Porsche 356 Registry Article

edsnova posted:

 

356 gear ratios:

(Note: these jokers inevitably discuss gear ratios using Porsch-ah code letters ABCD which are arbitrary and useless to everyone but they think it makes them sound kewl. So Porsche guys talk about  the relative merits of "AABB" gearboxes vs "BCCD" boxes. If you delve down past the letters they give you ratios in the form of tooth counts on the goddam cogs! So you get 12:33 or 18:29 instead of something a normal person would say such as "2.75 to one." They do this because they are better than us VW fools and so here I go transliterating the high-roglyphs fo ye). (I assume @ALB and @Gordon Nichols will have something to add).

 

1st (B designation) 11:34 = 3.09; (C) 12:33 = 2.75

2nd (A) 16:31 = 1.94; (B) 17:30 = 1.76; (C) 15:32 = 2.13 (D) 18:29 = 1.61

3rd (A) 22:27 = 1.22 (B) 23:26 = 1.13; (C) 1.04; (E) 20:27 = 1.85 (F) 18:29 = 1.61

4th (A) 25:24 = .96; (B) 26:23 = .88; (C) 27:22 = .81; (D) 27:23 = .85; (G) 28:21 = .75

R&P: 7:31 = 4.42

Given this differential, which is comparable only to the highest and least likely-to-be-in-your-case VW R&P at 4.375 to 1, it may be helpful to calculate each of the gears as a final drive ratio to compare to a typical replica Speedster box with a 3.875 R&P. 

The bottom line of course is that old Porsches are often screaming at normal highway speeds. You guys think 3500 at 70mph is loud and scary?  Try 4300.

This is why I advocate for the 3.44 R&P on our cars. It puts your first and second 6000 RPM shifts (of course you rev to 6000 in first and second on the regular, right?) exactly in the MPH neighborhood of early Porsches, but lets you enjoy a 70mph cruise speed at 3000-ish. 

The price of this is some diminution of off-the-line neck-snap, but since you're probably running twice the torque those old cars had, and in a lighter envelope, you're still actually much faster to 60mph than they were (or are likely to be now).

Your 2110's (or even 1914's—and never mind your 2332's) useable power band means even the relatively wider gear spacing of the common (3.8, 2.06, 1.26, .93) VW cogs will not pull you off your cam unless you're short shifting all the time. 

And a Subaru engine will of course pull any gear from any speed. 

In fact, imho, the only way to make a VW box not work beautifully in one of these cars is to run the (formerly common "Freeway Flyer") .82 4th gear, which opens up the 3rd-4th gap just frustratingly beyond the realm of what a nicely tuned Type 1 will gladly tolerate. 

 

The reason is that those guys actually watch the alphabet channel ....  ABC

Stan said: "for a reasonably economical solution to the puzzle, a stock 1/2/3 with a .93 fourth and a 3.44 R/P is about as nice as you can get south of $2000."

Yeah the Spyder box was under $1,000 and the MG was under $1,500 and it all depends on what you're starting out with. With Bridget I traded in a pretty high-mileage two side cover IRS transaxle for a completely rebuilt and beefed up stock single side cover case with the new gears, sliders, at least one synchro and the beef-up stuff. 

I was especially glad I had Sartwell go through the Spyder trans because although it was marked as a rebuilt "freeway flyer" box with a 3.88 R&P it turned out to be a 4.12 ring gear and a .82 4th. 

All clean and neat and new but just not the optimal (or advertised) gears imho. 

On a Spyder build of course the Suby box would be ideal...if only it could be configured to run the swing axles or—as if by magic—one could bolt-on a usable IRS system back there. Alas....

IaM-Ray posted:

You can do subie tranny with a Kennedy trans adapter to a vw engine... they fit in a standard VW why not a Speedster you can get one with a new gearset or rebuilt gearset.

I looked for that and not sure Kennedy makes it. However Subigears DOES make one, it's $1250. But can you make any of them a swing? NO, except for Berg.

It's megabucks to really customize a VW 4 speed. I've looked pretty hard at it. I have a couple rebuildable IRS and swing trans(all double side cover) and am planning to do one in the near future, since I can rebuild my own. It's far cheaper to just change 3/4. Anyway, I've looked hard at changing the mainshaft as Stan says. That is definitely the more expensive option.

