Posted By: wyldebill
whose the fastest on an 8 3/4 - 03/04/15 11:05 PM
I know thumper dart has gone mid 9's. Who's gone faster, what's in it?
whose the fastest on an 8 3/4
Posted By: BradH
Re: whose the fastest on an 8 3/3 - 03/04/15 11:06 PM
Quote:
whose the fastest on an 8 3/3
Last time I did fractions, 8 + 3/3 = 9.
Posted By: wyldebill
Re: whose the fastest on an 8 3/3 - 03/04/15 11:08 PM
Lmao. Fat fingers strike again.
Posted By: wyldebill
Re: whose the fastest on an 8 3/3 - 03/04/15 11:09 PM
Fixed it 
Posted By: TheOtherDodge
Re: whose the fastest on an 8 3/3 - 03/04/15 11:23 PM
Got a buddy with a chevy powered vehicle that has gone 8.5's with that rear end.
Posted By: wyldebill
Re: whose the fastest on an 8 3/3 - 03/04/15 11:28 PM
Any idea what was done to it?
Posted By: 70dusterjohn
Re: whose the fastest on an 8 3/3 - 03/04/15 11:30 PM
We went 8.20 in an arrow that we had back in the 90s 1.18 was the best 60 ft ! Nothing special inside axles need bearing and Richmond gear 
Posted By: TheOtherDodge
Re: whose the fastest on an 8 3/3 - 03/04/15 11:32 PM
Quote:
Any idea what was done to it?
I think it had a spool...That's it. But it was a rail that weighed about 1,800 lbs if I remember correctly.
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/04/15 11:34 PM
Quote:
I know thumper dart has gone mid 9's. Who's gone faster, what's in it?
I'm running 8.90s with a 1.19 60'
Posted By: BradH
Re: whose the fastest on an 8 3/4 - 03/04/15 11:50 PM
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these. 
Posted By: GY3
Re: whose the fastest on an 8 3/4 - 03/05/15 12:41 AM
Quote:
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
Looks like you just volunteered..
Posted By: racerx
Re: whose the fastest on an 8 3/4 - 03/05/15 12:48 AM
Wouldn't say the fastest but 9.42@141
Posted By: BradH
Re: whose the fastest on an 8 3/4 - 03/05/15 01:07 AM
Quote:Quote:
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
Looks like you just volunteered..
NFW... I'm moving on from this sillya$$ debate!
Posted By: DavidDean
Re: whose the fastest on an 8 3/4 - 03/05/15 01:10 AM
I went 5.60s @ 120 1.24 60' but then I broke it. I have a dana now. 2800# SB w/904
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/05/15 02:05 AM
Quote:
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
I have always said its weight that kills the 8 3/4..
greater weight has greater friction on the track..
and the weak point is the caps if its back braced
Posted By: Monte_Smith
Re: whose the fastest on an 8 3/4 - 03/05/15 02:13 AM
Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
Posted By: Quicktree
Re: whose the fastest on an 8 3/4 - 03/05/15 02:15 AM
Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/05/15 02:18 AM
Quote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
Posted By: Quicktree
Re: whose the fastest on an 8 3/4 - 03/05/15 02:21 AM
Quote:it is fact I can show you the piecesQuote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/05/15 02:23 AM
Quote:Quote:it is fact I can show you the piecesQuote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
You act like EVERY one will blow the sprag... NOT..
and I have a trans that says so
Posted By: Quicktree
Re: whose the fastest on an 8 3/4 - 03/05/15 02:26 AM
Quote:I didn't say that, but the chances are pretty goodQuote:Quote:it is fact I can show you the piecesQuote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
You act like EVERY one will blow the sprag... NOT..
and I have a trans that says so
Posted By: BradH
Re: whose the fastest on an 8 3/4 - 03/05/15 02:31 AM
Quote:Quote:I didn't say that, but the chances are pretty goodQuote:Quote:it is fact I can show you the piecesQuote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
You act like EVERY one will blow the sprag... NOT..
and I have a trans that says so
Then it's not a fact, just a highly probable outcome.
Posted By: D-50
Re: whose the fastest on an 8 3/4 - 03/05/15 02:32 AM
When I broke my passenger car 9 in rear I took my stock 727 trans out because I was afraid I killed the sprag but everything was fine so I told the guy to put it back together.
