CHRIS CLARK Posted April 8, 2001 Share Posted April 8, 2001 This should start a few entries! I have the chance to use a six speed g/box, or stay with my 5 sp. The car will be set up as an 1800, ported V V C head, DTH TB's etc etc.It's use though will be for fast road/ touring; not track. Which way to go ?; answers on a website........................... TIA, Chris Oh yes, Diff is the std NON lsd 3.92 unit! Edited by - chris clark on 8 Apr 2001 19:49:49 Link to comment Share on other sites More sharing options...
Shaun Soanes Posted April 8, 2001 Share Posted April 8, 2001 I have 1.6ss with 6 speed, great coupling. seems to suit the engine. One of my fellow Suffolk/Essex owners had a 1.8 with 5 speed as a new car and was back at Caterham within a couple of months changing it for a 6 speeder, he says there is no comparison the 6 speeder wins hands down! Go and get it, you know it makes sense! Shaun Link to comment Share on other sites More sharing options...
Gridgway Posted April 8, 2001 Share Posted April 8, 2001 6 speeder no doubt. Graham Link to comment Share on other sites More sharing options...
Shaun Soanes Posted April 9, 2001 Share Posted April 9, 2001 chris, Thanks for the e-mail, didn't get round to replying today, so here i am on the web. I have a standard 3.92 as does Carlton (fellow suffolk/essex member) have thought about LS (3.62) but would loose on acceleration I think? box is a caterham supplied and fitted 6 speed. Shaun Link to comment Share on other sites More sharing options...
stevefoster Posted April 9, 2001 Share Posted April 9, 2001 If you want the 6 speeder then get the higher diff ration of 3.62 or is it 3.64. On 3.92 you will only have the equivalent of the 5 speeders 4th even though you are in 6th. Even with a revvy Rover that would be tedious on a road car. It is down to personal preference. Whilst I agree that the 5 speed with Ford ratio's is terrible, try a 1.8+ car with the CR 5 speeder in semi heli form and you may be surprised and over £1000 better off! With torque in the right places you can actually save time not having to change gear as much! /Steve Link to comment Share on other sites More sharing options...
Richard J Darnell Posted April 10, 2001 Share Posted April 10, 2001 I have been thinking about cahnging to the six speed box but was concerned that my standard 3.92 diff would mean it would be a bit much for (occasional) cruising. I could always change the diff as well, but this will add to costs. The other variable must be the size of wheels - or at least the overall diameter of the wheel/tyre combo. I have 16" wheels and 205/45 tyres. Does anyone know what a change to 13" wheels will do for the gearing ie. would a switch to 13" wheels be equivalent to a change in diff from 3.92 to 3.62? Link to comment Share on other sites More sharing options...
Nick M Posted April 10, 2001 Share Posted April 10, 2001 I'd have thought changing to smaller wheels would lower the gearing, i.e. it would be more like swapping from a 3.9 diff to a 4.1. If you want to swap the diff (assuming it's a de dion car), you can pick up a 3.62 LSD from a breakers yard for about £100. Most Sierra XR 4x4s had the 3.62 LSD diff fitted as standard (only the 2.0 litre cars had the 3.9 diff if memory serves correctly). They're pretty much bomb-proof and should fit straight in. Link to comment Share on other sites More sharing options...
V7 SLR Posted April 10, 2001 Share Posted April 10, 2001 What you all need to do is check out Dave Andrews' web site. He has a download for a gearing program which he wrote. It is THE only way you will ever decide what gearing suits you. You enter your wheel size, diff ratio and then can either select from a selection of pre-programmed gearboxes, or can input your own ratios. http://hometown.aol.com/DVAndrews/index.htm My thoughts: 1. If you are on a 3.92 diff with a 5 speed box and want to know if you can live with a 6 speed one, try driving around without using 5th. If you can live with the revs then you're OK. 2. The 6 speed box is a FAR superior item to a standard type-9 5 speeder, but there are other options. Alex Wong has a Quaife gearset in his SPC gearbox, which is a joy to use. He retains the long 5th (although not as long as the stupidly-long original) but has closed up al the other ratios, moving the stupidly-short 1st closer to 2nd. 3. Wheels and tyres. If you are on 16 inch wheels already, with a 3.92 diff, then you could move to 13" wheels and "feel like the rest of us". If you ALSO move to a 6 speed box you will think your car is always bouncing off the rev limiter. Change one, see if you can live with it, then try the other. Smaller wheels are a cheaper way of "shortening" gearing, and have the other advantage of improving the handling of the car. Link to comment Share on other sites More sharing options...
stevefoster Posted April 10, 2001 Share Posted April 10, 2001 Due to the wheel's I had I am running 13"x7" rims on 205's on the rears. These work out as very close to the 14" wheels on 185 width for diameter. I swapped down from the 16"HPC wheels. My 2 prev 7's had 13" wheels they also only had 4 speed boxes which got tedious. Hence my caution to 6 speeders on higher diff ratios.... Link to comment Share on other sites More sharing options...
