.

I haven't noticed any difference in bias, but it would also be hard to differentiate between the effect of new/changed front disks, callipers, pads, tyres etc over the development life of the car.

Lyndon

[grumpysnapper]

Originally Posted by solidONE

I would see if I can do some kind of clear heat shrink or wrap on the canisters and shock socks, at least for the front strut. Gotta protect that beautiful finish.

Great minds think alike! I was thinking of a couple of layers of clear heat shrink over the canisters, but the strut 'bodies' can fend for themselves!


Lyndon

[churchx]

Well, i guess bias change in absence of brake torque dyno rig can be checked only very roughly, on eg. skidpad with switched off abs, when one end frequently locks up before the other, if it is similar to stock bias or not.
Safest way, if car is not running something like differently staggered tiresize or noticeably different aero downforce front/rear setup, or staggered brakepad choice, is simply to not perform any brake retrofit on one end, not designed for particular car or with particular specific other brakes on other in mind. Both cases, when brake bias deviates noticeably from stock, will introduce issues. Be it underbraking due one end locking much sooner and thus increased braking distances, be it stability loss due one end locking. It may matter less for one only daily driving theirs with all nannies on, never on grip limit, but if performance or sport or on reduced grip pavement (such as gravel roads or on snow/ice) driving is in mind, i wouldn't want braking subsystem be compromised.
From pic it looked as if you had essex apr fronts? AFAIK those were designed to keep brake bias stock if paired with stock rear brakes. As fronts are ones usually doing most braking, there won't be much lost if rears will stay stock, not heat capacity wise, not wear wise (eg. i usually wear front:rear pads as 2:1, which should illustrate little wear/heat put in rears). In your place i'd probably put stock rear brakes back instead of those STI ones.

[grumpysnapper]

Originally Posted by churchx

when brake bias deviates noticeably from stock, will introduce issues. Be it underbraking due one end locking much sooner and thus increased braking distances, be it stability loss due one end locking. It may matter less for one only daily driving theirs with all nannies on, never on grip limit, but if performance or sport or on reduced grip pavement (such as gravel roads or on snow/ice) driving is in mind, i wouldn't want braking subsystem be compromised.
From pic it looked as if you had essex apr fronts? AFAIK those were designed to keep brake bias stock if paired with stock rear brakes. As fronts are ones usually doing most braking, there won't be much lost if rears will stay stock, not heat capacity wise, not wear wise (eg. i usually wear front:rear pads as 2:1, which should illustrate little wear/heat put in rears). In your place i'd probably put stock rear brakes back instead of those STI ones.

I guess my point was that it doesn't really feel as if it is noticeable and/or problematic, even assuming that there may have been a small change.

I've driven with this exact brake set up now for 3 years and been extremely happy with it, and no one else who has driven the car has made any mention of bias issues... so I don't quite understand your reasoning as to why you would change the rears back to the original disks now?

Lyndon

[churchx]

Because apart from having better looking caliper i see no gains of. Several gains for OE rears though, eg. better wheel clearance (matters, if for offroading one tries to fit some 15"-16", though possibly non issue, as wheel set probably will be same on all four corners, and there might be reduced clearance in front already due APR front BBK), ability to use OE parts on it (sometimes for example aftermarket pad selection is better for specific OE calipers then for specific BBK), and assurance that brake bias is as manufacturer intended (with possibly better braking distances, not possible stability issues, nannies are also designed around expecting bias) and around which possibly some aftermarket suspension or aero parts are designed of. If extra heat capacity in rears are not that needed (main actual benefit of BBKs) see no sense to change them out 'just because'. Or if changing, then to kit that is designed to keep bias same.

[grumpysnapper]

I promise this is my last self indulgent picture post of my latest fixation!
A lovely little box was part of the shipment, packed with the camber 'bushings', (all laser engraved with their settings), and the little rebound/compression adjustment tools.
The other thing that caught my eye was the lovely custom lower rear mounts, and their O ring seals.


Lyndon

[Racecomp Engineering]

Originally Posted by Tokay444

Schumacher was telling his team "Softer spring. More damping" for years while he was still winning world championships.

It's crucial that everyone understands that the "more damping" in these Ohlins (and other good shocks) is very different than just turning up the damping on some BC coilovers.

Lots of rebound damping with a soft spring is bad.

Lots of compression damping....done correctly....can be quite good with a soft spring.

Also a rally car shock dyno with good compression damping does not look the same as a track car shock dyno with good compression.

- Andrew