Coil Overs and Frame Notchers With Big Tires, Jump In, Looks Like We'll Need A Custom Bracket

[GNVYUS 1]

Picture is of Ridetech coilovers with their mounting bracket off the rear end. The Viking and UMI bracket looks like it would have the same interference.

There's no room for a 325/50r15 here with coil overs, even if you had a BS of 5.5" let alone greater than 5.5". The bracket is designed with the full rear frame in place, understandable.

Frame notchers, big wide tires, coilovers, what did you do to stuff them in? Anyone do this?

I'm gonna have the local, high end fabricator, design, weld, install, scan and sell this bracket for us. Then my other buds with sell a Viking CO Frame Notch package for us with these new brackets.

Brackets getting made hopefully soon so I can send the wheels out for widening.

Starting this thread for start to finish progress on this and to have a solution for us current and future frame notchers. This isn't going to be cheap either, Jesus it never stops. LOL

 

[3.8 LA LEY]

subscribed.. wanted todo 17x11 s71 weld rts with 5.8 BS as well as run some ridetech's and a notched frame out back

 

[TType85]

move the shock mount further inboard? Be interested in what the solution is as I have the same coil overs and was thinking of doing a frame notch.

 

[Chuck Leeper]

move the shock mount further inboard? Be interested in what the solution is as I have the same coil overs and was thinking of doing a frame notch.

This.
Stand the shocks up. Makes the adjustments more effective.
Turn the mounts from sideways to ft/back. When the car launches, and the axle attempts to rotate, the shock base is put in a bind.
If those shocks are adjusted to ride hgt, the springs are too short.
Just sayin...........
Merry Christmas all!

 

[GNVYUS 1]

Thanks, I planned on doing just this initially, move them in 1-2" and get clearance and a move to a straight up and down shock travel. I assume this has benefits just in itself, straight compression vs slight angled.
I'd also assume the shock length will be used better for going up or down aside from the adjustment holes.

What I'm curious about in these deals is, why did they do it the current way, ease, better geometry IL I'm unaware of etc?

Luckily a guy with a 7.7 ET 4 cylinder race car is the fabricator and eyes on the prize, he'll get it right and store the design in his plasma pen machine tracing and cutting out the panels.

 

[ravege]

The DSE solution appear to be a little shorter and doesn’t protrude beyond the wheel rim.
I’d also add, though the original OP is probably aware, those ears weren’t meant to take that load and will flex. I installed the upper plate per DSE’s photos, which is to say, pointing up. There was a good amount of clearance and yet they left good impressions on the underside of the trunk - that’s how much flex you can expect. Turning the bolts over might resolve the trunk contact, but the flex is still there. Bracing the ears could be worthwhile, I’ve used the UMI brace.

 

[GNVYUS 1]

Thanks for the reply, that is exactly part of the solution.

DSE = Detroit Speed & Engineering?

Detroit Speed 042420DS Detroit Speed Rear Coilover Conversion Kit - Factory - 2-3/4 in. Axle Tubes

The Detroit Speed G-Body Coilover Conversion Kit allows the latest in coilover spring/shock technology to be bolted on to any G-Body, bringing your classic's handling and ride into the 21st century with our 'Detroit Tuned' valving. The base coilover package offers extensive ride height...

www.detroitspeed.com

Upper plate goes where, at the top mount of the shock?

I'll contact them but I have a feeling they're not selling this bracket kit separately.

 

[ravege]

The plate is on the underside of the shock ear, the coil over does not use the stock shock mount. Here is a link to the instructions, you can see the installed plate on page 3. I’d also add the lower bracket is a bit wider than the factory shock mount, one needs a spacer turned or several washers to keep it from flexing when the cross bolt is tightened. Can’t hurt to ask if they could part out the kit, but I suspect like you the answer would be no.

https://documents.detroitspeed.com/dse-f501-154.pdf

 

[GNVYUS 1]

Thanks for that pdf.

I thought the plate you were talking about was an extra support brace up top etc, got it now.

I called DSE = nope the lower bracket isn't for sale.

Time for the bag of Franklin's to come out.
I'll have my guy make something similar and we'll offer it separately or with Vikings through my other buddy's suspension shop.

 

[ravege]

I misunderstood about the upper plate, the shock brace is this:

1978-1988 GM G-Body Rear Shock Tower Brace, Bolt In | UMI Performance

This 100% jig built, bolt-in brace ties the rear upper shock mounts together to share the load and stiffen the chassis. Strong 1-1/4” tubing is MIG welded to 3/16” thick laser cut brackets for a per

www.umiperformance.com

 

[GNVYUS 1]

That has popped up a few times, might be a good investment if things start moving some too much.

 

[ttypewhite]

TRZ Motorsports has mounts that fit in the stock location. This is what I have on my Acfo double adjustables. I run a 325/40/18 M&H drag radial. Frame is also notched.

