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Lui
Samba Member
Joined: March 12, 2004
Posts: 151
Location: East TN
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 Posted: Thu May 05, 2005 12:21 pm Post subject: |
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| westy78 wrote: |
I hope that's not a premonition for a before and after shot.  |
Me too. I suppose that would be a good time to "stop and give the engine a rest" . . .maybe get some coffee, forget about the gas, though I might have already peed after that experience. |
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ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
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| Posted: Thu May 05, 2005 1:52 pm Post subject: Re: Five speed tranny? |
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| Lui wrote: |
| I was wondering how practical is it to get a five speed tranny put in my bus so the rpms are not so high at 70 mph? |
4th gear in the bus is already overdrive: 0.89. If you want to lower the rpms at speed you need to go extreme overdrive:
Only some 901 transmissions have a higher 5th gear (the Y and ZD gear pairs) so you may have to rebuilt it first. The 915 uses a 0.7586 5th so it would be suitable also.
Mounting and shift rod coupling will be your biggest obstacles after cost (buying a used 901/915 in the first place). You should read the disclaimers in this article before tackling this project:
http://www.geocities.com/MotorCity/Speedway/1974/freewayflyer.htm
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ
Last edited by ratwell on Thu May 05, 2005 2:06 pm; edited 2 times in total |
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shiningstar76
Samba Brewer
Joined: July 12, 2003
Posts: 2689
Location: Savannah
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| Posted: Thu May 05, 2005 1:56 pm Post subject: |
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| Lui wrote: |
| westy78 wrote: |
| shiningstar76 wrote: |
| a fifth gear = higher speeds with lower rpms~cooling air and increased headwind. 60 in fifth might become 50 in fourth with the idea that we have a groovy fifth gear and running at hightway speeds for a long time with less rpms might cause the motor to run hot. Is this what we are considering in a 'well planned fifth gear?" I am tempted to think that VW thought of this. |
A well planned fifth gear to me would be one that kept the optimum cooling/rpms at the desired cruising speed. Say you want to cruise at 75mph. If you could match the gearing to give you 3400-3500 RPM's at that speed you would be matching the same temps as cruising at 65mph in Ratwells graph with stock gearing. |
That's about what I had in mind, more or less.
New question: If I have planned extensive travelling at 65, what are good times to take breaks? -- i.e. let the engine "rest." Obviously not when the engine is really hot, but after every three hours on the highway? Four? Any thoughts? |
I break whenever I run out of coffee. But seriously, I plan my breaks around my head and oil temps and if they reach a point where the temp holds a little too high for a bit that is when I will take a break. No gauges? Just check the temp by feel periodically.
_________________
KK4NTP
96 Tacoma
86 4Runner
My bus caught on fire and is now on the other coast with someone who gave me money for it. |
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Lui
Samba Member
Joined: March 12, 2004
Posts: 151
Location: East TN
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| Posted: Thu May 05, 2005 2:14 pm Post subject: Re: Five speed tranny? |
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| ratwell wrote: |
| Lui wrote: |
| I was wondering how practical is it to get a five speed tranny put in my bus so the rpms are not so high at 70 mph? |
4th gear in the bus is already overdrive: 0.89. If you want to lower the rpms at speed you need to go extreme overdrive:
Only some 901 transmissions have a higher 5th gear (the Y and ZD gear pairs) so you may have to rebuilt it first. The 915 uses a 0.7586 5th so it would be suitable also.
Mounting and shift rod coupling will be your biggest obstacles after cost (buying a used 901/915 in the first place). You should read the disclaimers in this article before tackling this project:
http://www.geocities.com/MotorCity/Speedway/1974/freewayflyer.htm |
Thanks!! -- to Ratwell and all!!
_________________
-Lui
1976 Westy
"If at first you don't succeed, skydiving is not for you. . . "
Please feel free to visit my "Westfalia" website and sign the guestbook!
http://www.geocities.com/lilithomson
Last edited by Lui on Fri May 06, 2005 8:55 am; edited 1 time in total |
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Rocknrod
Samba Member
Joined: November 02, 2004
Posts: 2157
Location: North Carolina
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| Posted: Thu May 05, 2005 2:33 pm Post subject: |
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Colin beat me up about this one a few weeks (months?) ago...
Basically for a stock bus the regular gear ratio is in perfect harmony with the engines ability to motor it around at highway speed.
The general consensus was... at the time... to lower the speed to get better gas milage rather than drop RPM. Unless of course you were to rebuild the motor to make more torque at a lower RPM and speed up the fan at the same time.
