Let's Talk Tires!

Ok so as I mentioned in my post where I described taking the car to Nismo Omori Factory (again), I mentioned that in addition to getting the biannual Shaken done, I also needed to replace the tires.

When the 33 GT-R first came out over 25 years ago, the OEM tires were either the Bridgestone Expedia S-07 (on the V-specs) or the Bridgetsone Potenza RE010 (on the standard car).

Traditionally, the Nissan race cars of this era were on Bridgestones too.

I took this photo of the LM racing car at Nismo Festival 2017

Taken at Nissan Global Headquarters Gallery

Also at the Gallery

Nismo has confirmed with me that traditionally, their recommended street tire used to be one of Yokohama Tire's top sports tires being offered at that time. As shown on the CRS cars.

I took this photo at Nismo Festival 2017 - the Advan Sport is Yokohama's Maximum Performance Summer Tire 

Couldn't resist posting this, so clean!

Next, I have to figure out what polymer coating they use...

And yes, I've been on Yokohama Advans since I got my R35 brakes installed... back in 2011!

Metadata date is October 15, 2011!!

But about 7 years ago, Michelin started making inroads with Nissan... witness their gigantic trailer parked at last year's Nismo Festival, for example.

The Super GT cars began wearing Michelins around 2013.

The new e-dams Formula machine... wearing Michelins!

And then suddenly Nismo started to use Michelin tires on their CRS cars too.

My Lexus IS-F came OEM with the Michelin Pilot Sports, so I know that they are good tires.  But then I stumbled on this video.

And if it's widely acknowledged that the Pilot Sports 4S is even better than the Pilot Sports...

However, just because Nismo now uses the Pilot Sports tires, doesn't mean I do.  Putting price aside, I decided to do some research and compare the PS4S against the two tires I would normally decide between, the Bridgestone RE71R and the Yokohama Advan A052.

Interestingly, I found that on TireRack.com, they consider the RE71R and the Advans to be "Extreme Performance Summer Tires" ("Hyperfocused on extreme dry grip, but gives up wet traction, confort and life to get it") while the PS4S is a "Max Performance Summer Tire" (designed to "deliver the highest combination of dry and wet traction along with reasonable ride and treadwear").

In other words, the Extremes are for track/dry weather use, while the Max tires are for great all around use (except obviously snow and ice).  Normally I would agree that, since I never drive the GT-R in the rain, I could focus and buy one of the Extremes.  However, there were 2 things to also consider - what if I got caught in a downpour or end up on a road up in the mountains still wet from the day before, and second, is there a Max tire that has just as good dry performance as an Extreme tire?

Now, for those you who question my research at TireRack.com -while their categorization is useful, what I'm really interested in are the ratings by actual owners. Somewhat like how we check Customer Reviews on Amazon or feedback given in the App Store, I tend to disbelieve what the "experts" say - even in famous magazines or youTube channels - because most of the time those people are given some kind of financial incentive to not say anything negative about the products they review.  The average consumer, however, is usually much more truthful because it's their experience and money. In fact I usually go to the negative reviews first, pissed off consumers are usually very informative (if not entertaining)! But I usually go along with what the majority say.

So first the customer experience on the RE71.  Overwhelmingly, most people seem to buy these tires for track and/or autocross use.  For those who do drive with these on an daily basis, these tires seem to not be as good in the wet as they are in the dry.

Second, what about the Advans?  Very few reviews on the A052 but again the majority of reviews reflected track/autocross driving. Just in case I also checked out the reviews for the AD08R, the successor to the tires on my car, but the feedback was similar.  And the overall rating, like the A052 and the RE71, showed only "good" and not "excellent" subjective wet performance.

Ok then what about the PS4S? Well first, this tire showed "excellent" in both wet and dry performance, but the reviews showed that overwhelmingly, this tire is not for the track. Some of the users who used this tire for the track had problems with premature wear, and some even outright mentioned the RE71 as a better tire on the track... and especially in the dry.

So in conclusion, the PS4S appears to be the best high performance street tire. And, given that I can currently get these tires at about half the price of the others, I can convince myself to go with them, even though I'll likely never drive in the rain, and I've been itching for a track day.  If I ever get back to do a track day, I will have to mount some Advans or the RE71 (purchased as cheaply as possible) on my spare set of wheels (LMGT4s).

Incidentally, if pricing was comparable amongst all three tires, I would likely go with the Bridgestones, given their OEM association when the car first came out.  Never mind that I don't take the car to the track these days and I don't drive it much (and when I do, and I wouldn't do so in the rain anyway).  Just wearing JDM best might be good enough...

Stay tuned! Another post coming soon! Stay safe everyone.

New Speakers - Kenwood Sound Cruising System?

