RMMGS4

iTrader: (5)

Appreciate your faith in me Chris. It is more than just me though, as I'll point out later.

As far as my AP set up. The front 6 pot brakes were designed specifically for the Supra TT. If you check AP now, they actually have a GS application for front ONLY. My plan is to utilize the TT rear brake set up to go along with my fronts. This therefore makes my set up balanced in terms of it was a known set up for the Supra. I know there are other variables, but let's leave those out of the discussion for now.

I have two items that must be addrssed to make this set up happen.

1. The rear rotor from a Supra will bolt on and the e-brake will function correctly, but the caliper bracket bolt spacing is not correct. I will need to fabricate a bracket, "better known as the THINGY" to make it fit.

2. This one may be a show stopper. As some of you know, I am in the market for new wheels. One thing I am not willing to lose is rear lip. If the new wheels clear the Ap TT brakes, this project will happen. Otherwise it wont.

Chris,
you, me, Rominl, redgs4, and several other locals are all engineers of one discipline or another. Over the 3 years we have known each other , we have often put our heads together on ideas such as these. Between all of us, we have the ability to test, evaluate and assess our understanding of applied brake theory.

You know we are still testing, but down the road this information will be published to the CL community and I'm sure others will benefit.

I'm not able to respond to the brake theories discussed in this thread, because of being busy lately, so I might not have time to respond to comments on what I am about to say.

One point I want to mention is that too much rear brake bias is much worse than too much front. The locals all know that I have done extensive brake testing with my car and other locals cars with different brand BBK systems. Too much front bias will promote more understeer when braking hard while in a turn. This will affect handling while braking hard ONLY, and it is rarely an unsafe condition. However, as far as braking in a straight line, my car will stop shorter than a stock set up or a TT set up. No unsafe condition in straightline braking. Remember, the ABS will kick in the front or rear depending on the brake balance and the road/driving conditions. It is much more critical to have good brake balance on a non-ABS equipped car.

There is no argument that adding more rear brake bias will help most BBK front set ups, but you gotta be careful not to have too much rear bias.

lexforlife

iTrader: (7)

to chris and glenn , you guys bring up very valid points


glenn, i chose not to do the supra in rear for a couple of reasons, one is , the calipers would have to be processed.. the mounting ears have to be sliced off and new mounting holes retapped.. a real pain in the ****...the second was the pad size on the ls430 was larger then the pad size on the supra so friction surface was better with the ls430.. the ls430 is considerably lighter then the supras and they are momoblock


i am one not to always believe what i hear right from the start.. logics and common sense prevail when i do research... i dont buy the complete story from rotota or stop tech or brembo that their systems were designed to work in balance with the rears being stock... it really does not make sense to me.. in fact , on a porshe ferr or even the lancer evo , brembos are on 4 corners so how in the world can you jump from a 2 pot to a 4 or 6pot and not affect balance./bias.. it does not add up in my book , the rears will and have to surrender to the braking or clamping forces generated in the front unless the rears have a upgrade to compliment the fronts ... i believe that alot of it is just marketing hype just like intakes and exausts are ..they look nice , perform some improvement but ???????



this is just my opinion and observations and from now driving on these for 10 days or so observations... i can literally stop from 90mph with little pedal effort which brake modulation has improved 5 fold atl least and the stopping distance feels like i am stopiing from 45mph .. its that good , just ask johnee78 , he still cant believe it

RMMGS4

iTrader: (5)

Totally agree with ya Ed. Including the Ls rear over the TT. It's lighter and appears to have better braking force. Since you have a staggard rear set up the wider rear tires can take more braking force, so a little more rear brake bias is even better.

This is all good info for others.

TTurboPimp

iTrader: (12)

Ive been reading these posts and biting my tounge......I really disagree with alot of the theory's on the bias and so called hype by the BB manufacturers. Also, to generalize a 4 pot or 6 pot upgrade is incorrect, there are other aspects that go into the specific applications....ie, not all 4 pots are alike in braking capabilities. Too much rear braking bias can be dangerous, simple and plain! Im not sure about the other companies out there, but I have read numerous articles about the amount of testing that Stoptech puts into each of their applications, on a car by car basis. I have read numerous brake review articles in car magazines where the front Stoptechs smoked the competition. These guys put countless hours of R&D into their set ups.....I would be weary about throwing together my own set up.....but hey thats just my opinion.

