Brake System upgrade talk

[Type 100]

Hi guys. I have a few questions on upgrading my Jazz's brakes. Currently it's got front discs and rear drums with a supposed stock 70%/30% split in brake bias front/rear. Nothing really wrong with the current items (except lockup---I got no ABS) but I'd like to improve on what I deem a critical part of the car.

I wanted to ask if upgrading/installing any of the following items would have an appreciable increase in braking performance.

1) EBC Greenstuff brake pads (for the front discs)
2) bigger rotors
3) braided steel brake lines (for the front discs)
4) a slightly bigger brake master cylinder (BMC) - I heard this can make braking a little more progressive and reduce the incidence of brake lockup.

Lastly are there any upgrades you can do for rear drum brakes? I know they have supposedly just 30% of the brake force on my car but any added performance will surely be welcome.

Thanks in advance

[mazdamazda]

Go for the performance brake pads & reface your rotors if it's already uneven.

Then from there, check if the braking power is enough for you.


__________________

bigbigcar.com Review: Toyota Avanza 1.5G

[mbeige]

When I drove the Jazz the brakes are already pretty strong, considering it's lightweight too. The ventilated fronts are enough for my needs, maybe something is off with your braking system? I don't know if your lack of ABS is a hindrance, because ours has ABS though one "upgrade" I'd like to do is lower the sensitivity of the ABS. More than once I've had surprises when driving and going over potholes when the ABS would activate and pulsate the brake pedal. Sometimes I go over the bumps while I'm not stepping on the brakes and I could hear the brake pedal pulsating.

I know there are conversion kits for the rears so you can have rear discs but I'm not familiar of its availability, installation and cost.

[Type 100]

mbeige:
Yep I actually like the Jazz's brakes as they are, with only one criticism: on non-ABS units like mine, it's actually pretty easy to induce a lockup. It's happened on more than one occasion.

Given this observation, I don't think the excessive sensitivity of the ABS sensors is excessive at all---it seems that's just them doing their job. The brakes themselves are just that easy to lock up. That's why I was considering a slightly larger brake master cylinder to help alleviate this---the larger BMC seems to make brake modulation more progressive instead of an "on/off" deal.

Correct me if I'm wrong, guys; this is just the conclusion I've arrived at after reading a number of tuning magazines and my own observations.

[niky]

Well... it'll all depend on the size of your wallet.

For me, the most "sulit" upgrades are stainless braided lines and good pads. EBC pads are great, but remember, that's an expense that you have to do over and over again as they wear down.

Lots of stuff you can do. For mild street use, you can upgrade to Runstop rotors... they're a cheap upsize/upgrade for your stock system... a friend in the fordclub is the local dealer, and he sells through Speedlab (just look up speedlab.com.ph ).

If it's too easy to induce lock-up, you can also look at another possible culprit... the tires. A better compound of tire will increase braking power at the edge of lock-up every time. I did this with my non-ABS disc-and-drum Sentra, and it stopped better than my ABS-equipped 4-disc Sentra.

Remember, your number one limit in braking force is the tires. Once you've upgraded to better tires and the brakes still can't cope, that's when you start tearing into your system.

[mbeige]

Niky has a point with tires. When I drove the Jazz with its stock 15" Michelin tires I would have to give it more time to brake than with the 17" Dunlops. Now that you mentioned it, it seems that activating the ABS was also easier with the Michelins.

You're right with the on/off feel though, especially when in stop and go traffic. Napapansin ko yon, you release the brake but only after a certain amount of foot lift will the brakes disengage, unlike other cars that feel more direct so when you release the brake you can crawl along with the brakes applied partially. With the Jazz you can, but it's margin is very small so it will easily grab, I think that's why it's easy to lock up and it's easy to trigger the ABS. Good point there, I didn't think of it that way.

I'm glad I wasn't the only one who felt this!

[Type 100]

Niky:
Thanks for the very sensible info. Yep, I upgraded my wheel and tire package recently, but I haven't really had to push the brakes to the point of lockup since then (no sudden stop situations encountered yet). Let's see what happens.

As for EBCs...the casa sort of bullied me into replacing my stock pads anyway on my last PMS. Those stock pads aren't cheap; they're actually close to the price of the Greenstuff pads IIRC. Most damning though is I found out the casa's replacement was unnecessary---I found this out via the electronic shop manual for the Jazz

mbeige:
Yeah the grabby modulation can be a b*tch at times...I got used to it in normal driving, but when you gotta brake suddenly for any reason, that's all too easy to forget.

