BaileyMex Posted August 6, 2008 Author Report Posted August 6, 2008 yeah...... anyone got a 3:9 for sale
kevmk2 Posted August 6, 2008 Report Posted August 6, 2008 Ive got a 3.75 in mine, i know im on 15's and an atlas, but motorway cruising is ok, i can sit about 75-80mph at around 3500rpm. And 130mph is 5500-6000rpm in 5th gear It does around 140mph flat out in 4th at 8000rpm.
X-pack-Glyn Posted August 8, 2008 Report Posted August 8, 2008 With the 4 speeds, 4th gear is 1:1 so whatever box you use the outcome will be the same, it's all down to the dif. Type 9s have a .82:1 5th, which helps on the motorways agreed, it is on the 5 speeds too, 4th just joints the input to the output and no gear is used, the car feels smoother without the gear and ive gotten a few blown type 9s home no probs using 4th gear as well. for the record mines a 2 litre 4 speed with a 3.77 Plate and its fine up to 100 on GPS, after that it starts to howl, but goes all the way up to 128 at 9000 RPM and was still pulling (i only did that once).
numbnuts Posted August 9, 2008 Report Posted August 9, 2008 3.9 seems to be a good all rounder! I have a 4.1 in my 105e axle but not fitted it yet so will probably swap it out for the 3.9. Mind you by my calculation theres not alot of difference. 4000rpm 185/60/13's 4.1 diff = 63.1mph 4000rpm 185/60/13's 3.9 diff = 66.3mph Is it worth the hassle of swapping it over? _________________ og kush seeds
DAZZA Posted August 9, 2008 Report Posted August 9, 2008 5 speed, 4.1, on 60's. 4000 @ 70mph Does my head in. 3.7 or 3.54 on the cards.
numbnuts Posted August 9, 2008 Report Posted August 9, 2008 5 speed, 4.1, on 60's. 4000 @ 70mph Does my head in. 3.7 or 3.54 on the cards. Even in 5th? Also does it annoy you arround town or on the motorway/duel carrage ways? or both!! _________________ The Office Forum
Toby Posted August 9, 2008 Report Posted August 9, 2008 yeah...... anyone got a 3:9 for sale Escort Tec will have one
BaileyMex Posted August 9, 2008 Author Report Posted August 9, 2008 yeah...... anyone got a 3:9 for sale Escort Tec will have one Already spoke with Darren and he's got a 3:89 for me, cheers anyway Toby
BaileyMex Posted August 9, 2008 Author Report Posted August 9, 2008 Just re-did that calculation thing, and if I have done it right then I think it will definatly be worth the swap Time to go and buy a slide hammer
numbnuts Posted August 9, 2008 Report Posted August 9, 2008 If you change the width of the tyre on that calculator above it changes the final speed in any given RPM. The rolling radius should be the same so why the change in speed? Don't make sense to me _________________ The Yazidi branch of Yazdanism Forum
Admin Vista Posted August 9, 2008 Admin Report Posted August 9, 2008 If you change the width of the tyre on that calculator above it changes the final speed in any given RPM. The rolling radius should be the same so why the change in speed? Don't make sense to me I haven't checked the calculator but if you change the width of the tyre but maintain the same profile the tyre height will change hence the change in rolling radius. For instance, a 205/60/13 has a RR of 288mm whereas a 225/60/13 has a RR of 300mm. The 60 figure is the ratio of the height of the tyre sidewall expressed as a percentage of its width
numbnuts Posted August 9, 2008 Report Posted August 9, 2008 Ahh right oh that makes sense. Thanx _________________ sour diesel sour bubble plants
BaileyMex Posted August 10, 2008 Author Report Posted August 10, 2008 For instance, a 205/60/13 has a RR of 288mm whereas a 225/60/13 has a RR of 300mm. The 60 figure is the ratio of the height of the tyre sidewall expressed as a percentage of its width I didnt know that, nice work
over_head_cam Posted August 10, 2008 Report Posted August 10, 2008 Col, there's a bit of a typo there m8. Should have put 3.89
Toby Posted August 10, 2008 Report Posted August 10, 2008 Col, there's a bit of a typo there m8. Should have put 3.89 Well done, I thought it looked odd but couldn't see how,
numbnuts Posted August 12, 2008 Report Posted August 12, 2008 Another good diff/speed calculator http://www.locost7.info/gearcalc.php _________________ Vaccinations Forum
SAF_Capri Posted August 12, 2008 Report Posted August 12, 2008 Ive got a 3.75 diff in my car, would going to 4... give a noticeable acceleration with my soon to be installed XE engine? or would it scream NO on the motorway?
MK2Ed Posted August 12, 2008 Report Posted August 12, 2008 Ive got a 3.75 diff in my car, would going to 4... give a noticeable acceleration with my soon to be installed XE engine? or would it scream NO on the motorway? What's your tyre sizes and gear box ratios for 4th/5th....? These can then be entered in the gear calc, along with diff ratio and hey presto it will give you your rpm in each gear...
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