Can't afford the splitter but you can get this huh? HUH! hahaha jk, but really:bored:
Blowfish shifter bracket
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Can't afford the splitter but you can get this huh? HUH! hahaha jk, but really:bored:
lol...working a shit ton of hours right now...and that splitter was expensive
oke: Nice though lol
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Has there been any FEA done where your bracket meets the existing transmission mount face? The horizontal bolt centerlines there are pretty close and your 7lb bracket cantilevers quite a bit beyond the mounting point. Just curious, as it looks like there will be one bolt in compression (the center bolt) and two in compression and you are now adding a bending moment that will vary with the vertical movement of the car under normal driving conditions as well as when a fore/aft force is exerted on the shifter which will be transmitted down through your bracket and dispersed by that narrow bolt centerline.
Tob, i see where you're going with this, but keep in mind the friction between the bracket and the transmission caused by the torqued bolts, along with the stock linkages still being used to resist the moment caused by this thing being a 7lb cantilever beam
I wouldn't mind seeing/hearing about FEA work done as well - just making sure your FBD is accounting for everything
essentially, its triangulated with the factory upper shifter box arm. no fea, as there is no way to identify the dynamic loads, but in laymens terms, the ****er is rock solid! you could use it as a diving board and it won't budge. it takes 50kN to shear a single M12 10.9 bolt. thats over ELEVEN THOUSAND POUNDS of force PER BOLT! good luck breaking it!
:rockon: can't wait to get this bad boy installed! Oh I now have a barton 2 post for sale...lol
I'm aware of the friction consideration but you're right, I was disregarding the linkage arm at the top of the shifter.
pufferfish said:
I'm not arguing the shear strength of the bolts. Aren't the bolts used on the MT82 at this location 8.8 and not 10.9? Are you offering new bolts with your kit?
Looking at this a little closer, you haven't "fixed" or truly triangulated it if you are using a non-solid bushing where the shifter arm attaches to the transmission body at the upper case.
From an engineered perspective, I'd think that flexible bushing up top should be replaced with a solid. There is movement there but yet the bracket, or last leg of the triangle, is fixed. I wouldn't expect an NVH change but would indeed expect an overall increase in strength.
Just to think out loud here - That linkage arm is obviously going to restrict motion front/back and allow motion up/down (or in an arc around the mounting location - but for this purpose we'll say up/down since the displacement is hopefully minimal). There isn't much support side/side, hence the benefits of a two post shifter bracket, which any of us with MGW's will still use (i don't think there will be enough side/side to worry about bracket failure). So most of the forces/moments will cancel each other out. The only one really left to worry about would be up/down which i imagine is more than handled with the friction of the bracket against the trans mount. This is how i'm picturing it in my mind - i may be missing something though . Vibration is the next thing to worry about causing failure, but I've done enough thinking for one day.
. Vibration is the next thing to worry about causing failure, but I've done enough thinking for one day.I agree with much of what you said. I wouldn't have raised an eye with respect to this except for the fact that mount for the bracket attachment point, while not only supporting a portion of the weight of the entire driveline via a flexible, rubber voided mount, now has a cantilevered beam attached to it that isn't truly restricted with respect to movement due to the flexible mount atop the transmission. The bushing atop the transmission served well when it was being asked to partially isolate the shifter body from the transmission itself as in the original configuration (when it also tied into the floorpan or transmission tunnel through the rear mount) but not anymore.
I don't know what the durometer is of the factory yellow bushing but had I an MT82 and were considering this modification, I'd be replacing it with a solid.
Puffer, don't get me wrong, your thinking outside the box with respect to MT82 troubles deserves a round of applause. Very creative solution.
I don't know what the durometer is of the factory yellow bushing but had I an MT82 and were considering this modification, I'd be replacing it with a solid.
Puffer, don't get me wrong, your thinking outside the box with respect to MT82 troubles deserves a round of applause. Very creative solution.
Just to think out loud here - That linkage arm is obviously going to restrict motion front/back and allow motion up/down (or in an arc around the mounting location - but for this purpose we'll say up/down since the displacement is hopefully minimal). There isn't much support side/side, hence the benefits of a two post shifter bracket, which any of us with MGW's will still use (i don't think there will be enough side/side to worry about bracket failure). So most of the forces/moments will cancel each other out. The only one really left to worry about would be up/down which i imagine is more than handled with the friction of the bracket against the trans mount. This is how i'm picturing it in my mind - i may be missing something though
I think you are right about the side to side and the bracket doesn't really matter since either the stock or MGW works with it, one is a two post and the other stock, don't see a real difference with this piece. Also on the vibration I can see what you're saying but I don't think you are introducing much more vibration with the bracket and if so all the more reason to use Loctite.
Ah, I see now. If i thought that bushing was at-all accessible without dropping the trans, I would probably do the same. I'm thinking it would be near impossible to swap while in the car...
I think the main idea is to keep the transmission and shifter moving in the same direction at all times thus improving your shifting confidence. To "fix" the transmission and shifter wouldn't make any sense. It'd be too rigid and you could count on failures. The whole reason our shifters are crap is because they float about and at certain points they can cause the shifting pattern to be imperfect enough to cause missed shifts.
Looks like a solid piece, another week and I would've made the first batch! oh well!
Looks like a solid piece, another week and I would've made the first batch! oh well!
The MT82 in the S197 chassis has a bit more room that the TR6060. That transmission is tight. Its a simple matter of removing the crossmember (obviously with the transmission supported) and tilting the driveline down. I'm running a pair of solid bushings at the twin fork ears cast onto that transmission (so are quite a few other GT500 owners) and it makes a noticeable difference. The deflection with a solid approaches nil. Getting it to zero would require quite a bit of surgery given the pin style locating arrangement used on that transmission.
this bracket can be installed with transmission in the car right?
Well, so long as the bolts are torqued and loctite is used I don't foresee any bolts coming loose. I'm more so referring to the natural frequency of the bracket or a fatigue analysis type thing. I have no idea what sort of frequencies you'd measure from our drivetrain (which is entirely dependent on your engine/trans mounts as well), but i wouldn't want to use a bracket who's natural frequency is 100Hz on a drivetrain that commonly sees 100Hz
. I'm not too particularly concerned since this thing is dampened by the shifter/trans mount/engine mount/etc.. but just something to think about.The idea is to fix the body of the shifter as if it were a cast housing, ala the Magnum XL. "Fixing" the transmission and shifter body is absolutely what this modification is all about. The goal is to minimize deflection in the support structure so that a shift can be as precise as possible. In this case, the shifter body is no longer tied into the vehicle body at the rear attachment point (tunnel), and will now move in sync with the transmission. You would see less failure (were you to see any at all) were this mod a solidly triangulated fixture. Fatigue is the more appropriate term, not failure.
Picture yourself as the linkage between the shifter and the shifter fork. The connection at the transmission side rotates due to engine torque and the other end is mounted to the floor pan of the car. This forces the linkage to twist/bend/deform which is how people easily get locked out of gears during spirited drives (hard acceleration/turns). Ideally, this linkage would stay as alligned as possible. This bracket "rigidly" mounts the shifter to the trans and allows them to move together, preventing any linkage misalignment - so all the gears are exactly where they should be. I say "rigidly" because as Tob pointed out, the upper mount is not fixed - this won't be as ideal as some other transmissions (Magnum XL), but its a hell of a lot better than the stock design.
Yes, if you put the car on jack stands and don't mind being on your back. Very easy and quick, 1.5 to 2 hours tops and most of that is jacking the car up and loosing the stock mount.
ok cool just making sure. I put the steeda bracket on so I figured would be just a step further than that.
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