Milo500 Posted March 25, 2018 Share Posted March 25, 2018 Hi, I have just changed my torque converter to a precision 3200 high stall and my old knackered auto box for another one (aristo box shimmed by David p). The car is a Turbonetics single turbo conversion from original twin (jap spec). It has a greddy emange blue piggyback ecu and made 474hp at hudson speed shop on a tune. However I need some advice as I have two problems. One of them is that when everything is warm etc, holding it on the brake and under throttle standing still, the revs go up and down about 1k over and over at around 2.5k-3.5k...which it didn't do before. I need this to work as the reason for the converter is so I can hold it in the brake on the drag strip. The other problem is probably not to do with the gearbox, but any advice is greatly appreciated. When driving normally, the car runs perfect...however when under full throttle It feels like its misfiring above 4.5-5k revs. Do you reckon this is fueling/electrical, or could it be to do with the map? (It was mapped about 8 months ago and ran fine before). It had this issue just before I changed the gearbox. Many thanks for any advice/solutions. Quote Link to comment Share on other sites More sharing options...
jcbt Posted March 25, 2018 Share Posted March 25, 2018 Point one as you still have the OEM autobox ecu you will need to remove the trac fuse to achieve the higher revs on brake hold but do not do this too often and always replace after drag racing. Point two misfires at that sort of revs is usually down to coil packs or clips and sometimes spark plugs. There are plenty of threads on misfires so the search button will be your friend. Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 25, 2018 Author Share Posted March 25, 2018 (edited) Point one as you still have the OEM autobox ecu you will need to remove the trac fuse to achieve the higher revs on brake hold but do not do this too often and always replace after drag racing. Point two misfires at that sort of revs is usually down to coil packs or clips and sometimes spark plugs. There are plenty of threads on misfires so the search button will be your friend. Awesome, thank you very much for the response....the misfire is a small problem, I was more concerned about the launching problem...what's the reason for replacement of the fuse after? Is it not the same as just deleting the trac control? And yea I'll only be brake holding it on the drag strip...really don't want to have to change the gearbox again too soon haha. Cheers Edited March 25, 2018 by Milo500 (see edit history) Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 26, 2018 Author Share Posted March 26, 2018 Also I have read that it's bad for an auto box to delete the trac control, why is This? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 26, 2018 Share Posted March 26, 2018 Hi stall converters generate a huge amount of heat in the auto box fluid, so you need BIG coolers, which will then OVER cool in normal usage, or as normal as one of the things allows, so you also need a good quality thermostat. The stock ecu does not expect to see zero road speed and a higher than stock stall engine RPM when in Drive, so it tries to stop the revs increasing. Removing the TRAC fuse probably overcomes this. Auto box abuse is a costly hobby, my stash of dead auto boxes from behind single turbo 2JZ engines increases regularly. The feel good side of things is you keep DavidP in pain killers and fags Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 26, 2018 Author Share Posted March 26, 2018 Hi stall converters generate a huge amount of heat in the auto box fluid, so you need BIG coolers, which will then OVER cool in normal usage, or as normal as one of the things allows, so you also need a good quality thermostat. The stock ecu does not expect to see zero road speed and a higher than stock stall engine RPM when in Drive, so it tries to stop the revs increasing. Removing the TRAC fuse probably overcomes this. Auto box abuse is a costly hobby, my stash of dead auto boxes from behind single turbo 2JZ engines increases regularly. The feel good side of things is you keep DavidP in pain killers and fags I'm currently not using a thermostat, can you link me or tell me what brand a good inline one would be? I have fitted a gearbox temp gauge etc so i can now see when it is warm/too warm. How much torque/power were you using each time you killed a box? As this is only my second at 474hp similar torque. Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted March 26, 2018 Share Posted March 26, 2018 If you look on the transmission group, you'll find all the information about the correct thermostat to use, and how to fit it correctly. I've just fitted one to mine, the same mocal one that is listed in the group Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 26, 2018 Author Share Posted March 26, 2018 Right, so it wasn't the coil packs...I officially have no idea what the weird miss fire at 5k revs is. It feels like the stock rev limiter, but at 5m revs... Need advice please Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 27, 2018 Share Posted March 27, 2018 I'm currently not using a thermostat, can you link me or tell me what brand a good inline one would be? I have fitted a gearbox temp gauge etc so i can now see when it is warm/too warm. How much torque/power were you using each time you killed a box? As this is only my second at 474hp similar torque. I use ones from Think Automotive. I am not a fan of big torque through the MKIV auto box, although some seem to find reliability with DavidP modified boxes. No idea what torque the engines had that broke boxes, all were stock boxes with plenty of miles on them. Some were run by people with delusions of drag strip time slips that would have given the boxes a good old hammering..... I am reminded by these threads of an old friend of mine that specialises in race US V8's. he had an assortment of mangled engine internals in a display cabinet in his workshop with a prominent sign abov "Speed costs money, how fast can *YOU* afford to go" I think with a stock based auto box behind a single turbo 2JZ one has to accept that `boxes will be sacrificial. There'll be a mathematical torque versus animal abuse versus number of dead `boxes formula you may be about to witness Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 27, 2018 Author Share Posted March 27, 2018 I use ones from Think Automotive. I am not a fan of big torque through the MKIV auto box, although some seem to find reliability with DavidP modified boxes. No idea what torque the engines had that broke boxes, all were stock boxes with plenty of miles on them. Some were run by people with delusions of drag strip time slips that would have given the boxes a good old hammering..... I am reminded by these threads of an old friend of mine that specialises in race US V8's. he had an assortment of mangled engine internals in a display cabinet in his workshop with a prominent sign abov "Speed costs money, how fast can *YOU* afford to go" I think with a stock based auto box behind a single turbo 2JZ one has to accept that `boxes will be sacrificial. There'll be a mathematical torque versus animal abuse versus number of dead `boxes formula you may be about to witness Yea Is my guess. My old box was very much toast...the fluid was black and stopped wanting to go into gear. The new one has 40k on it from a stock aristo, shimmed by David p, full atf flush, titan 4400, Lucas stop slip etc...so should hopefully be all right for a while. My main problem is this rev limiter feel miss fire...I am completely stumped Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 28, 2018 Author Share Posted March 28, 2018 Any guesses? Quote Link to comment Share on other sites More sharing options...
jagman Posted March 28, 2018 Share Posted March 28, 2018 Somewhere in the back of mind is something about a rev limiter around the 5000 rpm area , when the auto box is in neutral or in your case thinks it’s in neutral -!part of the NSS switch function Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 28, 2018 Share Posted March 28, 2018 I can make a myriad guesses, but if you posted a video of just what it is doing with an audio explanation of what you are doing at the time they might be more accurate Have you removed the TRAC fuse? I am assuming a stock ecu? A stock ecu will be FAR from ideal with a different stall speed converter, but buying, installing and mapping a high end Syvecs or Motec to do things properly won't be cheap (will it Frank Bullet? ) Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 28, 2018 Author Share Posted March 28, 2018 Yea it's stock ecu with a greddy piggyback. And no I need to try without a the trac fuse. When In neutral it can rev to the normal limiter when driving or stand still. Is only when in any gear. I'll get a vid tonight Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 28, 2018 Share Posted March 28, 2018 Sorry, you did say in the first post it had an Emanage on it. I would try taking out the TRAC fuse, as for the misfire it needs to go back on the rollers and have the AFR monitored, and the spark primaries and secondaries monitored on a scope, which will need either inductive pickup moved from coil pack to coil pack or the coils mounting remotely and using short leads to the plugs. Anything else will be hit and miss if you'll excuse the terrible pun. I'm assuming it's a proper 2JZ-GTE lump without a disi. Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 28, 2018 Author Share Posted March 28, 2018 Sorry, you did say in the first post it had an Emanage on it. I would try taking out the TRAC fuse, as for the misfire it needs to go back on the rollers and have the AFR monitored, and the spark primaries and secondaries monitored on a scope, which will need either inductive pickup moved from coil pack to coil pack or the coils mounting remotely and using short leads to the plugs. Anything else will be hit and miss if you'll excuse the terrible pun. I'm assuming it's a proper 2JZ-GTE lump without a disi. Yea it is originally a gte lump. I have asked the place that tunes it and he said it might be a speed sensor? As it doesn't feel like a misfire, I'd more like the a rev limiter has been put at exactly 5k revs, is 5k Every time. Also with the trac fuse, I heard someone say it damages the auto boxes to remove it? Or is that if you remove it permanently, also if so, why does it damage them? Cheers Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 28, 2018 Share Posted March 28, 2018 (edited) Its removal may make the box change gear harder, ask DavidP. The TRAC control (I believe) also softens gear shifts by magically taking control of the throttle valve during gear changes. But that aside the TRAC control is for traction control, so with your higher stall speed converter the engine will be able to do X RPM more than standard without the car moving. The stock ecu was never designed to accommodate or allow that, so it "thinks" the car has wheelspin, but without a wheel speed signal. in other words it doesn't know the hell has happened so it fails safe and limits the RPM, probably just via the traction control throttle valve in the throttle body, but possibly by altering other control functions. Basically you are feeding input parameters to the stock ecu it was never mapped to expect and it is seeing it as potential trouble. Removing the TRAC fuse crudely bypasses that aspect of its safety features. Aren't manual gearboxes with no electronic feedback wonderful? Or none electronically controlled auto ones Edited March 28, 2018 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 28, 2018 Author Share Posted March 28, 2018 Right, so I have taken two videos, notice how both misfire at the same time Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 29, 2018 Author Share Posted March 29, 2018 Opinions? Haha Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 why is your traction control flashing , is that due to the fuse being pulled? do you still have the limit problem with the fuse still in? i have seen threads like this in the passed try and search 5k rev limit I'm not sure what the out come was but remember seeing many of them Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 (edited) i just had a quick look and could be related to the neutral switch you may also want to check aristo vs supra pin outs on the autobox as they maybe different. can you get it to the red line ie put it in gear and go slowly to the redline Edited March 30, 2018 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
Milo500 Posted March 30, 2018 Author Share Posted March 30, 2018 Yea it's because the fuse is out. It does it with it in or out. I had a look and couldn't seem to find anything annoyingly. The pin outs looked the same as my other box and David p confirmed this. It did it with the old box aswell, and as the old box was on its way out I presumed it got worse and that symptom was the outcome....now I've changed the box is still does it Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 (edited) can you get to the redline in anyway ie no boost, to fault find you will need to put the fuse back in so you know its not causing another issue and work from there, when did it start happening was anything changed at that point? Edited March 30, 2018 by mellonman (see edit history) Quote Link to comment Share on other sites More sharing options...
David P Posted March 30, 2018 Share Posted March 30, 2018 (edited) It did it with the old box aswell, and as the old box was on its way out I presumed it got worse and that symptom was the outcome....now I've changed the box is still does it Because this problem was apparently same with previous box it looks to be an old problem that your new box has inherited? But to confuse the issue even more, the Aristo box has a different ratio pair of gears in the no. 2 speed sensor which has confused the gear-change tables? These gears can be swapped to increase or decrease gear-change rpm. Info here. http://www.mkivsupra.net/vbb/group.php?discussionid=229&do=discuss Ellis ran a converted Aristo box in his Supra, maybe he has input re. resulting gear-change speeds? Edited April 12, 2018 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted March 30, 2018 Share Posted March 30, 2018 if the problem is the same as before , we can surmise that its not box related , that being said there could be a damaged wire in the loom ? i have also seen similar behaviour from badly fitted FCD how its your ecu clamping the boost to the stock ecu. is it the same every gear even in neutral? is it the same with different boost loads? Quote Link to comment Share on other sites More sharing options...
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