ProVolks Official Shop-Car Build Thread. . .

[aircooledtechguy]

I figure I better have just one thread I can update. . .

Pulled the motor and trans out to get the last pieces out so they could go to the powder coater. While everything was out, I figured it was as good a time as any to get the Eberspacher BA4 gas heater fitted in it's final location. Since this will be my daily driver when finished, REAL heat is a MUST!! I ended up mounting this 180 degrees opposite of how it's normally mounted in the 411/412 cars so the air inlets/outlets could be more friendly for the T-3 body. I'm still going to be doing a lot of custom fabrication to get it all running out of the heater and into the body, but I don't think it will be too bad.





I still need to make an access cover in the cargo floor for servicing the glow plug and the coil but that type of stuff is pretty basic. I also need to decide where to run the wires into the cab under the rear seat and where I will have the relays mounted. Luckily, since I swapped the orientation of the heater, the wires will be on the opposite side of the rear seat area from the Megasquirt, EDIS and O2 sensor wiring.

I temporarily removed the rear suspension so I could cut the access hole for the shift linkage. I also made the final shift linkage piece. Once my rear engine mounts come back from the powder coater, I can get that all finalized. Fingers crossed but I'm confident this time the shifting will be spot-on.

[david58]

Nate I just took the grand tour of your shop by clicking the link in your sig. I am very impressed.

[jgm_72]

on the square im air riding the bags will be right about where your heateris. Ive found a cut out engine access panel for a bay and it seems that it will fit well between the back seat and the engine cover

[aircooledtechguy]

I worked on the shift-shaft and coupling for the Porsche 923 trans yesterday and this morning. After a partial redesign. . .

I now have 5 gears fwd and one in reverse!! Very Happy I have to do a slight bit of refining of the design, but it is working pretty darned well as it is.

Doing the shifter linkage forced me to re-install the motor/trans into the car. The rear hangars are at the powder coater, so it's all being held in place with a transverse 2X4 across the engine access and ratchet straps. It works well for mock-up, but I wouldn't want to drive that way.

While the motor/trans was in, I had the chance to see how close the BA4 heater is to the starter. . . Got plenty of room; no interference at all with almost 1" of room. So now I can proceed with wiring and ducting into the car and fab an exhaust for it.

[aircooledtechguy]

Awaiting parts on a bunch of stuff, due to all the snow we have around here, so I figured I would make the most of my time.

I decided the dash would be my focus. I'm replacing the stock 3 gauges in favor of a pair of Porsche gauges (since they fit so nicely ) and a VDO tach that I had laying around.

Before:



pulled the gauges out and drilled holes in the dash for the new idiot lights since the Porsche gauges I'm installing do not have these. I had to install one for the alternator, oil pressure, high beam and blinker. They turned out pretty good so I don't mind making the cuts.



Next I made a custom harness for the gauges so that I could simply plug into the Porsche gauges from the stock harness. I haven't tested the wiring yet, but how hard can a few idiot lights ans senders be, right?? Famous last words. . . I still have wires to run back for the oil temp and speedo pick-up on the trans. I'm planning to run them along with the other gauge wiring when I run the CHT, oil pressure and volt meter.

Finished:



I am probably going to clock the tach so that the entire sweep is within view when the car is driving again. The Porsche 930 wheel is smaller and blocks the view from about the 1-4 o'clock positions.

I also took some shots of the heater with the trans installed. Room-O-Plenty!! I'm going to spend the rest of the day making the adapters for the inlet hoses for the heater to car connections. I really like how the 69 Square with the BA4 had the fan mounted on the air duct. I may have to duplicate that!!

[aircooledtechguy]

Saturday I made some progress on the BA4 heater install and the dash gauges.

I spent some time making 3 wiring harnesses; L - BA4 dash switch harness, C - Speedo trans pick-up harness, and R - engine gauges harness (tach, oil temp/pressure and volt). I ran out of shrink-tube, so I'll have to finish these later in the week or next weekend.



Next I made a pair of these body adapters for the inlet air from the heater. I also modified a factory mount for the BA4 outlet air temp sensor to fit. This will be held with flex tube or possibly silicone stubs. It fits better than it appears to in the photo.




Finally, I installed the relay and safety switch in the car under the rear seat on the passenger side. I'm quickly running out of room for more wires under the back seat.

