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Discussion Starter · #1 · (Edited)
!!! INSTALLED 13 Jan 08 !!!

For Group Buy on this kit, click here: http://www.club3g.com/forum/group-buys/104725-gb-ls1-cobra-13-front-bbk.html

I originally was going to use a set of 2000 GT dual-piston calipers and go with a Powerslot BBK for the front of my car, but changed my mind. Instead, I'll be using pads & dual-piston calipers from a 98-02 LS1 Chevy Camaro or Pontiac Firebird, with 13" rotors from an 03-04 Ford Mustang Cobra.

The rotors will slip right on since we share the same bolt pattern (the first one will be here tomorrow and I'll buy the second after the caliper brackets are done). The calipers are aluminum, for a substantial weight reduction (see below), and are quite larger than the 2000 GT calipers as you can see in the pictures below. I'll have to make custom mounting brackets for the calipers, but it actually looks like it'll be pretty straight forward. Also, the brake lines for the Eclipse bolt right up to the Camaro calipers, so there's no special fabrication for the brake lines needed!

One of the nice thing about going this route, from both an initial conversion and a maintenance standpoint, is cost. The new rotors are only about $40 each at any local parts store, and I picked up the calipers for about $100 for the pair. Just to make everything nice and fresh, I even dropped what I thought would be small change on new seals, dust boots, and guide pins for the calipers so I can rebuild them before the final assembly...the guy at the dealer didn't read his screen right though, so what was supposed to be $18.01 for both calipers turned out to be just for one piston...so, I wound up spending just under $80 to rebuild both calipers...oh well, at least they'll be fresh. Additionally, there will be much more clamping force from the larger pistons, and the pad-to-rotor contact area is greatly increased (instead of the very narrow contact area of the Eclipse brakes). Also, unlike any of the 4-piston conversions (Evo Brembo, 3KGT, etc.), wheel clearance in front of the rotor shouldn't be an issue since these don't stick out much farther in that direction.

Update: The first two sets of brackets are are finally done and were made by a local fabrication shop so I could make any adjustments as needed. The prototypes are a little differnt than the final production brackets will be, but functionally they work just fine. The prototypes are made from steel since its cheaper and easier to make adjustments, but the final version should be CNC machined aluminum which will be coated for corrosion resistence. Once the prototypes have been tested and all the changes are decided on, I plan on offering these under a group buy for anyone who is interested...I will probably require a minimum of 5-10 people for group buy prices, but would still be able to offer these up for sale if fewer members are interested. As it stands right now, Steve at Sport Compact Customs (aka HIJACKER) will probably be making the final production brackets, so the quality and finish should be outstanding...:woot:

Update 14 Jan 08: Now that the brakes are installed, the stopping power is fantastic! The pedal feels a bit mushy, but I wasn't able to fully bleed the brakes last night when I installed them (I only gravity-bled the fronts). The fluid that was in the system was a little dark for my taste as well, so I'll flush the whole system soon and bleed it properly. Even still, the brakes are much better than they were before...plus, they look 10 times better! One other benefit that I forgot to mention about having the larger diameter rotors besides the added cooling is that the force has a greater degree of leverage...so, not only do the calipers clamp with greater force, but the force is multiplied by the greater leverage...the principle behind this is that the further out from the point of rotation, the greater the force that is applied...just like using a long breaker bar instead of a short ratchet...:bigthumb:

COST BREAKDOWN:
Used LS1 Calipers (pair):______$117.62 shipped (eBay)
Caliper Rebuild Kit (pair):______$77.83 (Chevy Dealer)
New Cobra Rotors (pair):______$85.96 (Advance Auto)
New DG Ceramic Pads (set):___$45.14 (Autozone)
New Mounting Brackets (pair):_$???

TOTAL: $326.55 + cost of custom brackets!

Without the caliper rebuild kits it would come in at $248.72 + the cost of the brackets...I glad I bought the rebuild kits now...one of my slider pins was stuck solid (we had to break out the torch to get it loose). Also, I ran into a bit of a snag...one of my bleeders is screwed up...it won't come out and it won't stop bleeding, so it looks like it's going to have to be extracted...once I get that done though everything should be ready to go!

CALIPER WEIGHT
2000 GT Caliper:__12.4 lbs (w/o hose)
LS1 Caliper:______9.2 lbs (w/hose)

ROTOR WEIGHT
RS Rotor:_____13.3 lbs
LS1 Rotor:____19.5 lbs
Difference:____6.2 lbs

The following are side-by-side comparissons between the LS1 calipers (on the left) and the 2000 GT calipers (on the right):

Here is a view from above. As you can see, the LS1 caplipers are much larger than those from the 2000 GT. Also, the fins along the top will help to reinforce the calipers as well as provide greater surface area for cooling.


Here's a view from below. Again, the size difference is readily apparent...especially when you compare the area that the pistons are recessed in. Also, again notice the cooling fins around the area where the pistons are.


Here's a view from below and slightly behind. I think it emphasizes a little more the difference in size between the pistons. Also, if you notice, the LS1 calipers also take a banjo style fitting for the brake line...I haven't tried it yet, but it looks like the SS brake lines I already have should bolt up without any problems at all.


