Classic Retrofit: Six phase high output alternator.
 

We're just closing out testing on our all new 6 phase alternator. We have chosen Denso 6 phase 'hairpin' internals. These units are in widespread use and have been designed to support the high loads of modern vehicles with all the gadgets and stop/start systems.

The units are highly efficient and generate very little heat which is the killer of rewound Bosch or Valeo units. They have internal cooling fans too.

The major work has been in designing a casing to fit the 911 fan shroud of which there are 3 variations over the years. The unit will fit the earliest fan housings without modification and the later years by using a spacer.

http://www.classicretrofit.com/media....jpg?width=800

http://www.classicretrofit.com/media....jpg?width=800

Some changes to the wiring are needed in the car, namely the positive and negative cables to starter and engine case need uprating to 25mm cable ( 4 AWG ). See the red and black cables in this picture:

http://www.classicretrofit.com/media....jpg?width=800

The alternator output specification is as follows. Note this is alternator RPM. Typically 911 fan pulleys are 1.8 ratio but they do vary over the models:

Weight - Kg 5.3
Alt RPM 175A
500 0
1000 0
1500 96
2000 135
2500 148
3000 156
3500 164
4000 169
4500 173
5000 176
5500 177
6000 178
6500 179
7000 180
7500 181
8000 182
8500 182
9000 182
9500 182
10000 182
10500 182
11000 182
11500 182
12000 182
12500 182
13000 182
13500 182
14000 182
14500 182
15000 182
15500 182
16000 182
16500 182
17000 182
17500 182
18000 182

Lamp off 500
Cut in 1050
Cut out 1025

Although the unit is rated 180A, it is unlikely that a single pulley would be capable of transmitting that kind of power. Internet wisdom suggests that a single pulley limit is around 120A but the Internet is full of it, best find out first hand....

We are currently running the alternator at 140A with no pulley slip. We currently have 90A at 950 engine RPM , falling slightly when warm. (To put this into context, a 964 110A unit only produces 40A at idle)

Great news for electric A/C and also for electric heat which is now in development.

Hope to have the alternator ready for sale in a couple of months. Pricing TBD.

Oh, this sound interesting, always wanted to get writh of the heath exchangers.

Any more info on your electric heat project. Will it work with your high power blower?

Awesome! We are very fortunate to companies like Johnny's, continuing to develop improved components for our classic cars. This is one component that has been sorely lacking. Converting to EFI, high wattage lighting, and of course, electric AC, etc, meant taxing the stock alternator beyond it's original design limit. Some of us northern babies even add heat to our seats! Thanks Johnny!

Any thought given to just putting a more off the shelf alternator where the AC compressor would normally be and running it off the accessory pulley?

This is great. The stock alternators are expensive and weak, and rebuilding is a bit of a gamble depending on who does the work. I'm hoping to put electric AC, heated seats, and a proper stereo in my car this year, and this will help. I find I usually need AC the most when stuck dead in traffic...where it's hard to get much at idle.

Are these the "large case" or "small case" hairpins? Is the voltage regulator adjustable or is there no real drop using fresh 4awg wires? What size are the existing wires? How hard is it to run wires in these cars...?

Very cool Jonny. I have my alternator out right now (part of my EFI/ITB retrofit) and if this were available now I would grab one to skip the double labor. I think I'll do the wiring upgrade now while I'm re-doing the the engine harness anyway. If you need a beta tester... just sayin'...

Quote: "Any thought given to just putting a more off the shelf alternator where the AC compressor would normally be and running it off the accessory pulley? "

I have seen that done and it is not very elegant...:( there is a big ugly lump and the fan belt go get in your way like the AC compressor which is a pain to work around or remove and hang on the rear fender. But to each his own I guess.

Rahl

I'm still interested in this solution, but I know of no off-the-shelf product one can buy to relocate the alternator...What is the fan attached to with no alternator?

