<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr">Thank you John, this is actually. Non-OD car with the 3.70 rear end. OD installed later in life by some PO. A very nice driving combo. </div><div dir="ltr"><br></div><div dir="ltr">Bill</div><div dir="ltr"><br>On Jun 1, 2020, at 2:36 PM, John Macartney <John.Macartney@ukpips.org.uk> wrote:<br><br></div><div dir="ltr"><meta http-equiv="content-type" content="text/html; charset=utf-8">It’s important to remember that cars without overdrive had a higher axle ratio than those with it. As an example, the GT6+ had a 3.27 final drive for non overdrive and 3.89 for overdrive. Just to complicate things, it was entirely possible to order a 3.27 diff with overdrive on top! The factory never promoted this facility for fairly obvious reasons. My own GT6 mk 2 was supplied like that becxause I knew my way around the factory build books. Iit made an excellent cruiser with good fuel consumption but could not pull more than 4000 rpm, even downhill on a motorway. That said, refuelling was a little less frequent.<div><br></div><div>Jonmac<br><br><div dir="ltr">At the Battle of Waterloo, 1815:<div>Lord Uxbridge: “By God, Sir - I’ve lost my leg”</div><div>Duke of Wellington: “By God, Sir - so you have!”</div><div><br></div></div><div dir="ltr"><br>On 1 Jun 2020, at 19:41, Dave MacKay <<a href="mailto:dave@mdmackay.ca">dave@mdmackay.ca</a>> wrote:<br><br></div><blockquote type="cite"><div dir="ltr"><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="Generator" content="Microsoft Word 15 (filtered medium)"><style><!--
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--></style><div class="WordSection1"><p class="MsoPlainText">>Date: Sun, 31 May 2020 16:52:23 -0500</p><p class="MsoPlainText">>From: bill beecher <<a href="mailto:notakitcar@yahoo.com">notakitcar@yahoo.com</a>></p><p class="MsoPlainText">>Subject: [TR] RPM speed calc</p><p class="MsoPlainText">> </p><p class="MsoPlainText">>Came across this calculator with all the right input fields. But, I wonder how accurate it really is given the following input. </p><p class="MsoPlainText">>TR3 with a 3.7 rear, OD at redline of 5,000rpm. Vredestein 165R/15 tires, 25.4? diameter. Should be moving along at 124mph!</p><p class="MsoPlainText">> </p><p class="MsoPlainText">><a href="https://wahiduddin.net/calc/calc_speed_rpm.htm">https://wahiduddin.net/calc/calc_speed_rpm.htm</a></p><p class="MsoPlainText">> </p><p class="MsoPlainText">>Anyone get a different answer? </p><p class="MsoPlainText">>Bill</p><p class="MsoNormal"> </p><p class="MsoNormal">Here (attached) is a spreadsheet that I wrote to calculate speed versus rpm given different parameters. I wrote it to check my speedo after I installed an HVDA transmission. If the spreadsheet doesn’t make it through the list as an attachment, just e-mail me directly and I’ll send it to you.</p><p class="MsoNormal"> </p><p class="MsoNormal">With a standard Triumph gearbox + overdrive, and the parameters you gave, I calculate speed at 5000 rpm in top gear (with overdrive) as being 124.5 mph. Note that, I think that the tire diameter is 25.25”, slightly less than you indicated.</p><p class="MsoNormal"> </p><p class="MsoNormal">I hasten to add that calculating a speed and believing it’s achievable are two different things!</p><p class="MsoNormal"> </p><p class="MsoNormal">Regards,</p><p class="MsoNormal"> </p><p class="MsoNormal">Dave MacKay</p><p class="MsoNormal">1960 TR3A s/n 68639L</p><p class="MsoNormal">near Toronto, Canada</p></div>
</div></blockquote><blockquote type="cite"><div dir="ltr"><Triumph rpm to mph.xls></div></blockquote><blockquote type="cite"><div dir="ltr"><span>** <a href="mailto:triumphs@autox.team.net">triumphs@autox.team.net</a> **</span><br><span></span><br><span>Donate: <a href="http://www.team.net/donate.html">http://www.team.net/donate.html</a></span><br><span>Archive: <a href="http://www.team.net/pipermail/triumphs">http://www.team.net/pipermail/triumphs</a> <a href="http://www.team.net/archive">http://www.team.net/archive</a></span><br><span></span><br><span>Unsubscribe/Manage: <a href="http://autox.team.net/mailman/options/triumphs/john.macartney@ukpips.org.uk">http://autox.team.net/mailman/options/triumphs/john.macartney@ukpips.org.uk</a></span><br></div></blockquote></div><span>** triumphs@autox.team.net **</span><br><span></span><br><span>Donate: http://www.team.net/donate.html</span><br><span>Archive: http://www.team.net/pipermail/triumphs http://www.team.net/archive</span><br><span></span><br><span>Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/notakitcar@yahoo.com</span><br></div></body></html>