Jump to content
SAU Community

Recommended Posts

I am currently running a 48mm progate and since fitting the 6870 it will not hold boost at the track.

It held it on the dyno with slight creep after 6000rpm but at the track I'm hitting boost cut in first no matter how low I set the eboost.

Has anyone done the straight swap for a 50mm? Will it hold it ya reckon?

Or will I have to get a 60mm and do a cut and shut job on the exhaust manifold?

Link to comment
https://www.sau.com.au/forums/topic/457965-48mm-vs-50mm/
Share on other sites

Want it to hold 30psi for 700hp (on dyno we had it set at 28 and it crept late then ignition break down at 7200)but as stated at the track I had it set 20 points lower on the eboost and it still hit 32psi as soon as it could in first gear.

60ft in 1.34. Was like a boost line was off.

Link to comment
https://www.sau.com.au/forums/topic/457965-48mm-vs-50mm/#findComment-7562021
Share on other sites

Try a much stronger spring first - as near as possible to target boost is better. Set your boost cut a bit higher. Does it overboost in the other gears (apart from 1st)? If you can borrow a 50mm W/G that would be worth a try but if you have to buy one I would go straight to 60mm.

Link to comment
https://www.sau.com.au/forums/topic/457965-48mm-vs-50mm/#findComment-7562108
Share on other sites

If a boost line was off it may have hit over 60psi, mine did.

Not sure about the gate you have, but Turbosmart had to re-design their spring caps to hold that boost. They made a much taller cap with springs 3 times as long, so the stiffer springs wouldn't limit the travel of the gate.

If you hit the soft limit at the track, that would cause overboosting no matter what the controller was set to.

Link to comment
https://www.sau.com.au/forums/topic/457965-48mm-vs-50mm/#findComment-7562133
Share on other sites

Interesting Scotty that sounds promising for the 50.

Jet I would just get the 60 but it's a manifold off job, which I will do if I have to but I'm sure ive read plenty of people having success with the 50 so just chasing feedback. So easy to just bolt the 50 on and go racing. 60 is a major for me at the moment.

Thanks for the feedback.

Link to comment
https://www.sau.com.au/forums/topic/457965-48mm-vs-50mm/#findComment-7562260
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Latest Posts

    • OK, so regardless of whether you did Step 1 - Spill Step 2 - Trans pan removal Step 3 - TCM removal we are on to the clean and refill. First, have a good look at the oil pan. While you might see dirty oil and some carbony build up (I did), what you don't want to see is any metal particles on the magnets, or sparkles in the oil (thankfully not). Give it all a good clean, particularly the magnets, and put the new gasket on if you have one (or, just cross your fingers)
    • One other thing to mention from my car before we reassemble and refill. Per that earlier diagram,   There should be 2x B length (40mm) and 6x C length (54mm). So I had incorrectly removed one extra bolt, which I assume was 40mm, but even so I have 4x B and 5x C.  Either, the factory made an assembly error (very unlikely), or someone had been in there before me. I vote for the latter because the TCM part number doesn't match my build date, I suspect the TCM was changed under warranty. This indeed led to much unbolting, rebolting, checking, measuring and swearing under the car.... In the end I left out 1x B bolt and put in a 54mm M6 bolt I already had to make sure it was all correct
    • A couple of notes about the TCM. Firstly, it is integrated into the valve body. If you need to replace the TCM for any reason you are following the procedure above The seppos say these fail all the time. I haven't seen or heard of one on here or locally, but that doesn't mean it can't happen. Finally, Ecutek are now offering tuning for the 7 speed TCM. It is basically like ECU tuning in that you have to buy a license for the computer, and then known parameters can be reset. This is all very new and at the moment they are focussing on more aggressive gear holding in sports or sports+ mode, 2 gear launches for drag racing etc. It doesn't seem to affect shift speed like you can on some transmissions. Importantly for me, by having controllable shift points you can now raise the shift point as well as the ECU rev limit, together allowing it to rev a little higher when that is useful. In manual mode, my car shifts up automatically regardless of what I do which is good (because I don't have to worry about it) but bad (because I can't choose to rev a little higher when convenient).  TCMs can only be tuned from late 2016 onwards, and mine is apparently not one of those although the car build date was August 2016 (presumably a batch of ADM cars were done together, so this will probably be the situation for most ADM cars). No idea about JDM cars, and I'm looking into importing a later model valve body I can swap in. This is the top of my TCM A couple of numbers but no part number. Amayama can't find my specific car but it does say the following for Asia-RHD (interestingly, all out of stock....): So it looks like programable TCM are probably post September 2018 for "Asia RHD". When I read my part number out from Ecutek it was 31705-75X6D which did not match Amayama for my build date (Aug-2016)
    • OK, Step 3, if you need to remove the valve body, either to replace it, the TCM, or to do a more complete drain.  First, you need to disconnect the TCM input wires, they are about half way up the transmission on the drivers side. One plug and the wires are out of the way, but there is also a spring clip that stops the socket from sliding back into the transmission. On my car the spring clip was easy to get, but the socket was really stuck in the o-ring of the transmission housing and took some.....persuasion. You can see both the plug to remove (first) and the spring clip (second) in this pic Incidentally, right next to the plug, you can see where the casting has allowance for a dispstick/filler which Nissan decided not to provide. there is a cap held on with a 6mm head bolt that you can remove to overfill it (AMS recommend a 1.5l overfill). Final step before the big mess, remove the speed sensor that is clipped to the valve body at the rear of the box.  Then removal of the Valve Body. For this the USDM Q50 workshop manual has a critical diagram: There are a billion bolts visible. Almost all of them do not need to be removed, just the 14 shown on the diagram. Even so, I both removed one extra, and didn't check which length bolt came from which location (more on that later....). Again it is worth undoing the 4 corners first, but leaving them a couple of turns in to hold the unit up....gravity is not your friend here and trans oil will be going everywhere. Once the corners are loose but still in remove all the other 10 bolts, then hold the valve body up with 1 hand while removing the final 4. Then, everything just comes free easily, or like in my case you start swearing because that plug is stuck in the casing. Done, the valve body and TCM are out
    • OK, so if you are either going for the bigger fluid change or are changing the valve body which includes the Transmission Control Module (TCM), first you should have both a new gasket 31397-1XJ0A and a torque wrench that can work down to 8Nm (very low, probably a 1/4 drive one). You can probably get by without either, but I really didn't want to pull it all apart together due to a leak. First, you now need that big oil pan. The transmission pan is 450 long x 350 wide, and it will probably leak on all sides, so get ready for a mess. There are 24x 6mm headed bolts holding the pan on. I undid the 2 rear corners, then screwed those bolts back in a couple of turns to let the pan go low at that end, then removed all the middle bolts on each side. Then, undo the front corner bolts slowly while holding the pan up, and 80% of the fluid will head out the rear. From there, remove the remaining bolts and the pan is off. You can see it is still dripping oil absolutely everywhere...it dripped all night.... I got another couple of litres when I removed the pan, and then another few when I removed the valve body - all up another 4l on top of the 3 already dropped in step 1.
×
×
  • Create New...