Molds

I have read threads in the past where wheel size / handling has been hotly debated.

What will the effect of changing from 16s to 17s be, if any? I am changing for looks but don't want to sacrifice performance. I am presuming at this size it wont make a lot of difference, but I would like a better understanding.

MY98 UK

Cheers
Matt

(Also posted in Wheels and Tyres http://bbs.scoobynet.co.uk/showthrea...02#post3150302 but only one response so trying my luck in General)

corradoboy

I don't think you'll see much difference only going up 1". The handling will be a little tighter, but shouldn't be harsh by any standards.

Useful

Also useful

T5NYW

iTrader: (4)

[QUOTE=corradoboy]I don't think you'll see much difference only going up 1". The handling will be a little tighter, but shouldn't be harsh by any standards.

I agree with Corradoboy, not vast differences in that tyre profile size. but the same 1" difference for a 18" to 19" is HUGE.

You may, make of wheel dependant get a slight increase in your Power to weight ratio as some 17" Ally's are quite a bit lighter than the original Subaru Classic 16" Ally's, so thus saving on the 'unsprung weight' and also giving slightly better turning could make a very nice difference without losing too much comfort

IMHO IIRC

Tony

ex-webby

Hi All

Changing wheel size can make a huge different to handling.

The two main things to consider are, the change in tyre profile, and the change in weight.

Lower profile tyre, typically means sharper handling, less compliance over bad surfaces, less forgiving, but ultimately more precise handling on smooth surfaces, etc.

Wheel weight is more complex. Without question it is important to keep your unsprung weight as low as possible for handling. There are pretty much no negatives to this, which is very unusual in vehicle dynamics.

Increasing the weight of your wheel does NOT necessarily mean an increase in unsprung weight though, as the tyre is likely to weigh less. So the wheel / tyre combination weight is needed to make a judgement on whether it will be better or worse from a weight point of view.

All the best

Simon

Molds

Thanks for the replies so far guys, even a repsonse from Webby! I'm not worthy, I'm not worthy...

My plan is to go for 17" wheels with few spokes as I like wheels with 5/6 slim spokes, so I guess they will end up lighter than the OEM 16s. I am not sure about tyre choice but I will want to ensure that I retain speedo accuracy and therefore choose a tyre with a profile to accommodate this.

The main concern was whether I would go for new wheels for the looks but then trade off handling performance. I don't mind things being a bit bumpier but as I am not a fantastic driver I didnt want to lose the flattery offered by the Scoob's built in abilities!

My original post in Wheels, Tyres and Brakes has an interesting opioin posted by NACRO: -
>>>
I tried a wheel swap this weekend and have the bruised knuckles to prove it.

I tried a set of 17's with Toyo's on them, my first impressions were that the ride quality had decreased. I then took the car over my favourite route- 5 miles of almost deserted twisty dual carriageway in the mountains. It seemed to me that the car wasn't handling the roads imperfections as well as it did on the old 16's. It seemed to tramline more and follow the ruts in the road. The car seemed to ride a lot harder without cornering flatter if that makes any sense.

Decided I couldn't live with the 17s put the old 16's back on (205/50/16 Toyos)then went on the same run. The car didn't tramline as much, dealt with road imperfections better but didn't look as good. As I don't care about cosmetics, after all I have an Impreza, merely dynamics I'll be sticking with the 16's.

Are 17's regarded as the ultimate for the Impreza? Maybe for the more sophisticated cars but a lightly modded UK 'classic' like mine seemed far better on 16's.
<<<

Started putting me off again!

Ooooh, decisions decisions - what to do!?

Fatman

Perhaps that would have been a different result with other (non-Toyo) tyres? Personally, I fancy a set of Pro Race One wheels (http://www.tsl-motorsport.co.uk/wheels.html) at some point. They look OK, seem to be very light indeed and are pretty cheap.

prana

The above most probly due to the tyres and to a less extend. Although a lower profile may make a car handle better, it does however reduce feedback from the tyre walls. So although you have less traction due to tyre wall deformation, it is "more fun" to drive due to the increased feedback.

But to each their own. I wouldve spent my monies elswhere

corradoboy

I can strongly recommend OZ Superleggera (or the new SuperT GT if it's out). Very light, much like the Pro Race wheels, and extremely strong. I put a set on my Corrado and the handling was transformed, so the Scoob will be getting some 18's when the wallet allows.
Avoid Fox, they buckle like crazy. IMHO, the more spokes the less likely they are to buckle/flat.

wiltshire_boy

I changed from 16" Speedline Chronos to 17" Team Dynamics Motorsport on my MY94 wagon and whilst i much prefer the look i'm not convinced by the handling.

My 16's were a 52 offset and the 17's are a 45 which i was assurred would be fine. I can just about live with the odd bit of rubbing at the rear (on lowered Prodrive suspension) but it also seems to have completely changed the handling and not for the better. The front does feel more "alive" but a lot of this just seems to be overt tramlining. The turn-in doesn't feel right and the back end feels very "loose" if you make any sudden moves, especially in the wet.

