Alex Wong1697456877 Posted May 14, 2007 Author Share Posted May 14, 2007 What Dave J and most K cars have GearCalc v2.0.0.3 Copyright ©2001, Peter Ogden Gear Ratio, Speed and RPM Calculator Gear set: Caterham 6 Speed Gear 1 2 3 4 5 6 Final Ratios: 2.690 2.010 1.590 1.320 1.130 1.000 3.620 RPM Limit: 7600 RPM @Peak Power: 7250 Tyre Diameter: 22.00 in Gear Mph per 1000 RPM Mph @7250 RPM Mph @7600 RPM -------------------------------------------------------- 1 6.72 49 51 2 9.00 65 68 3 11.37 82 86 4 13.70 99 104 5 16.00 116 122 6 18.08 131 137 Edited by - Alex Wong on 14 May 2007 18:17:36 Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 14, 2007 Author Share Posted May 14, 2007 Now that I look at it again, I'm not so sure....... The 3.62 is £200 cheaper..... Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 14, 2007 Author Share Posted May 14, 2007 GearCalc v2.0.0.3 Copyright ©2001, Peter Ogden Gear Ratio, Speed and RPM Calculator Gear set: Alex's Elite Sequential Gear 1 2 3 4 5 Final Ratios: 2.304 1.620 1.280 1.061 0.922 3.950 RPM Limit: 7600 RPM @Peak Power: 7250 Tyre Diameter: 22.00 in Gear Mph per 1000 RPM Mph @7250 RPM Mph @7600 RPM -------------------------------------------------------- 1 7.19 52 55 2 10.23 74 78 3 12.94 94 98 4 15.62 113 119 5 17.97 130 137 Link to comment Share on other sites More sharing options...
Rob Walker Posted May 14, 2007 Share Posted May 14, 2007 I would advise you fit the 3.62 with your engine. I have to say why do you want to rev above 9000rpm , It is going to need frequent rebuilds if you use those revs. Link to comment Share on other sites More sharing options...
Slipper man Posted May 14, 2007 Share Posted May 14, 2007 The 3.62 is more than £200 cheaper. I have one in the garage that you can borrow (long term) for free... R500's were supplied with 3.92 as standard, but like Alex I wanted something a bit more relaxed so got them to supply mine with a 3.62. After a cople of years I came to the conclusion that Caterham were right and changed it to a 3.92. I think the 3.62 will be perfect. Give me a call if you want my bits. K Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 14, 2007 Author Share Posted May 14, 2007 Hi Keith - Thanks for the offer but I think I'm going to take a chance on the 3.38. See you in France! Rob - Didn't say anything about 9000 rpm! a 3.62 would basically give me the spread of my Elite over 6 gears and the 3.38 would give me the spread of the quaife T9 over 6 gears. I think the first of those would be too frantic. It will feel faster but I think I prefer to give myself a bit longer between shifts. Thanks for you input though and as you can probably tell, I'm by no means certain this is going to be right but I think it'll be good. Edited by - Alex Wong on 14 May 2007 21:34:59 Link to comment Share on other sites More sharing options...
Slipper man Posted May 14, 2007 Share Posted May 14, 2007 What do you mean 'see you in France'?! I DO hope you aren't Le Septing - my wine bill will double because yo are such a bad influence Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 14, 2007 Author Share Posted May 14, 2007 Don't worry Keith. I'm trying to drive VDU down. It'll never reach the south of France! Your wine bill is safe. Link to comment Share on other sites More sharing options...
