simon's learning what to do with the polo thread

[simon k]

Sam was right about my noise, it was just the manifold gasket. I swear I put my hands all around it with the engine running when it first started but last week I was having a feel around and there it was puffing away. So i replaced that gasket last week and all good. I probably could have just tightened the nuts because some were a bit loose (Sam said to do that too). I figured after leaking for 25000km it'd be stuffed but when I took it out it looked fine. I was also concerned that the head or manifold face would have been eroded but all perfect... very pleasantly surprised!

[sambb]

damn I secretly wanted it to be a drama so you'd be forced to get an L280. Oh well, pennies saved, a good result!

[simon k]

damn I secretly wanted it to be a drama so you'd be forced to get an L280. Oh well, pennies saved, a good result!

Lol, sorry to disappoint. Maybe one day

[simon k]

Do you reckon you'll stick with 215 fronts? Not sure who your track tyre supplier is down there but now that IPRA and a few things have started it'll be worth finding out when those rounds are and then enquiring the following monday to see if they have an second hand tyres that have come in. Nothing like cracking into the next time bracket. well done

(replying here instead of filling the performance thread with chatter)

I'd like to stick with the 215, they feel good on the track, but I have a large stock of 205's to get through so I'll use them up first.

Here's what your tyre ended up like - it was still gripping, just making a thud-thud-thud noise and slight shudder through the steering wheel on left hand turns



The water temperature crept up a bit at one stage, it didn't seem to cut power so maybe the oil temperature had stayed down.. and the cicada under the bonnet was back by the time I got home. I found the exhaust manifold to turbo bolts had come loose a little bit, and one exhaust manifold nut needed tightening - but I could feel hot air coming out from between the manifold and the turbo so I think that's where the noise was this time

I'm very happy to have dipped below 1:40, it was just that one lap but the rest of the day I was in the mid to low 1:40's so with a little more practice I might be able to consistently turn 1:39 laps which will be great.

[sambb]

jeez that tyre really let go. Its good to know how far you can take them before they blister and die I suppose. Was that the meatiest of the 215's or the one that was already on a rim and low on tread to begin with. Sorry you didnt get more out of it.
RE exhaust leaks .... Thats why (one day) I want to get to running the TFSI turbo - just completely get away from the multitude of nuts and bolts that are impossible to get to that routinely come undone. It does your head in.

[simon k]

jeez that tyre really let go. Its good to know how far you can take them before they blister and die I suppose. Was that the meatiest of the 215's or the one that was already on a rim and low on tread to begin with. Sorry you didnt get more out of it.

Nothing to be sorry for! I had 2 good days on it, I'm happy. My mate didn't think it was a good idea to drive the 100k's home on it though.. I changed it before I left Winton

It was on the rim you gave me and already very worn

[simon k]

Winton again yesterday, took another poofteenth off my best time - 1:39.804 against 1:39.806 - I wonder what the track timing system's margin of error is. I don't think I'll bother putting it in the performance tracking thread! Andrew @ Traction didn't have any 215's (said they're very uncommon) so ran on some of Sam's 205's, I settled on 34psi front, 35 rear which seemed to feel the best, I had a smidge of oversteer on a couple of the flat corners but very predictable (for me).

I had one "oh sh*t" moment on the sweeper (fast long bumpy left) where I entered a little bit wide and floated a bit close to the edge of the swept line, I gently dabbed the brake and it turned in - but I still think the brakes are still sh*t... on the track when approaching a heavy braking zone I basically push the brake pedal hard and then wait for something to happen. I bled the fronts today and the fluid came out with a brown tinge so (I guess) that means it's been hot, but no bubbles came out with about 300ml of fluid through it. I drove to the supermarket just now and it feels like it did before I started fiddling with it, it feels like the pedal has to be pushed to the floor to make the brakes work. I want to feel when the pads grip the rotors, not when the car starts slowing down. I drove my daughter's Focus the other day and just about put myself through the windscreen, the brakes on the Polo definitely aren't right.

And the cicada under the bonnet is back... just letting it cool a little bit before I go and check the turbo bolts

[simon k]

had a sprint at my local track today but didn't enjoy it - I left after 3 sessions

I ran on very very worn 205 A050's that are now have no tread at all, so I was having a hard time with oversteer until they heated up a bit. I took Sam's 195 A050 softs with me to put on, which I would have done but the clutch started playing up in the 2nd session, it was engaging really close to the floor and was difficult to change gears. I bled some fluid out of it, no air came out but it seemed to be OK again, so I went out for the 3rd session and the same thing, after the first lap it started being hard to change gears so I pulled the plug. By the time I got home it was more or less back to normal. The clutch has done ~10,000km so it shouldn't be worn out, but whats weird is that its coming and going, maybe due to heat but it shouldn't be happening, and it hasn't happened before

The other problem is that the car has started blowing a bit of smoke - a friend who was following me said it has a "light haze" of bluish smoke on the straight, but a couple of times now I've started it after a session and it's puffed a cloud of oil smoke, it clears after a few revs.

Aaaand of course the brakes were sh*thouse. I've been experimenting a little bit with the brakes while parking/driving around town etc. and the brakes do work OK, they'll hold the car stationary on a slight hill with very light application (like 10mm), it's just that pushing the pedal that much doesn't take any effort or give any feedback... but after the first session the pedal was worse, as if the top half of the pedal travel wasn't doing anything at all. I'm using Penrite Super Dot 4 (525°F boiling point), maybe I need to switch to something higher temp than that?

[guile]

are your clutch and brakes on the same reservoir? may be you'll get lucky and a fluid change will solve both your problems. I use this stuff and rate it pretty highly for the price...

TRW GP600 Dot 4 Racing Brake Fluid

[sambb]

That sucks Simon. Seems like it was happening very early in the sessions which doesnt really point to boiled fluid especially given that you have just done a fresh flush. It wouldnt be a bent clutch release fork since the clutch came back to you when you were back on the road again. Sounds like there's air still in there but I dont know what to say on that cos I know you've already tried every which way to get it it bled properly.

You could do a comp test/leak down on the engine. It may just be that the turbo seals are on their way out. Might even be worth looking at the PCV system. You could have a dud open circuit PCV valve allowing the crankcase to pressurise which is getting oil up past the rings etc etc?

[sambb]

In the PCV vacuum line which goes from the crankcase T piece to the inlet mani, I run a proper 1 way valve in line with the PCV valve. That’s insurance to prevent the boost pressurising the crankcase as PCV valves fail all the time. Just use one of the n249 or sai ones that you probably have laying around. That’ll rule out boost pressurisation of the crankcase getting oil up past the oil control rings as a possible cause of the oil. Maybe plumb in a catch can too and see if there’s oil getting into the intake that way.