TT-CTSV1

Ok, so I'm building a TT V1, I'm new to this platform and have some questions about the rear setup.. Let me tell you my plan, I'm going with all GForce goodies, including 9" fabbed housing, and axles, now what I'm trying to sort out is, what would be the advantage to bolting in the 2nd gen rear setup if I'm using all GForce stuff, and going to go to 5 bolt??


I've looked at a bunch of pics, I just don't see that much different between the gen 1 and 2. I know the center section bolts in a little different, but that's not gonna change anything, really. I'm gonna solid mount the center section to the rear cradle. I need to go 5 lug, and I believe, 33 spline.

Anyhow, is there anyone around here that knows the 1st and 2nd gens well? This car is a SERIOUS twin turbo build, already has a full cage in it. I'm looking to sort out the rear, now.

Thanks guys!

MN_V

iTrader: (5)

Have you considered the 8.8 rear that is much more readily available and well proven?

TT-CTSV1

Gonna be making a solid 2000whp, and must have all the strength possible. I was going to dump the IRS and go with a 9" rear and some sort of 4 link, but decided to give the IRS a go. As I said, it'll be all Gforce stuff.

FuzzyLog1c

iTrader: (4)

That's absolutely not true. The 9" is just as available and more proven.

MN_V

iTrader: (5)

Sounds like a drag car - go solid axle if you can.

TT-CTSV1

I was gonna say that, just was trying to be nice.. 9" ford is the most widely used rearend EVER! I'm using all Strange carrier, pro gears, and spool.

How did you end up with 35 spline?? Excuse my ignorance in this department.

TorchRedRob

iTrader: (1)

The v2 cradle with gforce brackets is much beefier than the v1 cradle with gforce brackets. The size of the mounts are larger, and they spread the load better, in my opinion. At 2000whp, I'd want everything I could get to keep it from breaking. This is an easy upgrade if you're going all out. I'm sure others will have their thoughts, but just looking at the v1 vs v2 gforce bracket setup is night and day.

TT-CTSV1

It's a street car, but is gonna see a lot of track time. It's got all factory interior, ac, and ps.. I've been at this game for many years, and even though some of you " youngins" consider anything with a full roll cage to be a "racecar", this is anything but. You should see my other street car. Lol

MN_V

iTrader: (5)

My point was more available on our platform - can pick up an 8.8 kit in the classifieds probably right now. The fastest V1 is in the 9s on an 8.8 IRS.

TT-CTSV1

9's?? Lol. I'll be skipping way past that, by about 2 seconds. I've not really owned a car in the 9's for a few decades.

FuzzyLog1c

iTrader: (4)

The V2 subframe isn't stronger. It looks like it might be a little stiffer on the ends due to some angle bracing, but that's not where you'd break it. Nobody's ever broken a V1 or V2 subframe so it doesn't matter. In my opinion, the V2 subframe is cheaper than the V1 subframe to make because it's comprised of stamped metal pieces that don't need an extra bending step to roughly assemble them prior to welding.

A lot of it is stitch welded--for strength (and because it's easy), I'm probably going to redo it with a full seam weld before I paint it. It has massive rubber mounts, but those mounts are 50% air (whereas the V1 mounts were about 25% air). The real benefit of the V2 subframe comes from center section mounting provisions, which can provide more torsional stability for the center section than the V1's. Assuming you keep the same polyurethane mount hardness as you have on your V1 subframe, I would expect the larger V2 mounts to provide better noise isolation.

TT-CTSV1

Now we seem to be getting somewhere.. I've looked at pics of the V2 and can't find any major differences, other than the extra mount up front, I believe, and I'm gonna mount the housing with solid mounts, not rubber, and may mount the cradle with solid mounts as well, if not available, I'll just make some outta aluminum. I'll try the rubber first, if it gives me any issues, I'll wittle up some aluminum ones on my lathe.

FuzzyLog1c

iTrader: (4)

I have both the V1 and V2 subframes in my house if you need something specific.

Revshift will make you 75D versions of any of their polyurethane bushings if you ask them. They don't have the dimensions for the V2 subframe yet. I'd recommend 75D (equivalent to Rockwell 90 R) over Delrin and aluminum--it's very hard and controls very well but has just enough flex to attenuate high frequency noise.

