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| chappykg |
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Ok peoples of knowledge I have yet another question.
My son has a EF Fairmont auto 4L sedan and he want to change the read ratio to 4.11:1. Ok the questions are:- 1. Does the EF have 28 spline axels or 24 spline? 2. Will his existing carrier be able to fit the 4.11:1 gears? 3. What revs will he be doing at 100klm per hour? 4. Ok the speedo will read out we understand that so how do you get the speedo to read correct with the new gears? 5. I don’t know what gear ratio the existing diff is but we are hoping it will make the car more responsive of the mark. I gather there are many out there that have already made this mod so we are hoping for good feedback and info. We are also contemplating either fitting a LSD or Lock Right LOKKA diff lock unit as yet have decided Cheers. P.S. We are also interested if anyone has any of the above for sale.
_________________ Turned L.G.AUTOMOTIVE Townsville |
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| Mont5.0 |
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why 4:11, why not something more streetable like 3.7 or3.9?
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| Krytox |
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{USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? My thoughts exactly. Unless this Ford i6 rev's past 6k and has max torque at 4000rpm?¿ 3.7's imo would be the lowest. 1) Yes 28 Spline. 2) iirc, if he has a 3.23:1 housing it should fit (correct me if i'm wrong) 3) depends what wheels he has and gearbox ratio. 4) You can get speedo senders to suit upto around 3.7 i think, otherwise get a police cluster to compensate the rest. (yes, have a very low K'd one) 5) Slap an LSD in it, with the ratio's your looking at, I'm pretty sure it'll be bent within a few months.
_________________ Carefree, we may not be number one, but we're up there. |
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| Benjii |
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I'd venture a guess and say you be doing about 2600-2700rpm @ 100kph
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| chappykg |
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{USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? Why do you suggest those ratio's? We looked at 4.11:1 because its auto and with the turbo and cam it would make the vehicle easier to get moving.
_________________ Turned L.G.AUTOMOTIVE Townsville |
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| chappykg |
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{USERNAME} wrote: {USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? My thoughts exactly. Unless this Ford i6 rev's past 6k and has max torque at 4000rpm?¿ 3.7's imo would be the lowest. 1) Yes 28 Spline. 2) iirc, if he has a 3.23:1 housing it should fit (correct me if i'm wrong) 3) depends what wheels he has and gearbox ratio. 4) You can get speedo senders to suit upto around 3.7 i think, otherwise get a police cluster to compensate the rest. (yes, have a very low K'd one) 5) Slap an LSD in it, with the ratio's your looking at, I'm pretty sure it'll be bent within a few months. WHy will the diff bend within a month with 4.11: if this is the case a 3.7:1 would also bend I imagine.
_________________ Turned L.G.AUTOMOTIVE Townsville |
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| Krytox |
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It was my response to question 5...
If you were to choose a LOKKA Not the diff, the car... around a tree
_________________ Carefree, we may not be number one, but we're up there. |
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| bry40l |
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{USERNAME} wrote: {USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? Why do you suggest those ratio's? We looked at 4.11:1 because its auto and with the turbo and cam it would make the vehicle easier to get moving. 4.11 gears are way too low for a turbo 4l even in automatic, once boost hit with those gears youd just be spinning like crazy and changing through gears like crazy, even in automatic, fit a 3.45 lsd from an xr6\xr8 that should make it a little more responsive until boost comes on
_________________ BF XR6 |
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| Mont5.0 |
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{USERNAME} wrote: {USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? Why do you suggest those ratio's? We looked at 4.11:1 because its auto and with the turbo and cam it would make the vehicle easier to get moving. It would have been good if you had provided us with ALL info when asking the questions. How are we to know it was turbo'd?? Even more reason not to use 4.11's. As stated above 3.45's would be a better option, even LSD what ever ratio is already in it. Is this car to be rego'd or purely track work?- more info needed! |
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| bry40l |