murph7355 Posted April 10, 2001 Share Posted April 10, 2001 Caveat - I haven't had my ears tested in a while so I could be deaf. Now - the 6 speed box is perfectly fine for "touring". Even my other half never complained which pretty much made the box unique and somewhat of a double God send! 80mph is perfectly OK in 6th, even with the hood up. You'd have to drop the revs an awful lot to make it signifcantly better and then you'd need to be changing gear to overtake with any alacrity (and then the fuel pump noise would get massively irritating). On the right roads (abroad Ociffer honest) my natural cruising speed is well over this and is still more than bearable. With the roof off, the pounding the wind gives my right ear and tyre noise (from other cars as well as mine) is much worse than any perceived engine noise (which is nice anyway IMO). If it really gets too much, a couple of earplugs are all that are needed for those really tortuous journies. Alternatively get off at the next exit and use proper roads that need you to stir the gear lever a bit. At this point you will be very glad you bought the 6spd. The only other alternative would be a heavily revised 5spd. I'd go for the 6spd (a Quaife sequential would be my other choice but I'm not sure that these are fully on song yet?). I'll try and get to the next meeting you're at and you can try a similarly engined car to yours with a 6spd (I also have yet to fit an LSD). C7 AJM Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 10, 2001 Author Share Posted April 10, 2001 Thanks for the info. fellas. I have tried driving around with in the direct top (ie fourth) and it goes and sounds good. I think I could live with it and I think even 'Suzi Seven' is coming round to the idea. Thing is, I am running on 'Prisoner' 15" at present with Yoko 520's. I have some 13" 'Minilites' with AO 21's on but haven't got around to fitting them yet!!!!! I'll try 'em soon and see what the difference is! Link to comment Share on other sites More sharing options...
EFA Posted April 10, 2001 Share Posted April 10, 2001 I have 13" wheels, a 3.92 diff and a six speed box. I love the noise and the acceleration advantage (Oh no I'll start PC off again here...) At a ton I'm doing 5900rpm in sixth which is tolerable although if you have an ehgine reving to much less than 8000 rpm your top end may be compromised on track. Did you buy it Chris?? Arnie Webb The Fat Bloke blush.gif in a not so Slow Vauxhall wink.gif See the R500 eater here See the Le Mans Trip Website here Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 10, 2001 Author Share Posted April 10, 2001 Not yet Arnie, but 'we' are working on it!!!!!!! Link to comment Share on other sites More sharing options...
I.Mupferit Posted April 11, 2001 Share Posted April 11, 2001 Decisions, decisions, life is full of 'em, so Chris are you going for the 6 speed? When we last spoke I thought you were leaning towards the SPC 5 speed semi-helical. smile.gif Brent Link to comment Share on other sites More sharing options...
Peter Carmichael Posted April 12, 2001 Share Posted April 12, 2001 Chris, save the money on the gearbox by just sorting out the first to second change and spend the saved cash on an LSD. Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 12, 2001 Author Share Posted April 12, 2001 Hi Peter. So how does one resolve this 1st -2nd problem without going to straight cut ? Brent. Price of the SPC seems rather a lot, but I'll let you know!!!! Link to comment Share on other sites More sharing options...
I.Mupferit Posted April 12, 2001 Share Posted April 12, 2001 Chris, I will see if I can contact the guy my g/box came from to find out what ratios were fitted to overcome the 1st-2nd drop. I'll be in touch. Brent Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 12, 2001 Author Share Posted April 12, 2001 Thanks Monsieur Anorak!!!!!! Link to comment Share on other sites More sharing options...
Dartmoor7 Posted April 13, 2001 Share Posted April 13, 2001 When talking about wheels altering gearing remember it the wheel/tyre COMBINATION that decides gearing. 13" wheels fitted with 185/70x13 have same diameter as 205/45x16 so would not change gearing at all. Link to comment Share on other sites More sharing options...
Paul McKenzie Posted April 13, 2001 Share Posted April 13, 2001 No, they don't Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 14, 2001 Author Share Posted April 14, 2001 I have 15" 'Prisoners on at the moment shod with 195/50 x R15. The new 13"wheels/tyres (that I have yet to get around to fitting!) are 185/60 x R13. What's the change if any ? Link to comment Share on other sites More sharing options...
Dartmoor7 Posted April 14, 2001 Share Posted April 14, 2001 >>No, they don't They do according to the Yokohama tyre fitment guide that I'm looking at. Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 14, 2001 Author Share Posted April 14, 2001 What's the difference then ? Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 14, 2001 Author Share Posted April 14, 2001 Glitch!!! Edited by - chris clark on 14 Apr 2001 20:52:36 Link to comment Share on other sites More sharing options...
CHRIS CLARK Posted April 14, 2001 Author Share Posted April 14, 2001 double glitch !!! Edited by - chris clark on 14 Apr 2001 20:53:34 Link to comment Share on other sites More sharing options...
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