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jwalters
IPB Image

Thought of an interesting topic---has anybody put a beefed up bus or t1 trans in the teener----

I loved the gear spacing on my old superbug--and first gear for my car,,well,,,sucks ass--and second is too tall for a good start off--

Would rather spend 650 bucks on a pro-streeter WITH a rhino case and super diff than thousands upgrading my 901--

Sand rail mid engine cable shifter should be able to be adapted rather easily and the trans install is a non-event...

What you think???? IPB Image
TC/914
I'll tell you what I think if you PM me as to where that great avatar came from!

Swapping a type one trans would be pretty easy and has been already thought out by the mid engine sand buggy boys. A quick visit to

http://shoptalkforums.com/ or http://www.thesamba.com/vw/forum/

will answer all of your parts matching questions regarding brackets, shifter, etc. along with which starter will fit the type one trans and which flywheel will need to be used on your engine. I would suspect a 70 flywheel with a semi-automatic VW Bug starter will do the trick. Otherwise, just talk with the folks at RANCHO and describe what you want. Everything else is pretty much a bolt it.

Good luck with a cool idea!

TC
736conver
I had a 2.0 914 engine in a type 1 chassis, fiberglass dune buggy body. Dont remember the flywheel clutch combo though. It was also an IRS system. If I remember correctly the swing axles need some grinding to get flywheel clearance.
jwalters
IPB Image

TC--you would not want me to kiss and tell would you???

736- I know kennedy makes the components very cheap for this kind of swap--not much to it--I am REALLY thinking about this.

I already have an early style tranny--IRS, with the dual removable side plates--I could swap the ring gear in about 1/2 hour.

Cable shifter is about 150-250 bucks complete--

Wow, a true H pattern shift!!!

Plus with the rhino case--125 clams--super diff--110 clams and all the gear ratios I could possibly need for another 200 clams--AND a choice, a real choice of several ring and pinion combos!!!!! IPB Image

And these puppies are proven to hold 400+ ponies when the 3rd and 4th gear sets are welded to the shaft--hmmmmm

About 25 lbs lighter--hmmmm---easily make 65 mph in first at 6500k---hmmmmm

Synchro problems pretty much tossed out the window..hmmmmmm

This is a truely worthwhile expenditure for my poor broke ass..hmmmmm

Yep, I made the decision--gonna do it!!!!

My friends chide me as to why I hang on to car stuff--like a '69 model IRS bug trans---for YEARS---and know I am edified! IPB Image

Well, back to work! IPB Image
736conver
QUOTE
736- I know kennedy makes the components very cheap for this kind of swap--not much to it--I am REALLY thinking about this.


You can get the components anywhere. I didnt use any custom pieces for my 914 into the IRS trans. They were all stock. I just dont remember the combo of the clutch set-up. I know it was a mix of VW parts with the 914 flywheel.
Mueller
QUOTE
What you think????


sounds like a good idea if it works, there must be a reason we do not see this done more often???

at least here in our PCA region, the VW transmission would not be allowed in time trials (at least not in a specific class if someone complained)....you could run it in auto-x, but only in the exhibition class....
SpecialK
QUOTE (Mueller @ Jan 21 2005, 06:30 PM)
QUOTE
What you think????


sounds like a good idea if it works, there must be a reason we do not see this done more often???

at least here in our PCA region, the VW transmission would not be allowed in time trials (at least not in a specific class if someone complained)....you could run it in auto-x, but only in the exhibition class....

Leave the 914 shift knob on as a decoy IPB Image
jwalters
QUOTE (Special_K @ Jan 21 2005, 09:36 PM)
QUOTE (Mueller @ Jan 21 2005, 06:30 PM)
QUOTE
What you think????


sounds like a good idea if it works, there must be a reason we do not see this done more often???

at least here in our PCA region, the VW transmission would not be allowed in time trials (at least not in a specific class if someone complained)....you could run it in auto-x, but only in the exhibition class....

Leave the 914 shift knob on as a decoy IPB Image

IPB Image YEA, and never ever let anyone else drive it!!! Cause they would surely munch the box--- IPB Image
Aaron Cox
BUT....they are still 4 speeds IPB Image

berg 5 speed trans anyone?
jwalters
QUOTE (Aaron Cox @ Jan 21 2005, 10:07 PM)
BUT....they are still 4 speeds IPB Image

berg 5 speed trans anyone?

The berg is wayyy to much money- IPB Image -and with all the gear ratio and final drive ratio choices for cheap the 4spd will outgun the 5----excellant first--close second and third--with a nice overdrive fourth--get the right ratios and match the tire diameter accordingly..... IPB Image

4spds are not all bad--the 930's came stock with them---- IPB Image
Aaron Cox
QUOTE (jwalters @ Jan 21 2005, 08:15 PM)
QUOTE (Aaron Cox @ Jan 21 2005, 10:07 PM)
BUT....they are still 4 speeds  <_<

berg 5 speed trans anyone?

