this is on a 95 accord lx with rotor over hub conversion

well some will remember i started a project to do a rotor over hub with lude rotors and rx7 4 piston calipers....got most of it done my self(i hate paying for people to do stuff i could do) but this was a job for a mill and i had no mill ..so i had a guy i know do it all up for me ..charged my 150 canadian for about 6 hours of his time

from the start it looke tuff ..i was hoping the calipers would be so differetn i would just need to fab a adapter plate to make up the difference ..but i was wrong ..they were soo close it was a big problem (see other post)

i started by crinding of material from the calipers and knuckel so the off set was right ,this proved to be very hard and i ruined an knuckle in the process.

so i found a new one and talk to the mill guy, he siad no problem he had ans idea so away he went

heres how it looks now (dirty and not a finished project)

also i was able to keep the stock mounting holes in case i need the stock calipers to bolt on ...i did have them filled in with weld but we just drilled them out and taped for the stock accord caliper bolts ..kinda crafty
any who the pics







the whole 100 % of the pad is on there ..ive got clearance through the hole caliper ..although its tight it spins freely ..the caliper bolt holes were filled with a tig welder so we could drill new ones ,the holes were moved up about an inch (less chance of it snapping anyway )

all in all i think he had to take 4 or 5 mm off the calpiers and the knuckls were just clean up abit ..mabye 2 mm or so ..ill have to ask him

oh and the stock accord lines will bolt into the rx7 calipers ..just need to shorten them a bit

price run down in canadian dollars

rotors 35.00 ea
accor dwheel bearings 66.00 ea
acura cl hubs 64.00 ea
rx7 calipers abhout 100.00 can after shipping

milling 100
2 12x1.25 taps(one shattered )50
welding holes shut 35.00
hawk brake pads 65.00

that is it ..sure beat nsx calipers for the stupid price i see them for ..i was ona huge budget and wanted some better brakes ..so this is what i came up with ...theres always a cheaer way to do it ...mabuye ill paint them blue and get some spoon calipers

let me know whatyou guys think ..and any questions fire away


Modified by machine4321 at 3:07 PM 4/27/2005

 

Sounds like a fun project...

One thing, this is the suspension forum. This brake tech should be posted in the Accord forum...

 

lol yea thought about that after i posted it...i wont dare goto the auto cross forums since the price i paid for my setup is well below the acceptable brake job limit of over 2 grand lol , sorry about that stab

i did post it for the accord guys but as usual theres no intresst there
thought some of the suspension guys would enjoy it since most honda knuckles are fairly close

 

It would have been nice if you had taken pics of the knuckle befor & after the welding, and then once the new holes were taped. That is a pretty crafty setup. A couple quick questions though...

1. Are those rotors the same diameter as the stock rotors?
2. What are the caliper piston sizes your stock claiper?
3. What is the combined piston size of two pistons on your RX-7 caliper (the two on one side of the caliper)?

The reason I ask is because these are the all the factors that affect brake balance. I'm trying to figure out if you've shifted it forward/backward or not at all.

Also, do you have the car running? If so, how does drive now?

 

i too am concerned with over braking in the front ..i am also doing a rear disc conversion so the drums wont be there for long lol

the main reason i went with the rx7 calipers is because with the lude rotors on my car i needed lude calipers..i couldnt find any around me or on the net for under 300.00 canadian so it was a chance to try some ideas out and save some cash at the same time ..in the long run it wasnt much savings but it was fun and i love coming up with original stuff....there isnt much available for accords

stockk accord rotor is 10.1 to 10.2 depending on where you look

lude vtec is 11.2 and 23mm wide

2nd gen rx7 rotor is 11.2 to 11.4 depending on where you look but only 21mm wide

im gonna bust out the digital caliper when i get home and measure all the pistons since id love to hear what your up too

i hope to have the car on the road this weekend ..still need to drop the motor in and do some street tunning with the ITBs

cant move the car to put the motor in till the knuckles got back

oh and the knuckels are pretty much stock ..i had the bolt holse welded in in case we had to drill new hole but ended up with the stock hole location ..just clean up the surface on the mill so it was striaght


