Directscan Questions?

[rb68rr]

Just hooked up directscan and recorded a run. I noticed that the mph is way off. When I'm going 70 mph on the speedometer, DS says 43 mph. I do have the 145 mph inlay speedometer but can't remember if it has the reducer in it. Anyway, I take it this has a lot of affect on the timeslip and also H.P and torque readings. Right? What do I need to do to correct this? Thanks, R.B.

 

[jhanson1750]

I may be wrong on this but I think the DS reads the mph from the vss (vehicle speed sensor). I don't know how a modified speedo would affect the sensor. I would say check the vss and be sure you are getting a clean signal/pulse from there.

 

[Fuelie600]

Did you go into "Preferences", and set your parameters? Pay no attention to the HP #'s---they are WAY OFF.

 

[rb68rr]

Yes I did. My scanmaster also reads the same as directscan. My 1/8th mile timeslip on DS read 12.13 @ 56 mph! I know it's a little slow but not quite that much! R.B.

 

[rb68rr]

ttt

 

[Fuelie600]

Was your run on the street? If so, I wouldn't put much faith in the DS mph/et.

I would try to manipulate the MPH, by increasing your stated tire size ( under preferences ) untill the MPH is more in line with actual speed.

 

[TurboDave]

Yes I did. My scanmaster also reads the same as directscan. My 1/8th mile timeslip on DS read 12.13 @ 56 mph! I know it's a little slow but not quite that much! R.B.

Do NOT pay any attention to the HP and Torque figures in DS. They have absolutely no basis in reality. They are in fact nothing more than calculated values bases on a number of inputs and settings. With modified speedo's it's reading the wrong VSS signal abviously, so your HP, torque, 1/4 and 1/8 calculations are all going to be totally wrong.

 

[Jerryl]

Yes I did. My scanmaster also reads the same as directscan. My 1/8th mile timeslip on DS read 12.13 @ 56 mph! I know it's a little slow but not quite that much! R.B.

What version of DS do you have?
Anyone know if the version matters for this issue?

 

[FlightTest]

Like Fulie600 said you have to input the correct tire height, usually about 26 inches.

 

[rb68rr]

I had to change the tire height to 40 inches to make it match the speedo! Next question: Made a test and tune run out in the country today and the 02's started out at 830 and were at 710 when I crossed the 1/4 mile line. Directscan showed rich all the way through. What is the rich/lean condition based on? I was running 20 lbs. of boost on a Turbotweak 93 chip. I would think at 710 mv that it would show to be lean. Confused, R.B.

 

[tom j]

It is a touch lean, should be 760 to 780