Classic Retrofit: Six phase high output alternator.

[anglophone1]

Have one of these on the way!

[Jonny042]

Apologies if I missed it, but is there any weight loss benefit to the modern 6 phase design of the Classic Retrofit unit? Stock alt. for the SC is not particularly light and it seems the fan shrouds are prone to cracking from the load.

[Tom Elder]

CDN_Jonny, UK_Jonny’s alternator looks like a nice piece, weight for a 90 amp Paris – Rhone alternator is 5.88kg, Classic Retrofit 150 amp alternator is 5.16kg. Impressive power to weight ratio. Thanks UK_Jonny

[Jonny H]

Thanks Tom, I guess you had it on the scales!

Regarding fan housings, the later fan housings are the most fragile because Porsche had to remove more material to squeeze in the longer 75A and 90A alternators.

For our 150A unit, the mounting points are the same as the shortest early units. This means that it is a direct fit to the stronger/thicker early housings. Of course, you can still use our alternator with later housings by fitting our spacer/adapter rings.

[Jonny042]

Originally Posted by Tom Elder

CDN_Jonny, UK_Jonny’s alternator looks like a nice piece, weight for a 90 amp Paris – Rhone alternator is 5.88kg, Classic Retrofit 150 amp alternator is 5.16kg. Impressive power to weight ratio. Thanks UK_Jonny

Thanks, Tom!

[stephen1070]

Good evening - need help from the Pelican collective.

I purchased this upgraded alternator to install in a stock 1989 3.2 Carerra.

The black ground connection to the case was straightforward and self explanatory.

However I need help with the 40" red cable connection to the starter.

I read the instructions.. it says some cars need a hole in the engine tin - how do I know if I need a hole? - I'm ready with a drill and my car is on stands (aka ramp) but can someone tell me if I need to be drilled? if so how large?

""Replace the engine GND strap with the heavy duty black cable. Replace the main alternator cable with the heavy duty red cable. This needs to be routed to the starter solenoid. Easier to do this on a ramp. Some cars may need a hole drilling in the engine tin above the oil cooler but be VERY carefully. The engine tin in this area can often be removed with the engine in place.""

https://cdn.shopify.com/s/files/1/0049/4734/5506/files/150a-alternator-install-manual.pdf?15241926203698886546


Also from reading the thread above it appears that the existing connection needs to be 'insulated' (shrink wrapped) after this new connection is made. Can someone confirm this.

All advice would be welcome - thank you.

Regards,

Originally Posted by timmy2

I’m always up for some horse trading.
IIRC you would need a ‘78 CIS harness ?

[spuggy]

Originally Posted by stephen1070

I read the instructions.. it says some cars need a hole in the engine tin - how do I know if I need a hole?

I'm half-way through this, and got side-tracked into something else while i've got access...

I'd suggest to trace your harness and look at your tin. My 930 tin had a large, shaped hard-rubber grommet on the the top edge of the horizontal tin that all the wires to the starter solenoid/battery post from the engine bay passed through originally.

I intend to enlarge the hole in the grommet to enable the replacement cable and its friends to fit as the originals did. Just haven't found the best way to do this yet.

Originally Posted by stephen1070

Also from reading the thread above it appears that the existing connection needs to be 'insulated' (shrink wrapped) after this new connection is made. Can someone confirm this.

Not clear what "connection" you're talking about insulating?

If you're asking about re-wrapping the harness, trouble with shrink wrapping it is that there's a few extra wires that leave/join the harness back there, and kind of impractical to do this without removing the motor harness from the car.

Which you could do I guess - I wasn't planning to. It was suggested to me that Wurth-branded insulating tape is very close to what the factory used and doesn't ooze glue or unravel like cheap electrical tape certainly will...

I think possibly the most time-consuming part is getting the old cable out

[Tremelune]

Tesa tape (fuzzy OEM harness tape): https://smile.amazon.com/gp/product/B00EH6IZ6Y/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Cold shrink tape (non-adhesive, but sticks to itself): https://smile.amazon.com/gp/product/B00O7S1B4A/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

[Jonny H]

As spuggy says, the original red charging wire passes through a rubber block that clips to to the engine tin. Ideally, you would pull the original wire out, enlarge the hole and thread the new one through. That would be easy with the engine out.

With the engine in, it is easier to route the new wire via a different path through a new hole in the tin. In this case the ends of the disconnected original wire need insulating to prevent them shorting something out. Fold the ends back and heatshrink or tape.

[ClickClickBoom]

Originally Posted by Jonny H

Thanks Tom, I guess you had it on the scales!

Regarding fan housings, the later fan housings are the most fragile because Porsche had to remove more material to squeeze in the longer 75A and 90A alternators.

For our 150A unit, the mounting points are the same as the shortest early units. This means that it is a direct fit to the stronger/thicker early housings. Of course, you can still use our alternator with later housings by fitting our spacer/adapter rings.

So, if one was going to replace the fan housing on a 3.2 due to corrosion, and wanting to add a modern alternator like this, which "early" fan housing would be correct?

[Jonny H]

Originally Posted by ClickClickBoom

So, if one was going to replace the fan housing on a 3.2 due to corrosion, and wanting to add a modern alternator like this, which "early" fan housing would be correct?

