43,000kms update (4,000 kms post remap) + New rims and tyres!
Its been two months and nearly 4,000 kms since I did the Stage 1 upgrades on my car. The Bilstein B6s and the remap have truly transformed the car's capabilities. With the B6's it feels like the car has literally shed weight. Its great fun to chuck the car around corners. The car feels light and agile and ever ready to change direction. The already good high speed stability is further improved and you really feel the differene which changing lanes etc... on open roads. Between the remap and the B6' if I had to pick just one, it would be the B6's for sure.
The remap also is great and after 4,000kms I am happy its reliable too. Just after the remap I had some jerking issues between 2k and 3k RPM under hard acceleration. During service they said that the spark plugs were dirty and could be causing the jerks. After replacing the spark plugs the jerks have almost completely gone. I say almost coz there still is a slight hint of a jerk sometimes (not always) when I floor the pedal in that rpm zone. I put it down to the 91 octane petrol. I tried Speed 97 during one of my highway drives and there was absolutely no jerks with 97. I did not feel any major power difference though with 97 compared to the regular 91 octane petrol. Even the FE remained the same. If anything the engine feels just a wee bit smoother with 97. Not reason enough to pay huge difference in price IMO.
Post the remap I can say that in city driveability and mid range improvement is significant. Not so much the top end. The top end is slightly better and post 5,500 rpm you can tell that its running out of steam. Highway cruisability though, is vastly improved. The quiet nature of the engine and rock solid B6's mean that its quite easy to velocitize after driving on the highway. You need to look at the speedo to believe that you are doing 80 or 90 kph, which literally feels like 40 or 50 kph.
New Michelin PS3s + Borbet Lv5 Alloys
I did the upgrades at 39k kms, when my tyres looked in good condition and I expected them to last till 45k kms at least. Shibin of Head Over Wheels, Bangalore an associate of Pete's Cochin was very keen that I also go for 17" wheels during the tyre change. But I was worried I'd lose the practicality and go anywhere ability of the car and would end up worrying about the rims and tyres while going over every pothole. The ride was already stiffer with the B6's and 45 profile tyres over 17s would make it even harder. But I had started looking at alloy wheel designs by Borbet and really liked the grey matt finished design called LV5.
I started working on the tyre and rim upgrade project. Tyres and wheels are important safety aspects of any car, more so on fast cars. I wanted to be thorough with specs and numbers.
Now the stock specs on my car were as below
Rim : 16" x 6.5J (16" OD and 6 1/2" wide)
Offset : 50mm
PCD : 112
5 bolt.
I was keen on going for 225/50/16 Michelin PS3 as the size was perfect in terms of maintaining the outer diameter of the wheel and also the PS3's were good performance tyres as well. But I was not happy with putting such wide tyres on 6.5 inch wide rims. THe rubber would stick out too much and I don't know what impact it would have on the handling. This was one of the reasons for going for the Borbets apart from the fact that I really liked the design.
112 pcd is common with all VAG cars and Mercs so it was not much of an issue. The 16 inch LV5s came in 7 inch width, which was ideally suited for 225 tyres (though 7.5 would have been even better) There were a variety of options with the offset. We can choose from ET 50 to ET 35. The wheel offset determines how far in or out the wheel will seat in relation to the hub. With ET 50 the wheel will sit inside, whereas with ET 35 the same wheel will sit about 15mm outside when compared to ET 50. YOu get the same effect that a 15mm spacer will give, by changing a 50 offset rim to a 35 offset. I decided to go for 45 offset as it would space out the wheel a little and also give the inner tyre a bit of clearance with the suspension components. Going too far out puts extra load on the suspension and wheel bearings and the looks also can for a toss.
So here are the specs that I gave to the Pete's guys to order for me.
Borbet LV5
16" x 7J
112 PCD 5 bolt
ET 45
The rims had to be ordered and I was told it will take a full 45 days to get the same after placing order and making full payment. During this period I was given regular updates regarding the status of my order and sure enough after about 45 days I got the call that the rims had arrived.
My 16" Primacy LCs were going strong and even at 43 kms they looked like they could easliy take another 5k kms of running. Really good tyres these. No tyres have last more than 35k kms in any of my cars and these look good at 43k on the fastest car I've owned. The 225 PS3's were not easy to source and I managed to get what were the last 4 tyres in the whole of Bangalore. These are 2011 manufactured. I would have preferred 2013 or atleast 2012, but I figured with my kind of running I'll use up the tyres in the next three years.
Then came the issue of hub diameter. Skoda wheel hub dia is 57.2mm and the borbet alloy hub bore is 72.5mm. THe OE alloys had a bore of 57.2mm and obviously a perfict fit. Aftermarket rims' hub bore is generally kept as high as possible so that it fits as many cars as possible. With a bigger hub the Borbet alloys would fit on my car no doubt but the rim would then have be centered by the lug nuts. It would be lug centric and not hub centric. If the tyre fitment guys are a little careless its easy for the wheel to sit a little off centre and this can cause vibration issues. That's where hub centric rings come to the rescue. Pete's keep in stock the perfect rings that have an outer dia of 72.5mm (borbet size) and inner dia of 57.2 (skoda size). Put the rings into the borbet hub and voila the wheel fits as perfectly as the Skoda OE alloy.
This is what I like about the Pete's guys. My point of contact throughout has been Shibin of Head Over Wheels. They are very thorough, dedicated and not one to cut corners. Though I had done meticulous research on the alloys, the hub rings had skipped my attention and it was Shibin who gave me all this gyan. Any other alloy wheel dealer would have sold you the alloys and thats it. Not with Pete's. Shibin specifically asked me if the hub centric rings came in the package. When I told him they weren't there, he got it couriered from Cochin and delivered it to me the next day.
Phew that was a long post. Time for some pictures.
The new alloy hub The hub centric ring. Made of hard plastic. Tap it into the alloy hub with a small hammer. The hub bore is now same as Skoda OE alloy. OE Alloys and tyres will now be stored in the garage. Tread depth of worst looking Primacy LC after 43k kms of running Pictures of the car with the new rims and tyres.