By the way, whats balanced for a Supra or LS, is not necessarily going to be balanced for the GS. Different cars, different weight, different set ups all together.

lexforlife

iTrader: (7)

beleieve what you wish , i for one am not buying into their marketing hype.. common sense and logics prevail... you cannot convince me that a 4 or 6 pot can perform as oem does.. upping to a tt front and bringing up the rear makes sense for its allowing the rears to work i harmony with the fronts but in no way take over the fronts ....


i have it on and have been testing this for about 10 days now daily and it works and works well so again believe what you wish but this system is closer to the oem bal

DaveGS4

iTrader: (2)

Hey Ed just so we have it documented for other folks (never seen it posted here), what's the weight of the LS430 rear caliper / rotor and what's the weight of the Supra TT rear caliper / rotor? Good info!

lexforlife

iTrader: (7)

dave i will post it up for you by tomm am and the diff in pad sizes

TTurboPimp

iTrader: (12)

Im not even sure what your saying there......becuase that is far from what I was saying.

Independent tests are not marketing hype....its factual evidence on braking systems.

Im not here to argue with you, if you like what you have more power to you. I give you props for coming up with something new here in the states, I just dont buy alot of the logic thats being thrown around on this thread. We will agree to disagree on this one....thats part of the benefits to CL, take the info you read and decide for yourself what you buy into.

HKGS300

None of he independent tests i have read were about testing aftermarket brakes for the GS , and I guess every car will performance differently.

IMO ... What i do believe is that the stock brake components are tuned for optimal brake balance. If you change one component (e.g. bigger front calipers and rotors), the balance will be gone, and the braking will be front biased. Most people will like front biased braking better, better brake feeling, but often the stopping distance will not be improved, and mostly BBK will improve brake feeling and reduced the brake fading after multiple hard braking.

Therefore, if to restore the brake balance ... you need to upgrade the rear brakes as well. Some only upgrade the rear rotors and pads, but a more complete solution is to upgrade the calipers as well.

lexforlife

iTrader: (7)

i totally agree with you jeff


i just dont buy the hype and to me it sounds like hype , i too have spoken with stop tech , rotora and brembo and they cannot tell me specifically what makes their system work in harmony and deliver proper bias while improving front braking... that would be magic in my book

TTurboPimp

iTrader: (12)

Trust me, I would rather have a 4 wheel set up. But IM not going to do it just for looks. Here's something that struck me with the Stoptechs.....they make a 4 wheel kit for the pre 98 GS that will bolt right onto our cars....they strongly urged me not to buy it due to the bias testing they have done to the 98 and up GS. They could have easily made more money off of me, but they steered me away from it.......makes you think a bit! the way I see it is they know more than I do when it comes to braking.....I gotta go with their suggestions, hype or not.....I geuss im just a sheep!!


There is a good thing about what you did in my mind.....it seems they will fit behind a low disk rear wheel.....which the others wont do.

lexforlife

iTrader: (7)

well that makes sense to me why they did not want to sell it for they are offering either a 6/4 or 4/4 setup which will shift the bias back to the rear.. remember my set up is 6/2 (the rears are still 2 pots) but the rotors are supra tt 13 in approx and the piston size of the ls430 calipers are quite large but moreover the pad size is almost twicw that of the gs oem rears so the coff of friction will be greater then stock but the clamping forces will not be more then the front 4 pots


4 pots in the rear clamping force is too much for safe brake bias front to back without a bias valve hooked inline to the master cylinder to control the amount of force delivered through the 4pot calipers... thats the major diff

RMMGS4

iTrader: (5)

Like I said I knew this brake discussion would need more of my time to discuss, which I do not currently have the ability to go back and forth on responses. I'll respond when I can, but no promises. So far this is healthy conversation.

So in response to some previous comments and with all due respect to HKS and others, you guys are ONLY stating opinions , which everyone has a right to give, but if we are going to make any forward progress with this discussion, opinions are not going to take us very far.

HKS, I have no arguments with your reasoning, cause it is textbook correct, but to take such generalizations and make specific conclusions is not fair. I do agree that brake balance is the ideal way to go, but you make it sound like doing fronts ONLY doesn't add any value.