I'm planning on the stock 1-2(3.80/2.06) but shortening up 3 and 4 a bit, to 1.39 and 1.04(Ultimate trans would be this plus a .93 or .89 fifth, but no room for Berg5 in a Spyder). This 3/4 change completely eliminates that too fast for second too slow for third gear that I feel. I want to make a canyon carver, with a trans that can ALWAYS be in the right gear out of the corners. Lumbering along the interstate at low rpm is of zero interest to me.  I still would have a top speed of 123 mph(just about airborne at that speed) in fourth at 6000 rpm. But I'd get there FASTER due to the gearing. 80 mph is 3900 rpm(now 3350). 55 is 2700(2300). 62 is 3000(2600). 

My interest is also in a Torsen/Quaife differential. I have enough power that I'm losing traction out of corners with the open differential. Most people tell you the Quaife can fit with any R&P up to a 3.88. And also that it cannot be used with a 3.44. The 3.44 is the strongest ratio because the pinion is largest, plus it allows the tallest gearing without changing the mainshaft. You with me so far?

I've heard from one source(a trans builder in NJ) that you can machine a small portion off the end of the pinion and it WILL fit, so that is the direction I'm looking at. If that doesn't pan out, I'll be looking at a 3.88 R&P and all 4 gears custom, or at least 3 of them.

Again, changing 3rd and 4th is a bunch cheaper than the mainshaft and 1-2 idlers. But add a complete rebuild and another new 3.44 plus a Quaife, and it's not pocket change.

Ed: I also have a design in mind for IRS in a Spyder with no changes to exhaust and very little in the fabrication and welding on the frame fronts. It could be done to any Vintage for less than $500 including welding(since we already have coilovers and a front heim pivot). A Beck would require more work due to the torsion housing. Obviously I have to figure this out first as the differential has to be swing or IRS.

A couple of things-

@edsnova, Stan, Gordon and anyone else who follows our twisted gear conversations- I'ts a small thing, I know, but I found a mistake in your 356 gear list, Ed. 3E (20:27) is in your list as 1.85 but it's actually 1.35:1.

For those nutty enough to care/be interested (and yes, you may be excused from class if your brain is full)-

Gear ratios listed in the 1954 service manual (transaxle type 519)-                                1st- A- 3.18                                                                                                                                  2nd- B- 1.76                                                                                                                                  3rd- B- 1.30                                                                                                                                    4th- C- .815

Gears marked on a transaxle housing of a 1956 Speedster-                                              1st- B- 3.09                                                                                                                                   2nd- B- 1.76                                                                                                                                   3rd- B- 1.13                                                                                                                                   4th- C- .815

@IaM-Ray- Thanks for listing your gear ratios. With that spacing, the recovery rpm going up with each shift, it must be really nice to drive!

" Did you know the USA has an electrical generating plant technology running on NG that is a zero carbon emission producer"

Definitely a step in the right direction, now if technology could advance to where we weren't burning fossil fuels at all to create electricity. That would be something!

Still early here. Going back to bed for a little bit. Yoda out _{(don't cry- back I will be soon enough!)}

I considered a Subi tranny but they move the engine up and back which I didn't think would work well in a Speedster.

I had Wright Gearbox do my Berg 5 because they had the parts in stock and I didn't have to wait for Berg to make more bits.

DannyP posted:

 

My interest is also in a Torsen/Quaife differential. I have enough power that I'm losing traction out of corners with the open differential. Most people tell you the Quaife can fit with any R&P up to a 3.88. And also that it cannot be used with a 3.44. The 3.44 is the strongest ratio because the pinion is largest, plus it allows the tallest gearing without changing the mainshaft. You with me so far?

 

@DannyP Talk to Rancho. They have a Peloquin torsen diff made for Type 1 transaxles. I have one in mine with a 3.44. I think they are around $1500 now and have a good reputation. 

Thanks Michael, but that all depends on if I can do IRS, it's available in IRS only.

Oops, forgot to mention that, Danny. You're right.