Bracket Talk
9.5" rear gears

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February 18, 2019, 05:38 PM
gxp7903
9.5" rear gears
Been thinking lately, at what power level/ET would you think about 9.5" gears? Would they last longer, or just be stronger?
Also is there a noticeable power loss? Referring to a 1900lb dragster.

Sorry if this has been asked before, I searched and couldn't find much on this.
February 19, 2019, 08:49 AM
N2Ofrog
They are stronger which means they last longer. Not sure about dragster applications, but in a door car they seem to have value once you start getting into the 6.80s and quicker range. Didn't notice any ET change with my car or a friend's car.
February 22, 2019, 10:36 AM
gxp7903
Must not be real common for a dragster to run them with over 250 views and only one comment.

Thanks for the reply. That makes sense to me for a door car to see a benefit before a dragster might since they carry more weight.

When you say stronger means they'll last longer, do you think that is relative to the normal gear wear also? or just that they last longer against breaking?
February 22, 2019, 10:55 AM
pentastarrail
I don't know how fast you go but I ran my MW 9 inch for 12 years. The first 4 years running 6.80's (dragster), the last 8 years running 6.00's, same dragster just blown (actually 5's but we won't go there). I broke the aluminum spool in that rear (severe tire shake) last year and decided to put a steel spool in with 9.5 gears. The only reason I went to the 9.5 was I felt bad for the 9" gears. Never had the rear out other than that.

I can't say if/when you need to go to a 9.5, just telling you my experience.
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February 22, 2019, 11:15 AM
TD3550
I know the guys next door to me ran the 9" with the billet center with their TAD operation with no issues for 2 years at all. Always kept a spare. They did change it out once on a maint deal. Sold out after 2 years. Tough field is an understatement.

Nice car too..


February 22, 2019, 12:37 PM
wideopen231
We ran 9" in both TA/FC and TA/D for years as did rest of field. Tire shake in dragsters is nothing like in funny cars. We changed gears about every other year so roughly 150 or so runs.

Now that said I do see where a 9.5" gear would last longer due to be stronger piece.I am not to sure cost wise it would be a big savings,provided you check stuff on fairly regular bases and not just wait till it breaks.




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February 22, 2019, 01:30 PM
N2Ofrog
quote:
Originally posted by gxp7903:
Must not be real common for a dragster to run them with over 250 views and only one comment.

Thanks for the reply. That makes sense to me for a door car to see a benefit before a dragster might since they carry more weight.

When you say stronger means they'll last longer, do you think that is relative to the normal gear wear also? or just that they last longer against breaking?


They lasted longer against cracking and breaking. When we ran Pro Mod years ago, we switched to a 9.5" and got a lot more runs out of the gear. Like others mentioned, a lot of it has to do with weight and the abuse from tire shake .
February 23, 2019, 07:35 AM
gxp7903
Thanks for the replies guys. I do not have real big power. 1100 ish at 1900 lbs. Sometimes use the spray for q32s. Sounds like i don't need a 9.5" set.

So my next question, has anyone ever tried a ball/taper bearing pinion support? Do they wear the gear out quicker than a taper/taper support?

I have killed 2 gear sets with a ball/taper support. First set started making noise at the last race of year, about 180 runs going 4.70. Pulled second set this winter and they do not have much life left, about 250 runs going 4.50s. I think im going to switch back to taper/taper.
February 23, 2019, 10:26 PM
seabass
quote:
Originally posted by gxp7903:
Been thinking lately, at what power level/ET would you think about 9.5" gears? Would they last longer, or just be stronger?
Also is there a noticeable power loss? Referring to a 1900lb dragster.

Sorry if this has been asked before, I searched and couldn't find much on this.


Not sure if you need them or not but I do feel there stronger which is why I switched to them a few years ago. still going just fine, Knock on wood...


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