Tech - The NA Brake Upgrade / AWD Brakes on your FWD 3S

The NA Brake Conversion
AWD Brakes on FWD 3000GT/Stealth

FWD 3000GT/Stealth owners an actually get the benefit of big brakes using the AWD VR4/TT brake components. 3SX carries FWD big brake bolt-on kits listed on the Brakes page, but this gives an alternative using a mix of OEM and aftermarket parts. This brief guide is for those owners of FWD non-turbo 3000GT/Stealths that want a big brake upgrade, but not one of the aftermarket kits.

You will need the following parts for FRONT:

* AWD Brake Calipers Left+Right
* AWD Brake Rotors Pair - LINK
* AWD Brake Pads Front Set - LINK
* AWD Front Knuckles Left+Right
* AWD Front Hubs/Bearings x 2 - LINK
* AWD Front Tie Rod Ends x2 - LINK
* Optional: ABS Sensors x 2
* Optional: ABS Rings for half-shafts x 2 - LINK

You will need the following parts for REAR:

* AWD Brake Calipers Left+Right
* AWD Brake Pads Rear Set (to match generation of calipers using) - LINK
* You do NOT use AWD rear rotors - you still use FWD rear rotors.

Recommended components - "since you're in there":

* New Front Ball Joints - LINK
* 3SX Stainless Braided Brake Lines - FWD / NA (you do NOT use the AWD brake lines) - LINK
* New front brake line connectors - LINK
* SpeedBleeders to simplify bleeding the system - LINK
* Motul 600 Brake Fluid - 2 bottles for a full system flush and bleed - LINK

FRONT NOTES:

You can use either Gen1 (91-93) or Gen2 (94-99) AWD parts, but you will need to get rotors and calipers from same generation as the Gen1 calipers will not fit the larger Gen2 Rotors.

The FWD rotors are about 10.75", the Gen1 front rotors are about 11.5", and the Gen2 rotors are about 12.25", so you are gaining a LOT of braking surface if you upgrade to a Gen2 setup.

The knuckles are the same for all years on the AWD, as are the front hubs, so they can come from any year and work the same. The generational difference is in the calipers, the Gen2 calipers have longer "arms" connecting to the knuckles, thus use the same pads for all years.

If you have ABS on your FWD and want to maintain it, you will need a pair of front ABS sensors and a pair of AWD ABS rings that get hammered onto the end of your FWD half-shafts. You don't need the AWD shafts.

REAR NOTES:

The only thing really needed is rear calipers and pads. That being said, it's only really even worth doing the swap if you have Gen2 rear calipers as they are a 2-piston caliper while the Gen1 rear calipers are a single-piston setup just like the FWD rear brakes.

You still use your FWD rear rotors, but AWD rear pads. The TT pads will hang off the edge of the NA rotor a little, that's ok and has not proven to be an issue. You can not use the AWD rear rotors due to the difference in hub offset between the FWD and AWD rear rotors - see pics below.

You will probably have to do a little grinding on the caliper (see pics below) to get clearance on the rotors. It's close and it seems that some cars don't need it while others do.

3/11/13 UPDATE: It has been reported that the RDA427 / DBA427 rear rotors will also work (these are from the 92-95 Diamante Wagon, or the Magna in Australia) IF you are using the 2nd gen TT rear calipers. This rotor offers a larger diameter at 284mm with a nearly identical center-hat offset. Using the larger rotor means getting more use of the pad - there is still a LITTLE underlap of the rotor against the pad, but there is definitely MORE pad on the rotor surface, meaning more braking power in the rear. Again, this is if you are using the 2nd gen TT rear 2-piston calipers.

GENERAL NOTES:

* * * BIG NOTE * * * You can NOT use the Gen2 calipers on the stock NA wheels!!! When you make the conversion to Gen2 VR4 brakes, you put yourself into the category of needing wheels that fit 94-99 VR4 cars. Some of the NA rims will work with the Gen1 brakes - the 94-96 SL wheels (alloy 7-straight-spoke 16x8) will fit a 91-93 VR4/TT. The AWD rear brakes have not presented any known issues with caliper-to-wheel clearance on FWD wheels.

You still use your NA/FWD brake lines. If you are purchasing aftermarket brake lines (recommended) do NOT get the AWD lines - the rear lines are different and will not work on the FWD platform. Purchase the FWD brake lines.

It's a given - you will LOSE power and 1/4 mile speed. Eric lost about 1/4 second in the 1/4 mile after making the swap. The AWD rotors are significantly heavier than the FWD rotors, as well as 1.5" larger in diameter. But on the flip side of that, what you lose in straight line acceleration, you more than gain in braking ability for autocross and road course racing.

It is a DIY job if you have some mechanical abilities and tools for working on the car.

When Eric did his conversion, a sledgehammer was used to free up the knuckle from the control arm as the knuckle was pretty well stuck on the ball joint (added note: a pitman arm puller could be used if you have one available or can borrow/rent one - we don't recommend a pickle fork as that will destroy the ball joint boots). A mix of new and used parts were used. New parts: rotors, pads, lines, front line connectors, tie rod ends, hub bearings, ABS rings. Used parts: knuckles, calipers, ABS sensors.

PERFORMANCE

The nature of the beast is that this modification COSTS power! Second Gen TT front rotors are about 1.5 inches LARGER in diameter than the NA and weigh about 5 pounds more PER ROTOR. Eric's Stealth ran about 4 tenths slower on average in the 1/4 mile after making the brake upgrade. But that being said, the increase in braking strength in autocross and road couse racing more than makes up for the slight loss is straight line acceleration. When building an all-around performance NA Stealth/3000GT, the brake conversion is well worth it - it just depends on what you are looking to get from your car.

This modification is highly recommended for the FWD cars that have had the twin turbo conversion done and have the extra power to overcome the larger brake weight "disadvantage."

March 2010 Addendum: From Eric's "let's try it and see what happens" train of thought... Eric thought of trying to gain some of the lost 1/4 mile time back by using lighter rotors. The plan was to simply take off the TT rotors and replace them with the orignal smaller and lighter NA rotors. Measuring the rotors, the center "hat" offset is only about 1mm different. So he pulled off the calipers and swapped on the smaller NA rotors. A few presses of the brake pedal to clamp the pads down and everything seemed like it would work (check your brake fluid level first else chance having to bleed the whole system).

The idea worked as Eric took an average of about .25 seconds off his 1/4 mile and ran an average of 2-3 mph faster on track visits only 2 weeks apart. The "drawback" is the bigger TT calipers obviously hold the pads further out, and the pads only about half cover the rotors. So making the swap back and forth will also require dedicated pads to run the NA rotors on the TT brake setup.

The following picture shows how the TT rear pads wear against the NA rotors when you do the conversion. As mentioned, the pad does not fully fit over the NA rotor, but this does not adversely affect the braking of the car. These served duty on several autocross and road course sessions.

The FWD rear rotors have to be used due to there being about a half inch difference in the center hub offset of the rotors (and thus the hub configuration on the rear trailing arms) between the FWD and AWD rear rotors.

ictures and writeup provided by Eric Bowden who did the above conversion on his Stealth RT several years ago. 3SX has performed the swap a number of times as well.