Anyway, to repeat my question: is there any hope for upgrading the rear drum brakes? Not even a set of performance drum brake shoes?

[niky]

It shouldn't be an issue. 90% of the braking is in front. Best you can do, I guess... is wait for a wrecked 1.5 and get the brakes from that.

I don't know about the Jazz. but on most cars,, the brake bias is heavily geared towards the front... so the fronts will trigger the ABS first. So the rears shouldn't be an issue until you get to do some heavy track work.

[speedyfix]

tanabe pads should be ok. if stock they lock up then it might be a driving problem. hindi dapat mag lock up ganun kabilis unless you really stomp on them.

a bigger brake master will get you to lock up more since it will be pushing more fluid. only replace it if you are upgrading calipers.

it's going to be hard to find a set of ssbl's just for the front imo. APP has SSBL's available for the gd1 and gd3 chassis which are about 10k for the set. you will also need good brake fluid to go along with it.

[wildthing]

agree with speedyfix, may be you should look into your driving habits - in particular braking habits.

wouldn't it be safer to drive with the right speed that will allow you to brake properly without the brakes locking-out?!?

[Type 100]

I have only one thing to say: sh!t happens. I drive civilly, thank you. It's when sh!t happens that I have to brake forcefully and I get the lockup. Can't predict everything on the road now can you?

Thanks Speedy for the advice.

I'm just sharing my observations. On my old ride, a 1999 SX8 Honda City 1.5, I scarcely had lockup problems. Same driving style, same everything---I was even harder on that car.

Before advising me to change my driving habits, I would advise you to try driving a Jazz first and see just how easily the onset of lockup is achieved---Mbeige has already vouched for this.

Anyway I've upgraded my rubber as Niky's suggested, so I'll observe any improvements. So far the incidence of lockup has been reduced---maybe it is down to the rubber after all.

[s_quilicot]

in ABS equipped autos ba pag nag palit ka to bigger or smaller tires it would affect the performance of the ABS? and what is the remedy for a OVER-REACTING ABS?

[Type 100]

Update:
It looks like better tires did the trick! I was braking harder than usual this morning (safely of course), and I never got a single squeal of lockup from the tires.

Thanks Niky

[mbeige]

May I ask what tires you used previously? Good to hear you feel safer braking now. I hope sh!t won't happen for you for quite some time.

[Type 100]

Mbeige,
Thanks bro. My old tires were the stock Michelin Vivacys. The fronts had little tread depth left, so I switched them with the rears. However I noticed lockup even with the thicker-treaded pair up front. Maybe the tire compound has something to do with it?

[mbeige]

That's possible, like I said when I have the 15" Michelins (stock ones also) I find that when I toss the car around it slides a bit more and brakes a bit longer, though it's more compliant with the softer sidewall to dampen whatever they pass on, as compared to the 17" Dunlops.

[niky]

Michelin Vivacy? Are they "fuel saving" tires? Michelin's high economy tires have a downside... long braking distances. That's par for the course for economy tires, and part of the reason second-gen Prius's come on bigger rolling stock.

And it seems that your tires are past their good rubber. Some tires lose grip as you wear them down... they have harder, slicker rubber underneath the top layer.

A better tire compound should do. Though how much better depends on what your tire budget is. But you got new ones na? What type?

[Type 100]

I upgraded to Bridgestone Potenza S-02 Pole Positions in the 205/45ZR16 size, about two weeks ago. They're a pretty old design by now so they've depreciated by a lot. Induced a lockup this morning...it was notable how much more pedal effort it took to get a chirp out of them. I practically had to drop-kick the pedal. Color me impressed

Regarding the Vivacys as fuel saving tires, I'm not too sure...but they're definitely not the high-performance type. They came stock on the Jazz.

[mbeige]

I hope you didn't get NOS tires, the tires have a manufacture code stamped on the sidewall indicating what week of what year it was manufactured. Since I'm not familiar with the model of tires you purchased I'm just mentioning this in the interest of safety

What a way to break in (not so new) tires! I hope you don't do this often, as flat spots can happen which will lead to imbalanced tires. Well I guess maybe that's why you went with the cheaper ones to practice on? hehe

[s_quilicot]

OT:

sirs how can i determine if soft compound ang tire? yung GY eagle f1 ba soft compound din? TIA