I have a gsr swap in my car and the tranny is a S80. When I'm on 5th hitting 4k rpm the speedo reads almost 100 mph. I'm pretty sure that's not how fast I'm actually going. So does anybody know how fast I'm actually going at 4k rpm? And if it is reading wrong, what could the problem be?

 

well in my gsr i know that top of 3rd gear = 90mph (+/-). is the speedo jumping or anything like that? when i had a bad connection at my vss connector, the speedo would work normally and then drop to 'zero,' but it would jump around. if yours is pretty smooth i wouldn't worry about it.

btw do you by chance have bigger wheels than stock?? sometimes that can affect your speed sensor reading..

 

vechicle speed sensor, could just be a loose connection

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by delfast &raquo;</TD></TR><TR><TD CLASS="quote">vechicle speed sensor, could just be a loose connection</TD></TR></TABLE>

i was thinking that, thats what my problem was. but he didnt say it was jumping or inop all together, he just said he thinks the mph isn't accurate. i would venture to say that if it was a bad connection somewhere it wouldn't be inaccurate, it would be jumping or inop all together.

 

Yea at first I thought it might be the VSS. The speedo doesn't jump around or anything. It starts from zero and goes up smoothly. And the wheels aren't oversize or anything, the car's sittin on 205/50/15.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Smash03 &raquo;</TD></TR><TR><TD CLASS="quote">Yea at first I thought it might be the VSS. The speedo doesn't jump around or anything. It starts from zero and goes up smoothly. And the wheels aren't oversize or anything, the car's sittin on 205/50/15.</TD></TR></TABLE>

are you sure you're not being paranoid lol?? it sounds like everything is fine, imo. i would say, if you redline it in 3rd and you're right around 90mph, then its pretty accurate. and if its working smoothly, i wouldnt worry about it.

...or roll through a speed trap with your speedo on 100 and see how fast the officer tells you you were going lol

 

man i was cruising around the beltway today, and i just happened to look down and catch my tach at 4,000 rpm in 5th gear. turns out i was doing 80 mph, not 100 mph. then i started to think about which speed sensor you might have? if you have a sensor that's for something other than a gsr, it might give you a different reading... just a thought, not even sure if i'm right, but i guess its worth a shot.

 

Hmm....makes sense. Ima check that out when I got time. Thanks bro

 

5th gear 4,000RPM 80MPH seems about right