The berg is wayyy to much money- IPB Image -and with all the gear ratio and final drive ratio choices for cheap the 4spd will outgun the 5----excellant first--close second and third--with a nice overdrive fourth--get the right ratios and match the tire diameter accordingly..... IPB Image

4spds are not all bad--the 930's came stock with them---- IPB Image

930's had a ton more HP too IPB Image
bondo
Wow, I'm intrigued. How much HP and torque are you gonna bolt to it? I'm definitely gonna watch and see what happens.
Aaron Cox
QUOTE (bondo @ Jan 21 2005, 10:13 PM)
Wow, I'm intrigued. How much HP and torque are you gonna bolt to it? I'm definitely gonna watch and see what happens.

bodily injury or death are surely going to follow.... IPB Image
jwalters
QUOTE (Aaron Cox @ Jan 21 2005, 11:27 PM)
QUOTE (jwalters @ Jan 21 2005, 08:15 PM)
QUOTE (Aaron Cox @ Jan 21 2005, 10:07 PM)
BUT....they are still 4 speeds  <_<

berg 5 speed trans anyone?

The berg is wayyy to much money- IPB Image -and with all the gear ratio and final drive ratio choices for cheap the 4spd will outgun the 5----excellant first--close second and third--with a nice overdrive fourth--get the right ratios and match the tire diameter accordingly..... IPB Image

4spds are not all bad--the 930's came stock with them---- IPB Image

930's had a ton more HP too IPB Image

IPB Image so whats yer point young feller??? IPB Image
jwalters
QUOTE (bondo @ Jan 22 2005, 12:13 AM)
Wow, I'm intrigued. How much HP and torque are you gonna bolt to it? I'm definitely gonna watch and see what happens.

IPB Image Not really the hipo issue with me--my motor will be turbo, and will be strong, but for lack of funds I will not have the best heads, the best P/C set, etc....I will be retired from the service before I could afford anything of that magnitude..

No what I am striving for is getting the most bang for the buck--The 901 is a good tranny--but most of us that have one has age issues with it---For less than the complete set of synchros alone I will have a brutally built tranny with the proper gear ratios for my intended driving--but the real kicker is having a tranny that I know will last me a very, very, very long time with no issues arising--plus I really hate the 901 shift pattern. I have to hold a formal class to instruct any of my buddies on how to drive it and have a good Porsche experience, and even then it gets ugly with the slush box real quick....Not saying the T1 is better ( arguably ) but because the T1 people have access to the best equipment at a fraction of the cost and plus it bolts right up--just need a few little T1 specific items, like clutch disc, T/O bearing and pilot bearing--and the Jamar mid engine shifter-add all of this up and it is still less than a set of 901 synchros---

I am going to do it--I have two T1 trannies, one late irs and one early irs ( this is the coveted one, it has dual side plates, makes getting into it and modding it very easy ) Hopefully by the time I am done doing all this and prove it out I will be able to bring it to market for anyone else that might want to--rock on!! IPB Image
andys
What are each of the "net" ratios (1 thru 4 x final drive ratio)? I seem to recall that you can't get a tall enough 4th/R&P combo, as most applications are either for very tall tires and/or drag race applications. Can you point me to info on available ratio's that would perhaps suit higher HP motors? You will need about a 3.00:1 "net" ratio or better. The 901 is 3.14:1, a 915 is 2.94:1, and a 944T (016R) is 2.80:1..........Thanks,

Andy
jwalters
QUOTE (andys @ Jan 22 2005, 12:58 AM)
What are each of the "net" ratios (1 thru 4 x final drive ratio)? I seem to recall that you can't get a tall enough 4th/R&P combo, as most applications are either for very tall tires and/or drag race applications. Can you point me to info on available ratio's that would perhaps suit higher HP motors? You will need about a 3.00:1 "net" ratio or better. The 901 is 3.14:1, a 915 is 2.94:1, and a 944T (016R) is 2.80:1..........Thanks,

Andy

IPB Image yea thats easy--go to CB's website--they do tranny's too and list all the gearsets and final drives-----basically if you want a 3.88 R&P AND a stockish .85 fourth--you can have 1500 rpms at 70 mph--the ratios are mind boggling--the T1 guys have something close to 200+ different combos and each gear is about 35-75 bucks!!! You simply tell them your tire diameter and what kind of driving you do and what you expect and all the T1 tanny people take it from there....