It depends what you mean by correct as they can all be made to work. Earlier cars than the 3.2 are tapped for the coil mount which you won’t need. Probably the easiest to source would be the mid year, requiring a single 10mm spacer. Best to avoid the smaller early SC fan.

[ClickClickBoom]

Originally Posted by Jonny H

It depends what you mean by correct as they can all be made to work. Earlier cars than the 3.2 are tapped for the coil mount which you won’t need. Probably the easiest to source would be the mid year, requiring a single 10mm spacer. Best to avoid the smaller early SC fan.

Thanks!
A buddy and myself are looking into modeling the fan shroud and possibly CNCing a replacement out of 6061 or something similar, with the fan as a possibility. Since the only option is Vertex at a very handsome price, there might be a section of the market for a high quality CNC part, since the OEM parts are no longer available.
I watched the Vertex price rise from $395.00 to almost $800.00, this indicates that they think they have cornered the market and are taking full advantage of the cornering of the market.
What say ye?

[toddetch]

Hi Pelicans,

I am now working on this and have questions similar to Stephen's above. I guess I'm nervous about getting this right, especially when it might (probably) mean cutting a hole in the engine tin....

The engine is in, and given all the wires wrapped up together, it feels like it is going to be better to find a new route for the cable from the solenoid to the alternator. Going from below, I found a spot that seems to have, well not a grommet, but a kind of rubber sheath or something which I could push the cable under and up into the engine bay. Here is the view from below:



Here you can see where it is sitting on top of the tin - this is on the right side of the engine, underneath the airbox:



First question: is this an okay place to route the cable?

Assuming the answer to that question is yes, for the second question I'm wondering where the best place to cut a hole in the tin is? Maybe where either the yellow or green arrows are pointing below?



Third question: what is the best way to cut this hole in the tin? The flat part of the cable terminal is about a 1/2 inch wide and the cable is about 3/8 inch thick.

Last question: the instructions say that if I'm not removing the original red cable, to fold back the ends and wrap them. Makes sense. I can easily do that with the end at the solenoid. However, the end at the alternator has a second, smaller red cable that shares the terminal with the larger cable from the solenoid. Should I just connect that end or should I snip the smaller cable, get a new terminal for that cable, and wrap the alternator end of the larger cable? Pic below.

[toddetch]

Actually, I think I figured it out...what I was thinking was the engine "tin" is actually the engine shroud (the orange cover). I think the tin referenced in the instructions is the engine cover, part 4 in the diagram below. It does look like I can remove it with the engine in place with four bolts. Will try that tomorrow.

[Matt S]

Originally Posted by toddetch

However, the end at the alternator has a second, smaller red cable that shares the terminal with the larger cable from the solenoid. Should I just connect that end or should I snip the smaller cable, get a new terminal for that cable, and wrap the alternator end of the larger cable? Pic below.

I have the same question. I think the smaller cable runs to the external voltage regulator which, if you haven't already, you'll be decommissioning during this install. The Porsche Tech Bulletin leaves this positive cable and disconnects the thin negative (black) cable instead.

Can anyone confirm that the small red cable runs to the external voltage regulator, and that it can be disconnected and insulated when installing a Classic Retrofit Alternator?

[timmy2]

Small red wire runs directly to pin 14 of the 14 pin connector and supplies power to the top 2 fuses of the 3 fuses on the rear panel.
Cut it from the original fat red at original terminal and put a terminal on it to fit along with the positive terminal with the new cable.
Black DF wire is the only one that gets tied back regarding the now internal VR.

[Jonny H]

^ Confirmed. Thanks Dennis. Yes, the smaller red wires that are crimped with the original fat red wire need separating and connecting to B+ on the new alternator.

@toddetch, yes engine tin, refers to the part you have arrowed red in the drawing. Behind that part is the grey coloured part of the shroud that fits above the oil cooler. On my SC, I drilled a hole through the tin AND the grey part. Use a rubber grommet where the cable goes through the tin.

This brings the cable through into the area above the oil cooler. If you look inside the shroud, there is a another piece of tin which is horizontal, kind of like a shelf - the cable will come through above there then its straight forward to get to the back of the alternator.

[Cad.Guy]

Johnny -
Question for you about your alternator.
Is it normal for the voltage to fluctuate between starts ?
On initial start after install I got 14.5 volts. Next day it was 13.9, then 13.4, then it was back to 14.1.
Everything is tight, well grounded and wired and routed correctly.
Just seems strange for such fluctuation.
The only load is the stock fuel pump, ignition and running lights with all bulbs replaced with LEDs.
1979 911sc stock.

[timmy2]

Charge voltage is dependent on battery state of charge.

[ant7]

Its good that there are folk out there looking into the issue of relacement alternators for the 911, however; my thoughts on fitting an alternator with higher output are obviously on a diffrent path to most who have posted here ie; the alternator fitted to the later 3.2 era cars is well up to the job of supplying the necessary current needed for a car in standard form, even with extra's like upgraded sound systems [within reason] so I guess the only folk who would need to look seriously at a higher output alternator as described by the OP would be those who wish to fit more higher current hungry systems and devices than standard.
Remember too; the more load you put on the alternator, the more stress you are putting on the belt driving it, and also you will be using more power from the engine that could be used in more fun ways!
But as has been said; each to their own, and I wish the OP success with their products.