Shelby Posted June 5, 2004 Report Share Posted June 5, 2004 ok with 265-50 x15's i have 57 mph at 2k rpm's this is with an auto tranny , the 5 spd will be much diff ,,this is 3.5 miles per hour off on the speedo , speedo is fast 3.5 miles per , i can easily live with that those are a good bit taller then the stock quest tires Link to comment Share on other sites More sharing options...
haztoys Posted June 5, 2004 Report Share Posted June 5, 2004 Art how fare is your speedo off at 50 MPH? I've gotten speedo gears years back , My Wifes car the speedo is right I changed it years ago. At one time you could get the parts ? Have fun David Hazardous Toys inc Link to comment Share on other sites More sharing options...
artinist Posted June 5, 2004 Report Share Posted June 5, 2004 i haven't exactly compared it with another with a correct speedo car yet. but if i had to make a good guess, i would say its showing 90 when i am really going 80. so its probaby showing 8 or so more at 50. I will double check it one of these days. Link to comment Share on other sites More sharing options...
marksweet Posted June 5, 2004 Report Share Posted June 5, 2004 Someone with the 3.90's can check their odometer with a mile marker on the freeway and then calculate the difference in percentage. Obviously the faster you drive the more the speedo will be off. Also i believe from way back I calculated every inch difference in height is .13 or .15 difference in gearing. That means a 3" shortertire would be about the same as 3.90's on a 3.54 geared car. I know a guy with a mighty max that he races with the 2.6 turbo motor. He runs 20" slicks! He has also run 12.5's with it. The trucks are lighter but idon't knw how much. Every 100 lbs. is like a 10HP gain and a good .10 in the quarter. An auto guy should go with the 4.22's. In OD it would b like running 2.87's! If the tranny would hold up it would have a great 60' and a quick quarter! Link to comment Share on other sites More sharing options...
marksweet Posted June 5, 2004 Report Share Posted June 5, 2004 guys if  you  have never personaly  try'd swaping  gear ratio's  while drag  raceing please  say so  so  we can tell if your speaking from personal experiance or  hear -say that said if you have  no more  rpms to work with other then the stock  valve train ,  lower gears  may not help you , but if you  have  the  upper  rpm range to  be able to get to  6.5 and 7 k  then your  going to  need them Link to comment Share on other sites More sharing options...
marksweet Posted June 5, 2004 Report Share Posted June 5, 2004 I had a '66 Buick GS that came wit 2.92's. Put a chevele 12 bolt with 3,55's in that. Also an '82 Vette that came with 2.72'S! and an auto OD that dropped to 1.90's. It would do 90MPH at 3000 RPM's. Changed that to 3.73's and still got 20MPG. Gears are the most gain for the buck barring a turbo. They enhance all the other mods we do to the cars. mark Link to comment Share on other sites More sharing options...
YELLOWHELL Posted November 27, 2004 Report Share Posted November 27, 2004 all the speedometer talk , couldn't you just get the speedometer gears from a d50 that had 3.90's stock? that should make the speedo correct right? Link to comment Share on other sites More sharing options...
haztoys Posted December 9, 2004 Report Share Posted December 9, 2004 all the speedometer talk , couldn't you just get the speedometer gears from a d50 that had 3.90's stock? that should make the speedo correct right? I've just come across my notes on speedo gear part #'S .... If anyone needs to fix there speedo ,,, I do not know if you can still get the parts ,,,But I have the part #'s Link to comment Share on other sites More sharing options...
by_reQUEST Posted January 11, 2005 Report Share Posted January 11, 2005 Maybe Iam coming on a different angle with this as I am just getting into this car ( I was a Ford tech, I owned a Taurus SHO modded to teh max and worked in a performance shop and have swapped plenty of mustang gears) I see 3.90 as a pretty good performance ratio without being too harsh. I dont see much point in it if you arent really modding the car up. For example when you increase the gear ratio you are multiplying torque much higher than before, when you gain torque you usually loose low end ( as far as gear ratio's are concerened) however we are comparing it to stock power levels. vs the stock gear. When changing to a shorter gear you have to increase power levels to keep the over all performance ( top to bottom) the same. bUt what you get is faster acceleration becasue you are multiplying torque by a greater amount. top speed wont be affected as long as you have the proper power to overcome the gear, starve the gear for power and even though it will accelerate faster it is puttin gmore load on teh engine for the given power level. so I look at this car as my fun car, pulling the motor and modding it pretty heavily so thats what I am going to do... after all looking at these prices for performance parts compared to the Taurus SHO I had and the SUbaru 2.5 RS its a cheap car to modify respectively. if you have a 5 speed and arent going to put much more than bolt on's I cant see the real reasoning behind the gear swap ( becasue of the power that will be generated). Power is all in the cylinder head and cam ( rpm variable) its the internal parts that matter the most when it comes to making power. Once again I am new to hte Starquest game but I work for a Ford Dealer and we have connections with all the other dealers around us...including teh mitsu dealer. if someone could get me the drign adn pinion part number and speedo gear number I would appreciate it if not I could dig...or at least the year and model of the truck these are comngout of. thanks!!! SHawn Link to comment Share on other sites More sharing options...
dylanb Posted February 8, 2005 Report Share Posted February 8, 2005 Just thought I would throw in my 2 cents, it may or may not be very helpful. I'm a mitsu 4x4 guy, drive an '85 pickup. I've been trying to track down a starion donor to put a turbo 2.6 in it, which brought me to these boards. Anyway, the d-50 and ram 50 pickups had 3.90 gears in them, but they're open diffs, not LSD. The gen 1 montero/dodge raiders had LSD, but 4.22 gears. Also I have some part numbers for different size speedo gears that mount in the trans (for a montero/ram 50 anyway). They may be the same as those needed for a starion, so I thought I'd throw them on here. Hope some of this is helpful. MD705466 - Gear, Speedometer Drive (N=26) MD705464 - Gear, Speedometer Drive (N=24) MD705462 - Gear, Speedometer Drive (N=22) Link to comment Share on other sites More sharing options...
Shelby Posted July 9, 2012 Report Share Posted July 9, 2012 this is old news but useing the 5 spd speedo drive gear in an auto quest with 3:90 gears will make the speedo read with in 1 mphthe 5 spd cars use a 23 tooth gear the auto cars use a 17 tooth gear not sure about the D50 and MM speedo gears as the conquest drive gear houseing contains a speed sensor & and cable drive , maybe a newer truck with non cable speedo would work Link to comment Share on other sites More sharing options...
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