I just finished installing a b18c1 into my del sol S. WHile I had the engine out I put a ls 5th and jdm type-r lsd into the tranny. My problem is that my speedo is reading faster than I"m actually going. My g/f drove next to me to clock me and when my speedo said I was going 70 hers we going only 65. What is wrong? When I put in the lsd I put in the speedo gear that came with it. I'm think this might be the problem as the type-r has a 4.4 final and the gsr is only 4.26. Will the gsr speedo gear work with the lsd or are the teeth incompatible? Also, is it possible to change this gear without taking the tranny apart?

 

5 mph at 70 is acceptable. are your tires the same size?

p.s. a gsr is 4.40 also and a ls 5th won't change the way your speedo reads

 

opps, I see that my numbers are little off. The lsd is from a 4.78 final drive and my gsr is 4.4. So there is still a differnce there. My tire size is 205/50/15, and stock should be 195/50/15. This should have the opposite effect on my speedo. Making it read that I'm going slower than I actually am, not how it currently reads telling me that i'm going faster than I actually am. Does anyone know if putting the stock gsr speedo gear in would solve this issue, and will it even mate with the lsd?

 

Stock GSR tires are 195/55/15 which is a bit taller than the 205/50. Plus, even with the stock tires the speedo read a bit high, so with 205/50's it reads 4-5 mph high at 65-70. I don't know if there is a different gear that will make it read correctly.

 

gears are the same

 

So if speedo gears are the same then the diffs have different gearing for the speedo? Something has to compensate for the differences in final drive ratios. IF the diff is different then how can I compensate for it?

 

the speedo is reading wheel speed the final drive doesn't change that it only changes your engines rpm

 

OKay, then how would I go about correcting the speedo issue? I changed out the guage cluster in my S to a vtec one to get a higher redline, but when I did this I swapped out the speedo gauges so that it would read the same miles that I orginially had. Do you think the speedo itself could be causing the descripancy?

 

Is there any difference between the vss sending units on a d series vs b series? Perhaps a different calibration for pulses per mile?

 

You know you can buy a GPS speedometer which gives you satellite tracked speed in anything you mount it to. They aren't all that expensive, and they're perfectly precise.

 

correctly sized tires helps from the start.

Your running DOHC tranny, run DOHC size tires...........

Like 195/55/15 that came on GSR's