Journey in meddling with Car Dynamics

Words like control, response, precise, grip etc. are …yeah… very much cliché whenever some blokes blabbering on car handling. But it is undoubtedly the key ingredient in making driving enjoyable enabling you to grin from ear-to-ear as you kiss the apexes after another. And I believe in that absolutely 100x100% before tax and excise duty.

My yuppie driving days started with the Waja, Satria GTi and now coming to 3 years of ownership, the Pocong (Polo GTI), I’ve always trying to meddle with things to get the word like responsive, precise, tenaciously grippy, and adjustable on the limits to be associated with these cars. Because having mediocre technically sounds, things I meddled doesn’t always ended up to be rosy as hoped. Nevertheless, trial & error exercise is a good thing to know which worked and which won’t.

I can still remember the first time I drove the Polo GTI. It was torquey little car courtesy of the ancient but potentially potent VAG 1.8T. But I suspect things just got half cooked plus trigger happy VAG cost cutting exercises, the car’s achilles heels are in the dynamics department. On stock form, it drives with reasonable feel from the steering (mimicking Mk1 Golf GTI which my parent used to own two decades back), city car nippy through the turns and very adjustable on the limits which I love very much. Ok that’s the brownies but now is the BUT part.

At high speeds, it’s just frantically nervous upon lane changes hence the main reason I named the car as Pocong, it doesn’t glide but it HOPS! Reasonable feel doesn’t mean precise or responsive, that’s what the steering feels, and in today’s hot hatch world, it falls back on the loathering line of the people’s mind. And when I had it reflashed for more grunt, Ulu Yam is a scary place to be because it shows how mad it behaves. I had lots and lots of goose bumps as I prayed it didn’t hops or hell somersault into the ravine should things goes south and thanks to stock brakes I always have to second guess whether I can brake on time not to kiss lorries upfront. I even took it to the no nonsense place – SIC. It was worst! But I knew it has the chassis that is good enough to be explored, that’s where the ‘what if change this’ wish lists went on like a disease rotten up my mind and my pocket.

The first thing I did was to replace the stock spring with H&R’s. Cosmetically, it lowers the car by about 30-35mm from stock 9N3 Polo. That’s good. With lower CoG and less axis movement, the car corners flatter, more rapid and precise through the turns just like a normal run-of-the-mill hot hatch is supposed to be. Although H&R’s is progressive by characteristics, because its shorter and stiffer spring rate, it doesn’t gels well with the stock dampers. That’s where it rides noticeably choppy on uneven highways.

Second on the list was the braking. Audi TT’s 312mmx25mm vented solid rotors with ATE 54mm single potter plus steel braided lines brings more stopping power especially from 200+ kmh. Even if the car punches out 200whp, it should do fairly well in assuring me not to kiss cars upfront. Higher temp pads and heavy duty slotted rotors would be a big plus on further complementing this setup. The only gripe for me is the rear. At 232mm diameter, it looks horribly pussy.

Other things like Seat Ibiza’s solid rubber bushings on the front wishbones build up on more solidity feel in nursing the trigger happy torque steer coming from 253nm flat from 3,000-5,00rpm. And more impressive is the Federal 595 RSR. Who would have thought that someone from Taiwan can make good tyres. It’s like this thing has gotten a great spell by the great Merlin in masking Pocong’s achilles heels by instilling very direct response from the steering and provide very very tenacious grips. Throughout my stint with these tyres, I’ve never been in overcooked situation on sunday drives. In fact the more it loosen the thread, the more grip it gives unlike AD07 I heard.

When the car’s mileage went up to 60k kms, I was short on cash for H&R coilovers and reluctantly ended up with SuperSport. It was the cheapest dampers I managed to get hold on to at €200 including shipping. That’s 50% cheaper than originals. What I didn’t know is it does its job unexpectedly well even compared to Koni yellows/Biestein B8. It rides with more immediate feedback through the steering, it corners flatter and cover more ground in terms of lateral grip with more fluidity rather than outright harshness. And speaking of fluidity, I sense that the SuperSport dampers give much more composure dealing with uneven and bumpy roads which means I don’t need to slow down to readjust the music volume and my wife shouldn’t get sick every time traveling on long distance. Well that’s until I ruined it when upsizing the wheels.

I’ve always wanted to copycat Mini Cooper S’s wider chassis allowing the ability to mesh the juice from the engine and it should stick to the road ala AWD rally machines hence the reason why I wanted to upsize the wheels. In doing so, I’ve to admit, this has ruined the ride fluidity, fuel mileage and much more damage on the credit card. But in essence, it does resulting in wider track, it corners with lesser flexes and this setup serves as a good foundation for more lateral grip once I ditch the ‘geli’ RE001 for RSR. Not now but soon.

With all that in place, I’m very much content with the car’s dynamic behaviour on the winding road and it’s ‘liveable’ on day-to-day driveability. Now, it gives MCS-like chunkability when approaching corners, good steering feel and covers more ground in terms of the lateral grip (would be even better with RSR soon). And yet this still retains the adjustability on the limit characteristics in which saves the car few times from t-boning the lamp posts as it tail out at speeds. Having done some joint exercise with friends on sunday mornings, I could sense that the car should be able to smell FD2R’s exhaust fumes on medium-high sweepers of Ulu Yam without being left out too far behind. That’s good enough in my mind as FD2R is a legend precision tool on that area of expertise.

The only problem is to get the power down cleanly on tight sequence of corners like Batang Kali to Genting uphill stretch. That’s where it couldn’t tight up its engine gut to defy the laws of physics unless of course LSD fitted. Second thing is I need to find ways to soothing the mid-corner braking reaction where it just wants to dance, great feeling but can get me a little off-guard. Hmmm…having thing long and hard, should I want to go further on this car dynamics subjects, it would be these things on my mind:

1. Heavy duty solid rubber or PU bushes on rear axle beam, rear spring perch, ARBs.
2. H&R monotube coilovers and get tuned by someone who obviously know what he’s doing and that would NOT be me.
3. H&R ARB 26mm front and 28mm rear.
4. VF Engineering End Links.
5. Wierchers CF struts bars.
6. Peloquin or Quaife LSD with automatic torque biasing.

Hmmm going to have a very sweet and wet dreams tonight!

Journey on fine tuning the dynamics still far and away...

Thanks to Mugil, I've learnt a thing or two on SIC