I Updated My Wheels To 17'' From 15'', I'M Feeling That My Brakes Are Not As Efficient As Before

[WarpSpeed]

Eh. ? Is that Yank for something ?

You're so sheltered ol chum, not as far as I know?

http://www.google.co...G=Google Search

Hmmmmmm, your right, sheltered indeed, not thought of it cause don't plan on clocking out yet . Even this old git is aiming at a bigger weight at the gym before my number is up.

But, think they WILL carry me out of here. ........

BUUUT! The idea is to complete these things BEFORE you clock out, kinda hard to do it once the grim reaper has showed up.. Anyway were way off topic though this thread is close to running it's course hopefully Johan will get a solution and update us on it..

[WarpSpeed]

A single kilo on the wheels will have a huge impact on braking. A passenger sitting in the car is not the same as a wheel with direct contact on the ground.

I found a few "tutorials" on that on french forums (yes i'm french). They also experienced the same issues as me while upgrading because the new stuff was heavier.

I contacted EBC brakes and they told me to upgrade yellow stuff and green stuff on my actual rotors and i should be fine. They can ship the pads from Bangkok for 200 baht extra, total cost is something like 6000 baht.

Better be safe than sorry later for just 6000 baht.

I really feel a difference in the braking system, maybe is just too old as i drive sportively, 14 000 km, 2yrs old brake pads (yes i don't use my car too much).

Being from across the pond there's a lost of translation here (so don't laugh...): What does Prost and Meh mean? What is Green and Yellow stuff (on the rotors)?

Didn't see the green and yellow stuff on the previous post, it is related to the pads not the rotors, EBC brand as some others do who specialize in aftermarket performance pads have a color code for their pads which refers to the hardness and wear characteristics of the pad..

[thailoht]

Didn't see the green and yellow stuff on the previous post, it is related to the pads not the rotors, EBC brand as some others do who specialize in aftermarket performance pads have a color code for their pads which refers to the hardness and wear characteristics of the pad..

Thanks for that info!

Did you get to check out JohanBKK's brakes?

[JohanBKK]

Honda didn't had enough time to check the brakes on Tuesday...

[transam]

Rule of thumb, two sets of pads to one set of disks.

[WarpSpeed]

Didn't see the green and yellow stuff on the previous post, it is related to the pads not the rotors, EBC brand as some others do who specialize in aftermarket performance pads have a color code for their pads which refers to the hardness and wear characteristics of the pad..

Thanks for that info!

Did you get to check out JohanBKK's brakes?

Nope, never got contacted, not sure if Johan read my invite? It seems maybe not..

[PETERTHEEATER]

In my opinion, Increasing the overall diameter of the wheel/tyre combination will effectively change the final drive gearing so the vehicle will accelerate more slowly for a given throttle opening and will have a lower engine speed for a given road speed.

If you have first class insurance any changes to the vehicle from standard would need to be reported to them and agreed and recorded. There may be an adjustment to the premium. Otherwise, in the case of a claim it might be rejected especially if the insurance investigator is efficient.

Despite claims about improved braking, the reality is that brake effectiveness is critically dependent on the contact between the 'footprint' of each tyre with the road; reducing the physical effort required to operate the brake pedal does not increase braking effectiveness especially where ABS is operational.

[2unique]

Despite claims about improved braking, the reality is that brake effectiveness is critically dependent on the contact between the 'footprint' of each tyre with the road; reducing the physical effort required to operate the brake pedal does not increase braking effectiveness especially where ABS is operational.

But also remember the more work your pads and calipers have to do the hotter they get and quicker too which will reduce your efficiency in 2nd, 3rd 4th etc time braking - better grip on tyres, more road surface contact, bigger discs and better materials can't help but improve initial and repeat braking as anyone who has driven a Vauxhall Viva will tell you

[BSJ]

Despite claims about improved braking, the reality is that brake effectiveness is critically dependent on the contact between the 'footprint' of each tyre with the road; reducing the physical effort required to operate the brake pedal does not increase braking effectiveness especially where ABS is operational.

But also remember the more work your pads and calipers have to do the hotter they get and quicker too which will reduce your efficiency in 2nd, 3rd 4th etc time braking - better grip on tyres, more road surface contact, bigger discs and better materials can't help but improve initial and repeat braking as anyone who has driven a Vauxhall Viva will tell you

With bigger wheels there is more air space around the disk and caliper. It should be cooler.

