Driver_10

The C4 is far lighter, uses a standard driveshaft instead of a torque-tube (easier to swap and can use the stock tranny) and unlike the C5 IRS, it and can be altered to custom lenths... But thats about it.

Geometry wise, the C5 is far better.

LS1MonteSS

iTrader: (1)

I have read that you have to swap out the C4 diff for a Dana 44 diff. I don't plan on drag racing my car. My main focus is to be able to get parts when I need them and not have to go to some specialty vender or wait for back orders. I want to install wider rear tires (like 345's) and the GTO OEM IRS is very limiting. I'm also toying with the idea of maybe doing some auto-Xing with the car.

The 05 GTO tips the scale at 3700lbs. I'm hoping that the swap will drop that down a little.

99_orange_SS

iTrader: (20)

There is zero reason that you "HAVE" to swap the Dana 36 for a 44. If you are putting down 500-600+ at the wheels or do hard launches out of first and popping the clutch then I would definitely recommend it. Otherwise the 36 has stood up to ~600rwhp just fine if you are gentle off the line; it holds up slamming through the gears though with significant power running through it.

Now going with larger tires will increase the torque and pressures that the Dana 36 will encounter. One option is just going with the 36 for cost purposes and then when you are ready for larger tires also upgrade to a Dana 44 and all you will need to incorporate it in is either a new batwing or an adapter plate that is already out there.

No reason to go with a GTO IRS unless you have a GTO with it. In this case I would keep the GTO IRS unless planning on upgrading to a C5 setup; otherwise the gain would be so minuscule it would negate the cost and work required going to anything else. If you really want to improve the factory suspension that much start looking into having the stock parts cast in magnesium/aluminum alloys to lighten up the rear. Obviously your willing to spend the money and put in the effort. For this reason pioneer something new for your "field" so to speak. You could just as easily have your factory suspension cast in new lighter alloys and then create brackets to alter the geometry slightly to improve the handling and lighten up the rear. This would require about the same amount of work and money as going with a C4 but yield greater results.

99_orange_SS

iTrader: (20)

Same here man. This info is 100% accurate and I have the same exact experiences. I lucked out getting a '96 rear so I didn't have to hassle with new sensors. ABS is always off though so not much use

Driver_10

I talked with Alan Blaine (blainefab, for those who know of his legend) and he did a 4 Channel swap using a C5 EBCM. As it turns out, the unit is a perfect stand-alone.

Only one module and 4 sensors... thats it.

A perfect stand-alone. It will work on ANY application where you can fit wheel sensors. The tooth count (as long as they're are the same on all wheels) is irrelevent.

He has it installed on a RR car that he built and it works perfectly. No second modules or additional modding needed. The ports are even marked from the factory!

99_orange_SS

iTrader: (20)

That's some great info. Thanks!

Driver_10

Alan gave me these notes and instructions...

"...I started with a C5 EBCM and a wiring harness, Ken got them off of Ebay. I'll get you the part numbers. I needed the wiring harness only for the connector that plugs into the EBCM - it is a unique, multi pin connector.

The C5 ABS combines the hydraulics and electronics in the EBCM, so just the one module to mount. I replicated the C5 mounts, with 3 studs that engage rubber donuts in the EBCM, and located it near where the OEM Fbody ABS hydraulic module is located.

The ports on the C5 EBCM are labeled with function

For plumbing, I installed new LS1 Fbody front hardlines, they have a flex section at the ABS end, and the bubble flare fittings are compatible with the C5 EBCM, so just had to bend the hardlines up a bit, and plug them in.

I fabbed up new rear hardlines from the EBCM back to the axle, and used Global West chassis to axle flex lines. I fabbed new axle hard lines.

I put a new LS1 MC and booster on the car, and using a new set of LS MC hardlines as a starting point since the MC fittings are oddball, fabbed new hardlines from the MC to the EBCM. The rear line goes thru a Wilwood bias adjuster.

Electrical:

Red +12V thru a 25A fuse to the alternator
Blk, Blk/Wh Ground to chassis
Brn ign to switched side of ignition circuit - I put a dash switch with pilot light on this connection so the driver can turn the ABS system on/off on the fly.
Lt Blu stop to switched side of stop light circuit
a twisted pair from each wheel sensor:
left rear: Red/Blk
right rear: Wh/Brn
right front: Tan/Grn
left front: Yel/Blu

I salvaged the front hub harnesses, axle wiring harness and the rear bulkhead connector from a 4channel Fbody chassis, made up the rest of the rear twisted pairs.

That's it - no connection to a PCM, so this could go on anything, carb or EFI or whatever

There is no ABS ERR or ABS ACTVE indicators, nor any diagnostic port - those would need to be wired thru a compatible PCM.