In an earlier recent post, I mentioned that I had begun researching speakers and speaker locations after I had removed the overly complicated Pioneer CyberNavi system, and that I was looking to replace it with a simpler 1 DIN deck.

And yes, one of the tasks for Nismo Omori Factory this time is to remove that mess of wiring, remove the Morels in the A pillars and the doors, and move the old 3 way coaxial Pioneers in the rear deck to the front doors, so that whatever deck I choose can be installed very easily.  But these Pioneers are not a permanent solution, as I'm sure there are newer speakers on the market that provide better sound quality.

In my research for new speakers, one option I DID in fact think about was the optional Kenwood Sound Cruising system, which in fact was standard on the 4 door Autech GT-R (and it's something I became aware of several years ago). Described in the catalogs as "200W, 8 speakers, 1 DIN AM/FM electronic tuner, single CD player (with CD auto changer capability)" putting something like this back in my car would be cool - OEM yet digital sound, and with 8 speakers!

Buttons look faded, and the scratches on the display...

Ah, but what about the speakers? We would need good ones for digital sound, right? Well, previously,  I had discovered the fronts are separates and go into the A pillar and that all cars are prewired for it.

But I had never realized (despite the description of 8 speakers) that the REAR deck speakers were also a bit different than the norm, until I came across this on Facebook.

Credit to Kesh on Facebook, apologies! Thank you for letting me post this! (see his comment below)

So my takeaways - looking at this photo, at the very least, these speakers appear to NOT have cones made of paper, but maybe a slightly better plastic (or a plastic coated paper cone)?

Compare with regular OEM speakers from my car that I still had saved!

And it's interesting that the fronts utilize the same plastic door mounts as the regular speakers, but the rears have independent tweeters next to the mids, or maybe they are subs.

Clearly the small tweeters that go up front seem a bit small.

As above, taken from a Facebook post by Kesh - thanks again!!

So the question now is, whether these speakers are actually placed optimally with sound quality and imaging in mind, much like the modern systems of today, or whether Nissan put these tweeters here for convenience.  In other words, if I choose separates again to replace the Morel speakers, is this where I should be placing the tweeters?  Somehow I doubt that optimal sound staging was the idea here...

Then again, I have no idea why they decided that separate tweeters were necessary in the rear - it's common knowledge that staging is more of a front position speaker thing, with the rears, if used at all, providing fill.

Further, I'm sure both speaker design and material quality has substantially improved in the 25 years since the Kenwood system was designed.  Those tweeters look very small, so my thinking is that given their sound dynamics, they NEEDED to be placed as high up as possible in order to provide some decent sound.

I'm also curious about the 200W Kenwood amp that came with this system. How good it is and how does it compare to a modern Class D amp?

In any case there was one very simple and OCD reason I decided not to go with this system in the end - if you look at the photo above, you will notice that the white lettering on the buttons has turned brownish orange. If I'm going to go OEM, I'd at minimum want it to look brand new...

And so my search continues...

Problem Getting Car Ready for Shaken (Quickly Resolved)

Now this was unexpected...

A few days after I dropped the car off, and a couple of days before Nismo was getting ready to send my car to get shaken'd I got the following photos sent to me from Ochiai-san.

Hmm looks a bit dark on one side...

Interesting. Didn't know light was measured not in Lumens but in Hecto Candela for Shaken purposes

Yep, all that work to try to modernize the headlights and the right side bulb (showing a brightness of 71 hecto candela in the above photo) dies on me. Great.

Since I wasn't going to bother scrambling to find the exact replacement (Philips D2S/R bulb, 6200K, 3300lms - and no longer made!) nor was I going to pay an excessive amount of money for OEM (you know, I still have those bulbs somewhere...), I asked them to get something nearly equivalent in the aftermarket.

So they went ahead and got these.

From: SphereLight Website

So that's one problem (cheaply) solved. Hopefully.

What else?

Well, the HKS catalyzer. When taking your car in for Shaken, if you are running a non OEM catalytic converter, you need to have the paperwork from the parts manufacturer demonstrating that this part passes regulations. As I forgot to include this in the paperwork I left at Nismo, I had to scramble at home when I got the call and PDF it to them.

Looks like this - as you can see it has all the gas readings to show it actually reduces hydrocarbons...

This is actually for my old Apex'i one.

And then photos of how it's to look when properly installed.

The good news I got however is that the car passed Shaken and the guy didn't even bother to ask for this paperwork... oh well...

One more thing - I realized that I am getting a LOT of things done this time - but each item I have decided to do after lots of research and thinking (and budgeting, of course). So going forward, instead of showing everyone what I did when I picked up the car (which would be a very long post), I will be posting on the blog for each item I am getting done, and then when I pick up the car hopefully showing with photographs of the items on the car.

