Big Power, Auto, And Flex Plates

[satanic]

Some of you will know about the latest developments to my R34 which involved a RB2630 transplant still using the GTT auto gearbox. Was a long term project (1.5yrs) & was only finished in mid-September. Main obstacle was free-time, but also doing a lot of the R&D involved with tricking the system into thinking it was still running a RB25DET NEO. Anyways, that's all done, it starts, it runs, and it makes power...

And in case you thought you read incorrectly, YES! It's STILL AUTO!

Bit of History:

The gearbox in my car came courtesy of Abo Bob (Adam) and had already received the full works from Mike @ MV Automatics in SA. Anyone who has played with autos in a Skyline before will be able to tell you that Mike does an awesome job with the boxes.

The box I believe has been fitted with the shift kit, and been fully rebuilt using stronger items so that it can take much more stress than the standard item. A high stall torque converter has been fitted as well, 2,800rpm worth. We've also fitted up a Davies Craig transmission oil cooler and a DEFI oil temp gauge to keep things in check.

We thought it would be OK and would hold up fine... this was a very wild guess as we had no data from others to go by, was kinda paving the path as we ventured along~

Torquing about Problems:

Anyways, the car was run in over a 4/5 day period by a couple of people and all around Sydney - it was then sent back for power tuning. Aim was to run a between 1.5-2.0BAR of boost from the Turbonetics GTK 650.

Tuning was done in stages to test the limits of the system... thought it'd be better to play it safe than sorry (very paranoid about this after so much time n money spent on it)

At 9psi, the car made 240rwkw @ 6,000rpm

At 14psi, the car made 330rwkw @ 7,000rpm (487nm)

* there is a video on my Youtube Page showing the run that did the damage... link in signature below.

Munch Munch Twang Snap - Fail:

The 2nd last run of the day which generated 330rwkw was the last straw... the flex plate in the transmission had given up. Weird sounds came from the transmission & the car was promptly cut to prevent further damage.

The attached photo shows the extent of the damage after the inspection plate was taken off.

Not only were there signs of major stressing on each of the arms, and the very evident cracks / tears. One / two of the arms actually snapped right off (now sits on my shelf as a little momento).

Fix:

Naturally I was disappointed, but what can you do? I got on the phone with Mike @ MV Automatics that afternoon and racked his brain for a solution. Apparently out of all the Skyline boxes he'd done, I was the first to present this problem to him. It was decided that a new plate was in order, one fabricated from more durable materials and shaped for maximum strength (he advised that the shape of the standard plate was not the best for big power applications). Turnaround time was estimated at 1week provided I sent down a plate for him to take measurements off (next problem).

Sourcing the Part:

You'd think with the amount of people converting cars to manual etc that these would be in abundant supply... took me a full day to find one! Big thanks to Darrin Spencer for coming forward n answering the SOS.

Finished Item:

Mike called yesterday afternoon (30/09/2008) to advise that the plate was finished and looked fantastic. There were some issues with his laser cutter guy which added a day's delay on it which he was very apologetic for. This is a description that was given to me over the phone:

* Standard ring gear re-used

* Pressed-Out Plate design replaced with a Flat Plate Design

* 4mm Steel (treated for maximum hardness/rigidity)

* Total Cost $470.00 with Express Delivery

NOTE: It was perhaps really lucky on my part, but not so much for someone else there just so happened to be another R34 that had gone in with EXACTLY the same problem. Mike had expressed his surprise and was looking into packaging this upgraded flex plate with his existing gearbox upgrades (assuming you get the full works done)

Anywho, plate will be back hopefully tomorrow and will be fitted up Sunday to re-commence tuning. Will definitely post up photos of the new item so anyone who's looking at big power from their auto can factor this in as well.

Contact Details

Mike

MV Automatics

1 Stirling Rd

Blackwood SA 5051

PH: (08) 8370 0430

FX: (08) 8370 0431

[Abo Bob]

Actually I broke the flex plate with my massive power highflow turbo RB25 and hid the fact from stan.

[satanic]

Cool... I'll forward you the bill

[STATUS]

hmmm best i chat with my auto customer... asap.

how long did your std auto hold up for? i have told him to get in contact with Mike at MV's in regards to an upgrade... but the flex plate has me worried as its pushing a smidge off 300rwkw atm.

[satanic]

Only my flex plate was damaged, the box is fine... it is the worked MV job though. My standard box never really saw much power, well not anything more than 200rwkw.

Umm... the plate held for a total of 1 week?

Prior to installation it was inspected and was perfect, it was only at 240rwkw at that point though (under the RB25)

All in all I think it took about 10-15 dyno runs at 300rwkw+

And let's not forget that the Dyno runs are actually done from start to finish on the one gear, i.e. no changing gears mid way which would no doubt add a lot more forces onto the plate (I would think so anyway).

