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4G and 5G Big Brakes tips

Last update: 1-28-1999
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Posts by Brian Hasty, Eric Bauer and others, that I pulled from the board
Be sure to read Brian's 90-91 EX upgrade article, as it is essential to complete the 4G brake swap.

Here's what I've been able to determine from actually buying and
fitting parts on my 90 Si with the 90-91 EX front brakes.

The 93-96 Prelude VTEC rotors are a direct fit with the pattern
redrilled to 4x100. The hub register (the raised section in the
middle of the hub) is the same size on the EX brakes and all Integras.
You can put the larger rotors on the standard Civic hubs, BUT, the hub
is actually about 1" smaller in diameter and the register is smaller
as well. I would not recommend doing that. Besides, the larger Accord
wagon caliper won't fit the standard Civic knuckle anyway.

The 91-94 Accord Wagon front calipers are THE SAME CALIPER as comes on
the TypeR. EXACTLY THE SAME. The caliper bolts onto the EX knuckle
and everything fits fine. The splash shield may need to be trimmed if
bent. 15" wheels are necessary for this conversion.

Changing the master cylinder to a larger one would also be advised as
the Accord calipers are BIG.

Finally, I'm still trying to figure out if the different proportioning
valves actually do anything different. Since the Honda/Acura braking
system using a cross diagonal setup, how would the prop valve regulate
pressure between front and back?

Use the EX knuckles/hubs, 93-96 Prelude VTEC rotors, redrilled to
4x100, 91-94 Accord Calipers. Only mod is to redrill the rotors.
Sounds too good to be true, but it all fits together like stock. This
setup is almost 2" bigger than the stock setup so you'll see a great
increase in braking capacity. You should be able to stop better than
the TypeR due to reduced weight of the Civic, and these will be fade
free with Porterfield or Carbon Metallic pads.

The rear discs don't need an upgrade unless you can change the weight
distribution-too much up front means the rears won't do much, maybe
20% of the braking.

I paid $160 for the 90-91 EX steering knuckles and calipers, and
$75/pair for new EX rotors. I bought a Prelude VTEC rotor for $70 and
the Accord Wagon caliper for $45. Redrilling the rotor was $20. So
for about $200 you can have the TypeR size rotors/calipers on either
a regular Integra or a Civic equipped with the EX steering knuckles.
Remember you will have to use at least 15" wheels on cars equipped
with the Prelude rotors.

93-96 Prelude VTEC rotors-45251-SS0-A00 91-94 Accord Wagon Calipers- 45018-SM5-000RM and 45019-SM5-000RM

From looking at my hubs, there appears to be room to redrill to the
4x114 Prelude pattern, but not enough for the 5x100(?) TypeR pattern.
I wouldn't do it though, it's cheaper to redrill your rotors.

Actually the GSR uses the same rotors/calipers as the rest of the Integras and Civics/Del Sols/CRXs with 4 wheel discs. Which are the same front brakes as the 90-91 Civic EX. As far as I have able to determine the EX is the only 4G that used the 10.3" front brakes.

Hi McP,

On a 5G the calipers will simply bolt-on - no mod necessary.
As for rotors there is a cheaper place still - look in the back of scc
for a place called 'best price'. I called them up and got a quote for
$75 for slotted TypeR front rotors. No one has been able to beat that.

Do Not Get cross-drilled rotors for the front - Bad Idea!
Your fronts should be solid or slotteed, any more and once you get
some real heat in them they will warp or crack.

If you have to get cross-drilled get them for rear only as there is
much less heat buildup back there.

For confirmation, go look at old pics of the Touring Car Accords from
BTCC and NATCC - none of them have cross-drilled in the front - simply
too much heat generated there.

And once you get your rotors you of course have to redrill them to fit
your hubs.

You lucky 5G'ers - it's all bolt-on... I had to take my 5lug ITR hubs
to a machinist in order for them to work with the '90-1 Civic EX sedan
knuckles I am using. The result, no redrilling of rotors they simply
bolt right on. And in conjunction with my Spoon/Nissin AL 4pots it is
a very nice combination. Hide that behind some stealth lightweight
falt black AL rims and it is a really really nice setup. Oh yeah I
also got the bias proportionning valve from an EG6 and that helped

Check with Brian Hasty for the part numbers on the accord calipers (I
don't have those handy).

As for putting your front Si/EX caliper/rotor in the rear you are
going to run into a whole series of problems which would be avoided if
you got the right set from the start.

