piperporsche180944

eniac

I know mine can fit a 4" straight intake into the turbo however it does sit lower than Jay's. Originally I did not intend to cut the bracket down which lowered the alt even more. I did set it in place with the bracket unmodified and it clear my then 3" intake just fine.

Jay, nice work! Just curious though, if your doing the A/C delete, then why not just get the ac delete bracket?

The idea behind mine was to do as little as possible to the alternator so when it needed to be replaced, it would be a simple remove and bolt on a new one.

Fluidplay

eniac, did you have any problems adjusting belt tension with it sitting lower? I set mine in place last night and found the same situation, not wanting to, but needing to modify the mount to drop the alt. so the bottom mounting tab would line up. Scary process, but doable in the car with a small right angle drill.

eniac

Somewhere in this thread I think I posted what belt I used, IIRC it was 1" shorter. The factory belt was too long so I went to the store with the original belt and asked for a belt 2 sizes smaller, that was too small so went back and got it 1 size shorter which fit perfectly. No problems with tension, it all works just like that factory design(tensioned by the A/C adjuster).

Dare

Thanks, Stephen. To be honest, its mostly because I wanted to see if it could be done without one. I got the idea from a write-up by one of the 944-Spec guys (here) and figured I could make it work on a turbo with a smaller alternator. Plus I saved $80 on a new bracket!

But really, to anyone considering doing this, by all means, buy yourself an A/C delete bracket. It will make it that much more straightforward.

George D

A picture of a properly installed Nissan alternator in my car. We had to do this for the intake to clear. It's not as easy as any of the write-ups I've viewed. There is a reason CEP and few other folks sell these kits.

DIY folks with talent and ability that have done this within a few thousands know how much work went into making this work. Just grinding away, as I've seen in some of these posts isn't a good idea. If you don't need clearance, just get a factory alternator, or get a shop to rebuild your factory alternator.

Saving a few bucks isn't worth the effort unless you have intake clearance issues. A good alternator shop can rebuild your core for a few bucks. This is not an easy fix for an expensive part for your Porsche.

Dare

George, it would be great if you could provide some technical reasoning for why the approaches given in this thread are bad or inappropriate. Personally, I'm not doing this to try to save a buck. I'm doing it because I want to learn. If you have some technical insight on the topic that you can share I'd love to hear it.

That said, the point is fair that my approach is largely unproven. If someone wants a tried and true solution they should clearly stick with the stock alternator.

m73m95

I guess I'm one of the "grinding away" people you mention.....

I've put 30k miles on my car in the year since I "ground away" (I drive the **** out of my car). No problems at all. I even forgot I did it, until this thread came up again. The clearance added isn't the only reason to do this mod. Its nice to be able to buy parts in any town that has a parts store....any parts store. I travel extensively in my car (I am in Colorado as I speak). The easier it is to get parts that might go out, the better. Plus, its got a lifetime warranty.

The "holier than thou" posts bug the hell out of me.... If you need me, I'll be "grinding away"...

Dare

Excellent! I love real world data. Thanks for sharing, m.

So, any signs of unusual belt wear? Stress cracks around the grind points? Other oddities?

George D

My intention when posting is not to be an elitist jerk. The few of you that know me well, know I'm the opposite of this statement.

If your pullys are out of alignment, this will cause side loading on materials that are supposed to just be tensioned. I don't know the error in tolerance to allow a belt to last 5K or 75K. The member that was able to hand grind his mount and alternator well, without side loading from the belt is impressive. I used to over tension blower belts on my Expedition to stop slipping, and they didn't last very long. I kept a few in the box along with the pully tool.

You don't want a belt to break and strand you.

If we knew how much work went into modding the factory braket up front, we would have purchased CEP's braket. Granted, I prefer things to be done as well as possible.

Fluidplay

George, do you have a pic of this bracket and/or kit. The pic you provided shows the pulleys in great alignment, but no bracket can be seen. I'm assuming the bracket (plate) you're referring to is bolted to the lower mounting point and extends up to meet the mounting point on the alt.? I thought of doing something in terms of this idea, but found that by doing so, it raised (pivoted) the alt. enough where it was almost at the same height as the stock alt.

George D

Fluidplay,

We modified the factory bracket to allow the Nissan alternator to be aligned within a few thousands. It took much more time than expected. I'll take a picture below and send you a PM.

My point is that if you want this done as well as the factory belt alignment, it's a bit of work, and purchasing a completed bracket from CEP or another proven source would have been our choice if we had known the time and effort up front. We just read a post, and assumed that it was fairly simple. Garrity Repta did most of the work, and he has a full machine shop at his place.

Fluidplay

Thanks, look forward to your PM.

As I mentioned, it seems simple enough just to fab a small, but stout bracket bolted to the lower mount with enough offset to clear a second bolt to secure the alt to. You would need to remove however an equal amount of material (thickness of the bracket...say .250) off the lower alt tab to maintain alignment. Again, in looking at this possibility using the upper mount as a point of reference, you would be swinging the alt upwards toward the turbo inlet pipe. This in effect offers diminishing returns of using a smaller alt. to begin with. I believe it would still clear a 3" pipe, but as someone has pointed out the location of the stud for power connection is right at the top of the alt. and could possibly rub the pipe connection. Maybe.

m73m95

No problems at all. Like I said, I forgot I even did this, until the thread came up again.

I was careful with the belt tension at the beginning. The only time it would slip was when it was raining, or I ran into a puddle. I tightened up the belt a bit to cure that, and have had zero problems since. I ran the AC all summer as well (added stress to the belt).

I am good about checking the belts along with the oil/coolant levels when I fill up with gas, and the belt looks just like it did when I put it on.


I reread my post from a year ago. There was some "dramatic effect" used that I thought would be obviously seen. I remember it did take longer than I expected, and I had to grind a little more away from the alt/ac bracket than I expected...but all in all, it wasn't THAT bad. You defiantly don't need an engineering degree to get it right. Just some patience, and good judgment/test fitting on how far to go, and you'll be fine.

Dare

Not to worry. Constructive criticism is always welcome.

I've been doing a little research and the following white paper by Gates provides some insight into the alignment requirements for belt systems: Proper Alignment.pdf.

Following the approach described in the paper I've been using a precision straightedge to take some measurements with the stock alternator mounted. Interestingly, it looks like the angular misalignment of the stock alternator exceeds the Gates recommendation (0.45deg verses 0.25deg). My measuring technique is a bit crude right now (maybe as much as +/-0.27deg off) so I'm working on a way to incorporate a dial indicator to get a more accurate result.

After I perfect my measuring method I'll remount the quest alternator and see where I stand.