[adzR34]

Really really keen on seeing how long the box lasts and shifts.. Saw the videos, Stan this is one hell of a build up!

Keep up the good work

[satanic]

Thanks mate... I'm keen as to see this plate and even more so to see it back on the car!

[Angus Smart]

Go son!! haha cant wait to see how it goes!!

and some good videos also! p.s. you should introduce me to tom!! when i take the car there anyway.

[satanic]

Cheers Andrew!

There is speculation that there is a little Japanese man in Sydney who may be able to render assistance - verifying authenticity of the rumor now.

[Howie]

Insane stuff Stan... RB2630 in an Auto no friggen way! Love your dyno clips.

I'll be hitting up MV Automatics, next time my box is due for a service to get an shift kit installed. They seem to have a pretty good reputation here in SA and on the forums.

[satanic]

Hi all,

Hope you all had a nice long weekend... thanks to Australia Post being complete idiots, my R34 plans were cut short (leaving more time for boozing I guess, so win either way).

Anywho, this just arrived at Mitch's place so a quick snappy showing the new flex plate. Looks very tough, well at least tougher than the standard item As mentioned, the whole piece is now flat with 4 lugs in place to position it against he torque converter. Mike @ MV Automatics did mention that longer bolts will need to be used (12mm x 1mm, 25mm shank) so it's off to the engineering shop for some quality items soon.

Stay tuned for more...

[satanic]

Little update:

New plate has been installed and the car is now ready to commence tuning again... will have more results in a few days (hopefully). Also got more photos of the original flex plate damage, will upload shortly... let's just say it's EXTREME!

Request:

Can any R34GTT AUTO owners out there please do me a HUGE favour and take a photo of the Turbine Speed Sensor plug in the engine bay? It's a grey plug with three wires going into it from the G/BOX. Need a photo of the plug from the Gearbox side, not the engine side... had a small accident when taking the box off n pulled all three pins out of the plug.

[satanic]

More Photos of Flex Plate Damage:

[jbonez]

Wow thats amazing how mangled it is.

[dangerman4]

good job Stan

im running the same power out of my r33gtst rb25 auto with a fully built box from mv, and have been for 18 months with no flex plate issues.

must be a 34 thing, as i dont remember my plate looking anything like the one you have shown.

can you please throw up the dyno graph showing boost and power, and then one showing torque.

it would be a good comparison with my car running the 25 allthough with a heap more boost.

[satanic]

Yeah it must be a 34 / Stagea thing... I'm pretty sure the 33 flex plate is less "holy" Must've been a design fault or Nissan just never intended it to be under so much stress. Well the new plate is holding up fine - we've taken possession of the car back from the tuner due to the turbo > manifold gasket blowing out (weird since its stainless, but we'll see tomorrow). Went for a little quirt tonight after fixing the Turbine Speed Sensor wiring and it HAULS! (even with an exhaust leak )

Dyno graph - I've got them but can't put them up - no scanner I'll see what I can do at work tomorrow.

FYI for those whoe ever get as stupid as we did and go trigger happy on the Turbine Speed Sensor... the wiring goes White, Black and then Red. Took me three attempts but its all sorted, A/T light is GONESKIES! What a bloody mission to get that plug apart.

1 - Signal - White

2 - Ground - Black

3 - Ground with Shield - Red

[wisey18]

Just seen all your vids on youtube of your EPIC build and I must say congrats and it seems (well besides one small hiccup) that it has all payed off!

Very interesting combo you have with the 26 head and 30 bottem end... oh yeh and still retaining the auto box!

Can't wait to see your next dyno results!

Keep up the good work!

[satanic]

Well it's been a little while, and admittedly I've just been lazy with updating this

Anywho... upon discussion with others, we have decided to draw a sensible line to wrap up 2008 modifications - 350rwkw was what this line was, and that we got with 1BAR of boost. In doing so, we managed 526nm of torque which is a tad bit more than before... All the above was measured using a Dynojet Research.

The main thing after yesterday's touch up was:

1) Power delivery was smooth throughout the rev-range

2) Gear changes are now smooth as (achieved through the F-CON I believe)

3) AFRs set perfect

I can't really comment on how far this new flex plate has to go, as we were playing the "safety first" game... but I do believe it would be more than comfortable with another 0.5BAR of boost in there I must note though that at no stage during the 40+ dyno runs yesterday, did the AUTO OIL TEMP go above 70 degrees.

[Howie]

Good work mate. Can't wait for what's next

[satanic]

Cheers... and btw, if anyone else is doing this - be sure to use good quality turbo lock nuts, I can't believe they came loose TWICE (resulting in boost issues)