dr20t wrote:Rob just to be clear mate im not having a dig at all. As you know i am more than happy and willing to help people and share my experiences where possible to assist. I just really genuinely dont want you to be chasing unicorns unneccesarily.
No worries at all Mick. My comments were aimed at one specific individual who is not (to my knowledge) you. Who he really is, that's yet to be confirmed.
I'm not trying to start a shit fight either. And without getting into semantics, the ecu doesn't pull power either. It can pull timing, add or subtract fuel (in closed loop) and add or subtract wgdc to reach a desired outcome. Closed loop fueling limits what can be done in terms of target afr (always stoich in closed loop unless altered by tuner which is unlikely). If the ecu is pulling power up top, then its either through reduced timing or wgdc. No ifs or buts.
Yep, you're right here - it can pull timing, or adjust fuel, or change the wastegate duty cycle to impact how much power is delivered at a given time (within reason - it obviously can't make the engine produce more power than it can physically make bound by airflow and fuelling). The way I've described what Matt told me may to be blame here - basically, he said his tune of the ECU recognises when the transmission is slipping, and alters parameters to reduce power (realistically, to reduce torque, as that's what causes a transmission to slip, and power is a factor of torque).
If the tcu is allegedly pulling power, then the mechanism to do this is through solenoid function. Having seen and played with the valve body personally, I can tell you there isn't a solenoid for "line pressure". The torque c
Seems you missed typing here, to see what you were going to say about the torque converter would be good - but as I've noted, I think there was a misunderstanding that the TCU was pulling power - that's not what I said though, Matt can most probably explain a lot better than I can how he actually achieves this (within reason, there could be "trade secrets" involved in the actual method he uses).
Couldn't power being down after consecutive runs throughout the session be caused by something a little more palatable and orthodox? Like the heat, and heat soak associated with the TMIC?
The car was pretty warm to start with (we'd driven from the airport to Kirawee, and then the car sat for quite some time before the dyno runs were started - this would have allowed the transmission to cool a bit, but the TMIC would have actually gotten quite a bit hotter when sitting still for a while as it did.
Confused as to what parameters are indicative of burnt trans fluid here?
Pulling the transmission dipstick and smelling it made it obvious that the fluid is burned. The transmission also started to get noisy (and was getting noisier with subsequent runs) with progressive runs, Matt got out of the car at one stage and asked me if I was sure there was sufficient fluid in the transmission to start with - we checked it, and found it to be both a little bit over-full and definitely burned.
Easy way to check if you don't mind getting your hands a little dirty - pull battery out, loosen ATF filter in passenger side inner guard liner (just loosen it enough to collect some fluid) and get it tested before going to the extreme of a power flush (which is also dangerous to your pump servo in your 5eat if not done correctly)
The 5eat servo pumps about 5 litres per minute from memory (can check my manual from when I built my 5eat), so unless your able to hydraulically pump in trans fluid at the same or greater rate then you run the risk of trans damage.
Trying to save you some time, money and most importantly headaches or disappointment.
I appreciate your advice, and am absolutely taking it on board (I know you've had particular experience around the 5EAT transmissions). I'll do that, and will see if I can find someone who can do a reading on the fluid.
The plan with the power flush was to drop the oil in the pan, re-seal the pan, replace the dropped fluid, then disconnect a hose that runs to the radiator, allow it to pump about 2L out into a bucket, shut it down, add fluid to ensure it's full again, dump another 2L, repeat until fluid runs clean. Then close everything up, top up again, actuate the gear selector to make sure the fluid has settled right in, check the levels again, drive it slowly around the block, check the levels again. My understanding, with a capacity of just under 10L, was that this should be safe enough (and should ensure that issues like you mentioned earlier, where simply draining the fluid could result in stuff getting caught in the solenoids due to low flow as the fluid in the pan finished draining away) - if that's still not sufficient to protect against damage, I'll look at getting it done professionally.
Why so many contradictions...