Also look at rancho transaxles--they are one of the T1 industries leaders---there is another one made called a Mendeola 4 spd--this is good for 800 hp $$$$

About 3 years ago hot vws mag came out with an issue listing all the T1 hipo trannies and the makers--ungodly!!! Whatever you want--you can have......
andys
QUOTE (jwalters @ Jan 21 2005, 10:13 PM)
[/QUOTE]
IPB Image yea thats easy--go to CB's website--they do tranny's too and list all the gearsets and final drives-----basically if you want a 3.88 R&P AND a stockish .85 fourth--you can have 1500 rpms at 70 mph--the ratios are mind boggling--the T1 guys have something close to 200+ different combos and each gear is about 35-75 bucks!!! You simply tell them your tire diameter and what kind of driving you do and what you expect and all the T1 tanny people take it from there....

Also look at rancho transaxles--they are one of the T1 industries leaders---there is another one made called a Mendeola 4 spd--this is good for 800 hp $$$$

About 3 years ago hot vws mag came out with an issue listing all the T1 hipo trannies and the makers--ungodly!!! Whatever you want--you can have......

That 3.88 R&P and 0.85 4th is not nearly tall enough for the tires you'd run on a 914. I know there's a ton of ratio's for sure, but I don't recall seeing anything in a suitable range for a 914.

The beauty of this trans, are the incredibly cheap prices. Parts are everywhere!!

Andy
GWN7
I wonder how it would work with a V8?
jwalters
QUOTE (andys @ Jan 22 2005, 01:29 AM)

QUOTE (jwalters @ Jan 21 2005, 10:13 PM)

IPB Image  yea thats easy--go to CB's website--they do tranny's too and list all the gearsets and final drives-----basically if you want a 3.88 R&P AND a stockish .85 fourth--you can have 1500 rpms at 70 mph--the ratios are mind boggling--the T1 guys have something close to 200+ different combos and each gear is about 35-75 bucks!!! You simply tell them your tire diameter and what kind of driving you do and what you expect and all the T1 tanny people take it from there....

Also look at rancho transaxles--they are one of the T1 industries leaders---there is another one made called a Mendeola 4 spd--this is good for 800 hp $$$$

About 3 years ago hot vws mag came out with an issue listing all the T1 hipo trannies and the makers--ungodly!!! Whatever you want--you can have......

That 3.88 R&P and 0.85 4th is not nearly tall enough for the tires you'd run on a 914. I know there's a ton of ratio's for sure, but I don't recall seeing anything in a suitable range for a 914.

The beauty of this trans, are the incredibly cheap prices. Parts are everywhere!!

Andy


IPB Image well the bugs run 15 inchers as stock also-put a bug and teener side by side with stock ratios and stock 165-15's and the bug will be at 2800 rpm at 70 mph--my teener is at 3350 rpm and my tires are only 1 inch smaller than stock , so not really allot of diameter reduction to fudge the numbers--something like only 2.5%, again , not allot.-also the bug standard R&P is 4.88:1, I believe--I know it is more than 4.12:1--and what is the 901?? Something like 4.42:1??? Now for the guys putting 16's 17's and 18's on their cars--the rubber will be in most cases of a larger diameter with a inverse reduction in rpms--that is just for high gear analysis--Now take that same bug tranny and gear the lower cogs to match the torque curve--and voila--you have insane acceleration thru torque multiplication in 1-3 and because of the high ( numerically low) R&P when you do shift out of third to fourth, you are already smoking at close to 120 mph--In my superbug--stock engine, stock tranny, 1600--100 mph was all it could muster on a cold dense day--but at only 5500 rpm and in third gear, I was doing 80 mph. Now most hotted teeners will easily pull another 1000 rpms, and with optimized ratios coupled with careful tire selection--you have a beast.

The stock 4th ratio of a bug is .84:1 and the 5th gear of the 901 is 1.40:1--it is allot higher ( numerically smaller, the input shaft to output shaft is 22:31, meaning the engine is turning faster than output) ) Wheras on the bug the engine is turning less than once per revolution of the tire, the 914 engine is turning 1.4 times per revolution of the wheel--plug a 4.12:1 or a 3.88:1 R&P ( which already is taller than the 901 ) in to the bug tranny and you have a much more efficient combo with which to play with gear sets, much more latitude....and a higher top speed if the power is there. but again, it all depends on tire selection. So in fact this combo is MUCH taller than the 901 trans.

I always laugh at those guys that put 22 inch wheels on their cadillacs!!! Even in my teener they are no match----they take away so much torque multiplication with those large diameter tire combos, that 0-60 they suck ass--and inversely--they have a much higher top speed potential if the POWER is there--which it kinda is----

point is -whatever you gear your box to for a specific tire diameter, and then later change the diameter for whatever reason--you will no longer have the same speed / rpm shift points or top speed.