The external alternator was a flat fan 911 engine. Great looking engine except for the alternator hanging there. The fan could spin an a gutted stock alternator /shaft and bearings.

Rahl

Any thought? :eek: Remember this is all we do, all day, every day and sometimes at night even!

My guess is that the second alternator idea is driven by the notion that it *might* be a cheaper solution (even though we haven't announced a price yet). I don't think this would be the case if you think about all the parts involved to provide a complete kit (custom mount, alternator, belt, pulley, wiring, special regulator or splitter).

There are technical issues too, you can't just run two alternators in parallel, neither should you spin a disconnected alternator without it connected to a battery, it will damage it. Practically, if the alt is now on a separate belt, how would you know if your true fan belt is broken? (ignition lamp would not light).

The labour involved in fitting a second alt would be greater too as you'd have to get to the back of original alternator anyway which is half the job of changing it. I can't imagine any workshop recommending a second alternator as a sensible solution.

Sorry for the slightly negative response but we are dedicated to providing fully integrated and elegant solutions for these beautiful machines.

remote alternator
 

I run the alternator off the back of the 4,5,6 camshaft on my racecar.The only downside is there is no charging until 1800 RPM as the cam turns at 1/2 the crankshaft speed.I use a gutted alternator with just the shaft and there is no horsepower loss and you can spin it to 9300 and no belt issues or slippage.I wonder how much H.P. loss there would be at 140 Amps.Ciao Fred

Less than 5hp, I would expect...

https://electronics.stackexchange.com/questions/121662/mechanical-load-of-an-alternator

140A at around 13v is 1820 watts. 1hp is 748 watts. It's like 2-5hp from 100% efficiency to 50% efficiency on the alternator at full load (AC on, subwoofer blasting, headlights on, seats heated, charging your phone, charging the battery after an engine start, rear windows defrosting, etc).

Alternators aren't particularly efficient, but for intermittently powered devices, electricity is divine...and you can't beat the packaging advantages.

For HVAC concerns, the big win is having more power at idle than a stock setup does at speed. Having more on top while driving is a nice bonus, though...

Jonny, you strike again. I assume this work up through the 3.2 fan housing, but not for a 964?

Correct. Plans afoot for 964 though. Gotta keep on keepin' on! :)

With the belted in place, the inline alternator can be removed I would think. Helps preserve the precious fan housing with the reduced load and no more dealing with the pesky bat wing diverter for alternator replacement.

Labor is free for us DIY folks on this forum ;)

With the belted in place, the inline alternator can be removed I would think. Helps preserve the fan housing with the reduced load and decouples the fan speed from alternator, better in slow traffic. A dedicated pulley will also drive a bigger alternator than the inline given the single belt limits and additional space on the side compared with shoehorning into the fan. Your replacement already requires a new harness so that's a wash.

I'll sacrifice some engine compartment aesthetics, which won't be a lot given I'm running a stock CIS system now ;), for better cooling and cheaper maintenance.

A custom alternator seems like a great solution. A rigged up 2nd alternator might fly in an old Chevy but look strange in a Porsche 911.

Well soon I will have your AC in my Rat Rod, and I have your fuse blocks...so if you want some hot climate, humid climate, high load testing I am happy to test it here in Florida.

:confused: Try taking your alternator out and putting your engine fan back on. :D. Post a video of the engine running.

Yikes! Not a lot of critical thinking from that poster. LOL

You don't need the inline alternator with the belted one ... keep a shell or something else in its place, that is. Less load on the fan housing is a good thing. I'm looking at a cracked fan housing now.

Any thoughts on the rest ?

Stick to the technical discussion, plsz !!!

Stick to the technical discussion plsz !!! I come here to take a break.

You don't need the inline alternator with the belted one ... keep a shell or something else in its place, that is. Less load on the fan housing is a good thing. I'm looking at a cracked fan housing now.

Any thoughts on the rest ?

Stick to the technical discussion, plsz !!!