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vdubyah73
Samba Member
Joined: July 05, 2003
Posts: 2541
Location: somewhere in Texas, my house has wheels
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| Posted: Thu May 05, 2005 3:36 pm Post subject: |
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The same but different! I built a buggy out of my rusty bug,it wieghs 1500#.I put much taller tires on it and head temps went up for the same road speeds rpm is lower by about 500 temps are higher by about 20*. So, car is lighter by about 500# much more areodynamic (its a Bounty Hunter not a Manx style) than a bug. I think if I was pushing a stock bug with those tires my head temps would be even higher.I guess what I'm trying to say is them germans knew what they were doing. Doesn't the Berg 5 speed kit recommend the stock or close to stock 4th gear for the 5th gear and make 3rd and 4rth a closer ratio for best results.
Bill |
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ratwell
Samba Member
Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
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| Posted: Thu May 05, 2005 4:12 pm Post subject: |
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| Rocknrod wrote: |
| Basically for a stock bus the regular gear ratio is in perfect harmony with the engines ability to motor it around at highway speed. |
At night with the cool air and no other traffic around right? 
The problem I have with the stock gearing is the noise of the engine at those speeds. I have a quiet exhaust, westfalia cushioning inside but it's still loud to me ears.
_________________
'78 Westfalia CDN
'76 Doublecab
Read the Baywindow FAQ |
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BobDog
Samba Member
Joined: January 15, 2004
Posts: 1193
Location: Orange County
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Lui
Samba Member
Joined: March 12, 2004
Posts: 151
Location: East TN
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| Posted: Fri May 06, 2005 6:05 am Post subject: |
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I wonder if anyone has made a thermostat-controlled electric fan to cool the bus while in traffic on a hot day?
_________________
-Lui
1976 Westy
"If at first you don't succeed, skydiving is not for you. . . "
Please feel free to visit my "Westfalia" website and sign the guestbook!
http://www.geocities.com/lilithomson |
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josh
Samba Member
Joined: July 13, 2003
Posts: 1773
Location: laid back in the tall grass
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| Posted: Fri May 06, 2005 6:33 am Post subject: |
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| Lui wrote: |
| I wonder if anyone has made a thermostat-controlled electric fan to cool the bus while in traffic on a hot day? |
You can get a thermostatically controlled external oil cooler with a thermoswitched fan. That'll cool the oil but not the heads. |
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Rocknrod
Samba Member
Joined: November 02, 2004
Posts: 2157
Location: North Carolina
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| Posted: Fri May 06, 2005 7:50 am Post subject: |
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| ratwell wrote: |
| Rocknrod wrote: |
| Basically for a stock bus the regular gear ratio is in perfect harmony with the engines ability to motor it around at highway speed. |
At night with the cool air and no other traffic around right?
The problem I have with the stock gearing is the noise of the engine at those speeds. I have a quiet exhaust, westfalia cushioning inside but it's still loud to me ears. |
Are engines/transmissions rubber mounted in bays? Thats a pretty big deal... get harmonics through the motor mounts into the body. The vette guys are rather fond of dynomax pads (or aluminum backed closed cell foam insulation like what lowes carries!) Just to cut down on the amount of heat and noise. The big deal with the vettes is the fact that its a a composite speaker... but nothing at all like the early lotus! Lots of people spray in truck bed liner or undercoating on both sides of the panels to make the panels themselves a damper for vibrations/harmonics.
Is it as bad at low speeds as it is on the highway? 20-30 MPH full throttle does it blow your ears out... or is it just once its up to 65 on the highway? For that look at the tires! Tires are nasty at making harmonics. Lots of cars with sunroofs let you hear them real well at "around town speed." They've got a harmonic frequency that kicks in somewhere in the 30/35 mph that gives you the warbling buzzing noises inside the car.
Radio Shack has a decible meter thats pretty good for finding where your noise is coming from. Sit in the drivers seat and check how loud it is, point it around, point it at the heater vents... go back in the back and find where your getting the noise through the body! Then those little asphault tiles come into play (or the undercoating!)
Dont know if this helps or not... my solution has always been to have an exhaust louder than the engine!  |
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Rocknrod
Samba Member
Joined: November 02, 2004
Posts: 2157
Location: North Carolina
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| Posted: Fri May 06, 2005 7:59 am Post subject: |
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Is a VW fan direct drive... on all the time, no clutch?
On the GM's theres a little temperature coil clutch that lets the fan freewheel until the motor is hot. But then again... more complexity, you guys have brain washed me into the "KEEP IT SIMPLE STUPID" approach...