This is how many crotch rocket dudes set their top speeds--it is prohibitively expensive to change internal gear ratios--so they go to a larger diameter tire which gives more available rpms for a given top speed than at which previously they were redlined--again-they have the power to do this--and their 0-60 times slip only a little due to high power output. this is the poor mans way to change the final gearing w/o going into the boxes.

With my tire combo-I will be looking for a max of 45 mph in first, 70 mph in second, and at least 105 in third--kinda tall first, but I am turboing--so I will have available more torque in the lower rpm range to power thru the ratio deficit--then coupled with a close 2-3, because as speed increases the power required to maintain that speed is squared, you need close coupled gear sets to relieve the motor and take up all the air / drivetrain drag which is induced and robbing HP, hence, a better torque multiplication rule. Then a nice long tall 4th gear to maximize trap speeds--

What is sooo cool, that say an engine makes 200 hp on a direct drive dyno and 200 TQ. When you plug in the numbers, lets say, 3.25:1 first gear, the tranny is multiplying this 200 TQ by 3.25:1 or 650 ftlbs of torque is making its way to the final drive--the final drive is 3.88:1 so we plug these numbers in and get 2522 ftlbs of torque--not MEASURED tq--purely mathematical---but then factor in a diameter of say 32 inches, which is inverse to final drive, and you are back down to about 145 measured tq-at the wheels-or say a 28 inch tire, that tq is now about 180--so it is crucially important to finalize the tire choice first---too many people do not even think about factoring in tire size FIRST--and they never see the real potential of their car.

With this in mind it IS possible for the wheels to develope more tq than the engine actually makes--this is where cog and final drive selection comes in---

Another thing to think about--nascar engines put out about 650 hp in a 3000# ?? car, and they go upwards of 200 mph, with phone booth aerodynamics---Ferrari has to make 550 hp to touch 200 and with the very best aerodynamics possible--but the nascar one is not very street friendly..........this is a good case of gear ratios making more power available than the engine produces. And the 4 spd can trounce a five--the 930 did it--it had the power to power thru the deficit coupled with a high 4th--had an eyeball snapping 0-60 and an astounding top speed for its time.
jwalters
QUOTE (andys @ Jan 22 2005, 12:58 AM)
What are each of the "net" ratios (1 thru 4 x final drive ratio)? I seem to recall that you can't get a tall enough 4th/R&P combo, as most applications are either for very tall tires and/or drag race applications. Can you point me to info on available ratio's that would perhaps suit higher HP motors? You will need about a 3.00:1 "net" ratio or better. The 901 is 3.14:1, a 915 is 2.94:1, and a 944T (016R) is 2.80:1..........Thanks,

Andy

IPB Image The true net ratio of any trans is 1:1-however, none are made to this standard, therre would be no torque mulitplication-I believe you are referring to the first gear ratio in the tranny minus the final drive, if not, clarify. Also- the manufacturer net is subjective--it depends on the entire setup from the factory to include final drive ratio and factory specified tire diameter..again--TIRE DIAMETER as soon as you take off those 165-15's, the net is no longer as advertised by the factory. It changes to correspond with the new diameter.

The overall net ratio is highly dependant on engine produced TORQUE--not HP --torque wins this equation, because that is what the factory finalizes the ratio of torque multiplication. The factories with all the hard math still will try 100's of tire and cog combinations to match the INTENDED purpose of the vehicle-i.e. how much tq to make it do this....-as we all know the purpose of the 914 was not top speed, nor was it 0-60, it was just give it enough gear to get out of its own way--take a 85 hp 1.8l and bump it up to 150 with the commensurate rise in tq and those stock cogs are going to piss you off--that is if you had the knowledge to know better--and most people do not--I did not either till just about ten years ago until I picked up a book called "auto math" while in a bookstore getting some coffee and perusing the porsche pubs.

Truely enlightening read--all must go right now to the nearest barnes-and noble and buy one, it will astound you.

Top speed is more highly dependant on top rpm and the engines ability to redline in top gear--basically, if it does--then it needs more final drive or a cog change, or both. When you are able to attain top speed with the engine giving out at about 250 rpm below redline-you have a good final drive--the cogs are what get you to this level--it is a very involved process, one of which why top race teams will test for a week before race--it is to finalize final drive among other things.
SpecialK
I hear ya talkin', but all I see is your avatar IPB Image

You've done a little research on this subject, haven't you.

I'll stick with my 901, but this is an interesting read for sure.
redshift
You are never going to be happy with a gear that leaves you with revs on the table at speeds you need to be at on roads you have to drive on.

1500rpm would destroy your motor, and suck if you had to get out of the way.


