Jump to content
GTS Blonde

GTS Tyre Upgrade: Research & Decisions?

Recommended Posts

After 3.5 years of skating around on the original Michelin Primacy HP's, this lady is really looking forward to the vastly improved grip and handling to be afforded by a forthcoming upgrade to high performance tyres for the factory 17" wheels of her GTS.

 

Following a fair amount of research, which included interrogating many of my husband's motor racing contacts (including 86 racers and a couple of his competition tyre suppliers) at every opportunity, I have narrowed down my preferences to two tyres and a possible size option, which I am happy to share with the forum for the greater good. While the car is not 'tracked', it is regularly driven spiritedly on car club runs and holidays involving lots of twisty roads and will be doing a number of extended tours next year, so my personal performance priorities and trade-offs are:

1. Exceptional dry grip

2. Excellent wet grip

3. Excellent braking, wet & dry

4. Firm cornering

5. Acceptable road noise level

6. Tyre wear (happy to trade above average wear for grip)

7. Price (around $200 per tyre)

 

TYRE DECISION

We all know any R-Tyre delivers incredible dry performance, but I eliminated racing tyres from the outset because of average wet weather grip and shocking road noise. While the Pirelli P Zero, Bridgestone Potenza S001, Goodyear Eagle F1 and Yokohama Advan Neova AD08R all tick my first four priorities for a performance street tyre, I eliminated them also because of reputed high levels of road noise.

The two contenders are -

YOKOHAMA ADVAN SPORT V105 (well proven Japanese technology, award winner, factory tyre for some very powerful luxury sports cars)

MICHELIN PILOT SPORT 4 (the new kid on the block, latest European technology, launched with much fanfare this year, gaining a good reputation, rumored to succeed the Yoko V105 as the next performance car manufacturers' choice).

 

SIZE OPTIONS

While most tyre experts were adamant I will gain in handling and grip, with no downside (except some negligible effect on the speedo readout due to a slight increase in rolling diameter) by fitting a wider 225 x 45 tyre to the original 17"x7" rim (especially if I choose the higher 94Y sidewall loading option), there were a couple of non-tyre people who cautioned me that, while a 225 tyre is at the absolute margin for a 7" rim, it may produce spongy handling as the ideal rim width for a 225 tyre is 7.5".

The size options are -

215/45 R17 91Y (original size & safe bet)

225/45 R17 94Y (10 mm wider & with stiffer 94 sidewall to compensate, should improve grip, but could detract from lateral handling?)

 

I hope this helps fellow members with their upgrade decision making. For the record, I'm currently leaning towards the Yokohama V105 in the wider 225 size.

 

While I know either of these tyres are going to be a huge improvement, naturally I would appreciate any feedback from forum members that may help me make the best decision.

Share this post


Link to post
Share on other sites

I've had Eagle F1 (symmetric) on my previous car, the road noise wasn't bad. It got more noisy once it got a bit worn, but it was never bad. But you maybe talking about the asymetric, that I don't know of.

I had Pirellis, but not the p zero. I was very happy with the handling of those tyres, they were exceptionally good, but they were soft, and worn down pretty quickly. I'd still go for it, but money maybe an issue for you.

I've got some NT01's now for tracking...now that's bloody noisy. But grips nicely once it's warm. I'd never use it for everyday driving, though. I'd go mad. ;)

Also had some bad experience with bridgestone, although a very different car & tyre combo. That was noisy too, even though the dealer said it's very quiet. BS. Good grip, but noisy.

 

I'm running ContiSportContact5 for everyday use. (zero noise) It's not exceptionally grippy in the dry (good, just not exceptional), but boy it's a joy in the wet! That was my priority. In the dry it's easy to keep it on the road with any tyre - this car handles really well ! I've even had it on the track once, in the wet, and it holds up very well. Bit squirmy over 160 (in the wet).

 

The 225 width can be put on the stock rims, but you won't notice any difference in handling. Let's put it this way: It's 1cm wider. Also, the camber on the front (or the lack of it) pretty much negates any decent grip for cornering - so it may only affect braking performance.

Also the 225 is usually quite a bit more expensive, and the choices are very limited. Also, the wider you go, the heavier it gets. And this is rotating unsprung mass we're talking about, the worst kind. (this is the very reason putting 18" tyres on an N/A car is a stupid idea IMO.)

