Sams Polo 3.0

[sambb]

Luddenham happened. Unreal fun on a fun little track. Killed my K04-001 turbo. Just in case anyone didn't realise its the same car, I'm over here at the moment finishing off this project to get her running again with a turbo conversion:

Sams TFSI turbo conversion (maybe!?)

+ shameless plug - its generating some spare parts that I'm selling so if you are on the look out for anything check out the parts for sale section

[sambb]

so there's been a bit of action on the blue Polo latel. Some of it welcome and long overdue, others far from welcome.

FULL REAR BEAM SWAP

A few things prompted this. The blue car came with Audi TT vented rear discs and calipers. I've been pretty unconvinced of their necessity to be honest. For the extra pretty significant weight they add to the unsprung mass I'm just not sure they are even required. I had reshimmed the bean so that it was running similar geometry to the beam on my silver car, so suspension setup was more or less equivalent. Despite that it just felt heavy and lumbersome, didnt ride bumps well causing the ESP and ABS to jump in at bad bad times eg over rumble strips where it never did that on the other car. While they may have operated cooler due to the venting, the calipers were a fair bit bigger/heavier, yet the pad size was identical between the stock rear brakes and these. The Polo has a much more weight forward weight split than a Golf 5 or Audi TT that these bigger rears were intended for. Recently also, Wakefield park has shut leaving Luddenham (a go kart track) and SMSP (south circuit, north circuit and full circuit) as the only circuits I have access to. In general I'll be predominately on the less demanding braking tracks or doing hillclimbs where brakes are hardly even used, so again the need for the bigger rears seemed to not be justified.
The beam on the blue car also had superpro two piece rear beam bushes that looked to be an imperfect fit - you cant swap them out without removing the beam completely anyway. Also the other beam has spacers fitted to it to widen the rear track. I've wanted to move away from wide 225 rear rubber back to something smaller like 205's (I used to run 195 softs in the hillclimbs!) so to maintain a wide track but with skinnier rear tyres, I'd need these spacers. So in the interest of going back to a generally lighter rear end, with solid 1 piece beam bushes and track widening spacers, it was time for a full rear beam swap to tackle 3 things with 1 physical job.

When doing a rear beam (including re bushing) you HAVE to crack the brake lines and fully remove the beam. The time required to then get the other beam back in means you need a fair bit of bleeding afterwards. I rigged up this gravity feed to the master cylinder and then used a handheld vacuum pump at the calipers which got allo the air out aok.
Pic shows the 1 piece rear beam bushes taht are much stiffer duro than the superprp ones too, the machined aluminium spacers between the stub axle and beam to widen the track and also it is fitted with Speciality Shims to give roughly 2-3mm toe out total and 2/1/4 neg camber. This beam had wheel studs fitted to it too. All done and ready for some future track action.

[sambb]

WATER PUMP

So the water pump decided to spring a leak in the KFC drive through of all places. After speed reversing out of the lane before a car could come in behind me and trap me in an engine destroying scenario. After getting it home and removing the water pump it was pretty apparent that I was lucky not to have lost a cam belt. The pump was virtually locked. I unfortunately had to pilfer from the new built engines parts but at least was able to get cracking on a fix right away.


So this pic showing the new pump fitted also shows a ghetto timing belt system mod I've pretty much always run. You get an old hydraulic tensioner from the stock system, extract the hydraulic piston and then cut the body down - voila you have an idler wheel that performs the exact same function as the Integrated Engineering (IE) part that you'd buy if you were to move to a mechanically tensioned belt system. As long as the bearing is still good, you're good. You can then take your pic from a 100% manually tensioned tensioner roller or in this case a manual/mechanically tensioned roller off the 2.0L twin cam ABF. You just turn it anti clockwise so it hits the stop and then release it back clock wise until two lines meet up and it is then correctly tensioned with an element of built in damping from its internal springing. To my mind the 2.0L uses bigger NA cams with more lift so can handle 1.8L low lift turbo cams. You do need to put a washer under it to space it out from the block the required amount to get the belt to track centrally to the pulley but thats no biggy. There was no warning that this was coming. Had an ever so slight squeak that I thought was an accessories belt for a couple of days. If it hadn't sprung a leak which alerted me to the cactus pump it'd probably have locked and shredded the teeth off the cam belt. So I was pretty lucky there.