For one thing, what are you going to do about the lack of a parking
Second, I don't think the bolt hole spearation on the rear trailing
arm is the same as it is on the front knuckles. I don't think your
fronts will bolt up there.
I could think of a number more reasons why you shouldn't attempt

Remember that on a FF, some 70% of the braking happens up front. I
wish Chris 'Mighty Mouse' Capowski was on the Hybrid board as I would
point you to him. His road race crx still has the factory rear drums -
but in the front he has gone for a very very good race compound pad
and some uprated rotors. His braking (coupled with his excellent
knowledge of threshold braking) would really blow you away. Granted
that for every other set of brake pads (high abrasive content) he
needs new rotors... but point is you don't really need big rear brakes
on our lightweight Hondas'.

If you insist nonetheless then get yourself rear ITR or rear Legend or
rear Prelude VTEC calipers and use them in conjunction with rear (re-
drilled) ITR rotors. That bolts on.

A friend of mine for the rear brakes of his CR-X did manage to use NSX
rear calipers and front GS-R 10.2" vented rotors. All he had to do,
was re-drill (and tap) two holes in the NSX rear caliper bracket in
order to properly bolt up to his CR-X rear trailing arms. He has
reained the parking brakes of course.

This is in reference to the big brake upgrade thread from earlier.

I borrowed a set of Prelude VTEC rotors from someone and took them to a
machine shop and asked if they could redrill them for 4x100 bolt pattern,
and they said no, citing that it wasn't safe because of fears that it might
crack because of the "insufficient amount of material" in the mounting
area of the rotor. I went back to my mechanic and he advised against it as

Those of you out there who have already done this... have you experienced
any of the problems above?

I have spoken to the people at Baer Racing about the redrilling of the
rotors to the 4 x 100 pattern, and they have assured me that there is
plenty of material in the rotor hub for it. They sell their kits with
redrilled rotors and since they have to be concerned about product
liability issues, I'm sure they wouldn't sell them if there is a
problem. My rotor(the redrilled one) has at least 1/2" between any
hole, leaving plenty of support material in the hub.

Since I started looking into this issue, I've found redrilled rotors
to be quite common in the racing community, and as long as care is
taken where the holes are placed in the rotor hat, as to provide the
greatest amount of strength, redrilling is an acceptable way to
reconfigure a rotor.

Someone mentioned earlier that I have tried to get a run of rotors
from Brembo. I contacted them and gave them the specs I wanted and
they agreed to do a minimum run of 300 rotors drilled to the 4 x 100
pattern on the Prelude VTEC rotor. Unfotunately not enough people
seem interested to spend the $50 each on these rotors. $50 is CHEAP
for a rotor. You're going to spend at least $70 on a regular VTEC
rotor and another $20 to have it redrilled. SO for the cost of 1
redrilled rotor you could have 2 FACTORY drilled rotors. So if those
of you who want the VTEC rotors would step up and put up your money we
could have the Brembo rotors 12 weeks from the day we pay our money.

Food for thought.

Check out and you'll see they make an OE spec for the
Prelude VTEC rotors you need for the 4/5G conversion. It's not vented,
but I'll live. Odds are they make the OEM rotors, but who knows. Anyway,
I'm willing to bet that it probably meets or exceeds OE specs. Anyway,
called a distributor on their list and they're 45.86 each! 1/3 of the
price of Honda retail for the OEM rotors. Definitely the bargain of the
day. I placed an order today, and I'll let you know how they look. Part
#09.6752.10. Damn I love the web..gonna use the money saved to pick up an
Energy Suspension bushings kit for my civic..


The NSX caliper bolts on to all '92+ Civics and '90+ Integras, as well
as '90-1 Civic EX sedans.

BUT, yes you do need to machine off a little bit of the backing plate
(where the caliper bolts to the front knuckles). It is highly
recommended you use NSX rotors in conjunction as they are 28mm thick I
believe. ITR/Prelude VTEC rotors are by comparison 22mm thick.

And you of course need to redrill to 4x100.


I have NSX calipers on my 93 Prelude, and the bolt pattern is the same
to fit the caliper bracket to all honda knuckles back to and including
the 84-87 CRXs. So, they would bolt up, generally. but, the offsets
may still be wrong. FWIW, the Prelude VTEC rotors are 23mm, the
Integra rotors (non-ITR at least) are 21mm I believe, and the NSX
rotors are 28mm thick.

My friend also put some on his 94 GSR, with no machining required. He
went to custom rotors, but otherwise it was basically a bolt-on swap.
If you are talking about the splash shield (there is no backing plate
on the front of a disk-brake equipped car... that usually refers to
the backing of a drum brake system), yes I do believe he removed that,
but since it was only sheet metal, a dremel easily took care of it.