 

Depending how many km's you're doing yearly, you might want to get the Michelin, it's reportedly the best tyre-wear wise, and the grip will be very-very similar across all the (good) tyres.

It maybe among the pricier choices, but how often do you buy tyres? With public road use only, it may well be 3-4 years before you need another set. Saving a couple of hundred here is not really a big saving...$50/year? How much do you spend on your mobile phone per year average, just for comparison? :)

 

my 2c

Share this post


Link to post
Share on other sites

Don't forget Nitto Invos in your list. Another of the top tier road tyres. I'm really hoping the PS4 is indeed the sucessor to the PS2 and not a waste of space like I feel the PS3's were. I'd also recommend considering front Camper bolts instead of a tyre size upgrade perhaps. That tad more camber can make a world of difference. 

 

Good luck with the purchases.  

Share this post


Link to post
Share on other sites

I've had Eagle F1 (symmetric) on my previous car, the road noise wasn't bad. It got more noisy once it got a bit worn, but it was never bad. But you maybe talking about the asymetric, that I don't know of.

I had Pirellis, but not the p zero. I was very happy with the handling of those tyres, they were exceptionally good, but they were soft, and worn down pretty quickly. I'd still go for it, but money maybe an issue for you.

I've got some NT01's now for tracking...now that's bloody noisy. But grips nicely once it's warm. I'd never use it for everyday driving, though. I'd go mad. ;)

Also had some bad experience with bridgestone, although a very different car & tyre combo. That was noisy too, even though the dealer said it's very quiet. BS. Good grip, but noisy.

 

I'm running ContiSportContact5 for everyday use. (zero noise) It's not exceptionally grippy in the dry (good, just not exceptional), but boy it's a joy in the wet! That was my priority. In the dry it's easy to keep it on the road with any tyre - this car handles really well ! I've even had it on the track once, in the wet, and it holds up very well. Bit squirmy over 160 (in the wet).

 

The 225 width can be put on the stock rims, but you won't notice any difference in handling. Let's put it this way: It's 1cm wider. Also, the camber on the front (or the lack of it) pretty much negates any decent grip for cornering - so it may only affect braking performance.

Also the 225 is usually quite a bit more expensive, and the choices are very limited. Also, the wider you go, the heavier it gets. And this is rotating unsprung mass we're talking about, the worst kind. (this is the very reason putting 18" tyres on an N/A car is a stupid idea IMO.)

 

Depending how many km's you're doing yearly, you might want to get the Michelin, it's reportedly the best tyre-wear wise, and the grip will be very-very similar across all the (good) tyres.

It maybe among the pricier choices, but how often do you buy tyres? With public road use only, it may well be 3-4 years before you need another set. Saving a couple of hundred here is not really a big saving...$50/year? How much do you spend on your mobile phone per year average, just for comparison? :)

 

my 2c

Thanks YSU - your 2c is much appreciated. One of the reasons I'm leaning towards the Yoko V105 is I was taken for a pretty wild 15 minute run in a stock GTS fiited with them (225's too), which involved plenty of hard cornering and some freeway kms. Even though I was pinned to the door in a lot of corners, the car did not break traction at all - amazing. I also noticed the car seemed even quieter than my original tyres at speed on the freeway, which is impressive for such a lightly shelled car as the 86. If the Michelin PS4 is even better in both regards, that would be something. I'm not worried about price or high wear - as you say, skimping on performance to save a couple of hundred over years is a false economy. FYI - in 225 I can get the Yoko's for $225 (no pun) and the Michelin's even cheaper at $205 (and I haven't even haggled).

Share this post


Link to post
Share on other sites

Don't forget Nitto Invos in your list. Another of the top tier road tyres. I'm really hoping the PS4 is indeed the sucessor to the PS2 and not a waste of space like I feel the PS3's were. I'd also recommend considering front Camper bolts instead of a tyre size upgrade perhaps. That tad more camber can make a world of difference. 

 

Good luck with the purchases.  

Thanks thaneirwin - I'll check those out. As I told YSU, at least I have personal experience of the Yoko's as a benchmark. One of my husband's tyre suppliers said he'd might give me a call the next time he fits some PS4's to a GTS, if the owner is happy to take me for a spin (still waiting on that call). Then I'd really be able to judge if they are better than the V105's. So far, no one has posted that either the V105 or the PS4 is rubbish - so that is conformation in itself that my current options are sound.