M
carambola
i don't know about ratio's and stuff like that ... but i run 195's in the rear and 80mph indicated leaves me running about 4000rpm maybe a smidge under in my TI ghia
scotty b
Bus tranny will bolt right up to a type 4 engine, after all they were made that way!! Bus is stronger but won't have the top end without gear changes. Four rib trannies are the best, I think they were 72-75? I have a bus with a 2.0 type 4 in my baja and it is great, but again I'm not looking to run 7000 rpm in that car IPB Image
TC/914
I just had RANCHO build a type I swing axle trans for my 356 coupe for all of the same reasons quoted here. Cost and performance being most important. The trans has all of the go-fast goodies installed plus a combination of type I and II gears for an overdrive fourth WAY beyond their freeway-flyer version. I thought that the shape of the 356 could handle and deserved the higher top speed that a VW trans would offer.

I have an IRS VW (TransForm) freeway-flyer trans in the cellar, now it's definately going into the 914.

THANKS for the push . . . !!

TC
jwalters
IPB Image Hi guys! Man did burn the midnight oil last night--I cant believe my rant went on -and on--ohh boy--sure did not mean to put all that out-

Oh and by the way I need to correct myself--I fudged the numbers for the 901 5th speed set--it is actually .71:1 and not 1.4:1--big difference, but alas, a .84 and 3.88:1 R&P is still taller than our 901 with a .71 fifth and 4.429:1 R&P setup--which means better highway revs and economy.

Redshift-I am not going to go the ultimate freeeway flyer special--a guy asked what was the lowest gear set available for the T1 slushbox--And yes a stock T4 cooling system will not cool at 1500 rpms on the interstate--but--a 6 conversion would--the fourth gear set is like our fifth--would you just pounce on it at 70 mph and expect anything spectacular to happen?? No, it would not--unless that motor is hotted wayyyy up--but then again, my motor will be turbo--so my torque out put will be fat across the board- so even if 4th is long--2-3 is short and short coupled--just a single gear change and BAM! Gone from sight..

Carambola, are they 50 series?? What you did, and many people do, is go to a small sidewall, tire diameter reduction--they are more intersted in handling ( as if stock was not good enough in this little pocket rocket corner carver )--which does this:( rough example) With stock tires 165-15, and a 4.4 R&P-you drop down to 50 series and minus 3 inches of diameter--even tho you have not touched the R&P--it now "thinks" it is a 5.12:1--which means shorter--if you do allot of stop and go this is good, because it has a higher torque multiplication--hence, you accelerate like you have an extra 25 hp under the deck, but then at say 70 mph cruising speed, your rpm will suffer and your fuel economy will suffer and you will not be able to blast ( on a non-public road ) to the same top speed as if they were stock 165-15... IPB Image
scotty b
TC what did you have to do to mount the vw trans in the 356 and how has it performed?
jwalters
QUOTE (TC/914 @ Jan 22 2005, 09:57 AM)
I just had RANCHO build a type I swing axle trans for my 356 coupe for all of the same reasons quoted here. Cost and performance being most important. The trans has all of the go-fast goodies installed plus a combination of type I and II gears for an overdrive fourth WAY beyond their freeway-flyer version. I thought that the shape of the 356 could handle and deserved the higher top speed that a VW trans would offer.

I have an IRS VW (TransForm) freeway-flyer trans in the cellar, now it's definately going into the 914.

THANKS for the push . . . !!

TC

IPB Image very welcome man!!---so how does the 356 perform??? still got original engine or did you upgrade to T1 or T4? Congrats!

Oh and also--if ---when you do upgrade the teener--upgrade the cooling system as well- or it will overheat at low revs on the freeway--I myself am stacking 3 oil cooler fans to my deck lid grill ( underside) and running a microswitch to the cooling flap arm--when the flaps are all the way open it will energize a relay and turn on the fans to augment to stocker very important for me to seal the bay extra good so all that extra 2500 cfm of air goes thru the engine... IPB Image
carambola
i appologize must have been thinking of something else. not 195 but 165r15 and 185/55 15 up front for a total of 10% speedo error on the high side
TC/914
Hey Guys,

I just got the shipping confirmation from RANCHO so the trans will get here this coming week, The original engine and trans is out for now/for ever probably. The new engine is built around an aluminum race case with a drop in stroked Demelo crank and 94 pistons/barrels. It's got all of the usual stuff done to it, but the carbs are Kadrons rather than the old Webs. I thought that I'd give AJ's stuff a try and see what the fuss was all about.

Even though it's a 914 board, I'll try to (covertly) keep you posted on the progress. When the trans gets here we'll start fabricating the mount, probably base it around the 411 bracket with adjustable diagonals to the shock mount area for a bit of pre-load? Maybe even duplicate a cleaner version of the '68 Type II engine hanger as well. I've got all the VW bits and pieces along with most of the suspension parts from the old sand buggy so it SHOULD be pretty simple to fabricate something slick. I'd LIKE to have it be a bolt-in as well in order to save the originality of the tub (it's a Pre-A Continental Coupe), but I'm not married to the idea.

