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-   -   Rear subframe bushings dimensions? (http://www.camaro5.com/forums/showthread.php?t=222023)

camaro0220 05-07-2012 01:46 PM

Rear subframe bushings dimensions?
 
Has anyone "miked" the rear subframe bushings and gotton all the dimensions from them? I havent crawled under mine or the wifes camaro and dropped the subframe yet to do it myself. I was thinking if someone had all the dimensions on a set of these bushings, since I have some t-6 aluminum stock and a lathe.......I could turn some down myself and try them out. Any ideas??

JusticePete 05-09-2012 07:20 PM

Quote:

Originally Posted by camaro0220 (Post 4924052)
Has anyone "miked" the rear subframe bushings and gotton all the dimensions from them? I havent crawled under mine or the wifes camaro and dropped the subframe yet to do it myself. I was thinking if someone had all the dimensions on a set of these bushings, since I have some t-6 aluminum stock and a lathe.......I could turn some down myself and try them out. Any ideas??

Yes, don't do it unless you are planning on this being a full time race car. The welds in the sub-frame are not designed to take the loads of solid sub-frame mounts. The sub-frame frame welds are prone to crack. We have seen this with the Grand Am Challenge cars. If you were able to speak with an engineer from the Camaro TEAM they would tell you the same thing.

What were you expecting in terms of a performance gain from your solid sub-frame mounts?

camaro0220 05-14-2012 08:42 PM

Quote:

Originally Posted by JusticePete (Post 4937499)
Yes, don't do it unless you are planning on this being a full time race car. The welds in the sub-frame are not designed to take the loads of solid sub-frame mounts. The sub-frame frame welds are prone to crack. We have seen this with the Grand Am Challenge cars. If you were able to speak with an engineer from the Camaro TEAM they would tell you the same thing.

What were you expecting in terms of a performance gain from your solid sub-frame mounts?


Well Im superchared and chiped with a few other bolt on's. Im having horrible wheel hop issues. I havent been able to see what the car can do because I dont want to frag the rear end or grenade my driveshafts.

JusticePete 05-14-2012 08:47 PM

Quote:

Originally Posted by camaro0220 (Post 4962305)
Well Im superchared and chiped with a few other bolt on's. Im having horrible wheel hop issues. I havent been able to see what the car can do because I dont want to frag the rear end or grenade my driveshafts.

Where in Texas are you?

Synner 05-14-2012 08:47 PM

Cradle bushes cured mine. Did outer trailing arm bushings and an alignment later as well to be on the safe side and get the most out of my other parts.

camaro0220 05-16-2012 07:59 AM

Quote:

Originally Posted by JusticePete (Post 4962331)
Where in Texas are you?


Im in the Mount Pleasant area about an hour north of Tyler

camaro0220 05-16-2012 08:00 AM

I may try that Synner Thanks guys Im looking for anything that may work.

blazzin1 05-16-2012 01:06 PM

Quote:

Originally Posted by JusticePete (Post 4937499)
Yes, don't do it unless you are planning on this being a full time race car. The welds in the sub-frame are not designed to take the loads of solid sub-frame mounts. The sub-frame frame welds are prone to crack. We have seen this with the Grand Am Challenge cars. If you were able to speak with an engineer from the Camaro TEAM they would tell you the same thing.

What were you expecting in terms of a performance gain from your solid sub-frame mounts?

Pete, can you explain why then it seems like the Pfadt solid mounts are the most desired of ANY brand??? Aside from the astronomical price, the Pfadt units seem to be the "holy grail" of all the sub-frame bushings!!! And why is it that the Pfadt solid mounts are a "GM Officially Licensed Product"??? Surely if the Camaro Team didn't like them as you hinted above, they would not have GM officially endorse them, don't ya think??? There are a lot of members here on Camaro5 running the Pfadt solid mounts, and I have not heard of one single incident of sub-frame cracks because of them. I'm not doubting your expertise here at all, just trying to educate myself before making a purchase!!! Thanks.

PfadtRacing 05-16-2012 01:16 PM

There are some major benefits to running a solid subframe mount on these cars. We have been manufacturing them since almost the introduction of the 5th gen Camaro and they've been a great upgrade for many street cars. Mounting a subframe solidly to the chassis of a car isn't something new, the Corvette has been running a solidly mounted rear subframe for years now. We've just taken the same idea and applied it to the Camaro chassis.

What you will immediately notice is the car feels much more connected to the rear end than it did before. The factory rubber bushings are a major hindrance to performance and the car will definitely feel more confident while launching hard, or powering out of low speed corners. Here is a video we took before and after our subframe mount install. Notice how much deflection there really is at the rear subframe, that movement isn't great for overall performance.

Given that there is minimal impact to ride quality, and a major increase in performance we strongly suggest moving to Solid Subframe Mounts if you're going to be tracking, drag racing, or aggressively driving your high powered Camaro on the street.



