DSM calipers + Ralliart = Win.
Dec 11, 2006, 10:13 PM
#1
DSM calipers + Ralliart = Win.
Already, for those not in the loop, I decided to embark on a little experiment. 93-99 AWD turbo DSMs (Eclipse/Laser/Talon) have 2 piston calipers. Coincidentally, they also have the same rotors as us. I decided to verify the rumors, started when RPW said they found existing calipers that would fit, and try these on for myself. Here's what I found. (This will take a few posts, due to limits of 5 attachments per post.)
First, I found myself some calipers. I'm told they're kinda hard to come by, as many of the non-AWD DSM guys are after them, too, since they all have single-piston calipers, like us. Unfortunately, someone local to me had their garage burn down, and 4 DSMs were taken with it. 3 of the cars were destroyed. 1 of them, a 93 Talon TSi, only had the front bit burned, and most of the car is salvagable. I got ahold of the guy and snagged the calipers and brackets for $75. Not bad. They're in great shape, just need to be worked over with a wire wheel and some paint. I may replace the seals, though, since they are 13 year old calipers.
Here they are:
They are a hair larger that our stock ones, but not by much, maybe a few mm.
For reference, here's a shot of our stock calipers on the car:
And here's a shot with the dual-piston DSM calipers mounted:
Hooray, it fits!! Here's a picture of the clearance:
I just fits on there, not much room to spare, but enough.
First, I found myself some calipers. I'm told they're kinda hard to come by, as many of the non-AWD DSM guys are after them, too, since they all have single-piston calipers, like us. Unfortunately, someone local to me had their garage burn down, and 4 DSMs were taken with it. 3 of the cars were destroyed. 1 of them, a 93 Talon TSi, only had the front bit burned, and most of the car is salvagable. I got ahold of the guy and snagged the calipers and brackets for $75. Not bad. They're in great shape, just need to be worked over with a wire wheel and some paint. I may replace the seals, though, since they are 13 year old calipers.
Here they are:
They are a hair larger that our stock ones, but not by much, maybe a few mm.
For reference, here's a shot of our stock calipers on the car:
And here's a shot with the dual-piston DSM calipers mounted:
Hooray, it fits!! Here's a picture of the clearance:
I just fits on there, not much room to spare, but enough.
Dec 11, 2006, 10:19 PM
#2
Verification that it clears my steelies. If it clears these, it'll clear the stock wheels:
This all seems too easy. Yup, there's a catch:
Each of the calipers uses a different fitting for the brake line. Sadly, you can't just swap in the DSM line.
The line in the Ralliart is about 2.5x that length. Good news, though, is that according to RPW's website, they make brake lines just for this conversion. Hooray.
Come springtime, when it's warm enough to paint in the garage, I'll be installing these permanently. If you want to get these for yourself, but either can't find a DSM to pull them from, or don't want the hassle of cleaning up used rotors, I found that NAPA auto parts sells these as remanufactured units for about $120 each ($60 + $60 core charge).
This all seems too easy. Yup, there's a catch:
Each of the calipers uses a different fitting for the brake line. Sadly, you can't just swap in the DSM line.
The line in the Ralliart is about 2.5x that length. Good news, though, is that according to RPW's website, they make brake lines just for this conversion. Hooray.
Come springtime, when it's warm enough to paint in the garage, I'll be installing these permanently. If you want to get these for yourself, but either can't find a DSM to pull them from, or don't want the hassle of cleaning up used rotors, I found that NAPA auto parts sells these as remanufactured units for about $120 each ($60 + $60 core charge).
Dec 11, 2006, 10:26 PM
#3
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Looks good (actually it doesn't, yet
Sounds good though, with some decent pads those should work a lot better.
Are the rear DSM ones any better? Would they even fit? And I guess, would it even be worth it for a DD?
Sounds good though, with some decent pads those should work a lot better.
Are the rear DSM ones any better? Would they even fit? And I guess, would it even be worth it for a DD?
Dec 11, 2006, 10:30 PM
#4
Rear DSM ones are just single piston, not different enough from ours to make a difference, and not sure if the rears would fit. If the rears did fit, the only reason I could think of to swap them would be to get a greater selection of rear pads.
Oh yeah, that's another bonus, these calipers have more, and less expensive, pad options.
Oh yeah, that's another bonus, these calipers have more, and less expensive, pad options.
Dec 12, 2006, 06:11 PM
#10
I have a set of front calipers for sale that will fit with your banjo lines if anyone's interested. It's a 2 piston caliper identical to the one on a dsm, only with a banjo fitting on the brake. It's from my Evolution II.
PM me if your're interested.
PM me if your're interested.
Dec 12, 2006, 09:37 PM
#12
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sweet good to know! also with upgrading the caliper, how is that going to change the amount of fluid required? i know on doing rear disc converstions on some cars a larger master cylinder bore is required. does having 2 pistons/caliper affect that at all or are these 2 pistons calipers smaller or = our one piston caliper
Last edited by morpheus256; Dec 12, 2006 at 09:42 PM.
Dec 12, 2006, 09:49 PM
#13
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sweet good to know! also with upgrading the caliper, how is that going to change the amount of fluid required? i know on doing rear disc converstions on some cars a larger master cylinder bore is required. does having 2 pistons/caliper affect that at all or are these 2 pistons calipers smaller or = our one piston caliper
That's a good point. The pistons in that DSM caliper look a lot smaller than the stock RA one. Unless my hydraulics knowledge is mistaken, that will reduce the force that the pistons in the caliper put on the pad/rotor.
Dec 12, 2006, 10:27 PM
#14
Excellent questions. On the first one, I'm not sure if they'd need more fluid. Even though there's an extra piston, both pistons are smaller than the single piston on the stock caliper. I would think they'd balance out, but I wouldn't know for sure until I actually hooked them up to the car.
Edit: RPW has this statement on their site in regards to upgrading to dual piston calipers:
As for captain150's point, while each of the two smaller calipers might not put out as much force as the single large piston, it's their combined force, spread over a larger area of the pad, that makes them more effective.
Edit: RPW has this statement on their site in regards to upgrading to dual piston calipers:
Does not require any changes to the brake master cylinder assembly (Unless rear brakes have also been converted to disc from drums) or any custom fabrication.
Dec 12, 2006, 11:22 PM
#15
Piston size of the DSM caliper is 42.9mm. Area is 1445.5mm, and there are two of them, adding up to 2890.9mm.
The dual-piston calipers have a slight advantage over the stockers in both hydraulic power and how evenly the force is applied.
And it also answers the other question. Their area is so close, no changes will need to be made to the master cylinder.