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{USERNAME} wrote: {USERNAME} wrote: {USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? Why do you suggest those ratio's? We looked at 4.11:1 because its auto and with the turbo and cam it would make the vehicle easier to get moving. It would have been good if you had provided us with ALL info when asking the questions. How are we to know it was turbo'd?? Even more reason not to use 4.11's. As stated above 3.45's would be a better option, even LSD what ever ratio is already in it. Is this car to be rego'd or purely track work?- more info needed! yep spill the beans, what has this car got, how much at the treads and how much are you aiming for in the future, how much track work it does/street work etc
_________________ BF XR6 |
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| chappykg |
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{USERNAME} wrote: {USERNAME} wrote: {USERNAME} wrote: why 4:11, why not something more streetable like 3.7 or3.9? Why do you suggest those ratio's? We looked at 4.11:1 because its auto and with the turbo and cam it would make the vehicle easier to get moving. It would have been good if you had provided us with ALL info when asking the questions. How are we to know it was turbo'd?? Even more reason not to use 4.11's. As stated above 3.45's would be a better option, even LSD what ever ratio is already in it. Is this car to be rego'd or purely track work?- more info needed! Ok point taken and sorry. Street registered and blue plated. So far the mods are - Garrett GT35/82R water-cooled, 6Boost manifold, 36lb Bosch injectors, Crow valve springs, MLS-R head gasket, Bosch external fuel pump and serge tank, Wolf V500 ECU, Wolf Boost controller, inter-cooler, turbo 4" inlet and 3" full exhaust. ( A Camtech Turbo custom cam to be fitted at the end of the month) The vehicle is only running 7lbs boost at the moment,t made 257rwkw. The way it is tuned now it starts coming on boost at 1800rpm and full boost at 2500rpm. Has heaps of torque. When the cam is installed it will be re-tuned and pushed up to 10lbs boost, we are hoping for somewhere around 320 to 350rwkw then. All the turning and dyno work is done by LG Automotive in Townsville and the mechanical work is done by J.B Automotive in Ayr. Coming mods are - Spool Pistons(8.5:1) and conrods, full engine balance, Head CNC ported, crank shaft stressed treated and oil mods made. All this work will be done by J.B. Automotive (John Barbagallo) Now back to the diff ok point taken again, but my son still wants to run a lower ratio diff probably 3.7:1 possibly. I wonder what ratio the standard EF Fairmont auto sedans had from factory. Cheeers
_________________ Turned L.G.AUTOMOTIVE Townsville Last edited by chappykg on Fri Mar 16, 2012 10:37 am, edited 1 time in total. |
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| bry40l |
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if hes got 250 kw and looking at building a bottom end and custom cam and winding the boost up again just fit a 3.45:1, 3.7's is a bit of a joke, if he went down the quarter i rekin he would easily find the limiter in 3rd gear with those gears
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| TROYMAN |
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keep in mind a turbo with auto trans will spool up better with more load/ higher diff gears, imo 3.45 would be ideal, 3.7 may still be fine but may fall short on top speed..
but also look at your rev range, if your engine is set up and can rev to 7000rpm then you can get away with shorter gears.. im running auto with 3.45 diff gears and im shifting from 3rd into 4th gear @5500rpm just before the line down the 1/4.@ 113mph... and keep in mind the 4 speed auto's 4th gear is just an overdrive and not ment to maintain high amounts of torque under load .. |
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| chappykg |
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{USERNAME} wrote: keep in mind a turbo with auto trans will spool up better with more load/ higher diff gears, imo 3.45 would be ideal, 3.7 may still be fine but may fall short on top speed.. but also look at your rev range, if your engine is set up and can rev to 7000rpm then you can get away with shorter gears.. im running auto with 3.45 diff gears and im shifting from 3rd into 4th gear @5500rpm just before the line down the 1/4.@ 113mph... and keep in mind the 4 speed auto's 4th gear is just an overdrive and not ment to maintain high amounts of torque under load .. Ok thanks what sort of power yu running and what times1/4mile. Even though the motor will be capable of 8000rpm we are limiting it to 6,800rpm for safety.
_________________ Turned L.G.AUTOMOTIVE Townsville |
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| the sam |
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Remember at those sort of revs its not the rod/piston weight that you need to worry about if they are forged/aftermarket items. Its the rockers and valvetrain that has trouble keeping up to scratch above 7k.
Au rocker gear is preferred when revving higher because the rocker ratios are better suited to higher rpms than the e-series units.
_________________ LOW, LOUD AND LUMPY |
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