I was wondering what HT members are doing to correct their speedometers when performing a swap. I've got a K20Z1 in my 95 hatch. I'm running 205/50/15 tires. The stock RSX-S came with 17" wheels and tires. I spoke with Hondata and they said the only thing I could do would be to put the stock size wheels on the car to have the speedometer read correctly. I love my 15's. I recently spoke to Hybrid-racing since I saw a speedometer correction for the 2005-06 transmissions. They gave me this site: http://www.yellr.com/yb_home.htm
I'm not selling this. I'm interested in if anyone has used this product or some other product to correct their false speedometer readings. Aside from having a GPS in the car I'm not sure how to get accurate speed readings. Any help?

 

The yellow box is going to be the easiest way to do it. Check on the 350Z, S2000 and domestic forums.. all of those cars run that unit when changing rear differential gears.

 

Good to know that if I do decide to switch to 15's,there is a solution.

 

Solid, thanks for the help.

 

I'm pretty sure Kommon_sense runs that in his K20 swapped EG, I think there's a write-up for the install in his thread on K20a.org. I've been looking to pick one up sometime soon.

 

Yup, I'm running a yellow box in my k20 ek. I spliced it into my swap harness. I got lazy though, I don't think I ever updated my build thread to show the yellow box.

Unfortunately the original poster has the k20z1 with the magnetic pickup on the vss, so a yellow box won't work for him. Assuming he still has the 05-06 tranny with his z1, I believe that kpro has an adjustment option for that. Hybrid racing also offers a little conversion chip to do the job.

http://www.hybrid-racing.com/?cat=4&p=686

 

basically anyone doing a swap needs to do this if they want there speedometer to read correctly.
basically the rsx ecu is for 17" rims, and well not many ppl put 17" rims on your civic.

when im doing about 100 kms its reading about 117kms

i have an app on my iphone that is pretty accurate and i tend to use it when im on the highway, it reflects onto the front windshield

 

Just for clarification, it isn't the rim size, its the tire size. The overall tire circumference on the rsx is larger that civic/integras. This causes the bad speedo readings. I believe they are off by 7-8%. For normal street speeds, it isn't too bad, but my speedo was completely useless on track.

 

ever had problems with the rpm guage not reading correctly also... my rpm guage is off by 400rpms?

 

i believe mine is awell

 

This is god to know cause I never really thought anything of it. I'm running 16's with a 205/40/16 so I should be pretty close right?

 

Rim size has nothing to do with it. Its overall tire size. Your 205/40/16 is even smaller than the stock tire size on civic/integras. You really should be running 205/45/16. So in your case, your margin of error is even larger...

Your tire size is about 5% smaller than stock. Factor that in with the 7-8% and you are as much as 13% off. When your speedo says you are doing 80mph down the highway, you will actually be doing 70mph...

 

its pretty brutal when driving in km/h ..
i'll be doing "120" km and be getting passed by everyone ..
i need to do about 140 to do 120