What is the bearing life expectancy of an alternator not designed to have the mass of a 911 fan attached to it ? Is this a non issue ?



EDIT: I didn't previously notice that the housing , etc. were non OEM and made for the application. Judging by Jonny's other products, i'm sure bearing capacity was considered in design.

I believe this alternator was designed to take the lid of the fan. As for other alternators made to fit, I’d guess not super long.

Amen to that!! No reason to apologize. Keep up the great work!

Yes, the billet casing has been designed from scratch to be a direct fit to the early fan housing. We will provide billet spacers for mid year and C3.2 applications.

The shaft is custom too, allowing direct fit of the standard fan.

There is nothing special about the bearings in the standard alternator. The extra side load caused by the fan is insignificant compared to that of the belt. We did have concerns about the fan causing extra drag on the belt at higher loads, but this does not appear to be a problem, even at 145A.

The 911 is unusual (no surprise!) in that the belt is in contact with almost 180 degrees of the the pulley which helps a great deal. Having that amount of 'wrap' allows a single V belt to transmit greater load than ina typical 'triangular' belt arrangement.

Porsche's design of the split pulley and its shim stack is engineering genius.

The split pulley s great unless you try to change a fan belt in a 914-6. It can be done, but might be less frustrating to simply drop the engine, adjust the valve and replace the fan belt, then reinstall the engine. Great work on the alternator and AC system- keep up the wonderful upgrades!

Jonny H,

It's interesting reading your other AC thread that someone pointed out to you the benefits of a better alternator in place of the original compressor 2 years ago.

And you responded with


Did the beta testing change your mind ? There's nothing wrong with learning by trial and error, BTW.

Care to share your technical findings, given this is the technical forum ?

Jonny H,

It's interesting reading your other AC thread that someone pointed out to you the benefits of a better alternator in place of the original compressor 2 years ago.

And you responded with


Did the beta testing change your mind ?

I'll invite you to share those technical findings based on the real world tests so this technical forum can benefit from your experiments. There's nothing wrong with learning by trial and error, BTW.

Jonny H,

It's interesting reading your other AC thread that someone pointed out to you the benefits of a better alternator in place of the original compressor 2 years ago.

And you responded with


Did the beta testing change your mind ?

I'll invite you to share those technical findings based on the real world tests so this technical forum can benefit from your experiments. There's nothing wrong with learning by trial and error, BTW.

This alternator project is more about enabling electric heat and other projects to be a possibility. E.g. Heat needs double the amount of power that cooling does for the same kW output.

Sure, it means you can drive the AC harder.

Stronger, harder, better, faster...

Johnny,

Not a customer yet, but very much appreciate the cool things you’re working on for these cars.

If you’re taking requests, an engine management computer that can be mounted in the engine compartment would be sweet- mounting an unprotected unit under the seat of a targa has moisture risks and wiring is a hassle.

Best,
Rutager

+1. Salient points in favor of separating the fan from the alternator. But yes, with an AC compressor and an alternator on either side of the fan, that would add stuff to the engine compartment unless future tech provides us with smaller, more efficient units.

At any rate, the benefits would outweigh the minuses and probably minimize maintenance and overstressed fan housings (e.g. want momentary +5 HP? Switch alternator charging off or install an AC-like clutch pulley). Just think of an external alternator as a beloved long lost EGR pump. :)

JohnnyH. Sorry to digress. The high capacity alternator does provide certain advantages.

Sherwood

Guys, this idea of having an external alternator, so many issues.

