Anyone using the aluminum PST Driveshaft?

[AdamVR4]

PST Aluminum/Steel Hybrid 2-piece Driveshaft for AWD TT/VR4*-*Mitsubishi 3000GT*/*Dodge Stealth Parts (http://www.3sx.com/store/comersus_viewItemBundle.asp?idProduct=643)

How does it compare to the stock drive shaft and CF shaft? Will it survive all the abuse I could throw at it?

[AdamVR4]

Looks like quite a few people have installed these, including IPO on his personal car. Have they survived any impressive 60's? What's the fastest speed people have driven with them?

Is the PST shaft similar to drive shaft shop's?

http://www.driveshaftshop.com/import-driveshafts/mitsubishi/mitsubishi-91-93-3000gt-vr-4-5-speed-650hp-3o-aluminum-driveshaft

[Roybatty]

Looks like quite a few people have installed these, including IPO on his personal car. Have they survived any impressive 60's? What's the fastest speed people have driven with them?

Is the PST shaft similar to drive shaft shop's?

The Driveshaft Shop | MITSUBISHI 91-93 3000GT VR-4 (5-Speed) 650HP Aluminum Driveshaft - Mitsubishi - Import Driveshafts (http://www.driveshaftshop.com/import-driveshafts/mitsubishi/mitsubishi-91-93-3000gt-vr-4-5-speed-650hp-3o-aluminum-driveshaft)

The wife ordered the PST one for me last week =)

I had a failed lobro boot. I hilllbilly engineered a boot on it. The DS Shop one only replaces first 2 sections.

[CoopKill]

Had mine for about a year. It has only seen about 140 mph, and only abused by bpu 9b's.

Not had any issues, and was slightly noticeable after install.

Sent from my DROID2 GLOBAL using Tapatalk

[AdamVR4]

The wife ordered the PST one for me last week =)

I had a failed lobro boot. I hilllbilly engineered a boot on it. The DS Shop one only replaces first 2 sections.


It is nice that the PST one eliminates all 3 sections. I just hate that it doesn't seem to have any speed or power ratings.

[Broomfield Racing]

I have been running one since I started drag racing. Been perfect ever since. Very hard launches as I'm sure you know.

[AdamVR4]

I have been running one since I started drag racing. Been perfect ever since. Very hard launches as I'm sure you know.

Exactly the sort of response I was hoping for :headbang:

:peelout:

[AdamVR4]

Unless someone says something negative about this shaft, I think I'll order it this afternoon.

[Broomfield Racing]

I wish I had painted a line down mine when it was new. If you do end up buying one would you mind doing this? Id like to see if they twist after hard launches. I am going to add one on mine before next season.

[Broomfield Racing]

One negative point which I was unaware of...looks like the carrier bearing is different than OEM and priced at $170 from 3SX.

[green-lantern]

If it hasn't broke on Dave's car then it's a pretty safe bet it's a good part. :bigthumb:

I'd say a sharpie would be the best thing to use to paint a line down it.

[FeaRpb]

Totally jealous. Let me know how you like it once you get it Adam.

[niterydr]

Also interested in a review Adam as this is on the "2 year plan" for my car.

[NOMIEZVR4]

Why not the 1 piece driveshaft instead of the 2?

[CoopKill]

The only one piece is CF, and there have been issues with them vibrating/coming apart. (I'm sure that is all dependent on HP level, and abuse as with all)

[green-lantern]

One negative point which I was unaware of...looks like the carrier bearing is different than OEM and priced at $170 from 3SX.


NOTE: If you buy the driveshaft, a new PST carrier bearing IS included, you do not need to purchase one separately.

Looks like it comes with one so unless he wears that one out he is good.

[AdamVR4]

As far as I understand, it does come with the necessary carrier bearing. I just ordered it. Thanks for the feedback, fellas.

As for the line... If this shaft plastically deforms at launch (such that I would see twist in the line), it's going to fail in a hurry. I'm sure the shaft twists elastically (this is a perk because it will transmit less shock to the rear end), and it will one day fatigue fail (because it's aluminum)... but I'm not sure it's even worth it to make the line. Maybe I'll do it for shits and grins.