 

[GNVYUS 1]

Well SOB, they sell those little brackets for $35 and I literally just dropped the car off today at the shop, this is like 12 hours late, damn.

It looks like the coilover is installed upside down, so what does the top look like?
On my current setup the big end with the threaded height adjustment is the bottom but it looks like that bolt would still go through it.

Do you think that will work with other coil overs, appears it could?

I'm looking at at probably huge $$ here in a custom bracket like the UMI and you drop a link to a part that's $35, unreal. LOL

 

[GNVYUS 1]

I got that TMZ bracket coming but I have a feeling because it flips the shock upside down it might not have clearance for the big shock bottom. I'll report back end of week.

There are other brackets out there that might work but there's not many good install pics of them concerning wheel backspace.

I have Ridetech coilovers, I just talked to them, their bracket is NOT a UMI like I have from GNS. For some reason I have this giant UMI bracket vs the skinny Ridetech, not sure why GNS did this, costing me time and money here for no reason.

1978-1988 GM G-Body - CoilOver Rear System - HQ Series

RideTech continues to offer today’s hot rodders the ultimate inride quality, handling performance, support, and now,SIMPLICITY, with the new RideTech CoilOvers.

ridetech.com

The BMR bracket appears it can also work and do lower control arm relocation.

Free Shipping on all BMR Suspension packages!

Leader in High Performance Suspension and Chassis Products For American Muscle Vehicles.

www.bmrsuspension.com

 

[ttypewhite]

My strut is not upside down. The sticker on the strut is. Only mounts one way. 2 bolts up top in the factory location. and one bolt at the bottom like the factory. These are factory replacement Afco double adjustable struts.

 

[GNVYUS 1]

After talking with Afco, they created the bracket to have the shock go that way, eye lid of shaft as the lower mount. Most other coil overs are base with adjustment knobs as the bottom, its thicker. Afco tech didn't think the thicker base would mount in their bracket.

I got both brackets, I prefer the BMR after thinking about it since I can relocate the lower control arm for more accurate instant center during the launch.

I'll report back next week, I'm also probably going to Viking double adjustable rear shocks to take advantage of compression and rebound. I'll sell the whole Ridetech/GNS setup later.

 

[GNVYUS 1]

Great news so far...
BMR bracket CCK007

This bracket will work for us G body frame notches and has 3 LCA options.
This fits the Coil Overs where the fat base mounts at the lowest point where the threads usually are.
This bracket gives plenty of wheel and tire clearance, it angles the coil over inward and they even angled that bracing to stay away from fat tire buldge.
This bracket also offers 3 lower hole locations for LCA relocations. I started mine in hole 1 which is a good 1.5" lower than normal mounting.

Wheels at 15x10 with a 5.5bs, you're good with all LCA 3 holes.

For the few of us who like our wheels and are having them widened, 15x12 and 6.5bs, you need to chop off the lowest LCA hole, hole 3. This hole could interfere with a wider wheel that's 6.5"bs or deeper. The wheel lip coming in 2" looks like it might be an issue because the bracket will clear the tire but maybe not the actual wheel that's 2" higher up than the middle of the tire buldge. You'll have to see on your car.

I'll have pictures and more details soon.

I ordered Viking C211-T/14DP150 C w Thrust bearing, Double adjustable, 2" lowering possible.
$650 through my contact I'll pass on later.
BMR CCK007 $190
Cheaper, LCA options and frame notch practical for all us G Body's.

 

[TurboWh1]

Here are a couple of shots of the lower rear shock bracket I came up with. It's on a 9" though but food for thought.

 

[GNVYUS 1]

Nice, even gets the shock more straight up and down too with its even further back location. Looks like you have a better mounting ear on the 9" vs factory and that has extra LCA location holes. For us stock 8.5" rears the BMR does all that luckily.

Though that doesn't have a plated bottom for bracket rigidity, not sure it's a big deal on the shock. Thanks for posting

 

[ttypewhite]

Here are a couple of shots of the lower rear shock bracket I came up with. It's on a 9" though but food for thought.

Beautiful setup, looks amazing. Just food for thought. When I was doing the coilover setup in my car I reached out to TRZ Motorsports. In my opinion they are the Gbody kings for suspension upgrade because they are out testing at the track all the time. Mike at TRZ said that you "HAVE TO" strengthen your upper factory perch that your strut is bolted to. Weld gussets to it, or tie it in with a cage, or run a bar from one side of the frame to the other side of the frame, and weld brackets to that for the strut to bolt to. Reason being is that in the factory configuration, the strut and the shocks are in different locations from one another creating no stress in that spot. Once the strut and the spring are together, that upper perch is the weak point. It's thin gauged metal. He said it's not "IF" but "WHEN" that area becomes compromised on a launch, it is going to rip the strut clear out from that location and cause one hell of a mess to the rear end of the car. If it's just a street car you probably won't ever have a issue, but if you do track it from time to time then it is something that has to be addressed so your launches don't end up catastrophic.