Ed Sawyer

You can get the Prelude VTEC rotors from any good auto supply store,
but they may not have them in stock. Since you're going to have to
wait anyway why not call Best Brakes @ 888 782 3788 and get the
slotted Brembo rotors for about $75 each.

You can use the TypeR calipers/rotors if you redrill the rotors to the 4 x 100 Civic pattern. They will bolt on the Civic steering knuckles. Or you could buy the Prelude Rotors and redrill those. The rear brakes are a different story. Unless you have the trailing arms from the TypeR, or the spindles, you won't be able to put them on the Civic. The TypeR uses a different spacing/bearing/something than the CIvic for the rear disc brakes. Eric Bauer is working on installing the TypeR brakes on his CRX and can provide a more intelligent answer as to why the rears won't fit.

QUESTION: is the lug bolt the same diameter on my civic as it is on my prelude rotor? ie. Can he just drill the 4x100 holes using a bit that is the same diameter as the prelude 4x114 holes??

ANSWER: Yes they are the same. Tell him to use a 1/2 inch drill bit.

FYI, the EX rotor is also the same as:

94-95 Civic 3 door Si w/ABS
94 Del Sol VTEC


92-95 Civic LX/EX w/ABS (Coupe and Sedan I think - my notes made perfect
sense when I looked all this up.....)

Anyway, the part number for the rotors above is 45251-SK7-JOO

QUESTION: What if my car is an Si (95)? About the brakes.....I I think the EX discs are larger than mine... If so, I wILL need the knuckles too?? Is that what you were saying? Thanks for the info. You seem to be the only one to have at least tried this!!

ANSWER: If your Si has the 9.5" brakes, you will need the knuckles from the 5G models with the 10.3" brakes (EX's with ABS have them) OR knuckles from a 94+ Integra(they are the same).

EX knuckles, the big calipers

Close up of calipers

brembo rotors

Are the accord calipers REALLY the same as Integra Type-R calipers?

If you look up the parts in any interchange manual they are the same. In fact they are the same Honda/Acura part number too. I just called my Acura dealer to confirm this.

What about the basic rebuild kit?

A rebulid kit should be the same for this caliper as the regular Integra caliper because the only difference is the width of the caliper, the piston seal and dust seal are the same. Don't buy them from Honda, go to a AutoZone or someone else, they're all the same and a lot cheaper.


OK, here's what we know: The calipers that fit the 4G Civic with the
EX knuckles are stamped L (above the next set of
numbers)17CL15VN, then below the hole in the middle of the caliper it
is stamped NISSIN and below that, AT 54. The other caliper has a R and
17CL15VN, then NISSIN then AT 56.

I put these calipers on a 4G EX knuckle with the big rotor and they
fit fine. NO hitting anything, except the splash shield which was
bent anyway.

If you look at the SI, EX (or Integra) calipers that you may have, the
caliper bracket that bolts to the knuckle is shorter (measured from
the bolt hole outward toward the outer circumference of the disc
rotor). The Accord caliper brackets are about 1/2 taller than the EX
caliper brackets, in addition to being wider. The bolt
spacing(distance between the bolts) is the same. So if you took the
caliper off the bracket and compared it with the EX caliper bracket
you would see the difference. This is what allows us to use the
Accord calipers.

There should be no difference in mounting this Accord caliper to the
EX knuckles. HOWEVER, if you have the wrong Accord caliper, there may
be a problem. That's why it was so important to get the Accord Wagon

Now from what McP has described as to the problem he is having with
his 5G (6G?) it may be that he doesn't have the correct knuckle,
hopefully we can get this straightened out soon.

With the help of our illustrious board administrator Adrian Teo, I am glad
to report that the reason McP had problems with his Big Brakes was
because.......The rotor has to be shimmed out 2-3mm due to the offset of
the rotor not being sufficient with the Accord wagon/TypeR/Prelude VTEC
calipers. The TypeR has a slightly (5mm to be exact) wider track than the
regular Integra. This translates into about 2-3mm per side. This is
accomplished in the TypeR hub, which as we all know is different than the
regular Integra (and Civic that uses it) hub.

Now the remedy can either be done like McP did and have the bracket thinned
a bit, or you can get a shim and place it behind the rotor. So for those
of you waiting to do this on your 5G, go to it.


The Type R's have 10mm more track. That translates to 5mm on each
side. Putting a 3-5mm shim will work although I would suggest a 5mm
shim because the 3mm one might pose a problem when the pad wears out.

VERY IMPORTANT point. Before consideing shimming out the rotor, invest
in LONGER studs on the hub.

Ok. I've now warned you kids. I will not be responsible for any
damage/injuries/deaths from this point on.

Adrian Teo

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