New Wheels and Tyres

[antodeco]

So a few weeks ago, after finishing a morning of karting, I noticed a massive bang everytime I overtook a car on the motorway (I was about 10 miles on the road at this stage, and another 50 miles to go). It went on for another few miles, with me noticing it was whenever I went over catseyes. Anyway, I pulled over and realised to my horror that my front left tyre was completed deflated and that banging was pretty much my now, slightly warped, OEM Starmag alloy.

Great says I, as I had taken off the spare wheel last year. Thankfully had a can of Tyreweld to get me home (a cautious 50mph drive home). When I got home I did a full inspection, and realised that the front wheel was done. Time for a new one! After trying to source 7.5jj OEM wheel, I realised it was more important to treat myself at this stage!

So, I went for 4 Proline PXF brass wheels, and 4 new falken azenis fk510 tyres. 225/45/17 on the front, and 235/45/17 on the rears (with 35mm spacers). After fitting them on the car (took me way too long due to them being heat welded onto the hubs), I nearly crashed on teh first motorway spin. Thought to myself, was moving to 235 (from 225) on the rears made THAT much of a difference). The car felt spongey and wouldnt stay in a straight line if accelerating hard.

Took the car home and checked all the PSI on the tyres. Turns out they were at 48PSI on all 4 corners!! Dropped them down to 32PSI all around and its ALOT better now. Less road noise. However, I am now getting a squeak on the rear if I take a bump a little too joyfully. The tyres seem fine, so scrubbing on them, so Im going to assume the newer and wider wheels are just showing up a worn shock mount (I will get to that at some point).

Anyway, the car looks transformed now. Pictures below.

Before:



After:

 

[Dino D]

I’ve been having the same issue (soft back end and squirming under acceleration and backing off).

I went from 235/40/17 to 235/45/17
The increased rear side wall has made massive difference.
I didn’t think it would but I’ve played with pressures, damping rates and scrubbed them off very well! Better but still not right.
They will be coming off soon.
It’s a shame as I like the meaty look and improved ride quality.

You can see the difference in this pic between 45 and 40 sidewall:

I had this behaviour before when I briefly ran the original 16inch wheels on the back (with balloon tyres) and the low profiles with 18s on the front. It was all over the place. Didn’t expect the same behaviour with just a profile change from 40 to 45.

 

[Dino D]

Car looks good by the way, good colour!

 

[Scooblitz]

You can see the difference in this pic between 45 and 40 sidewall.

View attachment 101229

I had this before when briefly ran 16inch wheels on the back with balloon tyres and low profiles with 18s on the front. It was all over the place. Didn’t expect the same behaviour with a profile change..

Really hoping to see a nice change from 40 to 45. "downgrading" from 18's to 17's.

 

[Dino D]

Really hoping to see a nice change from 40 to 45. "downgrading" from 18's to 17's.

Just becareful with 45 on the rear (if it’s 235/245) this is what’s causing me funny handling. It’s supposed to be 245/40. Also works fine on 235/40 but 45 is causing me issues. Really surprised, didn’t expect it to be so noticeable.

When I had 18’s I ran 255/35.

These siteyshow you effects of changing profiles:
https://tiresize.com/comparison/

https://www.willtheyfit.com/index.p...2=45&wheel_size=17&wheel_width=7-5&offset2=35

 

[antodeco]

In hindsight 40s would have been the better choice, but will see how I get on with them. So far, pushing the car in the rain, it's seemed quite stable. I'll have a proper drove the weekend on the motorway and see how it feels!

 

[DavidM]

So a few weeks ago, after finishing a morning of karting, I noticed a massive bang everytime I overtook a car on the motorway (I was about 10 miles on the road at this stage, and another 50 miles to go). It went on for another few miles, with me noticing it was whenever I went over catseyes. Anyway, I pulled over and realised to my horror that my front left tyre was completed deflated and that banging was pretty much my now, slightly warped, OEM Starmag alloy.

Great says I, as I had taken off the spare wheel last year. Thankfully had a can of Tyreweld to get me home (a cautious 50mph drive home). When I got home I did a full inspection, and realised that the front wheel was done. Time for a new one! After trying to source 7.5jj OEM wheel, I realised it was more important to treat myself at this stage!

So, I went for 4 Proline PXF brass wheels, and 4 new falken azenis fk510 tyres. 225/45/17 on the front, and 235/45/17 on the rears (with 35mm spacers). After fitting them on the car (took me way too long due to them being heat welded onto the hubs), I nearly crashed on teh first motorway spin. Thought to myself, was moving to 235 (from 225) on the rears made THAT much of a difference). The car felt spongey and wouldnt stay in a straight line if accelerating hard.

Took the car home and checked all the PSI on the tyres. Turns out they were at 48PSI on all 4 corners!! Dropped them down to 32PSI all around and its ALOT better now. Less road noise. However, I am now getting a squeak on the rear if I take a bump a little too joyfully. The tyres seem fine, so scrubbing on them, so Im going to assume the newer and wider wheels are just showing up a worn shock mount (I will get to that at some point).

Anyway, the car looks transformed now. Pictures below.

Before:
View attachment 101216


After:
View attachment 101215

35 mm spacers - are they hub adapters that are bolted on? I have 25 mm hub adapters - changed my wheels and the bolts through the wheels to hub adapters didn’t seat properly - wheels had slight play in them and caused a squeak / squeal on the rears - changed to a slightly shorter bolt within safety margins and all fine now thankfully.

Might be worth a check - stay safe!

 

[Scooblitz]

Just becareful with 45 on the rear (if it’s 235/245) this is what’s causing me funny handling. It’s supposed to be 245/40. Also works fine on 235/40 but 45 is causing me issues. Really surprised, didn’t expect it to be so noticeable.

When I had 18’s I ran 255/35.

These siteyshow you effects of changing profiles:
https://tiresize.com/comparison/

https://www.willtheyfit.com/index.p...2=45&wheel_size=17&wheel_width=7-5&offset2=35

The 17's im putting on are 8j square so 225 45 should be 'the gloves.' .... Wheels tyres and offsets are a labyrinth. Hoping i get a good feet from the tyres. I' m thinking about the potholes and speed bumps being one increment smoother.

 

[Dino D]

The 17's im putting on are 8j square so 225 45 should be 'the gloves.' .... Wheels tyres and offsets are a labyrinth. Hoping i get a good feet from the tyres. I' m thinking about the potholes and speed bumps being one increment smoother.

Yes 225/45 should be ok as that is what comes on the fronts - as the tyre gets wider the sidewalk gets taller hence they use 245/40 on the rear with 225/45 on the front.

When running 235/40 all around on a 8j rim the car feels great. 225/40 will be about the same overall size.

 

[antodeco]

35 mm spacers - are they hub adapters that are bolted on? I have 25 mm hub adapters - changed my wheels and the bolts through the wheels to hub adapters didn’t seat properly - wheels had slight play in them and caused a squeak / squeal on the rears - changed to a slightly shorter bolt within safety margins and all fine now thankfully.

Might be worth a check - stay safe!

They are indeed. Sorry, here actually 25mm Hubcentric ones. I replaced all the bolts but have a look at them again