Protlum – Rally suspension upgrade

There is three most important upgrades on car – seat, tires & suspension. First two has been completed; only OEM suspension stand in the way of more cornering speed. After a long search I found Protlum.

PLEASE READ WARNINGS BEFORE YOU PROCEED !!!

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I’ve never been a fan of lowering cars and I don’t consider myself as tuner. I wanted to keep ride height same as OEM. I learn from first mistakes of Skoda Fabia HR II – I was too often scratching ground with front axle carrier.

Sure, I can go lower but I have to slow down because I cannot take fastes line throught out corners. My chassis setup is more rally compromise for rough tarmac and gravel mountain roads.

Seek parts for your driving style

Everything is about balance – changing dampers, springs without changing bushing brings more problems than fun. Further, it makes it even worst because OEM suspension is too soft and dampers don’t match springs.

OEM bushing deflects/bends resulting in worn tires from everypossible angle you can imagine. Furthermore, steering precision is catastrophe. You turn in steering wheel but chassis starts to float and nothing happens car still going straight.

I have long history with Powerflex and I have no compulsion to seek another product. Last time, I used Powerflex standard bushing replacement (violet color).

This time I was suggested black-series for my driving style and guys were not wrong (thanks to Powerflex CZ). Car does exactly what I want without any lag or wobbling of chassis. Of course it is not Uniball but it is just family car right 😉

If everything would work as supposed to I would be gillionaire today. I decided for SuperPro adjustable ball joints just to make sure there is more possibilities to fine tune chassis/suspension.

Unseen setback

Whole rear axle carrier was rusted and needed to be replaced. Scrappyard is the best place for shopping. Brake overheating problems and need for brake discs upgrade.

With used cars comes always a risk. Sadly, most cars had a crash and mine wasn’t exception. Whole right side is 15mm lower and car had weird behaviour until I started to meassure ride height. It would be more fun to meassure corner weights but I didn’t find anyone with proper equipment.

It took me five days to replace rusted parts, fit in bushing, replace brakes and dampers with springs. Rear axle carrier was unplanned time waste but it needed to be done because weird noise were coming from rear side of chassis.

Friday, the last day of upgrade, was dedicated to geometry and testing. Upset and stressed I though all is over now but it was just beginning 😀

Fine tuning in field

I rent a garage from my friend for all repairs but sometimes I still have to go some where else. Certified monkeys for replacing parts. Unless, you supervise these guys it rarely ends up well.

I told guys what I want and what they should adjust so I left ball joint screws loose for geometry adjustment. How naive I was – 500 km later I found out all wrong and whole front geometry screwed up. IF YOU WANT IT RIGHT DO IT YOURSELF.

I’ve got some ideas from Briskoda forum but car forums are full of eExperts and tuners who wish to socialize. Furthermore, you are robbing yourself from fun of trial-error and learning. Unless, you do it yourself you just repeat someone else ideas. As usually I was digging deep into the core of challenge. Along the way I found two masters to learn from. Carol Smith and Herb Adams.

It took me two months of fine tuning. Resolving challenges with ride height (due crash), understeer, tire pressure, geometry and so on. It is noisy but I can drive on the limit of tire traction around 1G. You have to choose what you want – comfort or handling.

During testing I managed to wear a set of Yokohama C.Drive 2 tires. In about 5000km front tires were worn beyond the safe use. Looks like there will be hunt for better tires. Once again, you have to choose what you want – traction or lifespan. Life is short and traction/cornering speed is the king.