[Broomfield Racing]

I have read stories of other platforms painting a red line and watching it turn into a candy cane. Would be cool to see :)

[AdamVR4]

I have read stories of other platforms painting a red line and watching it turn into a candy cane. Would be cool to see :)

Really?! They twist that much without failing?! Pics? Links?

[FeaRpb]

Really?! They twist that much without failing?! Pics? Links?

x2

:hahainternet:

[UTRacerX9]

Really?! They twist that much without failing?! Pics? Links?

The EV12 finally makes it to the track! - MBWorld.org Forums (http://mbworld.org/forums/w211-amg/421538-ev12-finally-makes-track.html)

It's not gonna come out looking all nice and neat like a candy cane, but they can twist in on themselves sometimes without snapping. First post has three pics on a MB with 850+ torque.

[AdamVR4]

I just shot PST an email asking for torque/power ratings, speed rating, wall thickness and alloy... Hopefully they get back to me.

[CoopKill]

I remember somewhere saying it was around 600 whp...

[Broomfield Racing]

I read it somewhere...google search found this..I have not found evidence though so maybe they were just talking without experience.

"Main disadvantage of the aluminum shaft vs. chromoly is that aluminum shafts have a tendency to twist and fail from repeated hard abuse. Some of the domestic guys will draw a line down a new aluminum shaft. After numerous passes, they start to look like a candy cane. After so much twist, it's time to buy a new shaft. That's usually cars with MASSIVE amounts of torque though and I have no idea if it's relevent to something like a GT42 powered EVO."

AWD Motorsports Aluminum Driveshaft.. Preview Pics!! - Page 3 - evolutionm.net (http://forums.evolutionm.net/evo-sale-engine-internals-drivetrain/370020-awd-motorsports-aluminum-driveshaft-preview-pics-3.html)

Either way, it's holding up to a lot of abuse.

[MR2]

I've been meaning to do a nice big mark down mine too.

I have the SCE center so in theory it's getting more power to the rear, shame it's not making much power and/or on slicks :p

[AdamVR4]

I remember somewhere saying it was around 600 whp...

Driveshaft shop's is 650 HP... If that's engine, it's pretty pitiful. I can't find any real specs or information on PST's.

Aluminum, unlike steel, WILL fatigue fail given enough cycles. If the peak stress is lower, the number of cycles may be really high. If you're pushing the limits of the shaft, approaching it's static yield strength, the number of cycles until failure may be very low. The fact that no one has asked these questions since 2008 is pretty disappointing.

With the OD of the shaft, the length, the wall thickness and alloy (hence the email), it's trivial to determine how much torque it would take to yield it. I suppose with the weight of the drive shaft assembly, I can get a rough approximation for the wall thickness.

[MR2]

I wonder if you could get them to make it out of 7073 as opposed to the 6063 or whatever it's currently made from.

[green-lantern]

Driveshaft shop's is 650 HP... If that's engine, it's pretty pitiful. I can't find any real specs or information on PST's.

Aluminum, unlike steel, WILL fatigue fail given enough cycles. If the peak stress is lower, the number of cycles may be really high. If you're pushing the limits of the shaft, approaching it's static yield strength, the number of cycles until failure may be very low. The fact that no one has asked these questions since 2008 is pretty disappointing.

With the OD of the shaft, the length, the wall thickness and alloy (hence the email), it's trivial to determine how much torque it would take to yield it. I suppose with the weight of the drive shaft assembly, I can get a rough approximation for the wall thickness.

on the other hand I've never seen anybody with a 3s break one. Not saying it hasn't happened but I've never seen it.

[AdamVR4]

on the other hand I've never seen anybody with a 3s break one. Not saying it hasn't happened but I've never seen it.

Right, but how big is the sample size? Dave is a fantastic data point, but we need more.

Based on what I've read, Chris Hill has the PST aluminum DS on his current VR4. He made dyno pulls up to 835.5 AWHP / 747 AWTQ per 3S Quicklist-www.import-power.com (http://www.import-power.com/3squicklist/dyno.html)

...While that's absurdly impressive power, he's never tracked that car, has he? He's definitely abused it on the street, but street launches never seem to do the damage that drag strip launches do... Between his car and customer cars, he's probably got the most experience of anyone on the planet with this part. Guess I'll shoot him a PM :)

[green-lantern]

Right, but how big is the sample size? Dave is a fantastic data point, but we need more.