The 9" V2 bushings that Geforce provides are 95A and that might be enough for you, considering how they're oriented vertically. Under torsion and thrust loading, when the center section is simultaneously nosing up and trying to twist itself out of the subframe, the metal cores on those mounts will limit how far the bushings can compress. Unlike the single V1 bushing that eventually gets destroyed by hard pulls.

TorchRedRob

iTrader: (1)

I guess I didn't make myself very clear. I wasn't saying the subframe was any stronger, I was saying the load would be better distributed across the gforce mounts. When I said "mounts," I meant the entire bracket structure, not just the bushing provisions. Anyway, I think we're ultimately saying the same thing. Given the choice, I'd dump the v2 frame in there because the way the 9" mounts into it is much better from a structural perspective, as opposed to the little cat ears on the v1 housing that are barely a foot apart.

TT-CTSV1

So let me ask, is all the suspension the same in the rear on the V1 and 2, it's some subtle things like the way the diff mounts in and the mounts at the chassis? I was considering getting a gen 2 setup from a standard CTS and upgrading it with all the goodies, but if there are no serious differences, I'll stick with my V1 cradle, and upgrade all the junk. Again, I notice you have 35 spline axles, what hubs did you use?

TT-CTSV1

I do see standard CTS gen 2 complete rear setups on carparts.com for 400.00, so it's not a big investment, but if all my suspension will bolt on, maybe I'll just look for the cradle itself.

FuzzyLog1c

iTrader: (4)

The V2 suspension is different. The rear upper control arms and knuckles are the same. The rear spring perches are similar but not identical. Should be compatible as long as you use two of the same type but I haven't measured them yet--I have extra sets of both here. You need to cut off the side of the spring perches if you want to run wide rear wheels.

The trailing arms are incompatible--the forward mount on the V2 is oriented horizontally as opposed to vertically on the V1. That was probably done to allow the arm to be removed without dropping the whole subframe. In the V1, the vertically oriented bolt bolt is captured by the body of the car once the subframe is bolted up.

TT-CTSV1

Not sure if this was answered, but can I install the V2 5 lug hubs in the V1 rear arms? I want to go with the largest spline count possible.. Are there aftermarket, or other hubs that are higher spline count? I'm looking to use the biggest stuff possible.

FuzzyLog1c

iTrader: (4)

There are three reasons why the V2/Camaro/C6 ZR1 wheel bearings aren't a direct fit. I don't have my handy wheel bearing spreadsheet on my phone, so I can't give you precise dimensions or part numbers. Ask me later if you want that.

The first reason they won't work is that the hub diameter is too big and won't fit the V1/STS spindles. The second is that the center-to-center spacing of the triangular hub flange bolts is larger. The third reason is that the newer wheel bearings will only work with newer, active-type ABS systems.

Active ABS systems use an encoder in the wheel bearings and a powered sensor embedded in the spindles/knuckles to generate a square wave whose amplitude is independent of wheel speed. Passive ABS systems generate a variable amplitude sine wave that gets larger as wheel speed increases. At low speeds, the sine wave is too small to be reliably read. So while passive ABS systems stop working below about 10 mph, active ABS systems can provide precise positional feedback all the way down to zero RPM. That enables wheelspin control starting from a stopped position.

The good news is that you can get 30 and 33 spline SKF 5x115 wheel bearings that are compatible with V1/STS spindles and C6 Z06 brake rotors and wheels. The other good news is that the largest ARP wheel studs are M12 and fit these wheel bearings. Those ARP M12 fasteners help bring the 5x115 bearings up to the same shear strength as their 5x120.65 counterparts, which use M14 fasteners.

Mercier

iTrader: (15)

Sounds like you are well on your way to a very fast V1. I like it.

I'll be the guy that asks the obvious(I think) question.. Are you wanting to do 2000RWHP through IRS just to be different? I am a fan and have been since the Cobras(though not the best-executed, I got some experience with it) however it feels like you might lose all that space you accomplished in the back seat with the cage..because it will be filled with spare axles.

Other than what you listed above, how do you plan to make those axles live any amount of time on the street and track at that power level? Is G-Force going to do something special for you? Am I underestimating their parts?