Posted By: Quicktree
Re: whose the fastest on an 8 3/4 - 03/05/15 02:33 AM
Quote:isn't that the same?Quote:Quote:I didn't say that, but the chances are pretty goodQuote:Quote:it is fact I can show you the piecesQuote:Quote:then you can buy a new tranny to boot....Quote:I have a formula.........when it breaks, you have gone too far with weight and or power............LOL!!!
Somebody should come up w/ some type of formula that takes into account car weight, engine HP & torque, 60-ft, ET, MPH, etc., to be able to define a factor to use in comparing these.
That ISNT FACT... when I blew the stock 8 3/4 I
pulled the trans to make sure.. it was fine.. still
running the same trans and the same sprag
You act like EVERY one will blow the sprag... NOT..
and I have a trans that says so
Then it's not a fact, just a highly probable outcome.
Posted By: mcat4321
Re: whose the fastest on an 8 3/4 - 03/05/15 02:44 AM
my opinion is, years in use is the biggest killer.
metal fatigue of the housing flexing over and over.
the older it is, the less force it takes to meet the fail line. the axle housing flexes putting extreme pressure on the caps in turn binding carrier eventually the gears cant handle the extra pressure. then new stronger gears are put in,same thing happens to axles so their replaced so now the carrier cant handle the strain, then comes a spool.. then the caps fail. so a new pumpkin is used.. the housing ignored most all the time...
metal fatigue of the housing flexing over and over.
the older it is, the less force it takes to meet the fail line. the axle housing flexes putting extreme pressure on the caps in turn binding carrier eventually the gears cant handle the extra pressure. then new stronger gears are put in,same thing happens to axles so their replaced so now the carrier cant handle the strain, then comes a spool.. then the caps fail. so a new pumpkin is used.. the housing ignored most all the time...
Posted By: 1967dartgt
Re: whose the fastest on an 8 3/4 - 03/05/15 02:47 AM
I have been 8.57@162 while weighting 3195. It has a 422 small block on spray in it. Only had 225 hp in it. The rear is still in n car and making passes. On another note when it sheared the ring gear bolts I pulled the trans apart and the sprag was fine.
Posted By: MattW
Re: whose the fastest on an 8 3/4 - 03/05/15 02:53 AM
Quote:
I have been [Email]8.57@162[/Email] while weighting 3195. It has a 422 small block on spray in it. Only had 225 hp in it. The rear is still in n car and making passes. On another note when it sheared the ring gear bolts I pulled the trans apart and the sprag was fine.
Man oh man! U R pushing your luck,
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/05/15 03:06 AM
Then it's not a fact, just a highly probable outcome.
BOTH YOU and Tony fail to ask the FIRST question and
the MOST important... is it a 904 or 727... a 904
is unlikely to blow it... a 727 MIGHT blow it IF it
was above 6200 rpm
BOTH YOU and Tony fail to ask the FIRST question and
the MOST important... is it a 904 or 727... a 904
is unlikely to blow it... a 727 MIGHT blow it IF it
was above 6200 rpm
Posted By: SpareParts
Re: whose the fastest on an 8 3/4 - 03/05/15 03:08 AM
He knows 
Us small block guys don't give a damn about stuff lol
Us small block guys don't give a damn about stuff lol
Posted By: BradH
Re: whose the fastest on an 8 3/4 - 03/05/15 03:14 AM
Quote:
Then it's not a fact, just a highly probable outcome.
BOTH YOU and Tony fail to ask the FIRST question...
Actually, I didn't ask ANY question. I simply stated that it's not a FACT (as Tony claimed) if there are examples that people have broken their diffs WITHOUT having subsequent transmission damage.
E-nuff of this. I have a beefed-up 8.75" and haven't broken it, but am upgrading my rear axle assembly so I'm not the next guy who has to end his day-at-the-track story with "... and then I broke the rear end."
Posted By: StealthWedge67
Re: whose the fastest on an 8 3/4 - 03/05/15 04:43 AM
I think Ron Nies' 63 is putting a lot of hurt on his 8-3/4, considering mid 10's in a B-Body that I'm sure weighs in at least 3600. His rear is pretty stock too, with a locker being the only upgrade I've heard him speak of.