[sambb]

MASTER CYLINDER

In doing the water pump you have the engine mount, fuel lines, engine mount bracket, coolant reservoir etc all removed from the engine bay. That kind of had me scratching my chin while looking at the box that had a new master cylinder in it and wondering if I should make a pretty straight forward job 5 times bigger. So I went ahead and removed even more stuff from the engine bay to make getting to the MC easier eg
such a s this guy, what a TFSI turbo'd Polo's TIP looks like.

So the MC I was putting in I bought about 2 years ago with Gav. Gav being more industrious than me got his in right away and loved it. It wasnt until the VW Nats at Luddenham earlier this year that I got to feel the change to the pedal and promised myself that I'd actually do it. So the stock Polo MC is 20.64mm diameter. The MC kit that I fitted is a Bora version with 23.81mm diameter bore. The Bora MC has the same bolt pattern to the booster as the Polo so no problems there, but the position it locates the POLO reservior in would have it hitting, so the kit comes with a spacer that is machined for sealing O-rings and a different MC pin/spigot to allow for that stand off which works with the different cylinder.

so you can see all the parts there. Basically with the stock MC removed you need to extract the stock pin from inside the booster. To fit the new Bora spec one in there you need to bend the 3 retainer tabs open, get the pin in there and the bend the tabs shut again with the pin in place. Not easy. The MC fit up easily but the problem is there is not enough room to fit up the MC with the reservoir already fitted. If this was possible you could bench bleed the MC and then have very little air to deal with when it came to bleeding. As it was the MC went in dry, the reservoir was then fit up and the MC was bled by cracking the two input lines to the ABS module and doing it from there.
I basically did this method but just ran longer lines from over above the ABS module to the reservoir. All the air bled out aok but needed about 40 pumps of the brake pedal to get ever last bit. Then reattached the lines at the ABS module and then bled out from the wheel. Order was drivers rear, passenger rear, drivers front and then passengers front.
Easy How To Bleed Brake Master Cylinder On The Car No bench bleeding.. - YouTube
I was aying to Gav the other day that this brake master cylinder mod is the braking equivalent of what a rear anti roll bar upgrade is to handling. I reckon so many people chase caliper swaps, bigger diameter vented discs etc etc and are never happy because at the end of the day you still have a pedal that is easily half way to the floor before it does anything, sinks even lower with stable pressure and gives you next to no feel/feedback so that you end up bringing ABS into the bigger stops. Half the brake swaps people do would exacerbate this because they put on brake calipers with bigger piston bores and loose even more pedal. The pedal is now rock solid right up near the top. If anything now the overboosting of the system is a bit annoying. It should really be the first brake mod done to a Polo and really transforms the car. I hate doing jobs like the water pump because its time and money commited and you don't go any faster, but I'm so glad that it created the opportunity to finally pull my finger out and get this done which is definitely going to make the car quicker around a track.

[Sydneykid]

Nice one Sam, I learned a long time ago that if you have a mushy brake pedal and all of the hardware is in good condition then you need a larger bore master cylinder and 20.64mm to 23.81mm is a decent step. The effect is much greater than the +15% bore would indicate. We often go from 3/4 to 7/8, which is 17%, and then find it's too much and have to drop back to a 13/16 which is +8%.

What is it with VW's and water pumps, both the Polo and Golf needed replacements.

Cheers
Gary

[sambb]

yeah I don't think I've ever done a timing belt at interval. Its always been done due to a water pump leak/failure.

[pogopins]

it's not 15% if you calculate master cylinder piston area tho is it, it's more like a ~33% increase?

[sambb]

hmm I did volume calcs assuming a 50mm stroke for both (just a constant number I invented) and the new MC was shifting roughly 33% more fluid. Either way the car needs it and you definitely feel it. I managed to get the ESP rattling away as I braked while turning over some rough potholes the other day. Best thing was the pedal stayed up and positive ie I still had a pedal rather than it sinking nearly to the floor like it used to previously. Thats the biggn for me. I was at the point of putting in an ESP bypass switch for the track but I might just see how it goes now. Might be fine as is.

[Water Boy]

Great update Sam!

[sambb]

Glenn Brinkman | VW Up | Whiteline Tarmac Rallysprint Series - YouTube

awesome little tarmac Up with a 1.8T 20V in it!!. I saw this advertised a while back. What an unreal build.