[jgm_72]

Man, this thread really has me thinking about a 5 speed for the notch. Arent 4th gear in a beetle trans similar to the porsche 5th gear as far as ratio? I thought I read somewhere that the 1-4 gears are close ratio. The notch (as of now) will be getting a 1.7l I have kicking around, so naturally a 5th gear sounds like a good idea.

[Piledriver]

I wish I had another (taller) gear, or at least 4 usable gears, 1st is only usable for crawling in traffic, 914 was about the same.

The overall ratio in 5th on the 914 trans was about same as 4th on the 4.12 T3 unit that's installed, maybe a little taller, but it's been awhile since I had a chance to drive it.

I'm running 205/60s on mine, so I spin ~3600 at 70ish MPH.
I'd like to knock off ~400 or so RPM, even with the 1.8 currently installed.

A freeway flyer with a tall 1st/second might be a more practical option for most given the torque and cooling capacity of a T4.
OTOH the Porsche 901 (and variants) are stronger than most "built" T1 transmissions.

The Porsche transmissions are simpler in some ways and have many gearset options available, and don't require all the weird special tools, ritual dancing and animal sacrifices like building a VW trans.
OTOH, those gearsets are for a Porsche, and they carry the expected price tags.

[supaninja]

I'm waiting on Alex from bug@5-speed to get back to me with the price for the conversion parts(weak euro and they have a promotion right now), then I'll go through the 914/901 and get it ready to stuff into my notch. Everytime I get onto the freeway I want to shift into 5th. With my 215/40's I'm turning 3900 @ 70mph, I'm with Pile, 3100-3200 would be perfect.

[aircooledtechguy]

The Porsche transmissions are simpler in some ways and have many gearset options available, and don't require all the weird special tools, ritual dancing and animal sacrifices like building a VW trans.
OTOH, those gearsets are for a Porsche, and they carry the expected price tags.

You got that right!! The early 911/912/914 boxes take only 2 special tools that are available for about $120 total!! I've been rebuilding these for several years now. I don't even bother with VW boxes. . . You seen the prices for all those tools you need?? Holy crap and then you can only get $350-400 for a completed box. . . Forget it. I do enough stuff for free at my shop OTOH, these Porsche boxes are EXPENSIVE to go through with parts. It's easy to get a 1.5K parts bill. . .

It's been a while since I drove my clients 912E with the same gears mine has. If I see him before I get my square back on the road, I'll get all the pertinent info on gearing with shift points @ 3.5K and the speeds they correspond to along with tire size/diameter.

In my 914 with 205/60s I'm hitting 70mph @ about 3100 RPMs True story: The night I bought my 914, I had my oldest daughter (17y/o at the time) drive me the 100 miles to Seattle in her Toyota Corolla to go pick the car up. We left Seattle after dark and when I got it both the dash lights didn't work and the speedo cable was broken. So through Seattle and Everett I was cruising up I-5 keeping with the flow of traffic. Once we got out of the metro areas and were a ways north, the traffic thinned out and there were few cars. So having years and years of experience driving by a tach I just drove at 3.8-4K like I always have in a VW. . . After about 10 minutes of driving at that pace, my daughter calls me (she's following) and it yelling "Dad, slow down!! We're almost doing 90mph and I'm scared!!" That was my intro to having an air-cooled car with a 5th gear AND Porsche gearing!! Now I never want to be without it.

[jgm_72]

Now were talking! I like the sound of that. It would be nice to cruise at 3100 rpms and keep up with traffic. Kansas went to 75mph on the interstates so 65 doesnt cut it anymore. The notch is still a little down the project list (start on it in april) but I'd like to get a game plan set. Thanks guys for the info, sorry for the thread jack. Carry on. PS Im really digging your square, aircooledtechguy! Cant wait to see it mobile. This forum is a great wealth of info!

[Piledriver]

Oh man, now I have to go measure the ears on a 914 trans and see if it fits between the IRS inner pivots...
(Edit-They don't... but that's a feature.
outside span 18",bolt CL ~16.5", but it is just right for the front trans mounts sit on TOP of the T3 pivots, axle CL/mount offset ~correct too)

Add cable shifter, flip diff, done.
(many, many steps glossed over to make it sound like an easy weekend project using only a sawzall and vice grips )

Heres the gearing of the 923 trans, mash up, sources courtesy of the 912 registry and rennlist
The 923 trans is basically a 915

Code: Select all

923/05                       11:35 	17:34 	23:29 	26:25 	29:21(.7241)      	6:29 (4.8333) 	5060001- 	'76 model year

914: (late/most)	             A 	   F 	         N 	         V 	         ZD                            final
901/11 or /12     5       11:34       18:34      23:29        27:25      31:22 (.7096)           7:31 (4.428:1)

I have no idea why I cannot get the formatting right, it's readable ...
Trying to find same info for T1 trans combos... The 914 trans is at least taller geared than the 923.