Posted By: onefastindy
Re: whose the fastest on an 8 3/4 - 03/05/15 05:02 AM
I've been 9.40's with mine.
Posted By: KOS
Re: whose the fastest on an 8 3/4 - 03/05/15 05:08 AM
ive been low 10s @3300lbs for 3seasons and never hurt anything.ive had good luck with 4.88s gear sets seems the thicker the ring gear they seem to last.ive ripped the teeth off of many 4.10s...too bad they dont offer a pro gear in a variety of ratios for the 8.75
Posted By: D-50
Re: whose the fastest on an 8 3/4 - 03/05/15 05:26 AM
In my Demon I broke the teeth off a set of 4.30's (7.20's in the 1/8)and one of the caps on the 8 3/4 with a set of 5.13's ( spraying 100 shot of Nitrous)and of course half the teeth off of the ring gear after that. The spider gears were welded together on both of them ( Poor mans locker).
Posted By: Guitar Jones
Re: whose the fastest on an 8 3/4 - 03/05/15 03:41 PM
Plenty of guys faster than my pile, see sig. Mine has the aluminum center section and pro gears, 30 spline spool and axles at 2760 pounds. Haven't broken a ring gear since going to the pro gear.
Posted By: Eric
Re: whose the fastest on an 8 3/4 - 03/05/15 04:54 PM
Wafflebatter has been in the 5.30's I believe with his 1900# Roadster..
Posted By: an8sec70cuda
Re: whose the fastest on an 8 3/4 - 03/05/15 05:26 PM
11.40s at 3700# broke the 8.75 suregrip. Upgraded to a spool and 35 spline axles.
When I put the Indy headed 440 in the car, the 8.75 sheared the teeth off the pinion and got some of the ring gear at 10.70s at 3700# while trying to sort out the new combo. After that, I put the Dana in and wound up going 10.40s all sorted out.
When I put the Indy headed 440 in the car, the 8.75 sheared the teeth off the pinion and got some of the ring gear at 10.70s at 3700# while trying to sort out the new combo. After that, I put the Dana in and wound up going 10.40s all sorted out.
Posted By: dizuster
Re: whose the fastest on an 8 3/4 - 03/05/15 07:49 PM
There is a lot to goes into it, that's why people have so many different opinions on it.
Everything has a fatigue life... crank shafts, ring gears, axles, etc...
The harder you stress anything (either more power or more weight), the shorter the lifespan of the part will be.
My 3.23 gear (heavy load) sheared the pinion off... didn't even make it 50 passes behind my 3700lb mid/low 10 second tuneup. But the STOCK axles survived.
Lots of guys have broken axles without hurting ring gears.
It's not one thing that fails, or one weight, or one power level, its a combination of things.
Generally though just from what guys have done, regular 3300lb race weight is good down to around 10 flat or so. There are certainly failures at that point, and certainly people that have gone quicker... but it's a good rule of thumb that will PROBABLY ensure a reasonable lifespan out of the parts.
For the record, my clean break on the pinion killed the sprag too. I highly recommend that you ALWAYS at least look at the sprag if you hurt the rear axle/u-joint.
Everything has a fatigue life... crank shafts, ring gears, axles, etc...
The harder you stress anything (either more power or more weight), the shorter the lifespan of the part will be.
My 3.23 gear (heavy load) sheared the pinion off... didn't even make it 50 passes behind my 3700lb mid/low 10 second tuneup. But the STOCK axles survived.
Lots of guys have broken axles without hurting ring gears.
It's not one thing that fails, or one weight, or one power level, its a combination of things.
Generally though just from what guys have done, regular 3300lb race weight is good down to around 10 flat or so. There are certainly failures at that point, and certainly people that have gone quicker... but it's a good rule of thumb that will PROBABLY ensure a reasonable lifespan out of the parts.
For the record, my clean break on the pinion killed the sprag too. I highly recommend that you ALWAYS at least look at the sprag if you hurt the rear axle/u-joint.
Posted By: BradH
Re: whose the fastest on an 8 3/4 - 03/05/15 07:58 PM
Quote:
I have a beefed-up 8.75" and haven't broken it...
... yet.