moosetestbestanden Posted May 15, 2007 Share Posted May 15, 2007 At a glance, between chart 'what I had' and chart 'what I'm going for', well, it looks like you'll be rowing more for the same effect. I'm not very sensitive so for me it's difficult to discern the difference between 138 mph and 140. But I can tell when I need 2nd to spin up to near 80, as opposed to needing to bang into the next gear another 10 mph sooner. Please note that I comment from the perspective of someone who uses my car almost exclusively on track. I would also like to mention that, if you've got those nice steel rods sitting on a shelf w/ intent to install sometime, wouldn't you want to consider the effects of gearing at higher rpm values than shown? I guess what I wondering is: If that VX makes big torque (we have no experience of them over here) then I kind of wonder why the change, at least as far as trackwork is concerned. If not trackwork, then, noting that the difference between the top gears of each is essentially non-existant, there won't be less engine buzz in top gear per 1000 rpm for the 6 speeder than the 5. So toodling down the motorway (or anywhere else) isn't going to significantly different, except for the quietness of the helical box of course. Those Quaife numbers w/ the 3.95 look pretty good to me. ------- Chris Exempli Blatia Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 15, 2007 Author Share Posted May 15, 2007 Hi Moose, Greeings from next door to the Swifts. The Quaife on 3.95 was good. then I sold it and went for the Elite on a 3.95. I geared that to try and get the spread of the 6 speed on a 3.62. That was great, but already alot of shifting on 5 gears for me although the sequential suited this. It felt fast but I feel the Quaife on a 3.95 was actually faster - less rowing as you say. I wanted a quiet but strong H pattern box and the 6 speed fits that bill well although Quaife's as yet unreleasd new box may be the optimal solution. Having made the decision to go with the 6 speed box, I wanted to get the gearing closer to the Quaife. I cant spread the ratios out as it only comes with the one set of ratios, so I thought it best to lift all those ratios up to make the changes happen at higher speeds when acceleration is slower and the shifts therefore are less frequent. This suits the Vx and although it feels less involving to be changing gear less frequently, I think it wont be much, if any slower in practice. The 2nd gear on the 6 speed will be interesting. I often found myself choosing between 1st and second with the Quaife and now it's between the two. If I could get a helical Quaife 5 speed with the reliability and durability I wanted, I'd have fone for that. If a helical dog box was an option, that would have been a good option. Thanks for taking the time to look at the ratios. I do agree that I may be changing gear more often than with the Quaife but it will be quiet and hopefully durable and I think it might fill in the hole that the Quaife sometimes suffers between 1st and 2nd. 6th will very rarely be needed on a track, as was 5th on the 5 speed, but its' good for the road. As for the steel rods, they'll lift the max rpm to about 8000 so no a huge change. Edited by - Alex Wong on 15 May 2007 23:33:11 Link to comment Share on other sites More sharing options...
moosetestbestanden Posted May 15, 2007 Share Posted May 15, 2007 Alex, Got it - makes sense. I'm hoping to be able to discuss such things come the 1st weekend of next month as I'll be there & I'm looking at various gearbox options myself. I'm very interested in hearing about your experiences w/ Quaifes & sequential shifters etc. Hope to meet you on the 50th weekend ------- Chris Exempli Blatia Link to comment Share on other sites More sharing options...
