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How fast with stock stubs and flanges?


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Hey all, Wondering how fast (ET) any of you have gone in the quarter with stock 280 stub axles and flanges? I am not pushing mine very hard with an auto, and a tight converter, and running 12.05 to 12.08. I am putting it up on the converter to stage, so everything is preloaded and there is minimal shock.(235/60 mickey dr's)

 

I would like to upgrade the heads, cam, ect, Should I upgrade the stubs before I go any harder? Thanks.

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Mine broke pulling away from a stop sign! 

 

Many posts in the drivetrain forum.

 

Where did it break? 

I have read many threads on doing the swap. But I haven't seen what part breaks on the stock ones.

Really wanted to know how much they will take. And how brave some have been with the stock ones. OK, and I just like a good drag race discussion. 

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Miles has a 240Z which has weaker hub axles than a 280Z.  Here's some threads re your question.  Search the names to get more information.  Rebekahsz is another who was drag racing, but on the stock axles.

 

http://forums.hybridz.org/topic/109324-ford-88-irs-conversion/

 

http://forums.hybridz.org/topic/121328-snapping-stub-axles-now-what/?hl=sunnyz&do=findComment&comment=1135160

 

And here's a guy supplying the market - http://forums.hybridz.org/topic/121613-s30-ultimate-88-irs-swap-kit/

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NewZed is correct.

 

My stub axle broke where the threads meet the splined portion of the axle. They also fail where the wheel mounting flange is welded to the axle.  See pictures.

 

Also, the flange is soft and easily bent. Not so much of a problem with drum brakes, but with disk brakes it caused the pads to drag on the rotor so  I replaced them Modern Motorsports stub axles:  http://www.modern-motorsports.com/stub-axles.html

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Edited by Miles
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Thanks for the responses. Looks like either way, the wheel and tire are going to do some damage to the fender well. Or walk out and exit the vehicle. Not good.

 

The bad thing about doing CNC turning for 25 yrs+, Is justifying $750.00 for something I could knock out in 4 to 6 hrs.(not including splines and heat treatment) But where does one find the time. Seems like the MM/ Checkered flag stubs are good insurance. 

 

I run the car in NHRA div 6 in sportsman. The cutoff is 12.00 flat, so if I do any upgrades to it, it will be too fast for the class. So I'm at the crossroads on whether to touch it or not.   

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Ask jnjdragracing. He's auto, big hp and fairly stock drivetrain. If you are going 12.0 and foot-braking? So you are at like 350hp? What trans and stall? At what rpm do you leave the line? What gear ratio? What tires and axles? What's your 60'? I'm kinda thinking you will be fine with stock stubs. The auto is your friend and so is the lack of a trans brake. Go bias ply slick and that helps surviveability even more.

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After years of putting 400+ hp through my 240z with stock stub axles, one of mine snapped during a uturn. After my experience I wouldn't even pose your question. I was lucky.
don't over think it. For your own safety upgrade your stubs. Think about what a cv flailing around can do to the rear of a z. Next upgrade consider cold forged solid ujoints! Relatively speaking they're cheap.

 

I just hate to see guys go cheap on safety parts. You ultimately loose. A strong drivetrain gives me piece of mind when I drive my z hard.

 

Not trying to tell you what to do. Just my 2 cents. 

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Ask jnjdragracing. He's auto, big hp and fairly stock drivetrain. If you are going 12.0 and foot-braking? So you are at like 350hp? What trans and stall? At what rpm do you leave the line? What gear ratio? What tires and axles? What's your 60'? I'm kinda thinking you will be fine with stock stubs. The auto is your friend and so is the lack of a trans brake. Go bias ply slick and that helps surviveability even more.

 

Yes, footbraking, With no idea on HP. Really mild 408sbc/700r w 2500 non lockup converter. I leave at 1500rpm. 3.54 r200, 280ZXT axles w/ homemade adapters, Chevette springs. 235/60r15 MT drag radials.  Best 60ft is 1.65, but it has slowed a bit since I bought new tires mid season.

 

To keep it in the class I run a holley 600vac secondary, and a single exhaust that is pretty quiet. 

 

 

 

TimO, Thanks for the input. I have spent too much time and $$ to have something come loose and do damage.

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They need to be crack tested, shot peened, and then cryo treated.  Makes no sense to cryo treat parts without inspecting them and doing a proper surface treatment.  Don Potter used to do that to new 280Z stub axles and companion flanges years ago.  For $750 you got those parts plus ARP studs, companion flange nuts, bolts, and washers, 280ZX axle nuts, Japanese bearings and seals, and a tube of Wurth SIG 3000 grease.