The 914 is NOW going to get the treatment as well, unfortunately . . . I've got the trans already hanging around and the old sand buggy will provide the shifter box and cable linkage. I also have the old Oberg oil filter and cooler so THAT part's also taken care of as well. Too easy to begin, and always too difficult to finish . . . now I'll have TWO Porsches up on jack stands.

If robin complains, I'll just tell her that it's "JWALTERS" fault. HE STARTED IT! !
jwalters
IPB Image IPB Image
Tom Perso
I had a Rancho IRS trans in my Bug with a 2270cc T4 motor. It had a 3.88 R/P and a bus 4th gear and it cruised on the highway at 75 running 3500rpm (195/65's on the back). It also had the SB mainshafts, yada yada yada. It was build for Shad Law's 2615cc (80mm x 102) Nikkies equipped motor in his T4 before he went with a 915 from a 912.

To bolt a T4 to an IRS trans you need a 210 or 215 mm bus flywheel with the center opened up to hold a T1 input shaft bearing. I had my flywheel EDM'd out to press in the bearing.

IPB Image

Then I ran the corresponding bus clutch and a KEP Gold 200mm T1 disc. Held the 2270 no problem.

It was no more expensive than doing a decent clutch job on a bug... No expensive conversion flywheels needed.

Later,
Tom
andys
QUOTE (jwalters @ Jan 22 2005, 12:40 AM)
[/QUOTE]
IPB Image The true net ratio of any trans is 1:1-however, none are made to this standard, therre would be no torque mulitplication-I believe you are referring to the first gear ratio in the tranny minus the final drive, if not, clarify.

Jwalters,

I guess I didn't make myself clear, so let me give it another shot. What I refer to as net, is the transmission gear ratio (any gear) multiplied by the R&P ratio. When you do this, it is much easier to compare the transmission ratios of one trans to another. If you don't, then you are always doing math. All the gear ratio charts that I have, have had this conversion done just for that reason. Tire size is of course yet another ingredient; BTDT. In dry lake racing, small gear ratio or tire roll-out changes can have a very significant impact on attaining top speed.

Back to my original comment, You will need something better than 3.00:1 (top gear, be it a 4, 5, or 6 speed, multiplied by the R&P ratio) to gain any significan advantage in lowering freeway/cruise RPM.

"but alas, a .84 and 3.88:1 R&P is still taller than our 901 with a .71 fifth and 4.429:1 R&P setup--which means better highway revs and economy."

Better try that math again....0.84 x 3.88 = 3.259.
0.71 x 4.429 = 3.145. The 901 has the taller (lower numerical) final (net) ratio yeilding a lower highway RPM.

Back to the Rancho/sand buggy racer transaxles. I only saw 3.86 as the tallest (lowest numerical) R&P ratio available. Are any 4th gears available that can take us to something better than the 901 final ratio? Sure would be nice......I just love those prices!!!

Andy
reverie
Tom Perso, that was excellent info... thank you!

The tallest VW gears I've heard of are 0.82 4th (some years of Bus?), and for
ring/pinion there's the 3.888 (Superbeetle?) and the 3.555 (aftermarket).

But what kind of 3rd gear to go with that.. IPB Image
jwalters
IPB Image Andys---I do admit I have not done this kind of math in a long time, and I do not have my cheat book auto math in front of me--but to kinda look at this from the other side of the coin:

Lets say that high gear is 1:1 + a 4.429:1 R&P , net ratio = 4.429

A .71 and .84 high gear is less than one--we are taking away--hence, subtraction, I do remember that much from the pre algebra course I took ( I am not a mathematician, and do not claim to be, I use cheat sheets all the time)

So this is not a multiplication problem----A 4.429 R&P is being turned slightly more than per engine rotation, or, .29 times more or put into a % --29% more if the input shaft = 1, and it does. Due to the overdriven .71 gearset

With high gear we have taken away tq multiplication--we are now subtracting tq from a 1:1 constant

So now plug this into the equation--

1 - .84 = .16
1 - .71 = .29 These are the difference of our 1:1 constant

We then take these away from our R&P : Because it is being overdriven by this much with our constant of 1 :

3.88 - .16 = 3.72 Final drive The engine is turning 3.72 times per full revolution of the wheel.

4.429 - .29 = 4.139 final drive The engine is turning 4.139 times per full revolution of the wheel.

This is a difference of .419 between the two, not much on paper, but a tremendous amount in practice.