1) You'll have to run a gutted out alternator... That's not a fun job.
2) Or make a precision shaft and bearing carrier for the fan. 3 of them in fact for the different shaped housings.
3) And make a mount and adjuster for the alternator. Where, how?
4) If you leave the original alternator and run it unplugged, it will be destroyed electrically.
5) if you leave it plugged in, it will not play nice with the external one. It certainly won't 'add' power, rather just make the weaker one 'lazy'. The igniton light won't work properly either.
6) How will you tell if your fan belt has snapped? Igniton warning light would be on external alt.
7) Not all cars have an 'accessory pulley'. Have to buy a new crank pulley and fit.
8) Can't fit to a car with an air pump and AC.
9) Won't fit any Turbo (pretty much all have AC and intercooler blocks the other side)
10) You'd have to get the wiring harness out of the shroud , reroute, extend it and fit a plug. Ugh.

I haven't even got to the bit about ugly...

If you want to pursue this, please go and do it. Talk is cheap.

Numbered items to address:
2. Yes a bearing carrier for the fan, now devoid of a weighty rotating stator. Stress is reduced due to minimized rotating inertia.
3. A mount would work as if there were an A/C compressor on the pass. side. Obviously those two can't occupy the same space, thus A/C-equipped car lose; or install a similar mount to the left of the fan housing.
4/5. Alternators require current flow through the stator to generate a magnetic field (and electricity). Assuming elec. connections to alternator are deleted, w/o current flow, it's merely dead weight. Chuck the factory alternator or use just a shaft to support the fan assembly.
6. An issue, but not insurmountable. Both fan and remote alternator could share the same drive belt (V or serpentine belt), or install a sensor to monitor belt tensioner position and/or fan speed.
7. Agree unless a single belt drives both
8. Agree
9. Agree
10. Agree. Bypass the shroud. Chassis harness connects directly to the alternator harness.

Agree, and the admission price to exchange ideas here is cheap. We're not in the engineering/prototyping stage, just tech brainstorming. It's not as though this hasn't been done before. To avoid confusion, I'm not attempting to circumvent/minimize your worthy product, and yes, we did segue from the main topic. Sorry. At this point, your high output alternator sounds like a more viable product than a non-competing fantasy external alternator.

Reminds me of several attempts to build a flat cooling fan. If naysayers prevailed, no one would ever attempt it.

http://forums.pelicanparts.com/uploa...1520993919.jpg
Air-cooled Porsche Flat Fan Kit in Testing (Video) - Ferdinand

Yeah, the belted comparo is a digression. However, in all engineering work, there is no solution without challenges to be surmounted so it is good to hear your technical rationale for not selecting that design.

As Sherwood pointed out, 4 is a nonissue. In the alternator, there's no current to create the magnetic field to induce the current from the rotation.

Totally agree.

Going back to discussing your inline design, what is the practical limit in your estimation for future improvements ?

^ Nice Motor.

I was just trying to illustrate that an external alternator is a more complex solution. What is the advantage to it? Stress caused by alternator inertia? That's an assumption. The fans crack as well remember.

The idea was put forward as 'just fit a second unit' like it was a walk in the park and the inference was a cheap solution. The reality would be very different.

I have a rash idea here. Jonny & Co are building a high out put alternator to replace the factory ones. They chose this route for the whole host of reasons they have listed, and many others I am sure, and this is their thread.

Why don't we leave this thread about their product, and all the "arm chair engineers" can start another thread talking about their own ideas on how to make an external one work. I am sure Jonny would chime in on that one and lend his experience in a positive manner. If you don't like Jonny's path forward, if other ideas are so good, build a better mouse trap yourselves in another thread.

It is so frustrating to see an actual business with actual real & great products, bring us a good new product in the latter stages of development so we can have some input into the final product, and others have to "think they know better," and clutter up the OP's thread with their own ideas. Most of these people have no products in this marketplace, and have no clue how to bring them to the market in a profitable and well received manner....wonders of the internet I know. No one pee'd in my cheerio's, it's just that this is the third thread, on the third board today, that I have been reviewing where this exact behavior manifests itself. I am also not trying to bust anyones balls in this thread, as this is written a bit tongue-in-cheak. I am more trying to offer up a suggestion.

Please keep us updated on when this might ship as a Beta or actual product. Keep on building great new products for our old cars!