I've been looking at just going with mucho sound deadening, but I don't think I'll make it >30MPG with these heads etc w/o dropping the RPM.
If I keep it a 1.8. I'll probably stick some 1.8S or even 1.7 heads on it and fix the deck while I'm in there.
(It will probably end up with a 2013 tho)

I got to actually work "on" the Pile for a few hours yesterday, went through the motions of installing the 996TT rear brakes on a spare trailing arm, with early 911 parking brakes.
Looks like the ID of the parking brake drums was consistent over the decades, and if I want wider shoes the 996 hardware LOOKS like it fits the 911 backing plates.

This is on topic as those 911 parking brake setups can be made to fit any T1/T3 rear arm as well, so I'm looking for another set of backing plates, rotors, and more $75/set monoblock LS430 calipers.

[aircooledtechguy]

The 912E trans has a significantly higher final drive in every gear due to that really tall R&P. It's similar to the difference between a VW trans w/ a 4.37 and a 3.88. The 912E gets more speed from each gear for a given RPM I do know that my clients 912E could push over 100mph at about 4.7K RPMs if memory serves me. My 914 is almost red-lined (about 5.2K) at 100mph.

I should be cruising 70mph @ around 2.9K-3K with the 912E trans in 5th. That should help my fuel mileage!!

[Piledriver]

Mmmm ... The 914 5th gear and final drive are taller than the 923/5 from the 912E, going by the data I can find.
Sure you aren't running 205/50s on your `teener? That might do it.

It's been awhile since I drove the Pile, too, but with 195/65s I don't recall being much over ~4600 before chickening out at 100++ MPH. With the 205/60s it was wound a tiny bit tighter, but nowhere near redline.

EDIT--I'm not crazy, 24.25" tires on a 914 give 103.7mph @4500 in 5th http://www.wallaceracing.com/gear-speed.php
Also useful if you think in KPH http://www.apexgarage.com/tech/gear_ratios.shtml

914/12: 4.428 final .707 5th ~3.14:1 total
923/5 4.833 final .724 5th ~3.49:1 total
late 71/72 T3 3.875 final/.88 3.41 total...
*(BUT that may be euro or fastback gearing, as my 73 squares gearbox code says I have...)
T3 Square June 73: 4.125 .89 3.67 total (~end of line for US T3s)
(T3 data pulled from KEP provided data at http://sandlizrd.baja.org/gears.htm )

The 923(AKA 915) is a far stronger transmission though, you won't have to baby first, on the 901 and friends 1st was literally tacked on a 4 speed design, one end of 1st gear is supported only by good intentions out in the nosecone.

The 923 is a much better choice if you are going to haul heavy stuff and/or run it at the strip.
...essentially a magnesium 915 with a push type(VW style) clutch setup.
It can easily get a taller 5th...

[aircooledtechguy]

The 923(AKA 915) is a far stronger transmission though, you won't have to baby first, on the 901 and friends 1st was literally tacked on a 4 speed design, one end of 1st gear is supported only by good intentions out in the nosecone.

The 923 is a much better choice if you are going to haul heavy stuff and/or run it at the strip.
...essentially a magnesium 915 with a push type(VW style) clutch setup.
It can easily get a taller 5th...

The jury is still out on this end anyway on which is higher geared. Having actually driven both w/in the past 4 months, I recall the 912E having a significantly lower RPM cruising on the hwy. . . Tire size may have played a part since I'm unclear as to the tires by client runs on his 912E. Mine, however are 205/60s. We'll see once my square is back going. I'll make a full report at that time.

The 901 is NOT the fragile trans people like to talk it up to being. These had flat sixes on them long before the humble 4-banger we are using was ever built. Yes it's supported on only one side by a bearings but with a T-4 like most build on here, I doubt anyone will have a single problem with them. I would NOT plug a V-8 on it or a built 2.4+ flat six and dump the clutch at 8K but they are more than capable of handling a standard performance 2270 or 2316 and beg for more. Most guys running a large motor don't even bother with 1st anyway since it's pretty low and useless with a torquey motor.