Details HERE, FWIW.
This was taking mid 1.4 60s and mid 10s at 3750+ #s.
Never broke a stock axle, but saw others do it at lower performance levels.
No problems w/ rebuilt Power-Lok sure-grip units, but broke a couple of Auburns when the car was much slower and simply gave up on that design.
As was stated above, it's definitely a combination of factors that contribute to what & when something breaks.
Posted By: MR_P_BODY
Re: whose the fastest on an 8 3/4 - 03/05/15 08:27 PM
I have a set of Strange 35 spline axles that had a
full spline width twist in the splined end right out
from the spool.. they were still working but I changed
them out only because I had another set of them.. I
paint a white line down the whole length of each axle
just to monitor the twist... the stock 8 3/4 that I
first started out with had stock axles... they had
just over a full twist in the length.. they didnt
break either but I knew it wasnt gonna be to long
for them... but then I blew the cap off the center
and thats when I changed to the alum center and the
good parts.. that was right at 600 passes on the stock
8 3/4 with 1.24-1.26 60'
full spline width twist in the splined end right out
from the spool.. they were still working but I changed
them out only because I had another set of them.. I
paint a white line down the whole length of each axle
just to monitor the twist... the stock 8 3/4 that I
first started out with had stock axles... they had
just over a full twist in the length.. they didnt
break either but I knew it wasnt gonna be to long
for them... but then I blew the cap off the center
and thats when I changed to the alum center and the
good parts.. that was right at 600 passes on the stock
8 3/4 with 1.24-1.26 60'
Posted By: cudaman1969
Re: whose the fastest on an 8 3/4 - 03/05/15 09:41 PM
Quote:
my opinion is, years in use is the biggest killer.
metal fatigue of the housing flexing over and over.
the older it is, the less force it takes to meet the fail line. the axle housing flexes putting extreme pressure on the caps in turn binding carrier eventually the gears cant handle the extra pressure. then new stronger gears are put in,same thing happens to axles so their replaced so now the carrier cant handle the strain, then comes a spool.. then the caps fail. so a new pumpkin is used.. the housing ignored most all the time...
IMO i think flex actually helps the life span, when flexing stops it brakes. think of the slipping clutches in the pro classes.
Posted By: cudaman1969
Re: whose the fastest on an 8 3/4 - 03/05/15 09:51 PM
Quote:
ive been low 10s @3300lbs for 3seasons and never hurt anything.ive had good luck with 4.88s gear sets seems the thicker the ring gear they seem to last.ive ripped the teeth off of many 4.10s...too bad they dont offer a pro gear in a variety of ratios for the 8.75
make your own, heat in oven to 425 degrees for four hours the let cool slowly. Softens it up to give, not shatter, street gears are very hard and brittle so they last, not good for racing. This is old guy stuff, Noah used it on the ark.
Posted By: KOS
Re: whose the fastest on an 8 3/4 - 03/05/15 11:55 PM
haha ya i did that.....callled it the hutch treatment...its what hutch transmission reconmended.they would last alittle longer just got sick of constantly fixing 8.75 junk went to dana60 on my 5th one never ever broken anything in any of them.
Posted By: Quicktree
Re: whose the fastest on an 8 3/4 - 03/06/15 01:23 AM
we should do a thread about how many people have blew up an 8 - 3/4 but we would run out of band width
Posted By: 72Swinger
Re: whose the fastest on an 8 3/4 - 03/06/15 03:48 AM
Whos the fastest? I think Buddy Baker went 212 mph or something like that with an 8 3/4?
Posted By: 340RICK
Re: whose the fastest on an 8 3/4 - 03/06/15 11:43 PM
Quote:
Whos the fastest? I think Buddy Baker went 212 mph or something like that with an 8 3/4?
Bingo
Posted By: ROSSIO
Re: whose the fastest on an 8 3/4 - 03/07/15 03:50 PM
WENT 9.16 W/1.35 60FT 3350LB DART ON 10.5
FIGURED I'D BETTER QUIT WHILE I WAS AHEAD
and put a dana 60 in----now 8.70's SAFLEY
FIGURED I'D BETTER QUIT WHILE I WAS AHEAD
and put a dana 60 in----now 8.70's SAFLEY