I am hoping some of you SFP guys can help me with this. Why does my speedo read 100 mph as I run down the freeway? No I'm not really going that fast. I think I am running about 70 mph. Is there an easy fix for this?
speedo reading way to fast!
- Thread starter Dlampe
- Start date
Dean,
How do you like your SPF? How does it compare with the RCR?
How do you like your SPF? How does it compare with the RCR?
I am still sorting things out on the SPF. I thought it would be interesting to write up a comparison when I get more familiar with the car. So far it is turning out to be a pretty cool car. I will keep you posted. Right now I am trying to decide whether some things are broke or if I just don't know how it works!:stunned:
Mine is pretty accurate. I seem to remember that when Dennis Olhoff did my install he put an adapter on the speedo output to shuffle the ratios slightly. I think there is a thread on that somewhere.
The SPF speedo is calibrated for 3.77 Ring and and Pinion, if you have a 4.22 ratio you need a reducer between the gear box and the speedo cable.
Dave
Dave
I agree with what Dave and Steve said. This might help you out.
Calculate Speed(MPH) for given RPM, Rear Gear Ratio and Trans Gear Ratio
Once you find out your trans gear ratio you can reverse calculate......
Rich.
Calculate Speed(MPH) for given RPM, Rear Gear Ratio and Trans Gear Ratio
Once you find out your trans gear ratio you can reverse calculate......
Rich.
Dean, impresses the girls though, did a cobra once with a 2 to 1 ratio on the speedo, 70 showed 140, way to get laid !
Jack Houpe
GT40s Supporter
Dean I sold mine and bought one that looks just like it from Speedhut.com. Its programmable and no cable to worry about. I also can see it at night. A couple of my friends followed my lead and did the same thing. What did you get?? Have you posted pictures?
flatchat(Chris)
Supporter
I reckon, that all speedos should be controlled by GPS ---it'd be universal and consistant :blank:
More popcorn please:shifty:
More popcorn please:shifty:
Thanks for the advice. I'll give Dennis a call today and get the adapter. I am pretty excited about the car and I will post some pictures soon but I am working on some graphics that I would like to get done first. I always wanted a car with those Hawaiian flames painted on it and now with decals, it is possible!!!:lipsrsealed:
when I got my adapter from him it was $95 IIRC.
I talked to Merlin in Dennis's shop and he priced the adptor to me for 105. I didn't order it becuase i wanted to check the ratio to be sure. He said most are going to the electronic speedo. I would like to find someone that replaced their old speedo with the newone and doesn't need the adaptor anymore.
This car has a ZF but I haven't had time to go check the ID tag to determine the Ring and pinion size. My speedo is working fine, it's just off by probably 40%.
Jack Houpe
GT40s Supporter
Richard, I want your transaxle or a new ring and pinion. Someday someday.
The speedo that was in my car had a 90 bend at where the cable screwed into the speedo, somebody from the factory just shoved the gauge in the dash and didn't check for clearance, not knowing this the first time I hooked it up it snapped and never worked. After seeing what a new cable and adapter cost I went electric.
The speedo that was in my car had a 90 bend at where the cable screwed into the speedo, somebody from the factory just shoved the gauge in the dash and didn't check for clearance, not knowing this the first time I hooked it up it snapped and never worked. After seeing what a new cable and adapter cost I went electric.
After using a cable with the gear reduction, I had Dennis change to the electric. It is right on per the GPS. I would suggest using the type Dennis O sales. Smooth operation. I have a different brand, new one in the box from Utah, and still waiting for them to get back to me about the input sensor....
Also you can see it at night because it is back-lit.
Grady
Also you can see it at night because it is back-lit.
Grady
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