Having said all that, I keep meaning to get to Cheltenham to get the geometry looked at and i don't know how much the tyres (F1's on my 16's, Toyo's on the 17's) are affecting the handling.

Hope this doesn't add to your confusion too much and is of course all just my opinion.

Roy.

Molds

Doh! I am never going to make a decisions

DaveR

...I just changed from 17' standard WRX newage wheels to 18' BK238s. Very chuffed with how they look, but not so chuffed with the handling.....

at high speed on the motorway the steering is now VERY light, and slight steering wheel movements don't seem to have the direct effect they used to......
plus there's more steering wheel shake generally

I think I may need to get laser realignment re-done or something

Molds

Hmmm, interesting that thus far there seems to be more negative views with regard handling post upgrade. I therefore find it surprising that so many people go for bigger wheels, and am struggling to understand those that choose 18s and the few 19s!

At this rate I will be looking for something nice, but in the same size lol.

ex-webby

I think the important thing to bear in mind is that it's personal preference. Firstly, not everyone places as much importance on handling as you (I personally do), and secondly, some people will prefer the handling advantages more than they will miss the disadvantages.

The important thing to consider (IMHO) above everything is the weight. If you fit really light 17" wheels, I would be stunned if you were not pleased with the difference. If you fit heavy 17" wheels, I would be stunned if you prefered them.

All the best

Simon

Paul_M

So Simon would you say that my car having 16" STi Rays (Volk racing forged wheels about 5Kg each) would noticably suffer if I were to change to 17s considering that I'm unlikely to get wheels anywhere near as light even taking into account tyre weight unless I spend megabucks?

I have long been considering the switch to 17s or 18s (say OZ P1 10 spokes) for aesthetic reasons but the thought of handling being adversely affected has put me off somewhat. I'm far from being a top-notch driver so what kind of noticable effect would it have for an average driver?

Paul.

ex-webby

hmmm

This is a difficult thing to answer.

If you increase the weight of your wheel tyre combination, you are almost without doubt going to negatively affect the handling / performance. This includes braking performance, etc so it's not a trivial thing.

The actual ammount it will affect it depends on the difference in weight. If it is a lot heavier, I would recommend against it, but if it's only slight, the improved precision of the tyres would probably counter this.

Difficult decision, especially as they're not cheap!

All the best

Simon

sammyh

iTrader: (1)

I was running 19" supper leggs on my car with 235-35-19 Falken tyres but removed them to get them refurbished. I replaced them with Prodrive FF7's in 18" with 225-40-18" Toyos.

To me its as clear as night and day, I get so much more feedback and grip through the 19's compared with the 18's that I can not wait to get them back!

I have had the back end step out on the 18's someting which never happens on the 19's and this was at a slower speed on a bend i know very well.

Also remember the 19's are running on a budget tyre and I still prefer them to the 18's

specialx

I have tried 16"s 17"s & 18"s on my scoob they all had good and bad points but all i can say is my car now runs on standard 16"s with pirelli p-zero's all round. the handling confidence given from 16"s is just amazing! no tram line following or bumpy ride. it's very hard with a scoob as 16"s look cr*p but do the best job imho

good luck m8!


so

if you like to drive like a nutter stay with 16"s

if you like to drive not to stupidly but want better looks go for 17"s

if you prefer styling over performance go with 18"s

if you are stark raving mad go for 19"s!!!

hope this helps

X

Stuart Page

iTrader: (4)

Go for 19's, something like six spokes K2's as you don't need a toothbrush to clean them!

peccy

if its a classic youve got then 18's are the optimum wheel size, the P1 was meant to run on 18's but couldnt be sold with them because of some EU law saying you need space to fit snow chains, so had to be sold as optional extra's

you can get 18s that are lighter then ya standard 16's but they may cost a bit cos will most likely be Forged or magnesium.

Molds

Geez, I really really don't know what to do now! Thanks for all the input guys and the techie stuff from Webby.

So how come as stock different models/and years of Impreza have come with different size wheels? Are the chassis different, sus setup etc in order to be optimised for the wheel they leave the factory with?

I'm kind thinking now either to go for some nice 16s - like some of the Volks, or sort out a light weight set of 17s but really cannot decide. I know a lot comes down to personal preference but sometimes it would make life so much easier if there were just a Yes/No answer to questions

Cheers

M

peccy

ive treid 16, 17, 18, prefered the 18's - looks, handling and couldnt tell a difference with performance, recenly put my 16's back on for a while, but the handling got a bit floppy.

vindaloo

I run a P1 on 18s. This used to viciously tramline on the Mway into lorry ruts and was a handful under braking on not smooth tarmac. That was running Bridgestone S02/S03PPs. Now it's running Goodyear F1 GSD3s, I feel much happier with it. I get the feeling the S03s have the ultimate cornering edge but I didn't care to try to get there and stay on the road.