[thailoht]

Despite claims about improved braking, the reality is that brake effectiveness is critically dependent on the contact between the 'footprint' of each tyre with the road; reducing the physical effort required to operate the brake pedal does not increase braking effectiveness especially where ABS is operational.

But also remember the more work your pads and calipers have to do the hotter they get and quicker too which will reduce your efficiency in 2nd, 3rd 4th etc time braking - better grip on tyres, more road surface contact, bigger discs and better materials can't help but improve initial and repeat braking as anyone who has driven a Vauxhall Viva will tell you

With bigger wheels there is more air space around the disk and caliper. It should be cooler.

This isn't a logical truism. There is a size / braking capacity relationship whose boundaries must be honored, in order to maintain safe braking .... Unique2's statement stands up to fact.

When it comes to the question of my vehicle's braking, as with everything else, I prefer to be on the side of having components and systems that are better than 'average' or 'just good enough' .... striving for nothing-less than 'performance rated' quality (or just-short-of) = worry-free contentedness!

Edited August 31, 2012 by thailoht

[hakku]

Going from 15 to 17 inch is not a major change, the overall diameter doesn't change more then the diameter changes due to wear of a tire from new to old. There's a lot of talk around the topic but the basics are simple; the tire/wheel change shouldn't affect the braking performance. Johan thinks it does, so he puts back originals wheels and finds out. The brake system on an accord has plenty to spare, 17inch isn't a big wheel given the numerous accords on 18,19 and 20 inch. You don't need racing calipers and discs on a road car, hell you don't even need them on a basic race car, you need good pads and straight discs. We run Toyota Vios'es in endurance racing with standard brakes, just a bit of cooling sorts them out.

I'm really hoping Johan will let us know how his new pads work out.

Hak

[Spoonman]

Going from 15 to 17 inch is not a major change, the overall diameter doesn't change more then the diameter changes due to wear of a tire from new to old.

Are you saying if the OEM tyre was a 195/65/15 and I put on 195/65/17 they would be the same rolling diametre............ inches on rims has nothing to do with it, its all about tyre selection.

[WarpSpeed]

Don't read his response that way, read it as him summarizing and assuming that everyone here to this point understands that the aspect ratio must be changed accordingly to accommodate the larger rims and maintain something close to original diameter, not even sure if a larger rim is even available in the same width as an OEM rim when you step up to a larger diameter of that amount..

Seems he's just saying that regardless of diameter and including width, stock brakes can more than accommodate that increase in grip and inertial resistance to stopping without an entire brake system upgrade.

Edited September 1, 2012 by WarpSpeed

[transam]

Don't read his response that way, read it as him summarizing and assuming that everyone here to this point understands that the aspect ratio must be changed accordingly to accommodate the larger rims and maintain something close to original diameter, not even sure if a larger rim is even available in the same width as an OEM rim when you step up to a larger diameter of that amount..

Seems he's just saying that regardless of diameter and including width, stock brakes can more than accommodate that increase in grip and rolling resistance without an entire brake system upgrade.

Correct. and does any one think that with all the snazzy wheels that we see out there that they had to have brake upgrades. Don't think so.

When a motor is given larger rims the norm is to reduce side wall height to bring the total circumference near stock. On a Vigo when Toyota changed from 16 to 17 inch they used the same size tyre but used a 65 profile instead of a 70, this provided virtually the same rolling circumference.

[2unique]

Don't read his response that way, read it as him summarizing and assuming that everyone here to this point understands that the aspect ratio must be changed accordingly to accommodate the larger rims and maintain something close to original diameter, not even sure if a larger rim is even available in the same width as an OEM rim when you step up to a larger diameter of that amount..

Seems he's just saying that regardless of diameter and including width, stock brakes can more than accommodate that increase in grip and rolling resistance without an entire brake system upgrade.

Correct. and does any one think that with all the snazzy wheels that we see out there that they had to have brake upgrades. Don't think so.

That's assuming the stock set up was adequate in the first place - For some reason I thought the OP had a Pajero Sport - a PJS weighs a bit more than an Accord or Vios and if the original set up was anything like the MU7's bare minimum supplied then even with incremental increases you'd notice the deficiencies particularly with rear drums!

[culicine]

I'm interested in knowing how weight distribution affects braking, if any. Two wheels / tyres with the same weight and overall diameter, but one is rolling on 15" and the other on 17" Would there be any noticeable difference in braking / performance, acceleration etc.

[transam]

I'm interested in knowing how weight distribution affects braking, if any. Two wheels / tyres with the same weight and overall diameter, but one is rolling on 15" and the other on 17" Would there be any noticeable difference in braking / performance, acceleration etc.