Share this post


Link to post
Share on other sites

Ah, yes, camber bolts - don't go to track without them :)  Even on the roads it helps, the stock front camber is zero on these cars, and with a bit of luck you can get 1.2-1.4 with some whiteline camber bolts.  Cheap & effective.

 

Wrt freeway sound: ask your mate if he deleted the sound tube.  That maybe another reason for the quietness :)

http://www.ft86club.com/forums/showthread.php?t=72263

 

If you have tested & liked the yokos, just get them.  There's not that much difference in (dry) performance with good tyres, the driver is a more important factor, usually.

Share this post


Link to post
Share on other sites

Well, following some definitive expert advice, at least one of the options for the tyre upgrade to my GTS has been decided. Whatever brand and model of tyre I end up with, I'll be absolutely sticking with the original 215/45 R17 size!

 

The advice came from a distributor of motorsport tyres who I interrogated at a social function last night (poor bloke). As the 86 was becoming the competition weapon of choice for many of his customers, about 18 months ago his staff conducted extensive circuit tests on a GT and a GTS, involving a range of both R-tyres and high performance street tyres, which included (you guessed it), a comparison between the 215/45 and 225/45 options on the factory GTS 17" x 7" rims.

 

While too many champagnes means I do not recall the technical jargon (something to do with the wider tyre not being able to expand sufficiently on the 7 inch rim, reduced road contact, the sides of the tyre flexing too much, etc), he was adamant that fitting 225/45's during the tests detracted from the car's handling in every respect. And (as some forum members have already mentioned) - you are also increasing the overall weight of the car by nearly 10 kgs and paying extra dollars for the privilege.

 

When I asked why many tyre places are happy to recommend the 225 option, he just laughed and said: "responding to demand from ill-informed consumers" (wider always = better, doesn't it?) and "they often have the 225 size in stock, but not the 215". He also added: "the original Michelin Primacy HP tyres are so loose, fitting 225/45's in a stickier, higher performance tyre, still achieves a slight improvement which the average customer unfortunately thinks is the bee's knees". In fact, his operation simply refuses to fit the 225/45, period!

 

Good advice for the wise I'd say!

Share this post


Link to post
Share on other sites

Thanks so much for a great post - this has helped a lot. 

 

I bought a 2017 brz sports pack with 17*7.5 rims from the factory.

 

I intend on putting Michelin PS4 on from new; however, I wondered if the advice from your motorsport tyre distributor contact would differ for the 7.5 rim rather than the 7 (i.e. would 225/45 be a better option for the 7.5 rim?). 

 

At this stage I'm leaning towards keeping the standard 215/45 mainly to maintain the rolling diameter.

 

I would really appreciate any comment on the best size for a 17*7.5 rim. Thanks 

Share this post


Link to post
Share on other sites

Thanks so much for a great post - this has helped a lot. 

 

I bought a 2017 brz sports pack with 17*7.5 rims from the factory.

 

I intend on putting Michelin PS4 on from new; however, I wondered if the advice from your motorsport tyre distributor contact would differ for the 7.5 rim rather than the 7 (i.e. would 225/45 be a better option for the 7.5 rim?). 

 

At this stage I'm leaning towards keeping the standard 215/45 mainly to maintain the rolling diameter.

 

I would really appreciate any comment on the best size for a 17*7.5 rim. Thanks 

From the notes I made during my investigation, that extra half an inch would have enabled me to comfortably accommodate a 225/45 and maybe even a 235/45 (the latter however possibly creating the same handling issues as would a 225/45 on the factory 7" rim), but as you said, it is important to stay as close as possible to the original rolling diameter.

 

My husband advised that you sometimes can go with a wider tyre and still stay close to the original rolling diameter by selecting a different tyre profile, but that of course can change the handling .. not always for the better. If you are keen on the PS4 and their 225/45 or 235/45 have significant rolling diameter differences, then I'd say you have to stay with the 215/45. Remember however that a small increase or decrease in rolling diameter will have a negligible impact on the old speedo etc, so I would be talking with your Michelin dealer and looking at his charts to work out the differences if you go to the 225/45 or 235/45.

 

If you are not joined at the hip with the PS4, you may also want to check out other performance tyres like Yokohama, as they may have suitable 225/45 (or wider) tyres with rolling diameters closer to the factory diameter than the wider PS4 (I discovered that the rolling diameters of same size tyres varied between manufacturers). Good Luck.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...