Join Date: Jun 2001
Ye, I know it has been discussed few time without results. Because of that I have done a LOT of research on it and found out the following:
1. Fiat Coupe is designed with rims that are deeper in respect of hub-to-spoke distance. The rim spokes lays in a plane very far out in the rim and therefor there is a larger clearance between brake disc and rim spokes. The 155 is designed with smaller clearance between disc and spokes for a caliper with no piston on the outside.
2. There are three ways getting a Coupe 20V/GTV 3.0/GTA/406 Coupe/360 Modena caliper into a 155 wheel:
a, use other rims, perhaps with a spacer for the rim
b, use a large spacer for the rim (don't think it is possible because of the wheelarches)
c, move the disc inwards, perhaps with a spacer for the rim
3. I want to use the set of rims I have and have hunted parts for alternative c. The spindle joint in the wishbone dimensions the maximum disc offset and the most ideal disc I found so far is the BMW M3 E36 disc (315x28x52). From 90 Euro (Brembo original) and up depending on which supplier you choose. The BMW standard disc has a non deatachable aluminium hub and costs about 230 Euro. I prefer a disc casted in one piece of steel beacause it handles the necessary modifications better than the aluminium hub. With 16" speedline one might have to cut a few mm's on the diameter of the disc, but that is ok. So what you do is to drill 4x98 12 mm holes for the wheel bolts and 2x98 8 mm holes for the guidance bolts in the hub. Then you turn (?) a center ring for the disc guidance and it should have an at least 3 mm thick 115 diameter disc that serves as a spacer for the brake disc - just for the protection of the spindle joint rubber sealing that is a bit too close to the brake disc.
4. The brake caliper discussed is a good one and costs from 370 Euro each without pads from Peugot to 530 Euro with pads from Brembo. Another option is to use Porsche's monoblock GT3 (4 pistons) or GT2 (6 pistons) calipers. I don't have the exact meassures of theese yet, but monoblock calipers are usually mor compact. The GT2 calipers costs around 390 euro each and the GT3 must be cheaper. The drawback with Porsche calipers, except the Porsche logotype, is that they are designed for a 34 mm disc.
To be continued