Based on what I've read, Chris Hill has the PST aluminum DS on his current VR4. He made dyno pulls up to 835.5 AWHP / 747 AWTQ per 3S Quicklist-www.import-power.com (http://www.import-power.com/3squicklist/dyno.html)

...While that's absurdly impressive power, he's never tracked that car, has he? He's definitely abused it on the street, but street launches never seem to do the damage that drag strip launches do... Between his car and customer cars, he's probably got the most experience of anyone on the planet with this part. Guess I'll shoot him a PM :)

He did track it at NG in Memphis. Not sure if he had that shaft then or not. There hasn't been a lot of talk/info about them. I haven't heard of a lot of CFDS's breaking until last NG though. I thought the CFDS was about bullet proof but then they seemed to break right and left. lol

[Ninja Performance]

Hey all. I was hurting too much to get on the boards the last few days. Here is my take on it.

I do have it on my VR4. I have dyno'd 835AWHP 747AWTQ and many many dozens 800+AWHP runs and countless 700+ tuning, changing turbos, changing fuel types to test different setups and limits.

I have also run it at the track. A number of tracks. I have been thru a dozen transfer cases before finally going with the SS front and mid case. While I have only been 10.57 and 141MPH due to the lifter bleed down/girdle push 2 bolt issue I always had (now it is 4 bolt but didn't get a track run in after that), I did go 115MPH in the 1/8th. I have also abused it on the street. The shaft still drives smooth and I never had an issue with it.

I would recommend it.

-Chris

[NOMIEZVR4]

Would love to read a review on this thing once you get it mounted Adam...:)

I'm planning on picking one up next year because of the weight savings.

[green-lantern]

Thanks Chris, I'm thinking of getting one of these also. Hopefully I can raise the cash soon. So many mods, so little time and money. :sigh:

[AdamVR4]

Mark @ PST called me in response to the email... Said the shaft was probably good to 600-650 ft-lbs. It's 6061 (didn't specify temper), 3" OD, .125" thick wall. Not exactly what I wanted to hear, but oh well. I'll put a line on it and see how it goes. It's a good match for my current set-up, but will likely need to be addressed if I try for more power later.

[MR2]

will put a line on mine tonight as well

[AdamVR4]

You going to use a sharpie and a yard stick or what?

[MR2]

Permanent marker and little finger down side of shaft to guide (sounds dirty)
http://3000gt.com.au/car/Misc/Drive%20Shaft/2012-01-03%2017.05.09.jpg

[Ninja Performance]

Have put 747AWTQ thru mine. Never marked it so don't know if it twisted. Will mark it but won't test until late this year after a recoup from the transplant.

-Chris

[Chris@Rvengeperformance]

Mark @ PST called me in response to the email... Said the shaft was probably good to 600-650 ft-lbs. It's 6061 (didn't specify temper), 3" OD, .125" thick wall. Not exactly what I wanted to hear, but oh well. I'll put a line on it and see how it goes. It's a good match for my current set-up, but will likely need to be addressed if I try for more power later.

Is he saying its good for 600-650 ft-lbs in a RWD application or AWD?

[Ninja Performance]

Is he saying its good for 600-650 ft-lbs in a RWD application or AWD?

Good question, I didn't even think about that.

-Chris

[green-lantern]

Is he saying its good for 600-650 ft-lbs in a RWD application or AWD?

Very good question

[MR2]

in his words "the shaft is good for" so I would interpret that is the torque rating the shaft by itself can withstand

[NOMIEZVR4]

Hey did you install this thing? Any change in driveability?

[Chris@Rvengeperformance]

in his words "the shaft is good for" so I would interpret that is the torque rating the shaft by itself can withstand

there is a lot more torque at the driveshaft than 650 ft/lbs, due to gear reduction.

[anyonebutme]

there is a lot more torque at the driveshaft than 650 ft/lbs, due to gear reduction.

Other way around, since the shaft spins faster than wheels, torque is less than at wheel.