Remember, the high gear is overdriving the input shaft to the R&P, 1:1 is our base constant--if the high gear set was in fact 1:1, but because of the overdriven high gear we must take this difference away from the R&P.
only when the cogs are of a greater value than 1 do they become a Division equation of underdrive, hence, a 12 tooth input meshed with a 27 tooth output you get a ratio, or division of 2.25:1, hence the 12 tooth one will turn 2.25 times for one turn of the 27 toothed one. We are discussing less than one, .71 & .84 This is a division equation of overdrive to be subtracted from the R&P. All underdrive equations are added to the R&P.

The gear sets themselve only multiply torque, this is a theoretical value-they do not multiply themslves, they divide speed for speed.

I hope this makes sense, the term torque multiplication is just that--theoretical tq--the gears are meshed in a multiplicative manner--whatever gear is driving the other it has a constant of 1, no matter how many teeth it has, it is still 1-but by mulitplying 1 you only get the same constant--- therefore-they always divide speed for speed. A division of a ratio of 12:27 is 2.25:1, this does in fact mean that the work output is multiplied by that same constant, 1 x 2.25 = 2.25, or 100 ftlb of tq x 2.25 = 225 ftlb of tq. But work is not tangible, you cannot hold horspower in your hands ( the numerical value) so this stays in theory only.

But I also do admit that I could be wrong--as I stated I am no mathematician, and even I am staring at my avatar a little too much IPB Image
Cap'n Krusty
QUOTE (TC/914 @ Jan 21 2005, 05:07 PM)
I'll tell you what I think if you PM me as to where that great avatar came from!

Swapping a type one trans would be pretty easy and has been already thought out by the mid engine sand buggy boys. A quick visit to

http://shoptalkforums.com/ or http://www.thesamba.com/vw/forum/

will answer all of your parts matching questions regarding brackets, shifter, etc. along with which starter will fit the type one trans and which flywheel will need to be used on your engine. I would suspect a 70 flywheel with a semi-automatic VW Bug starter will do the trick. Otherwise, just talk with the folks at RANCHO and describe what you want. Everything else is pretty much a bolt it.

Good luck with a cool idea!

TC

Starter from a "semi automatic"? Same starter as the 914, so why bother changing it? European Racing (or Red Lion), sells the converted pressure plates. Other than that, it's a bolt in. For use in a 914, you have to figure out the linkage and some way to mount the trans at the rear. I've used T4 motors in Buggies and Bugs before, and it's no big deal. As for the lister who can flop the diff in 30 minutes, good luck! Without resetting the R&P locations, you're likely to eat them up in minutes. At a time when bug and buggie owners are looking for Porsche trannies, I fail to understand why anyone would be looking for their castoffs ...................... The Cap'n
jwalters
Yea well the buggie guys are more interested in trannies other than the 901-----

And to take off my side plates and swap the diff is a non-event--no pinion to pull--and just keep the same shims on the respective side--a quick check with prussian blue would show it will be more than ok for running---

but you do have to change the input shaft bearing--the T1 tranny snout is a larger diameter than the 901??

I know a 200 mm disc will run fine in the 215 flywheel and plate...and the linkage is still a pull, like the 901, and a quick check will show the pulley and mount will bolt up to the side case like the 901.

Mounting the trans to the 914 chassis is super easy--a pair of mild steel elephant ears bolted to the shift cap perimeter with extended studs , and with a section bent to the proper angle to mate to the rubber mounts is a brake press and plate bender away...too easy to do---and my cv output shafts bolt right up to the T1, so no changing components there-

I just want to do away with a red herring---I have 3 901's that all need work--and again, for the price of a set of synchros----------------------------

BTW- has anybody ever noticed that the 901 says VW on it???
andys
QUOTE (jwalters @ Jan 23 2005, 05:55 AM)
IPB Image Andys---I do admit I have not done this kind of math in a long time, and I do not have my cheat book auto math in front of me--but to kinda look at this from the other side of the coin:

Lets say that high gear is 1:1 + a 4.429:1 R&P , net ratio = 4.429

A .71 and .84 high gear is less than one--we are taking away--hence, subtraction, I do remember that much from the pre algebra course I took ( I am not a mathematician, and do not claim to be, I use cheat sheets all the time)

[Edited]

IPB Image

jwalters,

I have never seen gear ratio's calculated as you have, and I beleive them to be in error. I have attached a link to an easy to use gear ratio speed chart that will hopefully demonstrate the proper outcome. Just plug in the numbers. I think this would be easier than to debate on this forum. I hope you find this helpful, and leads to an accurate outcome. Also, I hope this VW Bus transaxle thing has some potential. It is an interesting and simple alternative. Good Luck.

http://www.geocities.com/z_design_studio/t...on_boxster.html

Andy
Mueller
Andy,

thanks for the link...that is pretty slick IPB Image
Cap'n Krusty
QUOTE (jwalters @ Jan 23 2005, 09:02 AM)
Yea well the buggie guys are more interested in trannies other than the 901-----


but you do have to change the input shaft bearing--the T1 tranny snout is a larger diameter than the 901??

