emas

Have an '07 TL-S. Have been having problemswith the rear calipers for a couple years, vibration issues which forced me to breakdown wheels/brakes every 10k miles to clean out and an re-assemble.
The left rear froze/locked up last evening, and cooked my pads and rotor. So its time to replace them. My front Brembos have been flawless, but the rears in comparision seem to undersized and/or under-designed, And I want to investigate upgrade options.
Has anyone upgrated their rear calipers or brake sets, and have any advice to offer???
Thank you,

truonghthe

caliper stuck is a common issue with Honda car especially the rear one. I would replace the whole caliper with a new one. You mention clean out? you mean rebuilt the caliper?

Turbonut

iTrader: (1)

Ever bleed and refresh the fluid?
The rears are fine as is, but as they get old, high mileage, any system needs some attention. If you've been screwing with them for 2 years, they should have been done 2 years ago. Need to check to see if brake line(s) or caliper(s) are the problem, or both, then replace along with new hardware, lube, and you'll be good to go.

emas

Fluid has been flushed and in general they have been well maintained. I have been exploring 4-piston (aftermarket) vs 2-piston (OEM) calipers as an option, and curious if anyone else has tried that ?

justnspace

iTrader: (1)

^are you concerned with upsetting brake bias?

polobunny

Clearly he is not enough.

emas

Honestly, I do not know what "braking bias" is. Should I be sticking with the OEM design?

polobunny

There's a certain percentage of braking power that needs to be applied to the front brakes and to the rear brakes. When justn said "braking bias" he meant changing the percentage of braking power on the rear brakes for your case. You don't want to change this percentage too much otherwise you will lose handling ability.

For instance, if the rear brakes braked much more than the front brakes, you would skid a lot while braking instead of stopping as the rear wheels would drag. Imagine this situation while cornering and braking hard and it's easy to see how it could be dangerous.

TacoBello

upgrading your rear calipers is a bit of a waste of money, if you're looking to stop the car any faster. Like with all cars, the great majority of your braking happens with the front brakes. I mean, you can add nice 4 piston rear calipers, but for the price, they'll do very little for you.

Also, I agree with the others- a good servicing on your brakes should help fix any problems you're facing. New pads, new rotors, new brake fluid (make sure to bleed them in the correct order), check to see if calipers are seized and if so replace them, lube the slider pins, check condition of brake lines, etc, etc.

vill0169

iTrader: (4)

now throw in the Electronic Brake Distribution the TL has and it'll really blow your mind on brake bias.




RacingBrake has an upgrade that uses the OEM caliper but with a bigger, vented rotor but you have to run a thinner pad that you can only get through them. Not worth the price IMO.

AlanW

Does the anti-lock brake system not adjust the bias as needed to maintain proper balance?
Has anyone improved the rear calipers somewhat and actually experienced problems with the bias?

Not arguing. Just asking. A discussion question if you please.

My 02 TL-S had the OEM single caliper F&R brakes with the exact same rear calipers-the braking was OK & balanced.

My 06MT has the front Brembos, which are massively better than the 02 OEMs, yet the rear calipers on the 06 are the same. If you greatly improve the front braking with the Brembos, isn't there some room for increasing the rear braking? Why is it not over biased to the front with the Brembos & the same rears

TacoBello

:pb: you shouldn't be braking hard through a turn anyway

polobunny

Psh, what do you know, your TL only weighs 2/3rd of a normal TL!


Life happens, you don't always have a choice.

vill0169

iTrader: (4)

I know right...

TacoBello

I think it's safe to assume Acura did their research when coming up with the brake sizing for our cars. They are very well versed when it comes to brake setup (ie: NSX old and new, Legend, any Type R, etc)

I forget what the part is called (proportioning valve?) that helps with this. So although the brake sizing is different between the two cars for the front brake, that valve may have been modified to handle that change in caliper.

thoiboi

The OP has a sized caliper, common issue, just replace the damn thing OP, don't go trying to UPGRADE unnecessarily...


"oh man my air filter is going bad... MIGHT AS WELL GET A CAI and larger bore throttle body"

NO

mvp2765

iTrader: (1)

only upgrade aka expensive replacement is 2piston Rotora bbk calipers i believe..Any 4 piston calipers will throw things off unless you upgrade to 6 piston bbk calipers up front

TacoBello

Didn't people have some major complaints with Rotora? Or am I confusing that with some other company?

thoiboi

Rota wheels perhaps?

TacoBello

Now usdmJON will come in here

emas

Has anyone tried the Fastbrakes Wilwood 12.2" rear brake kit?

TacoBello

Dude... don't do it. Just service the oem brakes.

thoiboi

but but but OP has he needs BBK rears..

screaminz28

iTrader: (1)

IHC said the Rotora's were not sized correctly for the proper bias. I believe he now has a Stoptech BBK that does keep the proper bias.

I could be completely incorrect - but if I recall, the key on the caliper as far as bias goes is the piston size. The Brembos could be keeping the same total piston size as the older 2G TLs - so it may provide better heat dissipation, it won't throw off bias.