Bit like you driving alone then carrying 4 passengers, you will feel something. A brake bias valve on any ride allows more power to the front brakes. On my fun ride with 315/60x15 on the rear and 265/50x15 on the front l had to fit an adjustable bias valve to redistribute the percentages.

[WarpSpeed]

I'm interested in knowing how weight distribution affects braking, if any. Two wheels / tyres with the same weight and overall diameter, but one is rolling on 15" and the other on 17" Would there be any noticeable difference in braking / performance, acceleration etc.

Bit like you driving alone then carrying 4 passengers, you will feel something. A brake bias valve on any ride allows more power to the front brakes. On my fun ride with 315/60x15 on the rear and 265/50x15 on the front l had to fit an adjustable bias valve to redistribute the percentages.

Maybe not 4 people, but................................................................... example made, point taken.. The likely hood of that scenario though is nearly impossible as there's almost always some deviation in weight when changing from OEM whether it's heavier tires or rims or a combination of both..

I might also add that many upgrades on new cars in the dealership are actually done at the dealer and offered as one off's with an upgraded package from OEM so given that fact and the fact that they begin with a base model and this goes for out of Thailand as well where the liability laws are much more strict I suspect if there was such a serious difference in braking created there'd be less dealerships offering such upgrade packages and backing them to boot..

Edited September 1, 2012 by WarpSpeed

[transam]

I'm interested in knowing how weight distribution affects braking, if any. Two wheels / tyres with the same weight and overall diameter, but one is rolling on 15" and the other on 17" Would there be any noticeable difference in braking / performance, acceleration etc.

Bit like you driving alone then carrying 4 passengers, you will feel something. A brake bias valve on any ride allows more power to the front brakes. On my fun ride with 315/60x15 on the rear and 265/50x15 on the front l had to fit an adjustable bias valve to redistribute the percentages.

Maybe not 4 people, but................................................................... point is valid.. The likely hood of that scenario though is nearly impossible as there's almost always some deviation in weight when changing from OEM whether it's heavier tires or rims or a combination of both..

My point was that if the same size wheel combo was fitted all round then it's just the feel of things, if bigger stuff is fitted to the rear then the factory auto bias won't do it's job.

[WarpSpeed]

Don't read his response that way, read it as him summarizing and assuming that everyone here to this point understands that the aspect ratio must be changed accordingly to accommodate the larger rims and maintain something close to original diameter, not even sure if a larger rim is even available in the same width as an OEM rim when you step up to a larger diameter of that amount..

Seems he's just saying that regardless of diameter and including width, stock brakes can more than accommodate that increase in grip and rolling resistance without an entire brake system upgrade.

Correct. and does any one think that with all the snazzy wheels that we see out there that they had to have brake upgrades. Don't think so.

That's assuming the stock set up was adequate in the first place - For some reason I thought the OP had a Pajero Sport - a PJS weighs a bit more than an Accord or Vios and if the original set up was anything like the MU7's bare minimum supplied then even with incremental increases you'd notice the deficiencies particularly with rear drums!

Accord, would he even be uprating from 15's to 17 on a PJS? Aren't they bigger then that stock? (meaning 15's not 17's) Same for an MU7 yes?

Edited September 1, 2012 by WarpSpeed

[taotoo]

Haven't read the thread, but presumably he how has wider tyres, and the brakes won't lock them as easily hence they feel less powerful

[WarpSpeed]

I'm interested in knowing how weight distribution affects braking, if any. Two wheels / tyres with the same weight and overall diameter, but one is rolling on 15" and the other on 17" Would there be any noticeable difference in braking / performance, acceleration etc.

Bit like you driving alone then carrying 4 passengers, you will feel something. A brake bias valve on any ride allows more power to the front brakes. On my fun ride with 315/60x15 on the rear and 265/50x15 on the front l had to fit an adjustable bias valve to redistribute the percentages.

Maybe not 4 people, but................................................................... point is valid.. The likely hood of that scenario though is nearly impossible as there's almost always some deviation in weight when changing from OEM whether it's heavier tires or rims or a combination of both..

My point was that if the same size wheel combo was fitted all round then it's just the feel of things, if bigger stuff is fitted to the rear then the factory auto bias won't do it's job.