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$730 gets chromoly stub axles from Joe. Still need your bearings and grease, but I wouldn't bother with the expense of cryo and peening. Even with chromoly, especially if you're drag racing, you can still break them, but they should hold up a lot better than stockers.
http://www.chequeredflagracing.net/Datsun.html

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I run the Chequered Flag stuff just to be safe like Tim O suggested. I kinda wanted to be "one and done." There's no right answer. So far I haven't heard of anybody breaking a Chequered Flag stub. And the automatic and easy launch is your friend that will protect you more than anything else. If you are doing 1-wheel burnouts, you need to look for an LSD. Open diffs and welded diffs break axles. The weak link is the cross shaft in an open diff. The cross shaft cocks, the spiders lock and the u-joint breaks when one wheel locks up at half track. A very messy failure cause the axle takes out your brake lines as it flops around. 1-wheel burnouts really accelerate cross shaft wear. Even if you think both tires are spinning, have somebody watch. My buddy's car spins one wheel til it gets sticky, then both wheels spin. That's hard as hell on a diff. He's on open diff#3 and Im on CLSD#1 and I have a lot more passes than him.

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  • 3 weeks later...

We are running the original stubs and rearend  that came in my Z. It is a 1976 280Z we have had a 412 sbc with NOS, 355sbc with 671 blower on C16 racing gas , same motor and blower but with Alky and a Birdcather mech fuel injection, and now a 355sbc with twin 65mm turbos with E85 EFI. we went 9.21@153 on the stock haftshafts with the blower on racing gas, we then went to the 300ZXT CV axles, and the car went a 5.61@129mph and a 8.67@158mph in 2012 with the turbo setup. The car now runs 5.40@135, we have not run it in the quarter since 2012 but it should go a 8.40 @165+ in the quarter.The last time we dynoed the car it made 945hp at the rear tires.I hopes this sheds some light on your questions.We have been running this car for 12 years now. Jerry

Edited by jnjdragracing
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  • 4 years later...

I don’t get it. In 95 I had a 77 Z with a Turbo Tom system. Had a ported head and Crower Cam. I use to break Axle Shaft U joint like Crazy. Had a local Machine Shop the cup opening and install some solid u joints. That fix that problem. Next I started breaking the Rear Gear. I would pull 3 or 4 teeth on Ring Gear. I use to go the the local U pick and pull every R200 with 3.90 gear I could find. I must of broken 10 or 12 of them. All were the same broken ring gear. I ended up putting a 9 inch and ladder bars in the car. I would go 1.55-1.57 60ft and run 11.80’s. Never had a problem with the stubs. How is some people running way more power and better 60 foots and not breaking the rears

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This is a bit of a necro, but it is an interesting point. I always thought the ring gear was one of the stronger pieces in the rear drive line. With a 60 ft less than 1.6 I imagine some kind of slicks or drag radial? The 280z stubs are noticeably stronger/thicker/more splined than the 240z ones, but I didn't think they would shift the weak point. 

 

Perhaps since most cars in the junkyard I have seen have fairly high milage and I doubt any service of the rear end, perhaps they were all primed for failure, but the fact not 1 was found that was decent seems highly unlikely to support that thought.

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9 hours ago, seattlejester said:

This is a bit of a necro, but it is an interesting point. I always thought the ring gear was one of the stronger pieces in the rear drive line. With a 60 ft less than 1.6 I imagine some kind of slicks or drag radial? The 280z stubs are noticeably stronger/thicker/more splined than the 240z ones, but I didn't think they would shift the weak point. 

 

Perhaps since most cars in the junkyard I have seen have fairly high milage and I doubt any service of the rear end, perhaps they were all primed for failure, but the fact not 1 was found that was decent seems highly unlikely to support that thought.

Remember we are talking about 1995. There were no Drag Radials back then. I used M T sportsman Pros. Some of the rears I pulled were not really  high mileage, some were wreck cars with 40k on the clock. Till this day I don’t understand why I broke so many. Then I see guys posting they went 8  ‘S and have 1000 horses and the rear is holding. 

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  • 3 weeks later...

We're really in the wrong sub-forum for this topic... but from memory, the big spectacular halfshaft disasters correlate with a lowered (or very soft) suspension that heavily squats on launch.  The remedy, at least anecdotally, is a setup where the halfshafts are approximately horizontal when the rear suspension is loaded.  For stub axles, the consensus (to the extent that one exists) is to consult with one of the aftermarket suppliers.  There was once - maybe around 2007? - a group-buy on custom machined stub axles.  This was led, if memory serves, by one JohnC, who died some years ago in a motorcycle accident.

 

Failure of the R200 itself, is reputed to be rare.  Mrod's example is the only documented case that comes to mind.  There is - again, in the Drivetrain forum - a spate of testaments of people running 9's in the quarter mile, with a welded R200... breaking half-shafts and stub axles, but not the differential (er, no longer differential) itself.

 

Regardless, it's a good problem to have!  An engine making enough power, together we enough traction, to break an R200... is an enviable achievement!

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