Bleeding - connect everything, bleed, leak check, drive it a bit in the paddock, carefully activating ABS, use some water or gravel if necessary, then bleed again. Rinse and repeat. It is important to get the system bled - air in the ABS system will try to kill you - ie pedal stuck to the floor with both fronts locked up. Do not drive it on track or on the street until you are satisfied that the system is fully bled of air..."

LS1MonteSS

iTrader: (1)

So this is what I have been looking for. C5-C6 Suspension components used with out the transmission or torque tube.
http://www.streetshopinc.com/images/...2_08_large.jpg

This shop uses a Viper diff and they narrow the aluminum cradle. The diff is secured to the frame and the cradle is just a bases for the lower suspension components.

99_orange_SS

iTrader: (20)

Ya that is a great option for anyone wanting to keep the transmission in the front. The kit I will design will incorporate the torque tube and transmission into the rear (requiring rear seat delete). In the above image the stock cradle really isn't needed. It would be better in my opinion to just incorporate a couple more mounts for the lower arm into the frame and do away with the cradle since it has nothing to do with the differential mounting. This would amount to no further weight savings but would be a lot more simple than trying to narrow the cradle and keep it square, level, and solid.

samckitt

iTrader: (5)

That is sweet, another option is from the Roadster Shop. All new designed parts for cruising & hard track time. A little more pricy though too.

lees02WS6

iTrader: (5)

There's a guy over on lateral-g that's using that set up. I like it better than Heidt's because it uses conventional outboard brakes.


As for the street shop, I alluded to that on page 1 of this thread. They make kits for early corvettes to retrofit c4/c5/c6 stuff on to them.

LS1MonteSS

iTrader: (1)

RS wants a lot of $$$ the for the rear end system.
99_Orange_SS,
I was thinking the same things you were. But then I relooked things from a maintenance point-of-view and came to a couple conclusions. The cradle has location pins built into it so removing it and reinstalling it is a simple task. The ability to remove the cradle will give you full access to the diff for swaps or what-not.
Weight savings going with a the cradle or fabing in another mounting system would be realy close once you take into account the weight of the seamless tubing and bracing to hold it in place. Add to that the weight for fasteners and plates to make some of the tubing removeable for diff access. I think this just boils down to personal preference as the other factors are so marginal or actually unknown at this point.

I did get a reply back from the shop that makes those frames..
I originally just wanted a rear clip to get the planning started. But it doesn't sound like they like that idea.

LS1MonteSS

iTrader: (1)

Lees02WS6,
I must have missed you mentioning that on page 1. Sorry about that.. Wasn't trying to steal your thunder or anything!
If I remember correctly the RS system was like 5K or 8K. That putsthe it too far outside my wallet right now. But it looks like an awesome set up for sure. Maybe I can use that in my 70 MC!

99_orange_SS

iTrader: (20)

Exactly what I was inferring but never directly stated. The design of cradle or no cradle is preference and what may be easier/more efficient for that particular install. Maintenance wise no cradle would be just as simple because you could design it where the diff just falls out when your ready with the braces being around it. Either way no benefit from one to the other, just preference.

LS1MonteSS

iTrader: (1)

Lees02WS6,

Need some assistance.. Got my 06 Viper Diff in and I can't find any replacement bushing for the front two mounting locations at the pinion. I shot Tray from Street Shop a message to see if he can help me. His shop uses them in their IRS builds.

lees02WS6

iTrader: (5)

This is the later model Gen III/IV diff? Looks like this:




Try mopar online parts, or check on viper alley.

LS1MonteSS

iTrader: (1)

Yes that is the one I have. Did you find that on Mopar One?
I actually happened across the Mopar One site this morning and I'll most likely get the things I need from them. Unless anyone knows a better priced site.

lees02WS6

iTrader: (5)

No I got it from a different site. I know a company that will make rubber bushings, but they'll be more expensive for sure. A Dodge dealer will also be just as expensive.

LS1MonteSS

iTrader: (1)

I'll stick with Mopar One. The prices seem reasonable enough!

6. Bushing Differential = $28.69 (I have to check to see if this is a full set of the four needed)
7. Hardware kit, Nut Hex Flange Locking = $2.50 (need two)
8. Insulator, Bushing Axle Mount = $21.60 (need two)
9. Lower bolt, Insulator = $4.13 (need two)

So I'm looking to put out between $86 to $114. I don't think that is too bad at all.

LS1MonteSS

iTrader: (1)

So a quick question.... I'm sure the answer isn't so simple..

What are the major differences between the C5 and C6 suspension?