Help! Speedo Problem

[Kenney07]

Hi guys.. Im New to the board. I have a 98 GT B&M Short Throw, Flow Masters American Thunder Catback, BBK H Pipe, Cold Air intake, and a Diablo Predetor Tunner.

I Just recently rebuild the rear end and put pro 5.0's 3:90's in the rear end. Now my speedo is all screwed up and they dont make a speedo gear for the 3:90 . Any ideas on how i can my speedo accurate again?

Thanks

 

[mrvax]

First of all, you don't want to go with the speedo gear change. Using the non-stock one will cause it to disentergrate within months. Mine did. Can't your Predator tuner adjust this? Check the manual. If not, see my sig, get the SpeedCal and hook that up. I've had mine for years with no problems. Easy install.

 

[Kenney07]

I thought the predetor could too but i guess the speedo only goes electronic with the computer at 99 and up. At least thats what the people at Diablo told me when i called them all ticked off.. So the speedo cal will make it 100 percent accuarate? I got a quote from a speedo shop for 250 to build a custom gear box. Which one would be the better choice?

 

[RandyStinchcomb]

you can get it close to wthin 10 mph but its going to require a gear change on the output shaft of the trans, which meenS the trans ext housing has to come off and a 21 tooth oem gear on the end of the VSS

 

[CobraRed_96_GT]

you can get it close to wthin 10 mph but its going to require a gear change on the output shaft of the trans, which meenS the trans ext housing has to come off and a 21 tooth oem gear on the end of the VSS

all you need is a speedcal, you don't need a new gear. Just program the unit for 3.90's

 

[RandyStinchcomb]

all you need is a speedcal, you don't need a new gear. Just program the unit for 3.90's

well maybe he dosn't want to spend that kind of money when all you need is 2 gears for @$35.00

 

[Kenney07]

Thanks for all the help guys.. Decided to go with the speedcal only because its supose to be more accurate and i dont need any speeding tickets and my millage on the odometer going up...