As with most projects and rebuilds, they all start in the same place, mine was no different. However, this isn’t truely the start of my forever ongoing Z project. I’ve owned this car (my second Z) since 2008 when I purchased it from a former member. For the first 5 or 6 years I did the usual mods with suspension parts and basic bolt ons. For reasons unknown, whilst running stock boost, piston 5 cracked a ring land during a track day at Castle Coombe. A forged build and a remap later all was well until a sunny October’s day 2013 at Bruntingthorpe killed that engine with what at the time was a suspected head gasket failure at 181mph..... And this is where I shall start my journal.

 

The Z was stored off the road from Oct 2013 until March 2015. I’d had a major knee operation at the beginning of 2015 which meant I was going to be off work for 6 months. I’d saved up enough to start thinking about a parts list to rebuild her and frankly, after a couple of months of staring at the same 4 walls, I was going stir crazy! I employed the help of a good friend and decided to pull the engine and see what was what.... just a head gasket my arse!

 

March 2015

Problem 1: It turns out stainless steel, exhaust wraps and condensation don’t mix well

 

Before I’d even got the engine out, a new set of downpipes was added to this list. These AMS items were only 2 years old, so I was far from impressed! I contacted the retailer and after a bit of tooing and froing I secured myself a set of replacements for free... how long they will last, only time will tell!

So I’ll be changing all 4 tyres. Last thing I want is a failure whilst up at the lakes! Michelin Pilot Super Sports all round

 

Like you I have tyres that need changing out due to their age. I'm going French this time and was intending to go with Michelin PS4S.

However, unless I import them from the US, PS4S are not available in the UK/Europe in 18" fitments. Its baby brother PS4 is available

over here and I thought you might find this link interesting regarding Michelin's PSS, PS4S and PS4 tyres. The relevant bits are posted

by Jamie McWhir, Michelin's UK technical manager.

 

http://www.tyrereviews.co.uk/Article/Michelin-Pilot-Sport-4-First-Drive.htm

Unfortunately I can’t get the PS4 or 4s in my rear wheel size (285 or 295/35) so my only Michelin options were PS2, PS3 (which wasn’t a great tyre) or PSS.

 

Such a shame they dont make the 4s in 18’s, I’ve got them on some of my work cars and they’re a fantastic tyre

Such a shame they dont make the 4s in 18’s, I’ve got them on some of my work cars and they’re a fantastic tyre

 

They do make them in 18" in lots of sizes only they don't sell them in the UK/Europe. Which is pretty strange for French company (IMO).

 

https://www.michelinman.com/tire/michelin/pilot-sport-4s (including 285/35).

 

These guys say they will ship internationally:

 

https://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Pilot+Sport+4S&sidewall=Blackwall&partnum=835YR8PS4SXL&tab=Sizes

 

https://www.tirerack.com/FAQ/index.jsp (Shipping tab)

 

I wonder how much it would cost to ship to the UK? I must say I'm tempted for the PS4S sizes I need (245/40 and 275/35).

However, Michelin are saying that the difference between the PS4 (which I can get in the sizes I need in the UK) and PS4S is

very small and really only noticeable on the track in tenths of a second. So it might not be worth the effort in importing them

for such a small benefit.

New rubber went on yesterday.

 

Aesthetically they’re not ideal, I forgot that Michelin’s are quite balloony in their fitment so probably should have gone with a 275 or 285 tyre,. But in this case, function wins over form. 295/35ZR18 103Y XL Michelin Pilot Super Sports and the Z now has a serious rear end foot print.

 

 

I’m probably going to have to do some clearance work where the bumper mounts to the quarter panel as it’s looks like it’ll foul on suspension compression. Also looking into corner balancing and geometry when I’ve tweaked the ride height.

 

Another random curveball appeared on the way back from the tyre place, a nasty oil leak from the left hand oil cooler hose. The Stillen oil cooler has a push in earls fitting, which appears to have torn the inside on the hose when it was pushed into the hose. Bearing in mind this cooler has been on the car for over 1000 dyno miles, it’s clearly been a slow time failure. Luckily I spotted it in a timely fashion and fitted a new section of reinforced rubber hose and she’s leak free yet again.

 

Just waiting for another free slot on the dyno and the power runs can commence

Well, I’m in a fairly down beat mood.

 

Yet again, another tyre failure. This time a 50 miles of use Michelin

 

 

Same side as the last failure. No signs of it catching or rubbing anywhere on the tyre. 32psi when cold, 45psi hot.

 

None of us (myself or the tuner) have any idea what on Earth is going on. He’s never had a failure in 10 years of tuning, never mind two on the same car on the same wheel

 

Yet again, exasperated :(

I would contact Michelin and ask for a refund. You shouldn't expect the tyre to fail brand new!

 

I have heard of dynos putting extra wear on tyres but not chewing them up. Is the wheel slipping on the Dyno before that happened?

No slip at all, still at wastegate boost pressures at 360ish HP

You can see it went under heigh pressure as you’ve got dirty edges inside and out but I’m sure the tyre is rated a lot higher than 45psi. I’m sure Michilne will replace it. Sorry you still not getting the luck you deserve!