Here's a view of the front of both calipers. In this picture, the LS1 caliper is below the 2000 GT caliper. Again, you can clearly see how the LS1 caliper completely overshadows the one from the 2000 GT.


Lastly, here's a little bit of a comparisson between the actual pistons of the two calipers, with the LS1 back on the left and the 2000 GT back on the right. The picture doesn't really do it justice, but I'd almost be willing to bet that the piston from the 2000 GT caliper would fit inside the piston from the LS1.



Here are pictures after the first mock-up...I didn't have time to take any measurements for the brackets since my jack took a dump (I had to use the crappy one that came with the car) and I ran out of daylight, but hopefully I'll be able to get them shortly. NOTE: All of these pictures were taken at the same distance from the car with the same camera settings.

Here's the starting point...the stock RS wheel with stock RS brakes.


Here's a shot of the stock RS brakes with the wheel off, for comparisson purposes.


Here's a shot of the Cobra rotor and LS1 caliper. Compare the amount of the lower strut mount area visible above the rotor in this picture to the one before. NOTE: The caliper is not attached (it's being held up by the can underneath it), and it will actually sit in closer to the hub...but, it gives you an idea of the size difference.


Here's a shot of the stock RS brakes with the 18" Black Racing Pro N-1 wheel I'll be using, for comparisson purposes.


Here's a shot of the Cobra rotor with the 18" Black Racing Pro N-1 wheel. NOTE: The LS1 caliper is not pictured since I didn't have a way to secure it tonight.


Here's a shot that shows how close the depth of the rotors are...it doesn't get much closer than this!



Here are pictures after mock-up with the prototype brackets. I didn't bring the pads with me, and still haven't rebuilt the calipers yet, but hopefully I'll get around to that this weekend since I'm off work for the next few days. As you can see, these fill an 18" wheel quite nicely!

Here are a couple pictures of the prototype bracket installed on one of the calipers. The brackets will actually have to be bolted to the spindle first though. As I said above, the final version will look a little different and be made out of aluminum though.




Here is a picture of the prototype bracket installed on the spindle. The dust shield has been removed as well.


Here is a picture of the rotor and caliper installed. I still have to shave out the inside of the hubcentric rings, but that will be done before everything is finalized.


Here is a picture of the rotor, caliper, and wheel installed. As stated above, these are 18" wheels. The width is 7.5" and I believe they have a +45 offset.


Here are a couple pictures that show the clearance between the caliper and wheel. As you can see, I have plenty of room to spare, but I'm not sure how much room there would be with 17" wheels...I also have plenty of room before hitting the spokes, which wouldn't be the case with 4-piston calipers.





29 Dec 07 - Here's a picture of the calipers nice and freshly rebuilt...it looks like I missed a tiny bit with the bead blaster, or my hand was a little dirty, but they still need to be painted anyways...damn auto hobby shop wouldn't let me have spraypaint in there...


14 Jan 08 - Installed pictures below...enjoy!









I plan on updating this as I go. Please feel free to provide any feedback and keep the questions coming!
 

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Nice. Yes you will have to make a bracket to mount them but if you can do that then things will likely work.

Have you checked the offset of the rotors themselves to the face of the center part where they will mount against the 3G hub? Would hate to see them real far inwards or outwards compared to stock. A little would be OK and can be compensated for but if it's a 1/2" or more it could be troublesome.

Sounds like in many ways you have a home-made BAER kit. I know my Baer's use Cobra pads, and it's quite possible that the rotors themselves are able to be transferred over to other cars as well. Line things up with the right adapting / mounting bracket for the caliper and you're ready to rock.

It's certainly do-able, would love to see how it ends up. Good luck -
 

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Discussion Starter · #3 ·
Nice. Yes you will have to make a bracket to mount them but if you can do that then things will likely work.

Have you checked the offset of the rotors themselves to the face of the center part where they will mount against the 3G hub? Would hate to see them real far inwards or outwards compared to stock. A little would be OK and can be compensated for but if it's a 1/2" or more it could be troublesome.

Sounds like in many ways you have a home-made BAER kit. I know my Baer's use Cobra pads, and it's quite possible that the rotors themselves are able to be transferred over to other cars as well. Line things up with the right adapting / mounting bracket for the caliper and you're ready to rock.

It's certainly do-able, would love to see how it ends up. Good luck -
Thanks for the words of encouragement! I just bought the pads and ordered one rotor so I can do a mock-up and get measurements and a template made for the bracket (the rotor will be here tomorrow). Pictures of the mock-up should be posted tomorrow night if all goes well. After I have the brackets completed I'll order the other rotor and be ready to go.


I updated the initial post with a cost breakdown...it looks like even with the cost of the brackets I should still be in under the cost of a Powerslot BBK, let alone a BAER kit!
 

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Discussion Starter · #5 ·
How do you plan on fabricating mounting brackets?
I'm probably going to see if I can "build" templates out of cardboard, wood, and or plastic, then transfer the design over to plate steel or aluminum to be shaped and drilled...I'll have a more definite answer once I have the rotor...
 