I got your point...as I noted and not arguing it....And I see you responded before my editing clarifications and my highlighting Culcine's scenario.. Edited September 1, 2012 by WarpSpeed

[WarpSpeed]

Haven't read the thread, but presumably he how has wider tyres, and the brakes won't lock them as easily hence they feel less powerful

Why one shouldn't jump the start, skip the middle and just go to end..

[taotoo]

Haven't read the thread, but presumably he how has wider tyres, and the brakes won't lock them as easily hence they feel less powerful

Why one shouldn't jump the start, skip the middle and just go to end..

At least my post was on topic.

[2unique]

Don't read his response that way, read it as him summarizing and assuming that everyone here to this point understands that the aspect ratio must be changed accordingly to accommodate the larger rims and maintain something close to original diameter, not even sure if a larger rim is even available in the same width as an OEM rim when you step up to a larger diameter of that amount..

Seems he's just saying that regardless of diameter and including width, stock brakes can more than accommodate that increase in grip and rolling resistance without an entire brake system upgrade.

Correct. and does any one think that with all the snazzy wheels that we see out there that they had to have brake upgrades. Don't think so.

That's assuming the stock set up was adequate in the first place - For some reason I thought the OP had a Pajero Sport - a PJS weighs a bit more than an Accord or Vios and if the original set up was anything like the MU7's bare minimum supplied then even with incremental increases you'd notice the deficiencies particularly with rear drums!

Accord, would he even be uprating from 15's to 17 on a PJS? Aren't they bigger then that stock? (meaning 15's not 17's) Same for an MU7 yes?

Both came with 16ins but 2012 PJS 178bhp moved to 17 I believe... i think i had many tabs open including the 3 months research PJS one and had a senior moment!!!

[BSJ]

If the wheels and tyres are uni-directional I would swap the 2 front, thereby reversing each one, and see if the situation remains the same. There has to be a reason the braking efficiency diminished. Try one thing at a time and you will end up with the solution!

[WarpSpeed]

If the wheels and tyres are uni-directional I would swap the 2 front, thereby reversing each one, and see if the situation remains the same. There has to be a reason the braking efficiency diminished. Try one thing at a time and you will end up with the solution!

There is, the rotors are glazed and the pads to hard..

[transam]

If the wheels and tyres are uni-directional I would swap the 2 front, thereby reversing each one, and see if the situation remains the same. There has to be a reason the braking efficiency diminished. Try one thing at a time and you will end up with the solution!

There is, the rotors are glazed and the pads to hard..

NOT suddenly via a new wheel set up. The bad brakes would have been felt before the wheel change.

[WarpSpeed]

If the wheels and tyres are uni-directional I would swap the 2 front, thereby reversing each one, and see if the situation remains the same. There has to be a reason the braking efficiency diminished. Try one thing at a time and you will end up with the solution!

There is, the rotors are glazed and the pads to hard..

NOT suddenly via a new wheel set up. The bad brakes would have been felt before the wheel change.

Maybe maybe not, besides who says it wasn't there already and nothing to compare it to? I've driven other competitors race cars when they thought it was perfectly set up and it turned out to be junk to an experienced professional and the same goes for brakes. Likewise have had others drive my cars and come out saying Jaysus! What a difference! Like it's on rails! With the track times to prove it..

Additionally now he has up-rated everything and it magnifies his problem which may have been less noticeable before.. Anyway wish I could have seen them before as he's not likely to get anyone who can give him a proper evaluation..Unless they end up agreeing with my diagnosis of course ...

Edited September 1, 2012 by WarpSpeed

[thailoht]

If the wheels and tyres are uni-directional I would swap the 2 front, thereby reversing each one, and see if the situation remains the same. There has to be a reason the braking efficiency diminished. Try one thing at a time and you will end up with the solution!

There is, the rotors are glazed and the pads to hard..

NOT suddenly via a new wheel set up. The bad brakes would have been felt before the wheel change.

Maybe, maybe not. Besides, who says it wasn't there already and nothing to compare it to? I've driven other competitors race cars when they thought it was perfectly set up and it turned out to be junk to an experienced professional and the same goes for brakes. Likewise have had others drive my cars and come out saying Jaysus! What a difference! Like it's on rails! With the track times to prove it..

Additionally now he has up-rated everything and it magnifies his problem which may have been less noticeable before.. Anyway wish I could have seen them before as he's not likely to get anyone who can give him a proper evaluation..Unless they end up agreeing with my diagnosis of course ...

Of course!

'Too bad you can't check it out', is right, because I was so looking forward to knowing the resolution of his braking problem especially after the number of possible causes have been narrowed down!