RWD and Powerglide? ? ?
RWD and Powerglide? ? ?
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
I'm a firm believer that when one decides to "stir the pot" it is better to use a boat oar than a coffee straw.
Wayne H.
'91 Dodge Spirit ES 2.5L turbo 5spd
'05 PT GT 2.4T HO autostick (RIP)
'89 Plymouth Acclaim 2.5L turbo auto, "Slugmobile" yes, THE Slugmobile!
'89 Dodge Caravan SE 2.5L turbo auto, "Mean Mini" yes, Gus' Mean Mini! (Current best 11.699 @ 114.43 mph! - Oct 15th, 2022 Cecil County Dragway, MD)
MeanMini dragracing videos: https://www.youtube.com/playlist?lis...URZLB1RxGYF6vw
and other cars, trucks and motorcycles
https://www.youtube.com/user/SlugmobileMeanMini
Thanks for that explanation. I think see what you're saying there. How much force is put into the attempt at twisting the diff perpendicular to the axis of the axles? I would think that the snout of the diff would be a pretty good distance to counteract that with no problem? I could be way off as I'm like a child walking into the middle of a movie...
I really don't know why people would add all the weight of the scatter shield and not add a little extra to make it structural for the whole end of the case that seems to keep failing. I have wondered about how I kinda cheat and remove at least 1 block bracket to bell housing on some of my 3.0's (front usually) and on a high output setup, thats probably a bad idea.
BTW, how is all the shockload that transfers into the stock location rear mount playing out? I would tie scatter shield into that hardpoint instead of using the case to carry all the load.
Brent GREAT DEPRESSION RACING 1992 Duster 3.0T The Junkyard - MS II, OEM 10:1 -[I] Old - 11.5@125 22psi $90 [U]Stock[/U] 3.0 Junk Motor - 1 bar MAP [/I] 1994 Spirit 3.0T - 11.5@120 20 psi - Daily :eyebrows: Holset He351 -FT600 - 393whp 457ft/lb @18psi 1994 Spirit 3.0T a670 - He341, stock fuel, BEGI. Wife's into kid's project. 1990 Lebaron Coupe 2.2 TI/II non IC, a413 1990 Spirit 3.0 E.S. 41TE -- 1993 Spirit 3.0 E.S. 41TE -- 1994 Duster 3.0 A543 1981 Starlet KP61 Potential driver -- 1981 Starlet KP61 Parts -- 1983 Starlet KP61 Drag 2005 Durango Hemi Limited -- 1998 Dodge 12v 47re. AFC mods, No plate, Mack plug, Boost elbow -- 2011 Dodge 6.7 G56
I would love to know the forces of push out. Even straight cut gears have radial forces pushing the gears apart
The added scatter shield weight is appreciated by my nuts having run only prototype clutches in the car for 15 years and more than half of that without one.
Rear mount (and all mounts) are solid so nothing moves, but I too have wondered about the forces. Need to sketch of a free-body diagram... is DJ board at work this week?
JT
SDAC Director
SDAC-Chicago President
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JT
SDAC Director
SDAC-Chicago President
JOIN SDAC and your local Chapter TODAY! - SUPPORT the CLUB that supports YOUR HOBBY!
87 Shelby Z - 10.50@141.66mph
87 CSX #751 Clone - 12.88@102.88mph
www.badassperformance.com
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Submit your 1/4 mile times HERE!!
Support SDAC! Join Today!
"I'm not some pro athlete with a bajillion dollars, I'm just an every man"
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Is the engine/tranny mounted solid? Are you still using the bobble strut bracket? Is that mount solid with no bushings?
I'm a firm believer in rubber mounts. my engine moves a good inch or so and I truly believe that it's part of the reason I never broke an axle beside being an auto. my left axle is a stock L body from NAPA that's been in the car for 17 years. another added bonus, my car dose not shake like hell at idle. on a RWD you have a few places that take up the shock. FWD is a hole new ballgame.
You can get away with this as long as the suspension works in such a way that the angle on the joints and shaft aren't all whacky. Most people don't get that right (and it's not easy with things being that dynamic), so they find that limiting movement is the better choice for them.