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Discussion Starter · #7 ·
I've had them in my favorite links for quite some time now...I'm hoping to be able to make them myself, but if it looks like more fabrication will be required than I have at my disposal then I might try them...I might also see if there's any shops in the local area here that would be good, but I don't know of any yet...have you come across any?
 

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Discussion Starter · #8 ·
UPDATED: I added a weight comparisson between the 2000 GT calipers and the LS1 calipers. Even though they're much larger, the LS1 calipers weigh 3.2 lbs less, each...and that's with the hose still attached.
 

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Keep in mind the pricing. To only make 2 brackets will cost you a fortune on that site. Your pricing really won't drop unless you make 10 or more.



You mentioned cardboard template and transferring over. As an option, if you create me a drawing as detailed as this, I can fabricate two of these for you (I would need the thickness as well.)

Here's a good example of a one off I made for another client. (simple piece, but you get the idea).

Drawing


Production
 

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Discussion Starter · #10 ·
Keep in mind the pricing. To only make 2 brackets will cost you a fortune on that site. Your pricing really won't drop unless you make 10 or more.

You mentioned cardboard template and transferring over. As an option, if you create me a drawing as detailed as this, I can fabricate two of these for you (I would need the thickness as well.)
Yeah, pricing is definitely something I've been keeping in mind...that's why I've been hoping it would be straightforward enough for me to fabricate. If it seems that it's beyond my abilities I'll definitely send you a drawing...I may do that anyways now that you mention it since I know the quality would be top-notch...is there a certain format you prefer? One of these days I'll break down and buy Rhino, but for now I mainly use One Space Modeling for my CAD/CAM needs...I think I can export the drawings in pretty much any standard format (it's been a while since I've designed anything with it).
 

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Yeah, pricing is definitely something I've been keeping in mind...that's why I've been hoping it would be straightforward enough for me to fabricate. If it seems that it's beyond my abilities I'll definitely send you a drawing...I may do that anyways now that you mention it since I know the quality would be top-notch...is there a certain format you prefer? One of these days I'll break down and buy Rhino, but for now I mainly use One Space Modeling for my CAD/CAM needs...I think I can export the drawings in pretty much any standard format (it's been a while since I've designed anything with it).
Format doesn't matter.. hell, it can be JPG for all I care. I prefer it to just be graphically so its easy to read and the measurements are accurate. :)
 

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Discussion Starter · #12 ·
Format doesn't matter.. hell, it can be JPG for all I care. I prefer it to just be graphically so its easy to read and the measurements are accurate. :)
Ok, cool...I'll see what I can put together...hopefully I can get you at least a rough draft sometime this weekend...
 

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Discussion Starter · #14 ·
Pictures after the first mock-up are posted! I didn't have time to get any measurements before the sun went down, but more to come...
 

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Discussion Starter · #16 ·
I really like your rims
Thank you...from what I've been able to find through research, I don't think you'll see too many like them in the 18" size.

While I was trying to find a couple center caps, which I've now decided not to use, every place that sold this model wheel said they only came in sizes up to 17", and that the 18" would have had to of been special ordered from Japan...whether that's true or not I don't know (I bought them used), but I have yet to find one distributor that has carried the Pro N-1 in 18" here in the states...
 

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UPDATED: I added a weight comparisson between the 2000 GT calipers and the LS1 calipers. Even though they're much larger, the LS1 calipers weigh 3.2 lbs less, each...and that's with the hose still attached.
Thats awesome that you can get a weight reduction in that area, but the rotational mass added by the rotor will be quite a bit. At least the rotor weight difference between stock/EVO rotors are huge.

Would you weigh the different rotors and post? I never thought to do that while doing my swap.
 

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Discussion Starter · #19 ·
The bigger rotors do so much for the appearance of the car. Good luck man, ill definitely keep an eye on this thread.
Thanks! Yeah, now that I see how well the Cobra rotor hides the area behind the wheel, I'm not sure I would have wanted to use these wheels without them!

Thats awesome that you can get a weight reduction in that area, but the rotational mass added by the rotor will be quite a bit. At least the rotor weight difference between stock/EVO rotors are huge.

Would you weigh the different rotors and post? I never thought to do that while doing my swap.
I can weigh a stock RS rotor (with about 8-10K miles on it) against the Cobra rotor, but I don't have any 2000 GT rotors...I'd imagine they'd be close the same as the RS rotor...maybe a little more. I'll try and get the weights tomorrow...
 

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Thanks! Yeah, now that I see how well the Cobra rotor hides the area behind the wheel, I'm not sure I would have wanted to use these wheels without them!



I can weigh a stock RS rotor (with about 8-10K miles on it) against the Cobra rotor, but I don't have any 2000 GT rotors...I'd imagine they'd be close the same as the RS rotor...maybe a little more. I'll try and get the weights tomorrow...
I have an old stock GT rotor kicking around somewhere in my garage. It has about 100k miles on it, however.
 
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