Tubular K-Member With Stock K-Member Style Mounts?

[revan]

Not sure how well it would sell, but I for one would LOVE a tubular k-member that has the same style motor mounts as the stock k-member rather than the usual poly mounts. I did the tubular k-member from BMR back in 2011 on my 08 GT500 to get weight off the front. I LOVED the better handling that came from pulling all that weight off the front, but the NVH increase was an annoyance. When I later pullied the stock blower, the extra whine (which I loved by itself) combined with the extra NVH from the solid bushings was just way too much. I was going to put the stock k-member back in, but I ended up doing a TVS blower on the car and with the lower boost level (2.8" pulley) there's no whine from the TVS so the overall noise isn't as bad anymore.

 

I know these tubular k-members are really meant for track application for those who don't care as much about NVH but I know if such a k-member came out tomorrow I'd buy two of them - one for the 500 and one for the shelby GT I know the solid mounts keep the motor from moving around which helps handling, but I'm thinking some like myself might be ok with the tradeoff for a more streetable experience.

[Jer]

Not sure how well it would sell, but I for one would LOVE a tubular k-member that has the same style motor mounts as the stock k-member rather than the usual poly mounts. I did the tubular k-member from BMR back in 2011 on my 08 GT500 to get weight off the front. I LOVED the better handling that came from pulling all that weight off the front, but the NVH increase was an annoyance. When I later pullied the stock blower, the extra whine (which I loved by itself) combined with the extra NVH from the solid bushings was just way too much. I was going to put the stock k-member back in, but I ended up doing a TVS blower on the car and with the lower boost level (2.8" pulley) there's no whine from the TVS so the overall noise isn't as bad anymore.

 

I know these tubular k-members are really meant for track application for those who don't care as much about NVH but I know if such a k-member came out tomorrow I'd buy two of them - one for the 500 and one for the shelby GT I know the solid mounts keep the motor from moving around which helps handling, but I'm thinking some like myself might be ok with the tradeoff for a more streetable experience.

 

Good input. Thanks, I'll look into it!

 

 

Jer

[revan]

Thanks Jer. If you need a test mule, I'm a willing volunteer

[Jer]

Thanks Jer. If you need a test mule, I'm a willing volunteer

 

I'll keep that in mind!

 

Jer

[ViperNC]

I just got my k member on and don't mind the vibration, but the increase in noise (and not a good sounding noise) has me wondering if I got too aggressive with the upgrade. Kelly at BMR suggested we loosen the motor mounts and rotate the poly bushing 90 degrees and this should help eliminate the excess engine noise. We did that late yesterday and I'm taking the car out this AM for a drive to learn if it worked. I certainly hope so....... wonder if a larger poly bushing would solve the issue?

 

Edit:

 

Update - Just got back from a 2 hour drive. The more I drive the car, the quieter the interior engine noise becomes. I guess turning the poly bushings helped and maybe they just needed to seat in.... or something. Either way, it is better than it was the other day... a lot better. Sounded like a diesel truck in the cockpit!

Edited April 3, 2014 by ViperNC

[SSGT500]

I've been considering buying one of these K members. I think I'll wait and see if BMR improves the mounts first. I'm disappointed that BMR has not successfully addressed this issue. I can't see rotating the poly inserts as making any difference. Perhaps they could add some poly washers under the flat washers? A better design would be to incorporate a motor mount similar to the Prothane one. That would retain the stock three bolt mounts. The problem as I see it with the current BMR design is it's use of a single bolt thru the center of the engine bracket to the K member.

[msb64]

More of a motor mount issue than a k-member one.

 

How about something like a hybrid version of the old school lockup motor mounts, retain rubber for isolation, but instead have it lockup against poly instead of steel.

That way the increased noise and vibration would only occur under heavy load.

 

Another option might be to use a conventional rubber mount combined with high tech torque strap(s).

Design the straps so that they have a bit of give to them, but after a limited range of motion also bottom out on poly instead of steel.

[revan]

msb64 is right - it's not the k-member that's the problem, it's the mounts. The k-member itself is actually very well done and solid. There's no way you'll get the same low level of noise going from the much larger prothane bushings to smaller fixed poly bushings. But you also have to keep in mind the design goals that the k-member was designed for in the first place - road racing. Having solid poly bushings keeps the motor from moving and twisting as much as the stock ones do, and that translates to a better handling car on the track. Their original target audience was people that build up their cars for track use and don't care about the extra NVH, but now that so many have discovered the benefit of the weight drop on a street car, we've found a whole new purpose.

 

Personally, I think a relatively simple way to go about this would be to design a new tubular k-member that reuses the stock mounts off the original k-member. I would think that would give us a good weight drop while maintaining the same noise levels; might not handle QUITE as well as the current design but the tradeoff for a mostly street car would be worth it. And design it to still position the engine 1/2" lower would further improve handling as it does with the current design.

 

But I don't know anything about designing these parts so there may be reasons it's not feasible.

Also, not sure on others experiences, but I only notice any increase in NVH on my GT500 when going at full throttle. Idle cruising there is no difference, though the early model GT500's have a lot of vibration and noise already so maybe it would be more noticeable in a v6 or GT.

[ViperNC]

My increase in NVH is more at idle and RPMs below 1500... Above that there was little difference.

[03 DSG Snake]

Maximum Motorsports has a new KMember in the works. I'd be curious to see what their solution is.