[MR2]

to my knowledge not a single one is broken, 650lb foot sounds like shitloads :p worry about the 6 speed TC gears first, we're breaking those :)

[Chris@Rvengeperformance]

Other way around, since the shaft spins faster than wheels, torque is less than at wheel.

that's true, but say you are in 1st gear. The shaft will see a lot more power than at the flywheel.

[AdamVR4]

I assumed he meant dyno WHP, but I'll do my own quick and dirty analysis and report back when I'm done.

[green-lantern]

I assumed he meant dyno WHP, but I'll do my own quick and dirty analysis and report back when I'm done.

I'm thinking that also but if they are talking about a RWD then wouldn't AWD be able to handle aprox twice the power?

[MR2]

Nah, most of the actual power ends up going through the rear wheels (weight tranfer etc) I imagine the front wheels are doing bugger all really.

[green-lantern]

Nah, most of the actual power ends up going through the rear wheels (weight tranfer etc) I imagine the front wheels are doing bugger all really.

On a launch a good portion goes to the back but give me a break. What is the use in AWD with your logic?

[MR2]

pulling you out of corners :)

by not doing much I expect 75%+ of your "hard launch" power is going through the rear wheels...

I know when I dump it for the first few seconds the front wheels just seem to spin..which I expect is when your pushing your highest torque load through the shaft...

engine at 4k, wheels not moving at all, clutch release...that's when you'd put most strain on it...and the rear wheels are likely to grip rather than just offloading the torque by spinning (aka front)

[green-lantern]

pulling you out of corners :)

by not doing much I expect 75%+ of your "hard launch" power is going through the rear wheels...

I know when I dump it for the first few seconds the front wheels just seem to spin..which I expect is when your pushing your highest torque load through the shaft...

engine at 4k, wheels not moving at all, clutch release...that's when you'd put most strain on it...and the rear wheels are likely to grip rather than just offloading the torque by spinning (aka front)

You are ruining a SC center diff right? Your front's are going to still pull some of the stress. Most VCU cars are probably pulling from the front. I knew someone would say this. :sigh:

The reason I said "aprox" as in "approximately" is because of times weight transfer etc. on the dyno (like we were just talking about) this isn't really an issue. I didn't think it was necessary to point it out though.

So now back to.... If this was rated for RWD wouldn't it stand up better in an AWD car?

[anyonebutme]

I leave 4 equal black lines on the ground during launch...

Torque applied to ground is a function of engine torque and gear ratios. Until there is wheelspin, weight transfer doesn't have jack to do with where torque is "applied" around the car. In an open differetial (which our VCU replicates on initial torque application), when the fronts spin, they reduce the available torque to the rear wheels, as the fronts are converting torque into velocity, which what is converted can't be sent to the rear.

That's a sh*t explination, but you should get the idea. Until there's wheelspin, about 55% of the engine torque goes through the rear axle with the stock center diff.

[MR2]

Schweeet, so your still going with up to what..55% of torque/power can go through the Driveshaft under normal circumstances?

what I was attempting to say, is I suspect that even with the center diff folks might, under drag circumstances, push more than 55% through it, sound plausable? I am including under front wheel slip conditions??

[anyonebutme]

If you get the rears to spin, and some other situations, it's possible to get more than 55% of torque to be sent rearwards. Problem with the spinning scenario is that since you are converting torque to velocity through wheelspin, the actual torque being absorbed by the shaft can not exceed the traction ability of the tire. Send more torque, wheel spins faster, not "harder".

It's easy to see when strapped to a dyno, as even as the car bounces around (weight trasferring everywhere), the power split remains constant.

[AdamVR4]

Bumping this just to point to my related thoughts at this post: http://www.3sgto.org/f2/1-piece-2-piece-aluminum-driveshaft-should-i-have-made-7563-2.html#post147076

I still plan to do the analysis to determine the safety factor with a 3" shaft at ~600 whp...

[AdamVR4]

I added to an old spreadsheet and did a simple static analysis...
6061-T0 shaft will fail around ~450 ft-lbs. T6 should survive to ~1100 ft-lbs. Given impact loads, 600 to 650 ft-lbs is pretty reasonable. Did I mess up?

http://i26.photobucket.com/albums/c115/adamvr-4/driveshafttorsionalstress5spd.png