I’m looking for technical help or recommendations on: Alignment
Hi all
I’ve just fitted some wider wheels (15x8 et20) and the other evening, testing them out on a nice twisty road in the Peak to see what they were like I realised that the advice on tyre and wheel choice might not have been sound The steering is very light (I’ve looked into this and my understanding is that moving the weight outwards from the centre of the hub is the cause of this) and the car understeers pretty badly. Thank f##k nothing was coming the other way! I don’t know if the understeer was a result of not being able to feel the steering very well and not trusting it enough to turn in more or if it’s something else, I slowed down after that point.
I was told that wider wheels with a slightly stretched tires (195/50) would improve the handling. Seems it hasn’t though. I’m waiting for a day next week to fit some tein street basis and lower the car a couple of inches which I hope will help a little but my questions are:
Will a combination of the coilovers and a good wheel alignment solve the problem fully, a little bit or not at all?
I’ve got some alignment settings from the Bofi website (see screenshot) are those numbers best for standard wheels or will they work with the wider wheels?
Does anybody else have this set up and what have you done to bring the handling back to what it was, or better?
Thanks in advance
I’m interested in how the stretch affects the handling. Online I can find arguments for and against. From what I can tell, extreme stretch has a negative effect but mild stretch like mine is similar to having reinforced sidewalls and means there’s less weight than having wider tires. The garage that fitted them said it was a very mild stretch and they went on super easy.
What’s your understanding on how stretch has a negative effect on handling?
Easy fella… I’m asking about alignment settings, not a talking down to. I took one corner on a quiet road at night when I could see nothing else was on the road, at a speed I’ve been around it just fine before and slowed down when I found the handling wasn’t on point. I should imagine there’s plenty of people on this forum with enough experience and knowledge on this to give me the advice you say I should get… Hence the post
Thanks. Do you know what it is about the stretch on the tires that would make it feel twitchy? Would it be similar to having too much pressure in the tire?
It is more like going from very soft sidewall tyres to very stiff sidewall tyres.
Also - 29psi in your new setup will feel much stiffer than 29psi in a non stretched tyre.
The correct size tyre for a rim is designed to have an amount of slip angle when working that gives FEEL.
Your stretched setup will have removed a lot of this designed in slip angle so the tread of the tyre is now trying to do the job of the carcass ( flex to conform to the road )
Brilliant, thanks for explaining this to me. That would explain why the steering felt so light and vague. I forgot to check what pressure the garage put in the tyres in my eagerness to get out while it was dry. I’ll check this when I get home.
How about alignment? Will changing it help at all?
You could make the car feel more dozy with alignment changes ( sorry not sure what would need changing )
BUT
The best way would be to run a wheel/tyre setup that is more suited to a car you want to drive.
( Rather than some of the show queens that look fantastic but drive horrible )
You are currently fighting two major changes
Stretched tyres
20mm change in offset from what the suspension was designed for.
Yep, I thought it was going to come to that. I’ve listed the wheels so hopefully they’ll sell and I can get a different package. I’m looking at 7J ET38 with the same size tires. Online it says that’s a suitable tyre for that width rim. What are your thoughts on that?
It’s all about keeping the cost down, ironically. Obviously that’s not going to be there case if I need to change them but the alternative wheels I was just looking at were reduced. 205/50/15 are pricey too, which is why I was going for the same size tires. I got my Avon’s at a good price. That deal has finished now
Thanks for your reply. I did also say I’ve figured out the advice I did get before changing the wheels turned out to be not that sound. Seemingly the guy was more focused on stance and not functionality.
Lots and lots of people have run this size of wheel, offset and tyre width before. I would check your tyre pressures and allow for the fact tyres are new before throwing it out the window.
Just a little bit about me before this post attracts too much more of what seems to be some sort of talking down to or telling off! I’m not a young lad. I’m someone who’s worked hard for 25 years doing a job I love rather than a job that pays well.
I’ve always driven old vans and ■■■■ boxes. I’ve always fixed them myself when I could. I can change pads, calipers and disks, track rod ends, springs, cam belts, injectors and the likes.
These past few years though I have found myself with some “expendable income” and for the first time in my life I’m enjoying having something I always wanted as a young lad. It’s not a Porsche but it’s the next best thing in my eyes. Something fun, reliable and affordable, and puts a smile on my face. Something I can enjoy with my 12 year old son.
Repairs might not be new to me, but modding is. I’m learning and yes I’ve listened to some bad advice and made mistakes. I’m sure I’m not the first person to do this. My point is, I join forums like this for advice from a friendly like minded community. What I’m not after is feeling patronised. I’m aware the tyres are stretched and not the right size. I’ve asked people about MOT and insurance implications. All I’m after are helpful answers to my questions. Thank you all for your replies, in particular the three or four who have been helpful. If anyone else feels the need to reply with anything that is other than helpful, please bury the ego and refrain Thanks.
If you fit lower offset wheels, and et20 on an 8" width is very common, then you push the tyre contact patch outward and the effort in steering should increase. As a byproduct you will likely notice tramlining a lot more. As you have said the steering feels light, I expect the tyre pressures are quite high. They will have been left at whatever pressures the tyres popped on the beads at because dropping them back to “correct” is time consuming and in a busy workshop, ain’t nobody got time for that s***.
The steering is very light (I’ve looked into this and my understanding is that moving the weight outwards from the centre of the hub is the cause of this) and the car understeers pretty badly. Thank f##k nothing was coming the other way! I don’t know if the understeer was a result of not being able to feel the steering very well and not trusting it enough to turn in more or if it’s something else, I slowed down after that point.
