Solid body mounts and subframe connectors

[aray327]

The subframe is about to come off my 69 camaro for body/paint. I am going to add connectors (once back together under full weight) and will be replacing the body mounts. I have been reading posts including the sticky and see several suggestions for solid body mounts when using connectors.

I think im going to use DSE because of the reputation for low viability and high structural addition. I have seen BMR connectors that also look pretty good and surprisingly similar to DSE. I have three questions.

Are solid mounts a must?
What is the difference is ride quality with solid mounts?
Does anyone have any comments on BMR connectors compared to DSE?

[Gitter Dun]

Hey Aaron, You definitely cant go wrong with the DSE connectors. I have no experience with the BMR's but if they are similar I would imagine it would boil down to cost. As far as body mounts go, IMO, we aren't driving Cadillacs in the first place and I dont think you will notice much a difference with the solid. Dont forget, you also have the option of body mounts with 1/2" drop.

[aray327]

I was thinking about the 1/2 drop. My car sits nice in the front already, i actually want to bring the back down a touch more. How does the 1/2 drop impact my trans tunnel clearance? I know a 1/2" doesn't sound like much but...

also what about aluminum vs Delrin bushings? Check out these from Competition Engineering they are 1/4 the price of BMR and DSE.
http://www.summitracing.com/parts/CEE-3027/?rtype=1

Gaetano I'm gunning for your time at Buttonwillow? I gotta have a target to shot for. Maybe next time I can get in the right run group and try to keep up. Maybe this summer if im lucky.

[johnny68]

ive got dse connectors with have height mounts i would say yes solid bushings are a must but havent got the car back togeather yet
john

[67 455 Bird ragtop]

While solid body mounts are not too bad rememebr to keep your radiator support busshings rubber to absorb any shock. I've seen some radiators vibrated to pieces, over time, when solid bushings were used on the radiator support.

Just my .02 on the topic.

[68Formula]

No ride degradation. Haven't had any problems in the last several years with vibration either and with my setup I get a lot of it just at idle.

[Gitter Dun]

Trans tunnel clearance isn't an issue and I wouldn't worry about the front stance for just a 1/2". What you need to ask yourself is where you want to go with the car. If you choose to set up for more of a track car you have to go a minimum 650 lb spring up front especially with a stock sub frame. Stock subframes have more than desirable flex to them and act as part of the suspension when driven hard in the corners. I personally like a 700 lb spring but everybody has their own opinions. As far as dropping the rear, I have 3" drop rear leafs and that still wasn't enough. The guys at DreamSpeedMotors raised my front leaf spring perches another 1 1/2". Not only does this lower the roll center in the rear but also gives you more bite coming out of the corner. Unfortunately, one speed fix leads to another. Once we lowered the rear of the car over the rear of the tires that created the need for a watts link due to the lateral movement of the axle. We came to find out that the rear axle was shifting close to 1" from side to side hitting the inside of the quarter panels and even hitting my exhaust. If you choose to stay with leaf springs look into the Fays 2 bolt on watts link set up. As far as solid leaf spring bushings go, I haven't tested that far yet but I'm thinking it's the way to go for road course set up. If you plan on alot of autocross I would go with polyurethane because the extra roll in the body will help you roll through the slower speed turns. I'll PM you next time I go to Buttonwillow(I think its April) and take you for a ride. This will give you an idea of how stiff the car rides and maybe help you decide what direction you want to go.

[Rod]

my car was built as a project test car for a shop that I was working at, so I had a chance to run many different configurations. First the car ran with rubber bushings and no subframe connectors for about 2 weeks and the ride was comfortable but spongy(all tested at a SCCA races), then I added Hotchkis subframe connectors and the ride stiffened up, and handled better, and after that I switched to the polyurethane bushings (from Prothane) and I didn't notice any difference in ride or handling, next I ran the Global West aluminum bushings(standard height) the car seemed to have a little more Idle vibration and the ride felt the same but the turn in on corners was a little more aggressive, I know that's all seat of the pants testing, but I hope that helps

and I agree with the watts link suggestion above

[aray327]

Thanks for the info. Rod seat of the pants testing is exactly the info i was looking for. I don't think anyone would argue the benefits, but i was definitely looking for info on the change in ride.

Does anyone have an opinion on the lesser expensive competition engineering aluminum bushings or should i just spend the extra cash for DSE at twice the price?

[77thor]

IMO, go with the solid mounts... you won't regret it.

As far as lowered mounts... I've heard of people having issues with the stock fan hitting the fan shroud after installation.

BTW, I bought the Hotchkis SFC's... they are supposed to be the tightest fitting to the floor...

[LeighP]

Pro-touring F-Body's subframe connectors also sit right up tight to the floor pan and require no body mods...can be welded or bolted in. They recommend solid body mounts.

[MrQuick]

The reason for solid bushings is to avoid cracking at the body where the sub bolts to.

The connectors are solidy mounted to the rear body then welded solid to the subframe. If the subframe where allowed to move and flex as it would with pliable bushings it would cause the body to crack at the floor around the nut cage. Bad news.

[BMR Tech]

Most people don't realize it but the Competition Engineering solid body mounts are only "one-sided". rather than have two "halves" to each bushing that capture the frame between them, the Comp bushings only go between the frame and the body and use a large washer on the bottom side to hold it all together. This is basically why they cost half the price, there is literally only half the materials (6 pieces vs. 12).

[aray327]

Thanks BMR. I've ruled out the Competition Engineering solid body mounts. But i am completely surprised you didn't take the opportunity to talk about your products. I was considering your frame connectors. Any comments?

Also you offer Delrin bushings. Do you consider them solid? They aren't metal but i know Delrin is pretty hard material. Is there any benefit one over the other?

[BMR Tech]

Thanks BMR. I've ruled out the Competition Engineering solid body mounts. But i am completely surprised you didn't take the opportunity to talk about your products. I was considering your frame connectors. Any comments?

Also you offer Delrin bushings. Do you consider them solid? They aren't metal but i know Delrin is pretty hard material. Is there any benefit one over the other?

Sorry for the late reply, I am not sure how this thread got past me! We do consider the Delrin to be a solid bushing. We have had very good results with the Delrin body mounts. They do everything an aluminum mount does and you never have to worry about corrosion. You can torque them to spec just like a solid bushing or a sleeved rubber bushing. Delrin is practically as hard as aluminum but self lubricating so they never creak like some solid bushings tend to do over time if you don't re-tighten them. I don't mean to sound like I am bashing aluminum bushings (I ran them for years in my 69 and 70 Camaros), it's just that the delrin bushings work so well I can't believe we were the first to think about building them!

Our through-the-floor subframe connectors are profiled very similar to the DSE connectors with the main difference being the front subframe mount. The DSE design has two "ears" that weld to two sides of the front subframe. These permit you to bolt the subframe to the subframe connector. We thought it would be preferable to provide a fully welded box that encloses 3 sides of the subframe on each side. The top is slotted and "sandwiches" between the body mount making 3 connection points on each leg of the subframe, (2) 1/2" bolts and the main body mount bolt. This design still permits removal of the front subframe after the connectors have been welded in.