ManwithSupra Posted June 7, 2013 Share Posted June 7, 2013 (edited) I am not as clued up as I could be about Diff Ratio's etc. What defines a Diff Ratio, I assume its just the Ring Gear and Crown Pinion or is it a combination of the Ring Gear, Crown Pinion and internal gubbins on the Diff? I am maybe looking at changing my diff but I would like to keep the stock Auto LSD Ratio really as the Auto LSD Diff with a V160 really suits the track well. Cheers peeps Potential issue found...see this post Edited June 7, 2013 by ManwithSupra (see edit history) Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 7, 2013 Share Posted June 7, 2013 this will help im sure http://www.mkiv.co.uk/vbb/showthread.php?225050-Supra-specific-gear-diff-ratio-and-tyre-size-calculator Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 Wheel size and tyre profile are part of the equation too. http://www.alloywheels.com/Tyre_Calculator Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted June 7, 2013 Share Posted June 7, 2013 Diff ratio is determined by the crown wheel & pinion only mate. The ratio in my car originally was 4.083 - 49 teeth on the crown wheel, 12 teeth on the pinion. The ratio I retro fitted was 4.273 - 47 teeth on the crown wheel, 11 teeth on the pinion. Quote Link to comment Share on other sites More sharing options...
mellonman Posted June 7, 2013 Share Posted June 7, 2013 but tyre size does have an affect on the end gear ratio of the car Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 I'm running a 4.083 N/A Torsen with 285 40 18's which gives as near as dammit TT auto 3.769 with stock 255 40 17's. Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted June 7, 2013 Share Posted June 7, 2013 but tyre size does have an affect on the end gear ratio of the car I'm running a 4.083 N/A Torsen with 285 40 18's which gives as near as dammit TT auto 3.769 with stock 255 40 17's. Lads, I'm just answering the chap's actual question. Try it sometime, you might surprise yourselves. Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 (edited) Lads, I'm just answering the chap's actual question. Try it sometime, you might surprise yourselves. I am not as clued up as I could be about Diff Ratio's etc. What defines a Diff Ratio, I assume its just the Ring Gear and Crown Pinion or is it a combination of the Ring Gear, Crown Pinion and internal gubbins on the Diff? I am maybe looking at changing my diff but I would like to keep the stock Auto LSD Ratio really as the Auto LSD Diff with a V160 really suits the track well. Cheers peeps Edited June 7, 2013 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 Diff ratio is determined by the crown wheel & pinion only mate. The ratio in my car originally was 4.083 - 49 teeth on the crown wheel, 12 teeth on the pinion. The ratio I retro fitted was 4.273 - 47 teeth on the crown wheel, 11 teeth on the pinion. Ah cheers mate, I thought so I just wanted to double check So how is Ratio worked out, how do you get to 4.273 by counting teeth? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 Cheers for everyone's other comments too, its all useful information Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 Ah cheers mate, I thought so I just wanted to double check So how is Ratio worked out, how do you get to 4.273 by counting teeth? Actually don't worry about that question you just divide it lol I should have known that haha Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 OK, Looking at that spreadsheet and using my telemetry data (Speed vs Gear vs RPM) and taking into account Tyre size, wheel size rpm limits etc It does not look like I have an Auto LSD at all but a NA Auto Diff.... erm.... But looking back on Ryan's build thread It states that the car was installed with a TRD LSD. Do you think that it would be a NA Auto Ring gear on a TRD Diff?? - I suppose it must be! http://www.mkivsupra.net/vbb/showthread.php?170424-Supra-Track-Car-Project&p=2310146&viewfull=1#post2310146 Confused!! Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted June 7, 2013 Share Posted June 7, 2013 I am not as clued up as I could be about Diff Ratio's etc. His first statement is just that, a statement. His actual question was soley about diff ratio calculation. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 Actually what gear oil should I be using on a TRD Diff?? I must admit its news to me that it has a TRD Diff (I missed the fact that it is on the build thread) when I bought it off Ryan he only mentioned it was an Auto LSD which I then assumed it was a stock Auto LSD and not a TRD Diff. I am running Millers Oils CRX LS 75w-90 NT Competition full synthetic Oil which I now suspect is wrong for this Diff. Which now makes me think the issues I recently had could be down to me using the wrong oil and now potentially stuffing the diff... Arghhhhh. Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 His first statement is just that, a statement. His actual question was soley about diff ratio calculation. I am not as clued up as I could be about Diff Ratio's etc. What defines a Diff Ratio, I assume its just the Ring Gear and Crown Pinion or is it a combination of the Ring Gear, Crown Pinion and internal gubbins on the Diff? I am maybe looking at changing my diff but I would like to keep the stock Auto LSD Ratio really as the Auto LSD Diff with a V160 really suits the track well. Cheers peeps I'm running a 4.083 N/A Torsen with 285 40 18's which gives as near as dammit TT auto 3.769 with stock 255 40 17's. Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 Comon guys stop arguing on my thread I appreciate the info from both of you now now... Can anyone help with my recent discoveries especially surrounding the diff Oil question? Actually what gear oil should I be using on a TRD Diff?? I must admit its news to me that it has a TRD Diff (I missed the fact that it is on the build thread) when I bought it off Ryan he only mentioned it was an Auto LSD which I then assumed it was a stock Auto LSD and not a TRD Diff. I am running Millers Oils CRX LS 75w-90 NT Competition full synthetic Oil which I now suspect is wrong for this Diff. Which now makes me think the issues I recently had could be down to me using the wrong oil and now potentially stuffing the diff... Arghhhhh. Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 (edited) Actually what gear oil should I be using on a TRD Diff?? I must admit its news to me that it has a TRD Diff (I missed the fact that it is on the build thread) when I bought it off Ryan he only mentioned it was an Auto LSD which I then assumed it was a stock Auto LSD and not a TRD Diff. I am running Millers Oils CRX LS 75w-90 NT Competition full synthetic Oil which I now suspect is wrong for this Diff. Which now makes me think the issues I recently had could be down to me using the wrong oil and now potentially stuffing the diff... Arghhhhh. http://www.mkivsupra.net/vbb/showthread.php?291609-Which-diff-oil-TRD Not arguing, just answering Pedrodantic's questions as well as yours. I'm running a 4.083 N/A Torsen with 285 40 18's which gives as near as dammit TT auto 3.769 with stock 255 40 17's. Just crunched the numbers and make this 3.762. Edited June 7, 2013 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 http://www.mkivsupra.net/vbb/showthread.php?291609-Which-diff-oil-TRD Crap, do you think I have stuffed the Diff... Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 Crap, do you think I have stuffed the Diff... What's it doing or not, that makes you think you've "stuffed" it? Quote Link to comment Share on other sites More sharing options...
ManwithSupra Posted June 7, 2013 Author Share Posted June 7, 2013 This.. http://www.mkivsupra.net/vbb/showthread.php?291148-**Video-Added**-Major-Vibration-from-rear-over-25mph-(V160-with-Auto-LSD) I am not sure they would be related.. Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted June 7, 2013 Share Posted June 7, 2013 Not arguing, just answering Pedrodantic's questions as well as yours. I don't recall asking any. The Asperger's must be affecting your eyes too David. Quote Link to comment Share on other sites More sharing options...
Dnk Posted June 7, 2013 Share Posted June 7, 2013 Ah cheers mate, I thought so I just wanted to double check So how is Ratio worked out, how do you get to 4.273 by counting teeth? 47 divided by 11 Quote Link to comment Share on other sites More sharing options...
David P Posted June 7, 2013 Share Posted June 7, 2013 I don't recall asking any. The Asperger's must be affecting your eyes too David. They appeared questionable to me. Excuse me if I haven't got the hang of answering half a question with half an answer. Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted June 7, 2013 Share Posted June 7, 2013 They appeared questionable to me. Excuse me if I haven't got the hang of answering half a question with half an answer. The day I need an answer from you I'll drink the drain cleaner. Sorry for the meandering Rich, I'll leave you in the capable hands of David. He can answer all your questions. Even those you hadn't asked. He certainly cleared up what the P stands for in his user name for me anyway. Quote Link to comment Share on other sites More sharing options...
Nic Posted June 7, 2013 Share Posted June 7, 2013 The EPC lists all the available diff ratios for the A and B diff casings. Quote Link to comment Share on other sites More sharing options...
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