Jasper
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| posted on 6/7/03 at 04:13 PM |
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Help with info on Cortina 'Salisbury Type A' axles
Turns out I've got a 4.11 axle as it was from a Cortina estate donor, rather than the usual 3.89 or 3.75.
Thats' why the car accelerates like a b*stard, but sits at 8k revs at 80 miles at hour.
If I wanna use a lower diff ratio what are the options? 3.75's were in the 2L Cortina's, or for £300 you can get new 3.50 internals. Any
other options?
Anybody know how hard it is to change the gearing on these without having to swap over the entire axle?
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stephen_gusterson
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| posted on 7/7/03 at 09:43 AM |
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This intreagues (sp) me a bit.
ChrisG stated at the last show that the ninja had done an indicate 160 on the way to LE Mans, which was interpreted as nearer 140 mph.
I did a bit of research (not a lot!) on the internet and found it stated that the zx9r/ninja engine revs to 10,500.
You state that 80 mph comes at 8,000 rpm, giving a top speed of 105 mph in that case. A bit low.
Its also way out of the spec of PTM's car.
I did a quick calc of the improvement at 3.5 diff ratio. It will pull about 6,900 at 80 and do 120 if I havnt screwed the numbers. Still low compared
to PTM's machine.
Either my 10,500 limit is wrong, or others are using low ratios, or are revving like crap.........
It seems like a bigger jump in ratio is needed.....lowest I have ever come across is the indy system on the xj-s 5.3 litre v6 - 2.88.
atb
steve
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andyd
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| posted on 7/7/03 at 11:50 AM |
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What size wheels/tyres does Chris run?
The spreadsheet I put up on another thread gives me 8,207rpm at 80mph for our setup (3.89 diff) with a top-end being only 114.54mph. Of course this
is only theorectical speed as it doesn't take into account friction (road and air) but gives a rough indication and I'm assuming that
these speeds will not be reached.
I'm guessing but I think either Chris will have a 3.5 diff (which gives me a max of 127.3mph with the same wheels/tyres) or even larger rolling
radius than what I've got (1.8m). Either that or his speedo is way out at those speeds. 
[Edited on 7/7/2003 by andyd]
Andy
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stephen_gusterson
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| posted on 7/7/03 at 01:31 PM |
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i wouldnt mind betting you could go redline in top. my old 93hp metro turbo could go well into the red in top at 114 mph. A locost dynamics cant be
that crap that a 300 kilo advantage and about 10 more HP get cancelled out.....
atb
steve
my car should do 122 mph at the red line at a massive 5,900 rpm - but then thats a 2.4 V6 cologne for you.
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Jasper
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| posted on 7/7/03 at 02:05 PM |
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I don't recon PTM's car made 140, I was fairly sure he has 13" rims, so very unlikely. And by the feel of the way mine pulls in 6th
it will red line in top. I've also had her over 100 and there was plenty more left, so I would expect around 115 mph with current diff. I think
Jon runs a 3.75 with 15" rims and gets to around 128mph , with a slighly higher redline.
Question is, can I swap these diffs easily or do they need setting up?
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Jon Ison
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| posted on 7/7/03 at 03:47 PM |
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jasper, replied to your u2u.
steve, red line at 12600 rpm, redlines in top at around 132, and will hit limiter in top too, taking a bit of a pounding on neck by then though,
unless your slip streaming a skyline on M1 of course,
As iff officer........
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stephen_gusterson
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| posted on 7/7/03 at 08:20 PM |
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Jon.
screaming along at 132 at 12k plus would be good enuf for me!
Got stopped by plod last week doing 65 in a 40 - not residential - and actually managed to talk myself off it. the only decent copper in milton keynes
atb
steve
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Jon Ison
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| posted on 7/7/03 at 09:33 PM |
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wot was u drivin at the time ?
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stephen_gusterson
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| posted on 7/7/03 at 10:00 PM |
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nothing special - a W reg BMW 318i.
my mates reconed its cos it would never have stood up in court - 318 in that year makes a crappy 118hp
[Edited on 7/7/03 by stephen_gusterson]
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