Yet again, another tyre failure. This time a 50 miles of use Michelin

 

I wonder if the problem (with these new tyres) is lack of running in to remove lubricant left from the

manufacturing and this has caused the tyres to slip and overheat on the dyno roller and ~360 HP.

 

During the manufacturing process, tyres are treated with a lubricant to prevent them from sticking

to their moulds during the curing stage. When brand new tyres are fitted to a car this lubricant is

still present and can make the tyres slippery until it is worn away from normal driving over a number

of miles.

Maybe a silly thought but 2 tyres on the same side on the same dyno have you checked the roller carefully for anything on it?

There was no signs of any wheel spin on the dyno, as that was one of my first thoughts around the heat being generated.

 

Given how grippy the knurled rollers are, I would have expected a lubricant issue fairly early on during the dyno session, but given how hot they got I think it would safe to assume it would ha e been burned off pretty quickly

 

I’ve messaged and tweeted Michelin UK asking about a warranty claim. Even if I’d done a mahooosive burnout at 45psi tyre pressure, I wouldn’t expect to see that kind of failure until the tread was well worn. As you can see from the pic, everywhere Bar the delaminated part looks pretty brand new. Here’s hoping Michelin are willing to replace them (not holding out though, luck doesn’t appear to be on my side at the moment)

Maybe a silly thought but 2 tyres on the same side on the same dyno have you checked the roller carefully for anything on it?

 

Yeah, nothing obvious apparent. The rollers were re knurled about 6 months ago

You can see it went under heigh pressure as you’ve got dirty edges inside and out but I’m sure the tyre is rated a lot higher than 45psi. I’m sure Michilne will replace it. Sorry you still not getting the luck you deserve!

What are the edges on the opposite tyre like? Are they showing the same dirty edges?

If not that wheel has reacted differently to the slight change in size as the pressure increased.

I know I'm reaching a bit but trying to think out of the box for you. Something slightly ajar in the suspension might put differing loads on the tyres.

The car is anchored in the same position so all of that energy is through the tyre, nothing absorbed by the car or suspension.

I only glanced at the other side, but looked pretty similar

Well I’ve spoken to Michelin directly, and they’ve asked me to take the tyres back to the retailer for inspection/warranty claim..

 

I’m going to push for both tyres to be changed, given that the failure has happened inside the structure of the tyre, it’s not going to be visible from a visual inspection of the thread (unless it has started to go and we haven’t spotted it yet).

 

Fingers crossed for a positive outcome and some new, less explody, rubber

Well after several emails, phone calls and complaints I finally managed to pursuade Michelin to replace both my rear tyres. Further more, I managed to get them to agree for me to have a different tyre. I’d decided that aesthetically I didn’t like the 35 profile tyres as they were a bit balloony. Unfortunately, they don’t make the Super sport in 30 profile. So I managed to get a set of 295/30zr18 N4 rated Pilot Sport 2’s.

 

 

These were meant to arrive on Monday, then Tuesday..... then the courier somehow lost them so they didn’t arrive until this afternoon, which meant I missed today’s dyno slot. Sometimes I wonder if this thing will ever get mapped!

 

Anyway, I decided to bring it home to enjoy this glorious weather, even if it means staying off boost. It safe to say she still makes my willy tingle

 

 

Just waiting for a date for next week for more dyno time

Maybe a good idea to put a few miles on them anyway Nick. Good luck at the next dyno.

Well it appears Lady Luck May have shined on me.

 

The car was due to go on the dyno yesterday, but prior to doing so, I noticed a smell of fuel at the back of the car. Initially I thought one of my AN fittings had failed, so I replaced it with a spare. I took the car for a test drive only to find I still had a leak when I got onto any form of boost.

 

A bit of investigation later and i find that the weld on my AN fitting for the feed outlet has split. One exhaust flame on the dyno could have sent the whole thing up in flames!

 

So rather than modify the OE fuel tank lid further to accept AN bulkhead fillings, I’ve decided to have a custom fuel tank lid machined and drilled to use AN fittings.

 

All being well, it’ll be ready for the dyno on the 11th May... otherwise I may end up missing the Lakes trip (which I’ll be gutted about!)

A bit of investigation later and i find that the weld on my AN fitting for the feed outlet has split. One exhaust flame on the dyno could have sent the whole thing up in flames!

 

So rather than modify the OE fuel tank lid further to accept AN bulkhead fillings, I’ve decided to have a custom fuel tank lid machined and drilled to use AN fittings.

 

A dab of J-B Weld and she'll be as good as new!

A dab of J-B Weld and she'll be as good as new!

 

I know some people would actually do that!

New bulkhead fittings turned up today, so fingers crossed the custom tank lid will be ready for the end of next week.

 

In the mean time I noticed I had a little play on the hicas rack tie rods, so a new set of those have been ordered from CZP and fitted in time for its next MoT before the lakes trip

Picked up the new billet fuel tank lid. Mocked up the fittings, and lined up the new pump hanger for it to be welded into place tomorrow. Just need to find some longer bolts to boot it down

 

All finished (Bar a bit of wiring)

 

All finished (Bar a bit of wiring)

 

Very neat!

We need to do a HFEC NDT inspection of that weld Nick, if that fails, you’re up turd creek!