Modified by machine4321 at 2:59 PM 4/27/2005

 

Brake balance is what dictates stoping distance & charachteristics of your car. If you change your setup & shift balance around you may end up with a surprising result. Increased forward balance (from stock) will net you longer stopping distances because the rear brakes are not meeting their potential. If you shift it balance rearward, you can actually cause the rear brakes to lock up first. This is a dangerous situation because it will cause you to spin out.

Let's look at some things that affect brake balance that your messing with...

* Increasing the front rotors size, you shift brake balance forward.
* Increasing caliper piston area, you also shift brake balance forward.
* A grippier pad compound in the front than the rear will also shift balance forward.
* A rear disc conversion (with the proper proportioning valve) should shift brake balance rearward.

If you wan't to compare your stock single piston calipers with the RX-7's 4 piston calipers, you need to measure & calculate the accord pistons surface area. Then you compare that with the combined area of two pistons on ONE SIDE of the RX-7's caliper. This will tell you if you are in fact increasing your piston area, or decreasing it. Idealy you would want to slightly decrease the piston area when combining them with larger rotors. But not too much, otherwise you may get rear end lock up...

Once you get it all done, bed the pads in (Be very careful since your in uncharted teritories). During that process, you will definently be able to tell if your getting front or rear lock up...

 

good stuff ..i really appreciate the input

most guys in the autx forum went off on me making fun and what not ...none really had any info to backup there claimes ..just felt like they didnt like it cause it wasnt expensive

nice to get some info on this and i hope it will all work out

ill post up the sizes when i get home

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">most guys in the autx forum went off on me making fun and what not ...none really had any info to backup there claimes ..just felt like they didnt like it cause it wasnt expensive</TD></TR></TABLE>

Go figure...

Well good luck with your car. I hope you update this thread once your car is running again...

 

ok the stock caliper is a 57mm single piston

the rx7 calipers are 36mm each on all 4

i have no idea what to do from here lol

 

You are deffinently reducing piston area...

The accord piston is 8009 square millimeters.
The RX-7 pistons (two combined) are 6390 square millimeters.

This means that you should be extra carful when you get this swap done. Drive around & make sure your brakes work properly. Start with slow gradual stops, and work your way up to harder ones. Once you are stopping hard enough to lock the wheels, you should be able to tell if the rears are locking up first (car gets a little squirly). If the fronts are still locking up first & the car skids in a perfectly straight line, you should be good to go....

 

great ..thanks alaot ...what about bedding the pads in ...am i gonna runin them by doing slower stops at first ..i know this is gonna be a problem cause i need to make sure notin is gonna brake on me lol

so ven though theres still 2 more pistons on th other side they dont get taken into account ..

its my understanding that a 4 piston caliper will not give more clamping force,but use the force more effectively in making sure the pad is making better contact.

with the smaller pistons it should feel stiffer should it not ..im thinking like a 6 puck clutch disc and a full street disc. the 6 puck has les area but it grabs harder due to putting the same force in a smaller area .

remember as of right now i have rear drums on the back..i thikn when i get the rear disc i might by an adjusable proportion valve to even it all out ,if its needed


Modified by machine4321 at 8:19 AM 4/28/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">great ..thanks alaot ...what about bedding the pads in ...am i gonna runin them by doing slower stops at first ..i know this is gonna be a problem cause i need to make sure notin is gonna brake on me lol </TD></TR></TABLE>

Check out hawks website, and makes sure of the exact beding procedure. I know that the Axxis Ultimates require 6 easy/medium stops (60mph-5mph) to get some heat in the pads. Then it's followed by a 10-15min cool down. Then the braking is repeated with 6 hard stops (60-5mph) followed by another cool down drive. This process can easily give you a gradual step to your braking threshold.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">so ven though theres still 2 more pistons on th other side they dont get taken into account .. </TD></TR></TABLE>

