Speedometer question

[MufflerMan]

Two questions. I think my speedometer is reading slow. What speed are you guys showing in 5th gear at 3000rpm? Mine is just a tick above 60mph. Second, what is the redline on my car? I have the red ECU and I am not sure it has a limiter, so I have been short shifting. Thanks in advance for your help.

[mamovaka]

I could be wrong but i dont think the RED ecu disables the limiter, the engine WILL cut off the fuel supply at redline.. if I am not mistaken..

I think the REd ecu is like 7300RPM?

[ibandre]

I also have the red ECU, and it definetely does not disable the limiter. I have tried it several times. Mine goes to 7400 RPM.

[glynherron]

Two questions. I think my speedometer is reading slow. What speed are you guys showing in 5th gear at 3000rpm? Mine is just a tick above 60mph. Second, what is the redline on my car? I have the red ECU and I am not sure it has a limiter, so I have been short shifting. Thanks in advance for your help.

According to my service notes it the speedo should read 25.5mph per 1000 revs in 5th gear

Glyn

[MufflerMan]

According to my service notes it the speedo should read 25.5mph per 1000 revs in 5th gear

Glyn

Great, can anyone confirm this with reference to thier car? If that's the case, my speedo is definitley slow as it should show 76.5 mph @ 3000 rpm. Has anyone else had this problem?

[neal]

Great, can anyone confirm this with reference to thier car? If that's the case, my speedo is definitley slow as it should show 76.5 mph @ 3000 rpm. Has anyone else had this problem?

Mine reads perfectly according to the 25.5mph/1000rpm specification.

Check the pulse calibrarion of the speedo:

http://www.egauges.com/pdf/vdo/0-515-012-051.pdf

It should be set to 6170.

[MufflerMan]

Mine reads perfectly according to the 25.5mph/1000rpm specification.

Check the pulse calibrarion of the speedo:

http://www.egauges.com/pdf/vdo/0-515-012-051.pdf

It should be set to 6170.

Do you know how to change the setting?

[neal]

Do you know how to change the setting?

Read the pdf! I've actually changed mine so that the speedo reads perfect instead of the normal over by 5%ish

[MufflerMan]

Read the pdf! I've actually changed mine so that the speedo reads perfect instead of the normal over by 5%ish

Just read it. Thank you! Very valuable info, and I appreciate it.

[mamovaka]

I also have the red ECU, and it definetely does not disable the limiter. I have tried it several times. Mine goes to 7400 RPM.

At 7400 rpm doesn't the engine still have a safety? to keep it from overrevving and doing damage? even with the RED ecu?

[neal]

At 7400 rpm doesn't the engine still have a safety? to keep it from overrevving and doing damage? even with the RED ecu?

Yes, the stock V8 ECM has a 7000rpm limit, the V8-GT, S350/Hi-Torque and presumably red ECMs all use 7400rpm. Past that and it cuts the injectors.

But even without a limiter, an engine won't necesarily rev itself to destruction. Usually the valve springs start to resonate around that point (unless they've been upgraded to be stiffer) so the valves don't close properly and the resulting power drop off produces a mechanical limit. You could be unlucky and get valve to piston contact though.

What will kill the engine is if you downshift at too high an rpm or miss the gear, e.g. going from fifth to second.

[Advantage]

The V8 is actually a pretty good revver. (Not sure if that's a real word!) The limits set by the various ecus (stock/high torque/red etc) are a touch conservative as to what the engine is capable of without exploding into a gazzillion pieces.

For longevity though, it's best not to exceed low-mid 7k revs on a regular basis which is why the ecus have this limit. However, there's no need to be too timid with the throttle. The ecu sets the limit and the engine is safe to run it up to that limit - maybe not everyday, but it's certainly nothing to be scared of.

[hykam]

Mine reads perfectly according to the 25.5mph/1000rpm specification.

Check the pulse calibrarion of the speedo:

http://www.egauges.com/pdf/vdo/0-515-012-051.pdf

It should be set to 6170.

I got a new VDO speedometer in km/h. Pls advise what is the pulse for calibration.

Thanks

Raymond

[neal]

I got a new VDO speedometer in km/h. Pls advise what is the pulse for calibration.

Thanks

Raymond

I'd guess it would be the same. If not:

1. Try using 6170 * 1.61.

2. Try using 6170 * 0.62.

3. Experiment and align it with your GPS

4. Experiment and align it with your rev counter - a V8 does 41.0 km/h per 1000rpm in 5th.

[hykam]

I'd guess it would be the same. If not:

1. Try using 6170 * 1.61.

2. Try using 6170 * 0.62.

3. Experiment and align it with your GPS

4. Experiment and align it with your rev counter - a V8 does 41.0 km/h per 1000rpm in 5th.

Thanks. The new speedo I got is #A082N4057F (VDO #437 015 027) which is for 1998 or later V8.

The wiring does not fit my 1996 V8 that uses #A082N4051F which is obsolete.

Do you know a way to install this new speed to 1996 V8 ? Or is the speed sensor applicable ?

Raymond

[neal]

Thanks. The new speedo I got is #A082N4057F (VDO #437 015 027) which is for 1998 or later V8.

The wiring does not fit my 1996 V8 that uses #A082N4051F which is obsolete.

Do you know a way to install this new speed to 1996 V8 ? Or is the speed sensor applicable ?

Raymond

The pdf I gave above tells you how to set up the the VDO - you just need to figure out how to cross wire it. Shouldn't be too difficult - the V8 uses setup 3 in the pdf (i.e. the speed pulse comes from the ECM) so you just need to figure which wire on your old speedo is positive, ground and pulse. That and wire the illumination bulbs. Lotus tech might be able to help more.

[Advantage]

Have a look through this thread from a few months ago, the pictures might help a bit.

http://www.glcforum.com/esprit/forums/inde...?showtopic=6089

[fmxa]

Raymond - based on the factory wiring diagram the following should work ....

1) Speed comes from Pin 60 on the ECU and goes to Pin 8 on the speedo & should be orange/brown

2) Positive from the binnacle is the green wire and goes to Pin 4 on the speedo

3) Negative from the binnacle is black and goes to Pin 3 on the speedo

[hykam]

Raymond - based on the factory wiring diagram the following should work ....

1) Speed comes from Pin 60 on the ECU and goes to Pin 8 on the speedo & should be orange/brown

2) Positive from the binnacle is the green wire and goes to Pin 4 on the speedo

3) Negative from the binnacle is black and goes to Pin 3 on the speedo

Thanks everyone for the help. Will try and report.

Raymond

[hykam]

Thanks everyone for the help. Will try and report.

Raymond

Installed new speedo and it works. Speed shown is accurate.

Followed the wiring from Paul and everything works.

Odometer works accurate by default without adjustment.

Attached photo shows the original speedometer.

Thanks for the help from all of you.

Raymond

Installed new speedo and it works. Speed shown is accurate.

Followed the wiring from Paul and everything works.

Odometer works accurate by default without adjustment.

Attached photo shows the original speedometer.

Thanks for the help from all of you.

Raymond

More photos of the original speedometer.

It is from Caerbont Automotive #PES5-1131-13b (Lotus part #A082N4051F) in Km/H.

[fmxa]

Raymond,

That's excellent news! If you're interested there's still a matching tachometer (98> style) listed in the Lotus parts sale.