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Quick times=broken parts for me

Posted By: DavidDean

Quick times=broken parts for me - 11/13/13 12:29 AM

I've just finishing fixing my broken stuff. A couple of weeks ago I headed to Dallas Raceway for the Door Car Only race.I was excited, the first TT netted a new best of 5.66 @ 120.5. The car lived up to its Thrill Ride name with a big wheelie and a 1.241 60'. The fun ended though as I attempted to qualify for the quick 16 on the next pass. When the car launched it wiped out more than 1/3 of the teeth on my super beefy 8 3/4.It had maybe 75? passes on that R & P. I figured the sprag was also shot. When I pulled my 904 I also found it had broken the input shaft as well as laying over the sprag.Alot of work later and I hope to make the leftover nationals race at Abilene after thanks giving.It's obviously time to retire the 8 3/4 and possibly put in a glide.
I've also considered building a new 904 w/ a Protrans 2.28 low gear to try to calm the car down some more. I've got a lot invested in 904 junk.

Attached picture 7921971-bracketnationals.jpg
Posted By: CHAPPER

Re: Quick times=broken parts for me - 11/13/13 01:04 AM

Engine fluids containment system...any build pics & pointers??
Posted By: ram87

Re: Quick times=broken parts for me - 11/13/13 03:27 AM

Might be time for a glide. I try to drag my tired old rear out to see you after Thanksgiving. I am working for Lowe's and never know my work schedule until the week before.
Posted By: WHITEDART

Re: Quick times=broken parts for me - 11/13/13 03:50 AM

was that a stock input or an after market one and do you think the rear end had some thing to do with it braking
Posted By: racerx

Re: Quick times=broken parts for me - 11/13/13 01:00 PM

Who's r&p u runing(ratio),was this with a stock housing w/bracing..Thax
Posted By: J_BODY

Re: Quick times=broken parts for me - 11/13/13 02:22 PM

Quote:

was that a stock input or an after market one and do you think the rear end had some thing to do with it braking



absolutely the rear braking had something to do with the input shaft breaking. Same shock on the system is what also kills the sprag. I was surprised to see David's car still running the 8.75 when I saw it at Vegas.
Posted By: rickseeman

Re: Quick times=broken parts for me - 11/13/13 04:26 PM

I'm definitely not trying to be a smart a** here but an 8-3/4 in a 5 second car? A 904 in a 5 second car? You know better than to try that. God created Danas for a reason.
Posted By: JohnRR

Re: Quick times=broken parts for me - 11/13/13 04:32 PM

Quote:

Who's r&p u runing(ratio),was this with a stock housing w/bracing..Thax



I'm sure it has all the tricks applied to the housing but in the end the weak link is the ring and pinion teeth, you can strengthen everything else it's still going to rip the teeth off those 2 gears at some point.
Posted By: DavidDean

Re: Quick times=broken parts for me - 11/13/13 04:42 PM

Here's a pic of the belly pan. Most people on this site seem to favor a diaper. I like the pan its easier to fit, make and maintain the engine. A number of my top sportsman friends also use a simular pan. It follows the NHRA guidelines frame rail to frame rail trans housing to infront of the balancer. It has a screen in the bottom to hold the same pad as in a Jegs diaper. 2" + tall on the sides. My Bob's Profab K member made the installation possible.I just kept making cardboard patterns untill I had something that would work. My local chassis guy (Mike Carpenter)gave me lots of pointers and welded up the final design.
Hey Lynn it would be great to see ya there!
The input shaft was stock and so was the replacement I hope it'll stand up for a while.I would agree the rear breaking led to the input shaft breaking.
The R&P was and is 3.91 ratio. I shift this motor about 6800 rpm. The rear has all the tricks you can have in an 8 3/4. Billet caps, back braced gusseted outside as well as inside. It's not an alunimium housing though. I looking at a dana 60 as a replacement.
I'm trying to decide between a glide and and up dating my 904 w/ 2.28 1st gear. My 904 has some fairly nice stuff inside and its pretty fast.
Hey Lynn it would be great to see ya there!

Attached picture 7922680-bellypanupperside.JPG
Posted By: Brian Hafliger

Re: Quick times=broken parts for me - 11/13/13 05:30 PM

David did you end up changing the block or ???
Posted By: DavidDean

Re: Quick times=broken parts for me - 11/13/13 05:56 PM

I had Sunset repair the block and Ive routed water to the back of the heads and changed the tune up a little .So far so good
Posted By: CHAPPER

Re: Quick times=broken parts for me - 11/13/13 06:11 PM

Quote:

Here's a pic of the belly pan. Most people on this site seem to favor a diaper. I like the pan its easier to fit, make and maintain the engine. A number of my top sportsman friends also use a simular pan. It follows the NHRA guidelines frame rail to frame rail trans housing to infront of the balancer. It has a screen in the bottom to hold the same pad as in a Jegs diaper. 2" + tall on the sides. My Bob's Profab K member made the installation possible.I just kept making cardboard patterns untill I had something that would work. My local chassis guy (Mike Carpenter)gave me lots of pointers and welded up the final design.
Hey Lynn it would be great to see ya there!
The input shaft was stock and so was the replacement I hope it'll stand up for a while.I would agree the rear breaking led to the input shaft breaking.
The R&P was and is 3.91 ratio. I shift this motor about 6800 rpm. The rear has all the tricks you can have in an 8 3/4. Billet caps, back braced gusseted outside as well as inside. It's not an alunimium housing though. I looking at a dana 60 as a replacement.
I'm trying to decide between a glide and and up dating my 904 w/ 2.28 1st gear. My 904 has some fairly nice stuff inside and its pretty fast.
Hey Lynn it would be great to see ya there!





thanks.
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