Speedo and tach are wrong, hlsd the cause?

[dball33]

I just found out this past weekend that my speedo and tach are off. The speedo is reading 10 mph too fast and the rpms correspond to the speed shown. I was wondering if this has to do with my s15 hlsd. I didn't have the shop swap the ring gear from the open so is the higher speed because of the different gear ratios? 4.08 for open vs. 3.62 for hlsd? If so, what can I do to fix the problem? Thanks.

[OptionZero]

Just to add to the thread:

Dave, did you have the complete s15 pumpkin? I thought you only had the main helical unit and the two outputshafts, just like me. In that case then we wouldn't even have an S15's 3.62 HLSD ring gear to swap because we wouldnt even have another ring gear around...I think.

for everyone else:
the way we found the problem was along the way to Thunder Hill, dball was in the lead and drove 70mph the whole way- when we got there Turdz and I asked why he was driving so slow, and dball said he was giong 80mph! On the way home, I led and drove 80mph according to my tach, and that is what Turdz's car read as well, but Dball's car said it was going 70mph. Turdz and I have s14's, and dball has an s13 hatch.

[drew935]

Actually, the speedo and tach should be reading right. It's the output that is reading wrong. You can take apart the tranny and change the speedo gear that the vss rides on. Or you can change the ring gear in the diff. :duh:

Btw, is that the '05 Cusco queen in your avatar? :w00t:

edited: dball what tranny do you have? E/DE/SR20

[dball33]

Just to add to the thread:

Dave, did you have the complete s15 pumpkin? I thought you only had the main helical unit and the two outputshafts, just like me. In that case then we wouldn't even have an S15's 3.62 HLSD ring gear to swap because we wouldnt even have another ring gear around...I think.

for everyone else:
the way we found the problem was along the way to Thunder Hill, dball was in the lead and drove 70mph the whole way- when we got there Turdz and I asked why he was driving so slow, and dball said he was giong 80mph! On the way home, I led and drove 80mph according to my tach, and that is what Turdz's car read as well, but Dball's car said it was going 70mph. Turdz and I have s14's, and dball has an s13 hatch.

Hmm....yeah, I guess the hsld couldn't be the cause then since your speedo works fine. Oh yeah, my car read 90 mph when you guys were going 80 mph.

[dball33]

Actually, the speedo and tach should be reading right. It's the output that is reading wrong. You can take apart the tranny and change the speedo gear that the vss rides on. Or you can change the ring gear in the diff. :duh:

Btw, is that the '05 Cusco queen in your avatar? :w00t:

edited: dball what tranny do you have? E/DE/SR20


.......haha, I don't think I'm mechanically capable of doing any of those two options...

Not sure if she's the Cusco queen, but she was at JGTC in December. Hecka cute! :drool:

Tranny's DE

[drew935]

I would change the ring gear out of the hlsd. You will use gain more power with a more suitable final drive ratio. That's the easier way to go about the speedo and tach remedy.

Yes, she was at GT Live. She is the new Cusco Queen for '05. Kazumi, former queen, is now the manager/supervisor for her. She is still learning Engrish..hehehe, but is progressing very well. :hsdance:

[uno]

just get the speed sensor gear for different gear ratios through courtesyparts.com

[millelu]

Would anyone know what could be causing this in a car that hasn't had any modifications made to it yet? The plug underneath my car came undone once and I completely lost speedo, but plugged it back and it worked fine again.

Just recently noticed that the speedo reads about 5 over in town where the cops have setup one of those radar guns that show how fast you are going. Once I am on the highway it looks like it may be around 10 over, I followed my dad who always drive the exact 55 and I was reading 65.

Any ideas?

[uno]

Would anyone know what could be causing this in a car that hasn't had any modifications made to it yet? The plug underneath my car came undone once and I completely lost speedo, but plugged it back and it worked fine again.

Just recently noticed that the speedo reads about 5 over in town where the cops have setup one of those radar guns that show how fast you are going. Once I am on the highway it looks like it may be around 10 over, I followed my dad who always drive the exact 55 and I was reading 65.

Any ideas?
Tire size maybe

[WILDACEX187]

just get the speed sensor gear for different gear ratios through courtesyparts.com

can u link us? i want to know about this as well.

[uno]

http://www.courtesyparts.com/nms/s13/s13_4.html

[drew935]

http://www.courtesyparts.com/nms/s13/s13_4.html
good post and answer :bigok: :w00t: :2f2f:

[uno]

good post and answer :bigok: :w00t: :2f2f:
thank you, thank you, i'll be here all week :drama:

[dball33]

Thanks for the replies. I didn't recieve any notifications so I didn't check back. I went through this website http://www.courtesyparts.com/nms/s13/s13_4.html but I'm unsure of what to get. Can anyone help out? Thanks.

[NemeGuero]

Call courtesy and ask them. Give them your specs and they'll tell you which pinion gear you need.