A single piston "floating" caliper technically moves fluid for the pads on both sides. First it presses one pad onto the rotor, then continues to move outward forcing the whole caliper to move & squeeze the other pad against the rotor. This action moves just as much fluid as a Two piston fixed caliper. I've never had to explain this before (it's kinda difficult to put into words), so let me know if I'm making sense.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">its my understanding that a 4 piston caliper will not give more clamping force,but use the force more effectively in making sure the pad is making better contact. </TD></TR></TABLE>

Correct.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">with the smaller pistons it should feel stiffer should it not ..im thinking like a 6 puck clutch disc and a full street disc. the 6 puck has les area but it grabs harder due to putting the same force in a smaller area . </TD></TR></TABLE>

Correct, but you may have to physically press harder on the pedal. That isn't a bad thing though since the human body reacts better to this sort of input...

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">remember as of right now i have rear drums on the back..i thikn when i get the rear disc i might by an adjusable proportion valve to even it all out ,if its needed </TD></TR></TABLE>

An adjustable prop valve would be awesome, but it can be a little complicated on a honda. Your master cylinder has two outputs effectivly separating your brake system into two circuits (LF/RR & RF/LR). The reason for this is that if you loose one brake system, you still have the other to slow you down. If you remove your stock prop valve, and plumb in 1 adjustable valve, you effectivly loose your system redundancy. The trick is to install one adjustable valve per circuit, so expect to buy & plumb two valves...

 

your bedding procedure sound like it would work fine for me ...

and yes i understood your single piston caliper explanation

again great info i am really thankful..if all goes well i will update this with some road feedback on how it works


Modified by machine4321 at 12:23 PM 4/28/2005

 

I look forward to your write-up...

 

by any chance did you leave out the 1 inch increase in the front rotors..just wondering since you didnt mention it

 

No, I was just telling you to be careful since there is no way to tell where the brake balance will end up with your combonation. The larger front rotor will send the balance forward, and the smaller caliper will send it back again. I just have no idea how much these things actually move the balance, and only testing your brakes after completion will tell...

This combonation really sounds like your on the right track though. Most people add big Type R brakes to the front ends of their civic's, not realizing that the larger rotor & larger calliper piston actually push the brake balance way forward. This actually ends up increasing your stopping distance even if though the brakes feel better...

Everything I know about brakes I learned form the Technical & FAQ sections on http://www.StopTech.com

 

hah cool ok no more questions till i try it out ..thanks and im gonna read up that site ...i did read about bedding the pads in ther but didnt get into nythign else

 

they bolted on great after the milling was done
barley cleared my C8's...ill get some updated pics up ....BTW i love wrinkle finish ..get the oem look every time

 

well here is an updated pic ....oem look all the way wrinkle finish and flat black



heres my new desktop as well
http://machine.unknownsoldiers...4.jpg
its 2300 by somthing

 

Pretty funny it says "Mazda" right on the caliper.

Can't wait for your test drive results...

 

haha i know ..i might polish it up abit
should be this weekend if i get my throttle boddies back together

 

Bump more info and pics

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">haha i know ..i might polish it up abit
should be this weekend if i get my throttle boddies back together </TD></TR></TABLE>

You should just spot face the Mazda portion so it reads MAZDA in bright silver letters with the black wrinkle coat background. A piece of sand paper & some patience works wonders...

 

well had it out ..brakes work great..under hard braking the fronts do look uo first....im have a vac problem right now due to the itb so the pedal seems overly stiff...but when theres vacc it feels great...they squeal aot under slow light braking ..i hope i bed them in right ..but i also heard hawks are bad for that

 

Great news man. Happy to hear your car is running. I hope everything goes smooth while working out the bugs...