ELV15 Posted May 16, 2007 Share Posted May 16, 2007 Alex, are there any details available on the new quaife box? 🤔 It sounds like the 6speed will suit you fine, but that you really would like a helical dog box 5 speed. ELV15 - Tom in California - 200hp duratec powered 2003 Clubsport Build pics here: here Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted May 16, 2007 Author Share Posted May 16, 2007 Very few - it's in their new catalogue (which I haven't got) but not on their website. Doesn't exist unfortunately, apart from in sequential 6 speed form from Quaife (very expensive!) or in the Elite sequential which also can have helical gears. Both are expensive! Moose - Will let you know how I get on Edited by - Alex Wong on 16 May 2007 08:48:50 Edited by - Alex Wong on 16 May 2007 08:49:54 Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted July 10, 2007 Author Share Posted July 10, 2007 So I've done motorways, country lanes and a trackday now and I am totally sure I made the right choice for me. On the road - Motorway driving - 6th is great. Did 1000 odd miles of autoroute/motorway driving in 3 days and it was nice to not often need more than 4000rpm. Compared to the last european trip I did with the Elite, this was mush more relaxing and economical - close to 200 miles on a tank - unheard of in my car with this or the previous engine. First is fine in normal use and even hill starts, but is a bit tall in traffic jams resulting on alot of clutch usage. Most fast country lane driving is in 3rd/4th/5th which is fine. Seldom need to use 2nd. On the track - At Pau Arnos, I used 2nd through to 5th and had a good ratio for all situations. It felt very good - much nicer to use on track than on the road as the slightly sticky shift vanished when used hard. As predicted, it is in effect a close ratio 5 speed with a 6th for motorway usage. I'm very very pleased with it and would recommend the 3.38 with 6 speed for an all round road and track Seven with a high power/torque engine . For pure track use, I can see that the 3.62 might be preferable GearCalc v2.0.0.3 Copyright ©2001, Peter Ogden Gear Ratio, Speed and RPM Calculator Gear set: Caterham 6 Speed Gear 1 2 3 4 5 6 Final Ratios: 2.690 2.010 1.590 1.320 1.130 1.000 3.380 RPM Limit: 7800 RPM @Peak Power: 7250 Tyre Size: 185/+60 x 13 Gear Mph per 1000 RPM Mph @7250 RPM Mph @7800 RPM -------------------------------------------------------- 1 7.11 52 55 2 9.52 69 74 3 12.03 87 94 4 14.50 105 113 5 16.93 123 132 6 19.14 139 149 Mph RPM (in Gears) ---------------------------------------------------------- 1 2 3 4 5 6 ---------------------------------------------------------- 5 703 525 415 345 295 261 10 1406 1050 831 690 591 523 15 2109 1576 1246 1035 886 784 20 2812 2101 1662 1380 1181 1045 25 3514 2626 2077 1725 1476 1307 30 4217 3151 2493 2070 1772 1568 35 4920 3677 2908 2414 2067 1829 40 5623 4202 3324 2759 2362 2090 45 6326 4727 3739 3104 2657 2352 50 7029 5252 4155 3449 2953 2613 55 7732 5777 4570 3794 3248 2874 60 6303 4986 4139 3543 3136 65 6828 5401 4484 3839 3397 70 7353 5817 4829 4134 3658 75 6232 5174 4429 3920 80 6647 5519 4724 4181 85 7063 5864 5020 4442 90 7478 6209 5315 4703 95 6553 5610 4965 100 6898 5905 5226 105 7243 6201 5487 110 7588 6496 5749 115 6791 6010 120 7086 6271 125 7382 6533 130 7677 6794 135 7055 140 7316 145 7578 Gear Change RPM drop (change @7250) RPM drop (change @7800) ------------------------------------------------------------- 1 -> 2 -1833 (to 5417) -1972 (to 5828) 2 -> 3 -1515 (to 5735) -1630 (to 6170) 3 -> 4 -1231 (to 6019) -1325 (to 6475) 4 -> 5 -1044 (to 6206) -1123 (to 6677) 5 -> 6 -834 (to 6416) -897 (to 6903) Edited by - Alex Wong on 10 Jul 2007 14:56:41 Link to comment Share on other sites More sharing options...
Rob Walker Posted July 10, 2007 Share Posted July 10, 2007 Pleased to hear that your happy with the 6 speed box and diff choice. What oil did you fill the box with, Redline MTL improves the gear change considerably , 1 to 2nd can be sluggish without MTL when the box is cold. Rob Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted July 10, 2007 Author Share Posted July 10, 2007 Hi Rob, Yes MTL - The shift is a bit stubborn but it's getting easier. Alex Link to comment Share on other sites More sharing options...
N1ck Posted July 12, 2007 Share Posted July 12, 2007 Alex, sounds like you have acheived the ideal compromise. Where did you source the diff from? Not planning any imminent changes but compiling a "to do" list as and when. Would be nice to have a closer look. Happy to swap rides . Regards, Nick. Link to comment Share on other sites More sharing options...
Alex Wong1697456877 Posted July 12, 2007 Author Share Posted July 12, 2007 I sent the diff to Phil Stewart at Road and Race - ~ £20 to send via parcelforce and I think it was £400 for the change in Crown and Pinion. The 3.38 C&P is rare and expensive apparently! Would love to try one of your pukka cars compared to my charlaton of a car!! Link to comment Share on other sites More sharing options...
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