8000 rpm/300 bhp 3.2 rebuild

[Bruce M]

Glad it’s sorted but I don’t believe the sensor story.

The input circuits for hall and VR sensors are a different design. If the box doesn’t have a way to configure the input type then it must be built for a particular sensor type. That’s how we build our 3 pin (points) and 6 pin (VR) CDI boxes. Different components needed for each sensor type.

My conclusion is you got sent the wrong box or wrong sensor. Either way, it would be the kit vendor who would have to pick up the bill as they sent the wrong parts.

I’m not an expert like Jonny so had kept quiet but when they told you the recent version of the ECU can now handle the hall sensor, I suspected that the circuit change will have made it marginal for the old VR sensor which creates a different signal pattern. I prefer the hall sensor but if that is true, they should drop the VR sensor & only supply a hall sensor in the kit.
Perhaps they have developed a more advanced design that switches between different signal conditioning circuits based on the sensor signal or some test at start up…. Or not.

[Hugo 356]

IT RUNS!

[fcd911]

Absolutely brilliant news Graham, well done, it has been really tough but it will be worth all the angst - roll on Prescott.

John

[Jonny Hart]

Glad it’s sorted but I don’t believe the sensor story.

The input circuits for hall and VR sensors are a different design. If the box doesn’t have a way to configure the input type then it must be built for a particular sensor type. That’s how we build our 3 pin (points) and 6 pin (VR) CDI boxes. Different components needed for each sensor type.

My conclusion is you got sent the wrong box or wrong sensor. Either way, it would be the kit vendor who would have to pick up the bill as they sent the wrong parts.

I’m not an expert like Jonny so had kept quiet but when they told you the recent version of the ECU can now handle the hall sensor, I suspected that the circuit change will have made it marginal for the old VR sensor which creates a different signal pattern. I prefer the hall sensor but if that is true, they should drop the VR sensor & only supply a hall sensor in the kit.
Perhaps they have developed a more advanced design that switches between different signal conditioning circuits based on the sensor signal or some test at start up…. Or not.

Unlikely. Most designs use a dedicated VR chip (e.g LM1815) which can handle the bipolar signal of varying amplitude (2 - 50 v pk-to-pk depending on RPM). These chips also have built in hysteresis and latching which does all the heavy lifting so fool those who don't use them.

When a hall sensor is used, the signal ( which is 0 - 12V ) is AC coupled through a capacitor which produces a bipolar signal that can then be fed into the VR circuit.

In other words, you need to be able to switch the coupling capacitor (and some other stuff) into the circuit for Hall operation.

If a VR signal is put into the hall input circuit then the results would be -at best- unpredictable.

[911hillclimber]

The mod on the XDi is a simple jump call linking pins 4 and 5 plus the separate 12 volts.
Thus, to change back to vr you simply remove one leg of the jump lead.

[Jonny Hart]

^ Well there you go then. And you are sure that it was in the right config when you had the VR connected?

[neilbardsley]

Best news I've heard all day. Congratulations.

Do you think having a direct input from the battery helped?

Sent from my M2004J19C using Tapatalk

[RobFrost]

Great news. Really looking forward to hearing it.

Sent from my SM-G988B using Tapatalk

[911hillclimber]

Jonny,
Yes, I had the set up correct for the vr all along.
Only when you fit the hall do you need to add the jump wire.The jump goes in pin 4 and 5.
4 and 5 are open as supplied from Clewett using the vr supplied.
The 12v supply has to be found and added to the hall sensor.

This jump wire is supplied with the kit even when you have the vr sensor, the package states Not Needed using the vr sensor.
The new Hall came to me with the jump lead too.

It sounds great Rob!

[rhd racer]

Well done Graham, great news.

Even if the rework feels now like it was a waste of time, in the real world it should make the whole system more reliable, and give you lots of stress free, turn key reliability at events, which has to be a good thing.

I look forward to seeing and hearing it. I think the first time our paths will cross is Loton on 11th & 12th June

All the best
Wayne

[911hillclimber]

Can't do that Loton!
We will compare notes I suspect on the Prescott/Porsche day on 18th May.

[jjeffries]

Hillclimber,

This would certainly cause me to not do business with Clewett in the future. Totally shabby of him/them.

It’s interesting, my own cars/projects (82 SC and 87 924S), neither of which are much modified, have largely introduced me to only great vendors. But a friend who operates at the sharper end of the p-car world (here in the USA) has encountered some right buggers among well known product- and service providers. One theory we have is that with the rather insane, Bring a Trailer-fueled air-cooled Porsche world having punters lined-up at these shops with their wallets wide open, many traditional notions of having to earn and sustain a good reputation have gone bye-bye. I realize that’s a gross simplification and that, from the suppliers/shops’ perspective, they have to deal with some significant wanky nitwits as customers, but you’re not one of them.

I hope your back pain subsides.

John/Connecticut

[911hillclimber]

Thanks John, back/shoulder issues prevail, but a little lady is helping me sort them out.
Just hope I can drive the race car ok end of April.

The USA experience has been bitter or at best lack-luster.
However, I have found new specialists in the UK, ie Greatworth Classics, and a lot on the 5 forums this engine has been spread over, DDK, Impact Bumpers, UHR, PCGB and Pelican.

The forum where the car was first 'introduced' (I was looking to find the chassis number) has just topped 785,000 hits.

I say this because it is the mass response from very many that has helped so much to console me, guide me and advise.

The 3 gents who came to visit me from DDK and spend so much time on the ignition stand out, and the loan of a fab twin plug ignition system from Mike Bainbridge just in case was very welcome.

Overall though, it has discouraged me to do anything else like it, just too much hard work, tension and cost.
Still, it is done now.

Soon be on the hills with white knuckles....

[gridgway]

Hillclimber,

This would certainly cause me to not do business with Clewett in the future. Totally shabby of him/them.

It’s interesting, my own cars/projects (82 SC and 87 924S), neither of which are much modified, have largely introduced me to only great vendors. But a friend who operates at the sharper end of the p-car world (here in the USA) has encountered some right buggers among well known product- and service providers. One theory we have is that with the rather insane, Bring a Trailer-fueled air-cooled Porsche world having punters lined-up at these shops with their wallets wide open, many traditional notions of having to earn and sustain a good reputation have gone bye-bye. I realize that’s a gross simplification and that, from the suppliers/shops’ perspective, they have to deal with some significant wanky nitwits as customers, but you’re not one of them.

I hope your back pain subsides.

John/Connecticut

At risk of an unpopular thought, I wonder if there's a different view. It's extraordinarily hard as a vendor to help trouble shoot all the various installs that happen. I know we want to think they are bad people who didn't help enough and sold a dodgy product, but perhaps it's hard to do and they've experienced many customers in the past who don't have a clue. And they are unable to see someone who does know what they are doing. I think I'll take a different view.

[Jonny Hart]

^. We treat every customer the same, regardless of experience and location. That’s the only way.

We have many customers who have never asked a single tech question and some whose ‘hand holding’ is over a hundred emails long. It doesn’t matter where they are in the world. The only way to accommodate that is in the overheads of the business. That’s why you don’t get good support from ‘box shifters’.