If you were to replace the rear caliper with a Brembo, if there is increased piston size, youve now thrown off the bias. Even larger rotors will disrupt bias.

One thing I've seen people do is run a REALLY good pad on the rear, and an Good pad on the front - you'll move some of the bias to the rear, but not too much. I was looking at getting a set of the sintered CL pads, but I cant remember if they even make them for the rears for our cars.

ExcelerateRep

Yes we have seen a number of our customers switch to other braking systems. Rotora stopped offering replacement parts for many of their brake kits. Since then, many of our customers have gone with Stoptech Big Brake Kits and we've gotten tons of positive feedback. Stoptech also offers replacement parts for all of their kits, and if they don't have something in stock they will often machine it for you.

Wilwood makes good products too although we're not as familiar with them. The rear BBK options for the TL are pretty limited. Unless you plan on tracking the car, I'd make sure you do a full brake fluid bleed and stick with oem replacement caliper. Otherwise, if you are looking to upgrade, we have great pricing on the Wilwood kit.

Fastbrakes Wilwood 12.2" Rear Brake Kits - Excelerate - HOA - Japanese Performance Specialist

DomGSR-T

iTrader: (1)

I have that kit on my TL-S. It was made for me first by Brian then he put the kit for sale... Brake balance will get bad with the bbk. The braking distribution get to 50% front 50% rear based on rotor heat temp. I got it fixed with trial and error... now i'm at 70% 30% and it brake super hard vs stock... It brakes as hard as my Turbo Integra with 4 Nsx calipers

Turbonut

iTrader: (1)

Do you know:
Stopping distance 60-0 with A/S tires
Single piston f/r 131 ft
Brembo front single rear 130 ft

Not worth the effort.

emas

Thank you all for the advice. I'm sticking with the OEMs, and adding stainless brake lines.

mvp2765

iTrader: (1)

How'd u get 70% / 30%,? With your rear wilwood kit? What'd you change? And is this with front OEM brembos?

DomGSR-T

iTrader: (1)

I used a oil restrictor used on turbo oil feedind line like this one...
Oil Inlet Restrictor - .065" hole size 1/8" NPT (for Journal bearing and larger GT BB) : atpturbo.com
not sure which one but it took me 2 hole size to get this right.

screaminz28

iTrader: (1)

Dom- what rotor are you using? The picture Excellerate has shows a vented rear rotor - is it a custom one from Fastbrakes or a different vehicle's OEM rotor?

Does it keep the OEM parking brake?

How did you judge brake bias in the trial and error testing - rotor temp?

Timbert

Speaking of the job of the brake pressure proportioning valve, would not the pressure/volume of fluid having to push not one but four pistons on an "upgrade" actually decrease the force of the pads against the rotor? That's if you upgrade the rears and not the fronts. Don't upset the balance!

Demonstration: Find a safe place and hit your ebrake to lock or come close to locking the rear wheels. Keep the wheel straight. The car slows at rate X. Pretty poor stopping distance. Get back to the same speed and floor the normal brake pedal. The car slows at rate more like 5X. Do the math. Your front brakes/tires are doing 80% of the stopping.

I get that the parking brake is not actually using the calipers but the little shoes and a lever instead but the point is the dramatic shift in weight from back to front as you increase braking using the front wheels.

94eg!

A floating caliper (stock) uses one piston to do the work of two. Fluid is displaced to press on the backs of both the inside & outside pads. This is why you compare only half the pistons of a fixed caliper to all of those on a floating caliper. If half of the pistons in a "fixed" multi-piston caliper have the same "area" as all the pistons in a standard floating caliper, then system pressure will be exactly the same.

The differences come into play because the fixed multi-piston caliper is stiffer and has less play. Therefore brake system response should be increased (like adding stainless flex hoses). The other major benefit of a fixed caliper is that the of sizing of the leading & trailing pistons can be tuned to allow the pad to wear more evenly than floating calipers.

As for the brake balance (bias), it is also impacted considerably by rotor diameter. A larger front rotor increase front brake torque. This is bad considering OEM brake systems are already front heavy for the sake of stability. To offset this, you use less total piston area than stock in the front calipers. This maintains stock bias or even push it slightly rearward (this is when you get shorter stopping distances). The reduction in total piston area will actually make the brake pedal stiffer too. Win win, but it has to be done correctly.

A rear BBK could go another step further with larger rear rotors (more rear bias) and possibly the same or slightly smaller caliper pistons depending on how the math and real-world-testing plays out.

Systems like the TL's EBD may or may not be able to cope with these changes. Again this requires real world scientific testing. You definitely don't want to simply throw parts at a brake system and go drive hard on the street.