There's nothing wrong with that, but as you said things start vibrating more. This brings fatigue. I'm wondering if what we are seeing is partially a fatigue stress failure as well as a strength through design failure? We are talking about aluminum.
Yes, solid using stock mounting points that were originally designed for rubber. Have been thinking about a motor plate like Warren Stramer uses
I'm sure the rubber damps it some. I'm guessing the automatic pre-loading everything is the biggest help. You are right about needing some place to take up shock and right now its really only the clutch and axles. Twin disk clutch not so forgiving LOL
JT
SDAC Director
SDAC-Chicago President
JOIN SDAC and your local Chapter TODAY! - SUPPORT the CLUB that supports YOUR HOBBY!
87 Shelby Z - 10.50@141.66mph
87 CSX #751 Clone - 12.88@102.88mph
www.badassperformance.com
Check out Turbo-Mopar Times!
Submit your 1/4 mile times HERE!!
Support SDAC! Join Today!
"I'm not some pro athlete with a bajillion dollars, I'm just an every man"
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Bryan
86 GLHS #161, 2016 Impala
SDAC National Member, SDAC Buckeye Chapter Member
A man has got to know his limitations.....
JT
SDAC Director
SDAC-Chicago President
JOIN SDAC and your local Chapter TODAY! - SUPPORT the CLUB that supports YOUR HOBBY!
87 Shelby Z - 10.50@141.66mph
87 CSX #751 Clone - 12.88@102.88mph
www.badassperformance.com
Check out Turbo-Mopar Times!
Submit your 1/4 mile times HERE!!
Support SDAC! Join Today!
"I'm not some pro athlete with a bajillion dollars, I'm just an every man"
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Damn! Sorry about all the trans trouble you're having. I hope to see you at the Nats again this year.
JT
SDAC Director
SDAC-Chicago President
JOIN SDAC and your local Chapter TODAY! - SUPPORT the CLUB that supports YOUR HOBBY!
87 Shelby Z - 10.50@141.66mph
87 CSX #751 Clone - 12.88@102.88mph
www.badassperformance.com
Check out Turbo-Mopar Times!
Submit your 1/4 mile times HERE!!
Support SDAC! Join Today!
"I'm not some pro athlete with a bajillion dollars, I'm just an every man"
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Looking at your pics earlier I was wondering if the stress riser is at the base of the threaded hole for the selector bolt. The ones you just posted suggest this even more. Do you have an old broken case you could cut up to see how thin it gets there?
As for the bobble strut it would be a good idea to move. It only adds stress into the case that doesn't need to be there. I would try to build something off the bolts that hold the tranny/engine reinforcement plate at the back of the engine. I have hard time believing it will solve your failure issue as I don't think it has anything to do with it but it will remove some stress.
JT
SDAC Director
SDAC-Chicago President
JOIN SDAC and your local Chapter TODAY! - SUPPORT the CLUB that supports YOUR HOBBY!
87 Shelby Z - 10.50@141.66mph
87 CSX #751 Clone - 12.88@102.88mph
www.badassperformance.com
Check out Turbo-Mopar Times!
Submit your 1/4 mile times HERE!!
Support SDAC! Join Today!
"I'm not some pro athlete with a bajillion dollars, I'm just an every man"
Note: The information and any images provided in this post are not for distribution outside this forum without the author's permission.
I wonder if it is adding to it DJ. When the engine rotates backward, the bobble strut bracket is transferring the force in a counter clockwise rotational direction. That part of the case would see those forces, plus the typical gears pushing apart, the ring & pinion trying to side step each other and finally the "way over stock" HP & torque he sends through it. Add that this area is less reinforced than the 555 and my feeble understanding of force vectors, it looks like all added up are causing the issue. If one or more can be lessened and reinforcement added, maybe it will live longer.
Then again.......LOL.
Bryan
86 GLHS #161, 2016 Impala
SDAC National Member, SDAC Buckeye Chapter Member
A man has got to know his limitations.....
The backwards rotation should put that area into compression. Compression doesn't generally produce fatigue cracking but as you said it does still remove stress that doesn't need to be there. Without doing some FEA on the part it's hard to say anything for sure.