Quote:

Originally Posted by JusticePete (Post 4937499)
Yes, don't do it unless you are planning on this being a full time race car. The welds in the sub-frame are not designed to take the loads of solid sub-frame mounts. The sub-frame frame welds are prone to crack. We have seen this with the Grand Am Challenge cars. If you were able to speak with an engineer from the Camaro TEAM they would tell you the same thing.

Seeing that we actually ARE the suspension engineering expertise behind some of the "GrandAM Challenge" teams we can say that this has absolutely NOT been our experience. The stresses that a legitimate race car sees during a 3 hour race are significantly higher than what are seen on street cars, but even still we haven't yet seen an instance of a damaged subframe due to Solid Mounts being installed. We certainly haven't seen it on any of our street cars equipped with solid subframe mounts. GM found them suitable for use on the Chevy SSX Camaro, and we would absolutely recommend using them for any street or race car application where best performance is needed.

Here is Andy Lee and his Bondurant sponsored Camaro after winning the World Challenge GTS Class at Miller Motorsports Park 2012 in a fully Pfadted chassis. No signs of cracking at the subframe, and we don't ever expect him too.

http://www.pfadtracing.com/photos/da...20_800x600.jpg

http://www.pfadtracing.com/photos/da..._1632x1224.jpg

Apex Motorsports 06-05-2012 06:08 PM

We have set up literally hundreds of 5th gen Camaro owners with both solid and urethane rear sub frame bushings for street and track use over the last few years and I have never seen or heard of these welds cracking before I read this thread. If this has ever occurred I would be very interested in seeing some documentation. Until then solid has proven to be optimum.

Camaro0220, if you end up making your own be sure to post pictures. That would be cool to see what you come up with.

ITGuy11 06-05-2012 09:24 PM

Working for a weld engineering company, I can tell you that if welds are cracking then they were defective welds plain and simple.

A proper weld is as strong, if not stronger than the base material.

z28racer 06-05-2012 10:03 PM

Hotchkis subframe connectors work realy well. They take about a half hour to mount and make a night and day difference. Only way 19lbs made out of aluminium and tie the body together real nice!!!

JusticePete 06-05-2012 11:25 PM

Welding creates HAZ (heat affected zone). The metal changes and becomes more brittl and brittle leads to cracking when exposed to vibration. Add increased load to the increase in vibration and the probability of cracking is increased.

"The rear housing is chrome moly fabricated steel. I split a weld seam, from tire shake, at the bottom of the 3rd member mount."

http://www.ss3raceteam.com/rear_end.jpg

Most production monocoque race cars are seam welded to increase stiffness. The benefit of the increase in stiffness is improvement in handling at the direct expense of durability. A direct result of the increase in stiffness is the assembly becomes brittle. If it can't flex it breaks. Next time you are in commercial airplane watch the wings. They have a tremendous amount of flex designed in to keep them from from being breaking off.



Stock Car Stress - All Stressed Out
Develop A Checklist To Make Sure The Parts And Pieces On Your Car Aren't Under Too Much Stress
From the February, 2009 issue of Stock Car Racing
By John Gibson
Photography by John Gibson

Off-Season Stock Car Maintenance

Maintenance Tips For Between Seasons To Keep You On Track
From the February, 2009 issue of Circle Track
By Bob Bolles
Photography by Bob Bolles

http://image.circletrack.com/f/ultim...ance+guide.jpg

http://image.stockcarracing.com/f/te...acked_weld.jpg

The stiffer you make it, the more cracks you will see. Street cars take the opposite approach. The OEM engineers are expected to deliver a chassis that will last hundreds of thousands of miles at the lowest possible production cost. That is a brutal engineering assignment. The life of a weld, the life of a component is validated with OEM wheels and tires, OEM bushes, OEM shocks, OEM sway bars, etc. The ZL1 under went a grueling battery of hard launch test. We all expect the ZL1 rear to be exceptionally durable, until we start modding. There is a point where increased RWHP and increased traction will create a load so high something will break. We all understand this or we should. So why would we assume that we can replace a compliant set of four rubber bushes with solid aluminum and expect the sub-frame to live to an OEM standard?

I only control the products that Pedders puts into the market place. I know we lose sales when we say that solid high durometer differential bushes transit more gear noise into the cabin. We could omit that information, but why would we when we know it is accurate? We know that at some point in time the steering rack or pump will fail under the increased loads generated by suspension upgrades. Increased loads equate to increased heat. Heat kills. Our radius bush snubber (EP6578) request came from a GM engineer and I took it to the next level with the EP6579. We know it won't be in 50k, we doubt it will be at 100K, but we also know there will be a price to pay and we have a cautionary note on the product (EP6579).

Every time this comes up we do the same dance that equates to mine is better than yours. People will believe what they want to believe. Believe this. There is no such thing as a free lunch.

PfadtRacing 06-06-2012 10:43 AM

Well unrelated info aside, GM mounts subframes solid to many cars. Including the FRONT Camaro Subframe. You won't find any instances of either the front or rear subframes cracking because of the installation of our products. Period. Spreading rumors about products effectiveness with no actual evidence is something I hope the Camaro5 forum members can see right through.


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