I hate cars

That basically says it all. The tires determine stopping distance assuming you don't have other problems with the car, not the brakes. The stock brakes can lock the wheels just as the aftermarket ones can lock the wheels. On the Stoptech BBK but most importantly on the Hankook RS-3 255/40/17 tires I had a best of 91' 60-0mph and an average around 94' I believe. They were stopping quicker with every stop because they need heat so 91' would be hard to do without warming them up well. In other words, in the real world, 94' is the more likely number but it's still a vast improvement over stock.

I did drop a few feet of stopping distance when going from the Rotora BBK to the Stoptech. Stoptech keeps the stock bias with less piston area than the stock 1 piston caliper to make up for the additional torque of the larger rotor and the caliper is considerably stiffer than the Rotora giving better feel at the limit.

The only bad thing about the 1pc Stoptech kit is the rotors just won't stay true even in normal driving but there's nothing worse than the Rotora junk.

I hate cars

There seems to be a bit of learning with the EBD but it's still a mystery to me. Just having sticky tires changes target brake force distribution. I've found the best thing when making changes is to stomp the brakes like an idiot several times from different speeds.

Brake pads seem to make a big difference on stopping distance when ABS is involved too. The apply and release characteristics seem to be very important on the TL. That was another thing I hated about the Rotoras. The pads would bite hard but didn't release very easy. You had to back off the pedal a considerable amount to get them to release. The ABS would apply and then almost let off the brakes completely on a pulse which was scary a few times.

I feel that ABS holds the TL back on good tires in good conditions.

My biggest problem is with EBD. If anyone knows how to modify it or train it, reprogram it, or pull the fuse, I would love to know a way around it.

screaminz28

iTrader: (1)

IHC - couldn't you offset some of the front bias on the TL by running a sintered pad on the rear only? Granted, I've yet to find a sintered pad for our rear calipers, but even just a better pad on the rear vs the front - would that help?

I hate cars

Definitely. The problem back when I had the Rotoras was they did not share the pad type and claimed it was their own design so no other brand of pads would fit. I was trying to reduce the front pad friction. I believe I found which design they used right toward the end of my use with them but by then it was too late.


The stock brakes use a pretty aggressive pad in terms of friction. I can't remember if they're FF or GG but they're pretty grippy. It was hard finding a rear pad with a higher friction coefficient than stock.


Right now the bias is good, or at least stockish with the Stoptechs but the additional traction causing more weight transfer off the rear tires. The Stoptech pads in the front work great. There's a lot of tire squealing going on and you can feel that they're almost optimized. With the Rotoras the tires would barely squeal. It was like the ABS was confused and stopping distances were compromised.


I want to try the Stoptech pads for the rears soon. I've put it off since I don't track the car anymore but it would still be nice. Right now, the rears fade before the fronts. The first time it happened it took me a second to figure out why the car was still stopping pretty hard but not as hard as it should be yet I was still capable of engaging ABS. Once I pulled off I saw that problem. The rears looked like they had a slight glow but it was hard to tell. Rotor temp was over 1,000F if I remember right and the pads were smoking.


I'm going off topic again but I completely agree with you and I think that fine tuning via brake pad friction is a great idea. Currently I'm more interested in one stop stopping distance than all out fade resistance because it sees only street use so getting that front to rear balance as close as possible is a good idea. I love the idea of sintered pads. I've found only one maker of sintered pads for the Stoptech calipers and it's almost time to replace the pads so I'm probably going to pick up a set. The only problem is they're about $300 and who knows how well the ABS will like them. From past experience and even on my bicycle, their apply and release characteristics are usually very good but who knows. Are you running sintered pads on the TL?


I'm still in the dark on the EBD. Does it only work under non ABS conditions? I know one of the main functions is to be able to use the rear brakes a lot more under normal, easy stops. It's supposed to make the car track better and feel more stable under braking with a rear bias. Of course, it shifts the bias to the front under hard braking.


Does ABS nullify the EBD's importance when activated? If the ABS is engaged on all 4 wheels, how can EBD be important for all out shortest possible braking distances when the ABS is supposedly providing the best possible traction without locking a wheel? I honestly don't know the answer to the question.


Last, has anyone else tried out the ABS in 3 channel vs 4 channel mode? I've tried it both ways, sometimes it seems to be more aggressive in 3 channel mode but I have yet to measure stopping distances.

screaminz28

iTrader: (1)

I'm not running sintered pads yet since I can only find the front Brembo pads. I didnt want to throw off bias even more to the front by running a stock type pad in the rear and sintered up front. If I were to run a sintered up front, what would you recommend for the rear?

94eg!

OEM Pads are NAO and have an FF rating front & rear ("non asbestos organic"). The Stoptech compound is also FF. I have seen some aftermarket Integra rear pads from Nissin in GG so you might look into that brand for the rear (OEM Integra rear pads are Nissin FF). It's really tough to find concrete documentation stating the friction rating of pads. The best bet is to find actual photos of the pads in question and read the codes from that. Contacting dealers directly is not always helpful.

I hate cars

Thanks! I will definitely look into that! At this point in my life, I'm not looking for the absolute best fade resistance, just the best one-stop stopping distance.