I know a 200 mm disc will run fine in the 215 flywheel and plate...and the linkage is still a pull, like the 901, and a quick check will show the pulley and mount will bolt up to the side case like the 901.

Mounting the trans to the 914 chassis is super easy--a pair of mild steel elephant ears bolted to the shift cap perimeter with extended studs , and with a section bent to the proper angle to mate to the rubber mounts is a brake press and plate bender away...too easy to do---and my cv output shafts bolt right up to the T1, so no changing components there-

I just want to do away with a red herring---I have 3 901's that all need work--and again, for the price of a set of synchros----------------------------

BTW- has anybody ever noticed that the 901 says VW on it???

If by "input shaft bearing" you mean the pilot bearing in the flywheel (or gland nut or crankshaft), they're the same part number. VW used the same input shaft "snout" diameter on RWD vehicles until the end of the Vanagons. Porsche used it until the 915 tranny came into play. As for "opening up" the center of a bus flywheel, you simply knock out the sheetmetal insert, and insert the bearing. No machine work involved.

The 914/4 901 style trannies (actually called the "914" tranny), say VW on them, the REAL 901s, and the 911s, and the 914/6 trannies were made by Porsche, the 4s were made under license by VW. The Porsche made gears have matching numbers imprinted on them, the VW made gears don't.

As for the strength of 901s, a properly setup 914 tranny will hold up to a SBC or 911 motor for years of normal use, and I see no reason why it wouldn't last you for years using a T4 motor.

The Cap'n
Tom Perso
The diameter of all the input shafts (that we are talking about) are the same. It's the lenght. The T1 has the shortest, therefor, the bearing needs to ride in the flywheel. The other input shafts require bearings that ride in the crankshaft.

Later,
Tom
Cap'n Krusty
QUOTE (Tom Perso @ Jan 24 2005, 01:25 PM)
The diameter of all the input shafts (that we are talking about) are the same. It's the lenght. The T1 has the shortest, therefor, the bearing needs to ride in the flywheel. The other input shafts require bearings that ride in the crankshaft.

Later,
Tom

Isn't that what I said? SAME bearing, different locations. The Cap'n
bondo
QUOTE (Cap'n Krusty @ Jan 24 2005, 01:52 PM)
The Porsche made gears have matching numbers imprinted on them, the VW made gears don't.

Does this mean the gears are not matched? I know the factory manual says they should be replaced in pairs, but perhaps that is because if one is worn enough to require replacement the other must be as well.
jwalters
Yea, thanks andy--I can get somewhat discombobulated when factoring algebra--but I was pretty darn close! I was also using the calculator on CB's website---

The bearing was what I was wondering about also--Kennedy lists a mod to do to the flywheel--but did not really spell it out--Use the same starter from the 901?? or use a bug starter???

Capn, I got three 901's--two side shitters and one aft shitter--they all need work---for the price of a set of complete synchros I can get a T1 or T2 tranny with optimized R&P and gear sets--and I know this tranny will last me probably allot longer than the 901 when it comes to the dreaded first gear synchro--plus I can drop the hammer in first and really not worry about anything--really ever again--

Check out the latest Hot VW's mag--there is an entire section dedicated to this--really informative--they got like 8 or 10 industry trans builders to voice thier choices of gear cog combinations----For four different types of useage---!!!! IPB Image
jwalters
QUOTE (Tom Perso @ Jan 24 2005, 04:25 PM)
The diameter of all the input shafts (that we are talking about) are the same. It's the lenght. The T1 has the shortest, therefor, the bearing needs to ride in the flywheel. The other input shafts require bearings that ride in the crankshaft.

Later,
Tom

IPB Image So Tom, what you are saying is when the new bearing is pressed in, just do not press it in all the way???

I gotta headache from all this math IPB Image
Tom Perso
Cap'n - Yes, we are agreeing. Sorry I didn't read thru your whole post.

jwalters - The bearing sits flush with the flywheel and actually sticks a shade into the crankshaft. If there is an existing bearing in the crank, you need to remove it.

Later,
Tom
jwalters
QUOTE (Tom Perso @ Jan 24 2005, 09:15 PM)
Cap'n - Yes, we are agreeing. Sorry I didn't read thru your whole post.

jwalters - The bearing sits flush with the flywheel and actually sticks a shade into the crankshaft. If there is an existing bearing in the crank, you need to remove it.

Later,
Tom

IPB Image Wow, thats weird--I went and checked all three of my cranks and flywheels and they all have the bearing in the wheel--none in the crank--go figure..... IPB Image
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