Lexforlife has done some real world testing and so his impressions can be backed up with actual hands on experience, not by reading a magazine article, etc. We need to take his input and seek evidence to support or dis-prove it. That's how we can gain real knowledge on this discussion.

I have tested my AP and TT set ups head to head against stock, before and after the change using several cars to back up the test. We did repeated stops from 60 to zero mph. Rear brakes on all cars were slotted rotors with EBC green pads. Rominl, redgs4, jawnthen, synergy and others have participated in these tests in one way or another. All measurements were done on a G-Tech pro. I even have video of it !

People should know by now that I base my comments on factual tested data.

The bottom line is Stock had the longest stopping distances, followed by the TT, followed by the AP set up with the shortest disatance. This data was consistent from stop #1 to #6. Brake fade only made the BBK set-ups better. This is factual data not opinion.

So to say it another way, the straight line stopping distance is hands down improved with big brakes and by a significant amount. I have the actual results on my other PC and will publish it whan I get a chance.

I could go on about balance, safety, etc. cause I have some data on that too, but I'm only going to discuss this one point for now. Another discussion I will leave out is will balancing the above set-ups with better rear brakes improve the stopping distances? Well in my "opinion" of course , but until I do some actual testing, I won't comment more than that. We only have lexforlife's input for now.

Opinions are still welcome, but I for one cannot place much value on it unless you can back it up with atleast some type of first hand evaluation and preferably measured testing.

Don't get me wrong. I have respect for opinions such as TTpimps, but I'd prefer to hear more objective comments rather than subjective.


In closing, do you guys believe everything you read or what other people tell you and do you live your lives by it, or do you get out in the "real world" and verify some of it for yourself?

Get real !

rominl

iTrader: (4)

yes, i agree with jeff on the stoptech homework. they really do a lot of testing, i think it was car and drive mag. i was very impressed

rominl

iTrader: (4)

ok since everyone talks i will throw in my 2 cents as well. imho, if you talk about teh real balance, i can only imagine the stock setup being the most balanced. there isn't any reason for manufacturers (lexus, toyota) not to balance out the system, coz' from factory, the cost for the gs 2 pots and the supra 4 pots brakes they gotta be very similar.

now given that fact, then pretty much most aftermarket kits you put on they are going to eb front biased. stoptech, ap racing, brembo, endless, etc.... that might not be a bad thing though, coz' the sheer power of teh brakes themselve can indeed improve the braking of the car considerably.

i will just use my ap racing as example. it's 6 pots, larger rotors, quite a bit bigger pad size and also pistons size. so it's very natural to guess that it produce much harder braking force in the front than the stock. that will definitely create more brake bias to the front than stock, no doubt. you ask manaray and he will say the same too

but in reality? the ap racing stops much better than stock, much fater and much more consistent. though it does give me a feeling that the rear of my car feels weak when i am doing hard braking.

imho, if someone (in this case stoptech) says that their stuff are best to go with oem rear, that means couple of possibilities to me. 1 is that of all the size choices they have on their hands, that's the best they can get to produce the best stopping distance. that does NOT mean it's still as balanced though. 2 is that the setup produce just as much force as the stock one, that's a bummer but that keeps the brake balance. 3 is that they can't find anything better for the rear to match up with the front, which i would find pretty surprising.

in the case of ed. if he has supra front brakes, personally i think the supra tt rear brakes will be the best match. granted that yes the two cars (supra tt vs gs4) are different, but i would assume they are close enough, structural wise. so the supra tt rear would be a good fit. but since the ls430 (this one gotta be closer to the gs4) has 4 pots monoblock and the 2 pots rear, then it will be a nice balance to the gs and the supra. so i think ed putting the ls430 rear on the gs4 with the supra tt front is a good choice.

for the rest of us (ap racing, brembo, stoptech), seriously i think we are all front bias on the braking now. i don't see why not considering the increased size and power of the calipers. still that doesn't mean they don't brake better, at least on my ap racing it's considerably better than stock. but given a choice, i would definitely prefer to have a rear setup

in my case, i would definitely aim for the ap racing rear setup for the supra tt, which goes togerher with the kit on my car right now already. that's the best bet i can make. for stoptech? maybe the 4 pot setup for the rear is too much, how about the 2 pots they have? there gotta be a better setup to compliment the front.

so that's how i see it