2004-2007 Cadillac CTS-V Appearance Mods Discussion, 6 bolt to 5 bolt conversion... in Cadillac CTS-V Series Forum - 2004 - 2007; Having screwed up a hub and personally having to change one in the past got me thinking. All this wheel ...
Having screwed up a hub and personally having to change one in the past got me thinking. All this wheel talk and 6 bolt applications stink concepts are right so, let's talk about changing it!
Simple concept, surprised someone hasn't tried yet... take the CTS hubs and put them on the V.
I don't imagine the hub diameters are different, in fact I'd guess that they are pretty much identical pieces of hardware save the bolt count and degree location.
Anyone that's got access to parts, or a deep wallet can try this for us?
The hub for the front is 12413071 $126/ea (both sides same) and the rear is 25693148 at $207/ea (same both sides again). This is from Reed's excellent faq site's part diagram for 2003-2004 CTS, so YMMV, please check parts catalog for updated numbers.
Theoretically it should be a 1) remove wheel, 2) remove brake calipers, 3) remove hub, 4) replace hub, reverse rest of steps.
All that remains is some metallurgical analysis or some other engineering overview to ensure that the CTS hubs can take the stress of another 100 ftlbs torque and 100 ponies (or 200 each for the Maggies). Not being an engineer, I wash my hands of any legalities - your own necks go on this one. Of course if it pans out, I'll be joining in the fray too
So, let the slide rules and calipers come out to play. All I ask is if it flies, call it the Peet Hub Mod LOL.
Why would you want to convert to 5-lug? Maybe I'm missing the point? Please tell me its not so that you have a wider variety of wheels to choose from... Just get some custom forged rims and don't mess with the "CTS 5-lug" hub/brake setup (believe me, it will not be worth your while).
What about the big rotors? They are for the 6 lug hub. If you have to go with the CTS rotors also, then there go the Brembo calipers too, as I would suspect they wouldn't line up right with smaller rotors.
I did this swap on the front of my '94 Firebird Formula, switching it over to a '98+ bigger rotor assembly. Had to swap out the entire spindle assembly. Spindle, hub, rotor, caliper.
Sounds like you'd sacrifice a hell of a lot of stopping power just to get away from the 6 lugs.
Yup, you are forgetting the rotors but that is an easy fix. Have some aluminum hates made and have Coleman machine custom make a set of slotted discs. This will not only gain a bit of braking performance but also reduce unsprung wait wich is significant!
The 5 bolt conversion is to allow greater options in fitting wheels. personally, the 6 bolt hubs strike me as a cool idea!
Automobile(s): CTS-V CAI, CAM, BB X-pipe, Baer Extreme Plus
Re: 6 bolt to 5 bolt conversion...
Peet, I also have thought about doing the hub switch to get a decent amount of wheel options at a reasonable price.
As far as the brakes are concerned they will not be a problem, there are plenty of brake manufactures out there that can make a two piece rotors so the hat can be what ever bolt circle you need (five in this case) and the rotor dimensions could remain stock (or plus size now that you have wheel options for a reasonable amount), you would be able to use the stock Brembo caliper and get a much better braking system by moving the caliper out.
If I end up later this year doing some more mods I have been thinking about then these and other options will be very much on the table as I will need to slow this beast down (watch out Blitzer.)
I totally spaced on the rotors... but the light hat point is excellent. The expense of having to get custom (or maybe non) rotors with two-piece design is truly excellent. What you end up with then is a 5 bolt pattern that fits tons of wheels (why spend $5k+ on forged sets when you can get same/similar for less) and a lighter unsprung weight by changing the hat style. You also get a better performing brake, because teh cooling is more efficient in a two piece design, and lastly the two piece design is less likely to carry heat to the hub for performance use. DP: Can't wait to see what you come up with if you go there!
Brembo makes a 5 on 115mm Gran Turismo kit for the regular CTS. It's got 14" two piece rotors with aluminum center hats, and four piston calipers. The front calipers are one piece, rears are two pieces bolted together. They look slightly beefier than the V calipers. Pads are the same as the V's. Unfortunately, they don't sell just the rotors/hats (only the complete kit for ~$3500).
I think they're pricey because of the billet aluminum rear hats that need to include the parking brake drum. The front hats are off-the-shelf and drilled for the 115mm bolt circle. They're also very low volume production (special order only). Replacement disk rings are ~$350 each, with new hardware recommended at $85/corner. You can get them drilled or slotted, though.
I have a 14" used set (with drilled front rotors) waiting to be cleaned up and put on my regular CTS (for looks only, since I don't use my current brakes anywhere near their limits). Baer sells 14" two piece rotors for the 5 lug CTS, but I don't know if they're spaced correctly for the factory V calipers. By the time your done with hubs and brakes, it makes the price of a custom set of 6 lug wheels not look so bad.
For all you 5 lug haters...take a look at what Cadillac is using on the SpeedGT car...
Six lug wheels, forged cost a fortune. Imagine your delight when you need to replace an HRE wheel because of an accident or pothole. With 5 lug, there are many aftermarket wheels available that are "business", not rice. OZ(the CTS-VR wheel), Volk, SSR(the ultralight wheel), BBS, and the list goes on...including companies that make pure "race" wheels custom for your application.
And lets bring up the cheaper, cast wheel offerings for those of us looking for winter wheels. I recently bought a used set of Mille Miglias for my all-season needs...it really sucks that they are 8inches vs 8.5 of the stockers. I happen to think they look OK, but would not be the wheel I'd buy if given the choice. I'd love a set of 5 spoke, easily cleaned winter wheels in the stock size that could double as my summer R-compound race wheel. I am left with very few choices with the 6 lug wheel and they are disgracefully expensive.
Give me the choice to have a REAL lightweight race wheel that won't hurt the wallet too much when they need to be replaced and I'll be quite happy.
Yes, the 6 lug situation pure-straight sucks. Another engineer I'd love to torture....