That should allow me to post more often, and in more detail! Next post coming soon!

Guest Post - Tom Smith - Folding Mirror Repair

Every once in a while, a friend of mine (usually a fellow R33 GT-R owner) sends me something interesting.  In this case, my friend Tom from the UK, owner of a very clean black R33 GT-R (and a fellow admin in the owners only Facebook ClubR33) happened to mention that he was about to take apart and repair one of his folding mirrors. So thinking ahead I had asked Tom to take photos as he repaired his side mirror, and not only did he do that, he also wrote up a guide! Which he has kindly allowed me to publish on this site.  Please enjoy (not sure why the font changed on me when I cut and pasted over):

Guide to Folding Mirror Repair.

Firstly, it’s important to note this is not really an easy job, more for someone confident with small fiddly components. That said its more than possible with simple tools and for me at least it fixed my issue. I found a guide on a site in Australia but that one was distinctly lacking in pictures so hopefully this one is easier to follow. Remember when working with 25 year old plastics they can be brittle so take your time and be gentle.

*Please note that the screws to be undone are JIS Japanese industrial standard. That means they are subtly different to Philips and Pozidriv. Make sure you have a good fitting screwdriver. For the 3 screws on the mirror base you may even need a bit to fit in a socket wrench. They are very tight and have thread lock applied*

 First task is to remove the door panel. This is done by removing the 3 screws along the lower edge. Then the one in the bottom of the door pull. Gently lever the door handle surround away and put that to one side. Same with the window control switches pull up gently and unplug the switches. Last is the little pop clips just pull gently on them (located along the sides of the door panel) and the door panel will lift out of the groove at the top. Lay the panel down safely somewhere safe so as not to damage it. Before you go further if it works, using the adjustment point the mirror glass up to the sky. (this gives room to pull the glass from the bottom with your fingers)

Once that is done, we can now start to remove the door mirror itself using the following steps:

1. Remove the small plastic triangular trim from the inside of the mirror base. This just pulls off.

2. You will now see the wiring loom for the mirror, the mirror needs to be unplugged so trace the loom along the door you will see the white connector. If you still have it the plastic membrane on the door can be peeled back to gain access to the plug. 

3. Unplug the mirror and using a multi meter we now need to test the wiring and switch in the car for functionality. 

4. The plug in the door has 5 wires. We are interested in the 2 green ones (one light green with black stripe, one dark green with black stripe) very carefully with the ignition key turned to accessory position we need to probe the pins in the plug for the two green wires. With the mirror in the folded position first you should see 12v (or -12v) and in the open position the opposite of what you saw in the folded (either 12v or -12v). *If you short the probes on the multi meter across more than one pin it will blow the fuse so be careful- Perhaps ask someone to hold the plug as you test it*

5. If you see a reading of 12v or -12v in both folded and open positions, you know the car side of the wiring loom is good. 

6. Next step is to remove the mirror from the door and thread the wiring through the hole. This is done by removing the 3 10mm bolts from the mirror base. *Be careful not to drop the mirror* 

7. Now the mirror is free from the car, we can remove the glass. As it is adjusted up there is room to slide your fingers under from the bottom edge and gently pull it away. The glass hooks in the top and clips at the bottom so must be done this way. Place it down somewhere safe.

8. With the mirror free, next is to undo the retaining screw for the loom. This is located behind the foam as shown in the picture. Cut the foam neatly with a sharp blade for the best chance of putting it back where it was. In this case it had just fallen apart.

 


9. Next the three screws on the base of the mirror need to be removed, as previously stated these are tight. They have thread lock on them. For this I used a ¼ drive socket wrench with suitable bit to undo them. 

10.  Now the mirror can be pulled from its base by threading the loom through the hole. Pull as much loom through as possible you want the mirror and the base separated as much as possible.

11. You should now have access to the screw on the base, remove this as shown. 

12. Now looking at the mirror aperture where the glass was, there are 3 screws to remove the glass adjustment motor from the bracket behind, these are shown below. 

13. With this removed you can now remove the three holding the mirror folding mechanism from the painted mirror cap. Undo the screws as shown below. The painted cap now can be removed and slid down the loom to move it out of the way as best you can. 

