Stronger driveshaft replacement?
 

Hello

I have stock (engine-wise) 2020 BRZ and it seems I have bent driveshaft joints after 3 years of use (possibly leading to transmission leakage which was detected first). Since OEM driveshaft is kinda expensive (around 1500 usd in EU) I'm considering some aftermarket options that wouldn't fail so quickly,

Any suggestions? Is it... I wouldn't say "normal" but within expectations to kill driveshaft on stock BRZ in 3 years? It's driven pretty hard, also on track, using tw80 / tw100 tyres so there may be some slightly increased stress on it coming from increased grip but it shouldn't be too bad I believe... I dunno.

I’ve never heard of someone killing a stock driveshaft in one of these.

You are limited to the carbon fiber aftermarket options. DSS or PST. I don’t think Verus makes their’s anymore but they used to have one.

The DSS aluminum is not an option for cars seeing over 110mph. @blsfrs had one fail and did a thread on it. DSS admitted the diameter is not enough and the critical speed of the aluminum shaft is too low.

IMHO: I'd stick with the stock one.

https://www.ft86club.com/forums/showthread.php?t=154478

OP is in Poland. :(
@lapsio, I agree with others. Stock is the only safe bet. Something very strange must have happened to damage your original.

Stock is your best bet. All one piece upgrades will have speed limitations and are more susceptible to physical damage. If your stock got damage my bet it was from hitting something.

According to USPS, shipping a 20lbs item to Poland would be around $220. There might be cheaper options. That's better than $1500 for a nude one.

Do they not have wrecking yards in Poland?

;)

I've had my CF one piece up to 120mph a couple times. Smooth as silk.

I have a Verus and at 130 it starts to have a harmonic vibration.(it does not vibrate but makes a noise) You can push it past but if you do it repeatedly you are goin to have a catastrophic failure.

Oh, hell yes. Good point.

Also a good point. ;)

...well, question.

Mine is DSS.

Several months ago (in a galaxy far, far away) Didn't someone post about a CF driveshaft failure on their rally car.

Looks like about same diameter, that ones critical speed will be similar.

Yep, probably took a rock hit. CF is strong, until it get damaged then it is shit. I have the center tunnel covered to protect it from getting hit.

Just ask Stockton Rush.


https://upload.wikimedia.org/wikiped...e_logo.svg.png

I would say get the gr86 driveshaft but I’m not 100% sure they fit the first gen.

It fits and it's 1,5 kgs lighter. I would like to know is the diameter is the same, and how they achieved more lightness.

I’m down to order one and measure it for you, but do you remember if the automatic and manual driveshafts are the same?

Or you could check some documents that somebody has.

I know I was going to do my usual parts.subaru.com research but wanted to see if someone knew top of mind first lol.

Edit: it appears auto and 6mt have different part numbers, makes my eBay shopping slightly more complicated

I meant the stuff in my signature. Specificlly for the shaft diameters.

Thank you for your help. I confirm that both the propeller shafts have the same diameter, 70 in the first part and 57 in the second part.
Now we'd need to understand why the second gen is lighter, less material (so more flexible) or just different material?

I’ll take some comparison photos later this month when my GR86 driveshaft arrives!

https://i.imgur.com/1YeuoFO.jpeg

They are pretty identical but this section was different. Looks like they replaced the main U joint with a CV joint?

Thank you very much. Are you able to weight them?

Didn’t have anything to weight them with by unfortunately the gr86 is already on the car.

Any difference in driving?

Not that I can tell so far but I’ve barely driven the car since the install.

With the “new” bearing, U joints and new fluids everything feels very smooth but I will going to the track this Friday where I’ll get to ring her out and attempt to feel the difference. Will update once I know more.

So after putting on a few hundred miles & a track day I notice a slight improvement in peppiness but nothing major to write home about. I bought mine for $130 so I think it’s worth doing if you already have a lot of miles on your original/current driveshaft.

I did notice a slight increase in mpg but this could be due to the fluid swap. The replacement of the U joint with a CV joint also seems to be make things respond more quickly.