Why does the non turbo roll easier than the turbo

[Bouncer]

Say if going down a hill, the non turbo I've got freewheels in neutral easier (or in gear but with the clutch down), why is this....the brakes arent binding on the turbo because when I stop, there's equal amount of heat all around on both cars. Is there something different in the gearbox or diffs of a turbo that causes this, or is there still something in the brakes binding

[Gambit]

I'm not sure mate I would say it's to do with the diff myself. And you do make me chuckle 

[Bouncer]

At least I someone laugh, usually I **** them off lol

Just a thought, would 17s with 215/45s on the front and 225/45s at the back have anything to do with it

[Gambit]

I wouldn't have thought so. Just jive you more rubber on the back when you are racing around the mountains !Removed! people off ;) lol

[Bouncer]

There must be s reason for it, if the brakes are still binding it must be hardly anything but enough to cause this, but why aren't 1 or morehhotter than the others

[Gambit]

Have you got more meat on the turbo pads ? so it's holding it a bit more firmer.

[savage bulldogs]

Best indication which brake is binding would be to check for uneven lips on the discs/ wear to the pads.

The usual culprit is the inside rears (on the sliding single pot rear set up)

[Bouncer]

  On 9/21/2013 at 7:11 PM, Gambit said:

Have you got more meat on the Turbo pads ? so it's holding it a bit more firmer.

 

No they're all more or less the same

 

  On 9/21/2013 at 7:13 PM, savage bulldogs said:

Best indication which brake is binding would be to check for uneven lips on the discs/ wear to the pads.

The usual culprit is the inside rears (on the sliding single pot rear set up)

No uneven wear that I notice, having said that, there's a weird wear pattern on the rears of the turbo but not sticking to my knowledge, I'll check them again though

[benjilovett]

id like to throw in wheel bearings some better than others possibly 

[Bouncer]

Maybe, but so far there's no whining or rumbling ect

[benjilovett]

Different gear oils just guessing  but may help

[Jay762]

wider tyres do equal more friction and as a consequence higher fuel consumption however in this case I would point to the areas already mentioned, bearings gears brakes etc.

 

as they are two dissimilar cars wrt history servicing mileage etc why don't you try the comparison with a friends NA car and see if there is a similarity there?

[Bouncer]

I know wider tyres ect give more grip and as you say cause worse mpg....but it's not that bad that'd I'd notice it, or would I

What I might do is put the wheels from my 98 na wagon on (195/60/15s) and try it....as the wrx from 92/-4 came with 15s

[SteveF]

With those different tyre sizes you have different rolling circumferences/radius? So one diff is being rotated at a different rate than the other.

The 225's should be 35 aspect ratio to match the fronts, basically so front and back are the same diameter. This might also have something to do with the unusual wear pattern on the rears.

When you sort it I suggest you release the axel wind up that will have been created too. If the car does not free wheel easily and there's no other reason for it, I suspect there's buckets of it.

AIMHO, of course.

Hope it help.

[Miggs]

i would be inclined to agree, 4 wheel drive vehicles are supposed to have the same rolling radius, if you have wider wheels at one end than the other then different tyre sizes are a must to get the correct radius but if all the wheels are the same width then the tyres must be too

[Bouncer]

I know, I'm not happy about it either as I could blow the diff (so I was told), all I can do right now is use the 15s from the n/a (they were fine when I swapped them the other day) as the tyres are all the same size and good tread.

What do you mean about realising axle wind up, how's it's done....what do you mean buckets of it

[SteveF]

Yes you could blow a diff and if I may say, driving a car with different size tyres is very dangerous. If you have an accident and plod clocks it they will throw the book at you and your insurance company will disown you!

To release wind-up, whilst driving on an empty road or car park, in a straight line at 20 - 30 mph, pull up the handbrake and then quickly release whilst keeping your finger on the button. You may hear a bang from under the car. This is the stresses being released.

By 'buckets' of it I meant lots of wind-up. Oh, and this isn't one, its serious!

Get them tyres changed bud, you know it makes sense. ;)

[Miggs]

it's only illegal to have different size tyres left and right, front and rear there is no legality for it

 

non that i'm aware of anyway

[Gambit]

Yeah I've been speaking to a company today about my problem he was also saying the 225/35 you pay about £30 then 225/40 and can't understand why I have 35's all round and that I should go with 40's on the rear  He never said anything from a legal side of having bigger wheel's on the back.

[Bouncer]

I had bigger tyres on the back of a bm I had a few years ago as it was rwd....I didn't mean they're all diffirent sizes, just the ones on the back, but I still don't like it and know I can and does cause damage to the diff.....like I say, I'll either not drive it or put the 15s from the na on. It drove better with them anyway, I couldn't believe it....must be getting old :)

[SteveF]

The manufacturer recommends the correct and safe size(s) of tyres for their cars. I am not aware that Subaru recommend or advise different tyre sizes front to back, especially on their 4 wheel drive vehicles.

As to the legality, I would not like to argue the toss with the Policemen that attend an accident with a fatality involved. Nor with the relevant insurance companies.

As I said, AIMVHO.

Cheers.

[Gambit]

I'm not saying you are wrong mate, sorry if you thought that. I was just saying I would have thought the tyre people should not be telling me to have bigger tyres on the back if I run the risk of it being Ilegal. I was just going to ask them tomorrow when I order one that was all :D

[Bouncer]

I don't mean to cause any trouble either, I know you're in soapy bubble of one tyre's different on the same axle, if both the same it's fine

[Gambit]

No you're not causing any trouble mate I just know how thing's can get lost in text easy so I  just wanted to point that out, and I'm interested to find out now so when I speak to them again tomorrow if they are wrong I can give the company some !Removed! ;) 

I also know a few people that use the bigger tyre at the rear with smaller on the front I can atleast them know too :)

[SteveF]

Hi guys, sorry if I've stirred things up that was never my intention. Worth remembering that some performance rear wheel drive cars DO run a WIDER tyre on the rear, however this is usually compensated by a lower aspect ratio as I described earlier. Always worth sticking by what the manufacturer says in my view, they spent millions on development optimising the performance and safety aspects of their cars.

Some BM's run wider on the rear with reduced ratio to keep rolling radius the same, M-Sport models I believe?

Maybe you could Google the tyre options for your mota?

Cheers.