transit swb turbo conversion

[100ps_drw_hicube]

no crap on the brighton bypass i can get a 100mph if the hills were a little longer i can just get 105mph

[100ps_drw_hicube]

well how come with my 4.56.1 diff foot through the floor max revs down a megs hill i can only get 90mph

100ps has bigger dia tyres on his!!

do you think that 1 inch can make that amount of difference

[Luke]

well how come with my 4.56.1 diff foot through the floor max revs down a megs hill i can only get 90mph

100ps has bigger dia tyres on his!!

do you think that 1 inch can make that amount of difference

whats the size of your tyres i.e. ***/**x**

no crap on the brighton bypass i can get a 100mph if the hills were a little longer i can just get 105mph

ever wonder why your engines dont last too well

[100ps_drw_hicube]

my tyres are 185 r15 8 ply and the speed rating is r ye my engine doesnt seem to have a limiter it keeps going to 4300rpm the only limiter is the floor thats why they dont last on my old hi cube i seized it somehow by going down the mway flat out for about 4 hrs still at least it was a bannana engine easy to get hold of another

[Luke]

well according to my QUICK calculations - and i may be wrong cos i could do with the aspect ratio of the tyres but with a 5.16 diff @100 mph you should be doing 7000 rpm ish - so mabe your speedo's out!!

what rpm is it doing at those speeds

[stevew]

Nah your out a bit there!
My van with a 5.14:1 diff does 62.5mph (100kph) at 3000rpm. Scaling that up gives 100mph at 4800rpm.
I've had mine up to about 80 and a bit approaching 4000 rpm but bottles it! The engine realy screams.
Steve

[MrMPuk]

2 of my old works vans used to regularly get up to 95 on the clocks, but with the GPS in the van I found out this was only 80!

[100ps_drw_hicube]

what rpm is it doing at those speeds

it is doing about 4300rpm maybe a tad more tbh i am concentrating on the road more but i have been followed by someone on a cb400 and he said his clocks were up to a ton and mine were reading just over so i dont think the speedo can be that far out maybe 5mph

[Luke]

Hmmm yeah seems i'm out abit
i worked it out from the tyre back did seem a bit high i'd guess ive chose the wrong aspect ratio for the tyre what tyres have you got steve?
and also are all 5th gears the same ratio?

[100ps_drw_hicube]

aspect ratio?? that must be what the other 2 numbers are that are on the tyres mine is 102/103?? if that makes any sense?

[madmark]

maybe you have a 4.63 diff! my rac van has 5.14 in 5th it seems to get revy at 60mph! so mine will be about the same as steves! i am running 225/70/15 on the rear!

[100ps_drw_hicube]

might have but the tag by the back cover says 5.14 but arnt most turbos limited to 4000rpm as my dads seems to cut out when you hit the top of the revs also his is very revvy at 60mph theres definately something different about mine

[Luke]

aspect ratio?? that must be what the other 2 numbers are that are on the tyres mine is 102/103?? if that makes any sense?

mabe they are the Li the load the tyre can take
some commercial tyres dont have the aspect ratio on its the 225/THISBITx15

[Luke]

OK try again madmarks van with 225/70x15 a 5.14:1 diff and an MT75 with 0.82:1 5th gear

736 x 5.14 x 0.82 / 60 x 100 = 5107 revs per min @100 mph

same van with a 4.63 diff

736 x 4.63 x 0.82 / 60 x 100 = 4657 revs per min @100 mph

think thats right!!

[Luke]

BTW anyone know the answer to the origanal question

The question i would like answered is what has the 4.1-1 ratio rear diff ?