Some thoughts....

I wouldn't have thought that running bigger wheels and tyres without upgrading the suspension or lowering the car would help. If the car leans on 16s, it'll still lean on 17s and the tyre contact patch will probably suffer more with the lower profile 17" tyre than the 16".

Choice of tyre makes a massive difference to your perception of the car's abilities. The differences get more pronounced as the tyre sidewall gets lower in profile too, I think.

Running wheels with a different offset will change the handling, probably for the worse, unless it's done by design. Even then, it's probably changed for better lap-times at the expense of comfort, feedback etc.

Jeremy.

Molds

Hmmmmmmm

Webby, what about something like this http://www.rallynuts.com/motorsport/...ution_1121.asp

Also my car is running stock dampers but on Eibach lowering springs

Cheers

M

ex-webby

peccy

Be careful about suggesting that a certain wheel size is "optimum", as there is no such thing. Everyone has a different taste, and handling benefits and negatives of each size are a trade off rather than simple linear improvement.

Molds

Why do cars get released in different sized wheels? There are lots of factors. Sometimes a car is simply developed to have the developer's idea of an ideal set-up. Sometimes it's marketing, sometimes it's cost, etc, etc.

I have been involved in a few projects where we've recommended a specific set-up, after months of development, only to have the marketing bods lower it and put bigger wheels on - It's fair enough, as the difference (once played with again) is not huge, but it gives you an idea of why the wheels are different sizes on different models.

Those OZ wheels look stunning, without knowing what the weight is, it's difficult to tell how it will affect the handling, but OZ don't tend to make rubbish.

All the best

Simon

PS. good advice from vindaloo

wanted

I've just changed from standard sti 16'' 205/50/16 to OZ P1 17'' 205/45/17. I didn't notice any difference in weight, give or take a couple of pound. Handling goes hand in hand with performance on my list of prioritys, and I was as unsure as you are about making the swap.

The performance does not seem to have been affected. The handling has changed but I think for the better. On my own private track, whilst cornering hard and having to change throttle position the car doesn't seem to wriggle around as much and seems to be able to take more throttle coming out of the corner. I haven't had any tramlining and the turn in is sharper.

Both sets of wheels were running the same tyres.

Hope this helps

Molds

Cheers wanted.

Aside from the technical explanations I guess that's the kind of comforting I was looking for

Molds

Claudius

17 inches is the correct wheel size for most 300 - 400 bhp Imprezas, isnt it?

Lots and lots of tyres available, a nice selection of lightweight rims; enough grip, good enough for decent brakes, etc.

I would only fit 18 inch rims if I needed more clearance for a brake system.

19 inches is for posers!

pappasmurf

Very interesting debate. I thourght of changing my 16" rims for 17" rims but wasn't sure if the handling would be poorer. 17" would look better, but i bourght the scoob for its handling abilities not fancy wheels.
As i live and mainly drive in an area with appalling road conditions ( cambridgeshire fens ) I stuck with 16" rims and put on Eagle F1's and am very pleased. After all my UK turbo MY00 was designed for 16" rims was it not?
What i would like to spend my money on is a handling package like the one offered by Scoobyclinic as i'm told this makes a big difference in handling.
At the end of the day, i guess only by trying some light weight 17" rims on the roads around my way will i really know of any difference.
So its 16's and Goodyear F1's for me and the guys with there fancy 18's and lowered springs will eat my dust on the pot holed twisties of Cambridgeshire.

highlander

I just changed from running ATP Torsion 16" wheels with 205/50 16" tyres to ATP Torsion 17" wheels with 215/40 17" tyres.

I have noticed very slightly more tramlining but the handling is much sharper than previously.

My suspension is KYB Adjustable dampers (AGX) with Eibach Pro Kit Springs, front and rear Strut Braces, Whiteline front drop links, Powerflex Rear Drop Links, 20mm rear anti roll bar, 18mm front anti roll bar and powerflex bushes everywhere. Car is a 300bhp classic.

What I have discovered is that with my current tyres P7000 Pirelli's (which are getting changed pretty soon) the air pressure in the tyre seems to have more of an effect than with the 16" tyre.

If you are trying different wheel tyre combinations remember to try them all out with different pressures as this will make a big difference. I currently run with 34psi front and 36psi rear. Of course these are just the pressures that suit me and my driving style and car setup. All these things are very much a compromise situation - you just have to go with the balance you feel best suits your needs.

bioforger

iTrader: (1)

I went from standard 16" MY99 wheels to newage WRX 17" wheels and the handling is transformed. It might also have something to do with the F1 GSD3 tyres I'm using as well. Turn in, grip and ride is so much better now though. Also the car use to terminally understeer in the wet when pushing hard, this has now vanished.