14. Next is to remove the cap from the motor / gearbox assembly. This is held on with 3 little tabs 2 are easily visible but the third is behind some tape. Carefully peel the tape back to reveal the third clip. I used a small flat blade screwdriver to pry the cover off the clips and lift it off. *Pay attention to the routing of the loom as it exits from under the cover as it will need to go back in the same place, this is easy to see*

　

15. With the lid removed you are presented with the motor, the PCB for the folding mechanism and the gearbox.

16.  Now this is where the fun begins. Remove the connector from the top of the motor, this is just 2 pins and pulls off easily. Then undo the 3 screws highlighted below. I have also highlighted the split line on the gearbox this is important as we need to pry this open on the next step. *Note the PCB is held onto the cylindrical post by the white clips but also has a locating peg on the lower right of the board to make sure its in the correct place*

17. The next step is to lever the lid up off the gearbox. The reason for doing this is to slide the PCB and the white tabs holding it on off the black cylindrical post running up the centre of the 2. This subsequently allows the white tabs to be pressed in and the PCB lifted off the white plastic base. This is where the troublesome contacts are. The image shows the gearbox lid pried up around 5mm you want to lift it around 10mm to be able to press the white clips in. If you lift it all the way off it exposes the gears and ideally you don’t want to do that. 

　

18. What you will see once the white plastic and the PCB are separated is the two copper coloured contacts. One or both will be just broken away from their mounting points. This is what causes the folding function to stop working either in one way or both. In mine one was still in place hence it opened but wouldn’t fold. 

19. The way to fix the issue is to reunite the contacts with their mounting post and glue them carefully back into place. The centre hole lines up with the peg in the white plastic section. Note the orientation from the picture above. The contacts are designed to touch the tracks on the PCB above it so they must be proud of the base when glued back in.  

I have tried my best to show here the orientation at which they go back in. Bear in mind the arrow on the right shows the placement for the second contact. If both contacts have fallen out with the motor at the bottom the left side runs as shown and the right side the opposite. 

20. With the contact glued back into place give the PCB a clean with some electrical contact cleaner and carefully push it back over the white clips in the contact housing below. The assembly can then be slid over the black plastic cylinder on the gearbox cover. *Note as with disassembly the plastic posts will not depress if the black plastic tube is up inside it too far, so be sure to keep the white part free of the black part (shown by yellow arrows) until the PCB and contact housing are clipped securely back together. 

21. Reassembly is the reversal of the above steps. Be careful not to damage any of the screw threads when putting them back together. After step 20 it may be a good idea to take the mirror out to the car and test it. I asked my wife to help me hold the mirror while I checked the function of it. * Be careful when reinstalling the glass remember it hooks in the top and clips at the lower edge* 

*****

Anyway - hope people found this kind of post useful. If you've got something you would be willing to share, please drop a line and let me know! 

And now back to posts about my car...

One More Trip to Nismo Omori Factory... (Is this becoming an addiction?!)

So despite having had my car at Nismo Omori for a few months (conveniently while my house was being rebuilt) last year and getting the Nismo Omori Factory Chassis Refresh done, upon getting the car home earlier this year I realized there were a few more things I had to get done.

Ok... truth is I had to let my wallet recover for a few months before allowing them to do any more work!

This time, being that the car's bi-annual shaken is due in June, and in order to keep the car street legal, I decided to go ahead and have Nismo Omori take care of it this year. Turns out they are much closer in both distance and time to my house than Nissan Prince Tokyo Motorsports Factory as well as BeAmbitious, both places where I have had the shaken done before.  The fees and taxes are the same whoever does the work.  More importantly, I wanted Nismo to take care of a few things I didn't have the budget for last time.

Was nice to get the car out of the garage! Note the slightly overcast skies... better hurry before it rains!

First order of business - tires. Yes, ever since getting new tires back when I had the R35 brakes installed by Ninomiya-san at BeAmbitious back in November 2011(!!), I've had these Yokohama AD-08Rs.  Without even looking at the code on the sidewall, that means these tires are at least 9 years old!

Definitely time to change out for new tires. Stay tuned for what I decided to get!

Second, time to send in the Ohlins DFV (now called Road and Track) to be rebuilt (every 20,000km or 2 years). Last time I had them rebuilt was back in 2016.  This is actually fairly inexpensive, because I have chosen to keep everything the same, just renewed. Given the Chassis Refresh, I wanted to make sure that EVERYTHING - tires, coilovers, and bushes - are all new. I was suitably impressed with the result after the Chassis Refresh, but can't wait to experience how the car is when everything suspension related is new!

So those of you who are Nismo fans know that Nismo released their own Ohlins DFV coilovers back in March.  As far as I can tell, the only big difference to the original Ohlins spec is that the Nismo spec is a bit softer and thus a bit more street oriented (Nismo:  8.0(F)/8.0(R) kgf/mm; Ohlins original: 9.0(F)/8.0(R) kgf/mm).  I doubt I'll feel that much of a difference...

Parked and next in line for service - note the plastic cover on the steering wheel. Wouldn't want to get grease on the leather!

Weird how the color is different from inside at this angle...

What else? Well there are a few other things that need to be taken care of. Since they predict I will get the car back around the end of July (!), I will discuss some of those items in my upcoming posts. Stay tuned!