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westy78
Samba Member
Joined: August 20, 2002
Posts: 2005
Location: Portland OR
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| Posted: Fri May 06, 2005 8:05 am Post subject: |
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| Rocknrod wrote: |
| Is a VW fan direct drive... on all the time, no clutch? |
Yes, the fan bolts to the crank. Air cooled needs air all the time, they're always hot. 
With the noise, much of it comes from wind noise also. Basically you're driving a brick through the air. If you have a Westy there is even more wind noise due to the luggage rack creating more turbulance right above your head. That along with air getting under it, old door seals, no insulation up front on the nose just bare metal, etc. etc. All part of the experience!
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Jasan C.
'78 Westy
VW Campmobile, it goes on vacation with you. |
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Rocknrod
Samba Member
Joined: November 02, 2004
Posts: 2157
Location: North Carolina
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| Posted: Fri May 06, 2005 8:12 am Post subject: |
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Heck ya...
The "German Equivelant of Motorized Conostoga wagon."
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Lui
Samba Member
Joined: March 12, 2004
Posts: 151
Location: East TN
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germansupplyscott
Samba Member
Joined: May 22, 2004
Posts: 7093
Location: toronto
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| Posted: Wed Jun 15, 2005 11:41 am Post subject: Re: Five speed tranny? |
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| Lui wrote: |
| Hello all, I was wondering how practical is it to get a five speed tranny put in my bus so the rpms are not so high at 70 mph? |
there is no easy 5-speed option for a bus. you can get a taller 4th gear, like a .77, but the problem is that when you lose rpm, you lose cooling air flow also.
note that berg recommends using a 5th that is actually a stock 4th ratio, so you are not lowering your top rpm at all. your bus engine is designed to run at the rpm it runs at. with the 5-speed you are just making a close ratio gearbox, not adding a taller top gear.
the easiest way to do what you are asking to do is to use slightly larger tires, this will also lower your rpms, but it will have the effect of a taller gear ratio.
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SL
Last edited by germansupplyscott on Wed Jun 15, 2005 11:52 am; edited 2 times in total |
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germansupplyscott
Samba Member
Joined: May 22, 2004
Posts: 7093
Location: toronto
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| Posted: Wed Jun 15, 2005 11:50 am Post subject: |
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| Lui wrote: |
| He has them available |
the berg 5 will normally not work in a bay.
the photo in the shifter thread has me wondering what transaxle is in this bus:
it clearly has a berg 5 shifter, but the bus is a bay. the berg 5 modification is only for the beetle IRS transaxle. it's a mystery.
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SL |
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tristessa
Samba Member
Joined: April 07, 2004
Posts: 3992
Location: Portland, OR
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| Posted: Wed Jun 15, 2005 12:02 pm Post subject: |
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| germansupplyscott wrote: |
| it clearly has a berg 5 shifter, but the bus is a bay. the berg 5 modification is only for the beetle IRS transaxle. it's a mystery. |
Someone makes .. or *made* at one time .. a special intermediate housing that allowed the Berg 5 to work with a Bus transaxle. I'd have to dig through my collection of HotVW's magazine to find out who makes/made it, but IIRC they were somewhere around Vegas.
I've also seen Berg 5's done with Beetle swingaxle transaxles. |
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Devon-Dyno-Soar118
Samba Member
Joined: August 30, 2004
Posts: 849
Location: Devon UK
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| Posted: Wed Jun 15, 2005 12:09 pm Post subject: |
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There is a 5 speed adaptable to fit a bus- its called a Porsche box! By the time you have arsed around with the gearbox you might as well have tweaked the chassis, added some extra mounts and fitted a 5 speed porker box. There is a guy in the UK who does porsche 6 cylinder conversions for later bays. Can do earlies too but the extra expense on brakes etc is a pain. Then you can do 100mph all day in 5th (if you dare!) and blow the doors off hot hatches as well. Weren't some 914's fitted with 5 speed boxes- if so then that could be even easier, tho not any cheaper.
Check out the "freeway flyer" thread on this page for what was said on the RPM subject.
_________________
71 West coast Kombi
54 Oval, 60k km from new
Daves 68 Bug Project
Rust Collector.
Last edited by Devon-Dyno-Soar118 on Wed Jun 15, 2005 12:58 pm; edited 1 time in total |
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Randy in Maine
Samba Member
Joined: August 03, 2003
Posts: 34890
Location: The Beach
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| Posted: Wed Jun 15, 2005 12:35 pm Post subject: |
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I noticed this from the Berg website,
"Interesting that the factory Porsche and late 091 bus 5 speeds have the exact same design as ours. "
I was assuming that a 5 speed 091 might have come from South Africa, Mexico or perhaps a diesel vanagon? I don't know. |
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