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sharpstick
Samba Member
Joined: July 27, 2005
Posts: 447
Location: Amarillo, TX
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 Posted: Sat Apr 14, 2007 4:20 pm Post subject: Speed and RGB's |
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Hello,
I am the proud new owner of a 67 Bus. It has a 1600 DP and the stock reduction gear boxes. Right now I have the interior out of the bus cleaning everything so everything sounds really loud.
I have a 15 mile drive to work each day, all highway miles. Will a cruising speed of 60 to 65 mph put unnecessary wear on the engine or the gear boxes? I got on the freeway for the first time today and it just sounded really loud. I am guessing putting the interior back in will help with the noise. |
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Eric&Barb
Samba Member
Joined: September 19, 2004
Posts: 24736
Location: Olympia Wash Rinse & Repeat
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| Posted: Sat Apr 14, 2007 4:38 pm Post subject: |
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Hi sharpstick,
Having the interior out will definitely make your bus run louder. RGBs can easily handle higher MPH. You need to borrow or buy a tach for a fifteen minute drive, and have a passenger hold the tach and write down RPMs 1,500 & 3,000 @ what MPHs in each gear.
We got a bus years ago and turned out fourth gear topped out at 35 MPH at 3,000 RPM. So to do the 55 MPH that was the national freeway speed limit back then it had to do about 5,500 RPM. No wonder the DP engine that came with the bus had a connecting rod sticking out the top!
Investing in oil temp and pressure gauges will help greatly to keep your engine running better, & longer.
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In Stereo, Where Available! |
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sharpstick
Samba Member
Joined: July 27, 2005
Posts: 447
Location: Amarillo, TX
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| Posted: Sat Apr 14, 2007 6:33 pm Post subject: |
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| I just installed a tach and got it hooked up properly this evening. In fourth gear, 55mph is about 3500 rpm. It also turn out my 1600 is actually a 1641 from what the previous owner told me. |
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BarryL 
Samba Member
Joined: November 01, 2004
Posts: 14258
Location: Casa de Oro, California
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| Posted: Sat Apr 14, 2007 7:13 pm Post subject: |
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| RGBs are good: keep them. |
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BUS_AV8TOR
Samba Member
Joined: May 21, 2005
Posts: 177
Location: Kansas
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| Posted: Sat Apr 14, 2007 8:26 pm Post subject: Re: Speed and RGB's |
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| BarryL wrote: |
| RGBs are good: keep them. |
I'd love to get rid of my RGBs I just don't want to lower my bus to do it. IMHO RGBs were not one of VW's better idea's
| sharpstick wrote: |
I got on the freeway for the first time today and it just sounded really loud. I am guessing putting the interior back in will help with the noise. |
While you have the interior out install some sound deadener ( Second Skin, Dynamat ) I didn't put any in my sundial when I had the interior out and after riding in a bus that had sound deadener installed I'll be pulling my interior back out this summer  Are you going to be at the hooters car show next weekend ? I'd love to see your bus |
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67texan
Samba Member
Joined: December 24, 2006
Posts: 101
Location: Dallas, TX
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| Posted: Sat Apr 14, 2007 8:50 pm Post subject: Re: Speed and RGB's |
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| BUS_AV8TOR wrote: |
IMHO RGBs were not one of VW's better idea's |
Why not? |
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campingbox
Samba Member
Joined: November 14, 2000
Posts: 10196
Location: Petaluma, CA
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| Posted: Sat Apr 14, 2007 8:51 pm Post subject: |
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| Eric&Barb wrote: |
Having the interior out will definitely make your bus run louder. |
I disagree, sound louder, sure....but run louder? |
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BUS_AV8TOR
Samba Member
Joined: May 21, 2005
Posts: 177
Location: Kansas
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| Posted: Sat Apr 14, 2007 8:57 pm Post subject: Re: Speed and RGB's |
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| 67texan wrote: |
| BUS_AV8TOR wrote: |
IMHO RGBs were not one of VW's better idea's |
Why not? |
A waste of horse power ....They should of just built a bus trans instead of adapting over a Type 1 trans |
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campingbox
Samba Member
Joined: November 14, 2000
Posts: 10196
Location: Petaluma, CA
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| Posted: Sat Apr 14, 2007 9:10 pm Post subject: Re: Speed and RGB's |
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| BUS_AV8TOR wrote: |
| 67texan wrote: |
| BUS_AV8TOR wrote: |
IMHO RGBs were not one of VW's better idea's |
Why not? |
A waste of horse power ....They should of just built a bus trans instead of adapting over a Type 1 trans |
Well, reduction boxes effectively give you more HORSEpower. Is that what you mean by waste? These were designed to haul stuff, right? |
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truckersmike
Elder Sambanite
Joined: March 16, 2001
Posts: 2025
Location: Bellingham, WA
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| Posted: Sat Apr 14, 2007 9:32 pm Post subject: Re: Speed and RGB's |
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| BUS_AV8TOR wrote: |
| 67texan wrote: |
| BUS_AV8TOR wrote: |
IMHO RGBs were not one of VW's better idea's |
Why not? |
A waste of horse power ....They should of just built a bus trans instead of adapting over a Type 1 trans |
i hate when people complain about having reduction boxes. do you really want a bus or not? how fast do you want to go? how easy do you want to make it up that hill in your laden camper with a 1600 dp? do you want to travel faster then your brakes were designed? there are alternatives like freeway fliers with big motors and installing disk brakes but i would rather enjoy 60 mph and the lovely scenery going by. admittedly, i have a ff and big motor in my 67 camper, but i still only drive 60.
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59 DD panel. Former Romano's TV delivery bus
67 Westy SO-42 pop-t |
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BUS_AV8TOR
Samba Member
Joined: May 21, 2005
Posts: 177
Location: Kansas
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| Posted: Sat Apr 14, 2007 9:41 pm Post subject: Re: Speed and RGB's |
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| campingbox wrote: |
Well, reduction boxes effectively give you more HORSEpower. Is that what you mean by waste? These were designed to haul stuff, right? |
Anytime you're turning gears submerged in thick gear oil, it takes horsepower to turn those gears... so RGBs COST you horsepower... thats simple physics ...... u notice in 68 VW got rid of the RGBs and built a bus trans just like should have been done in the beginning...... You can still haul things in later buses and theres no RGBs on them. You just don't look as good doing it  |
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truckersmike
Elder Sambanite
Joined: March 16, 2001
Posts: 2025
Location: Bellingham, WA
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| Posted: Sat Apr 14, 2007 9:55 pm Post subject: |
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during the last shasta snow trip, a bay showed up unannounced. he struggled the entire time to keep up with us while we were blazing through the trails in 2nd and 3d gears. torward the end of the night, he bailed out on us saying he just couldn't keep up. yeah, reduction boxes suck.
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59 DD panel. Former Romano's TV delivery bus
67 Westy SO-42 pop-t |
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campingbox
Samba Member
Joined: November 14, 2000
Posts: 10196
Location: Petaluma, CA
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| Posted: Sat Apr 14, 2007 10:03 pm Post subject: Re: Speed and RGB's |
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| BUS_AV8TOR wrote: |
| campingbox wrote: |
Well, reduction boxes effectively give you more HORSEpower. Is that what you mean by waste? These were designed to haul stuff, right? |
:?
Anytime you're turning gears submerged in thick gear oil, it takes horsepower to turn those gears... so RGBs COST you horsepower... thats simple physics ...... u notice in 68 VW got rid of the RGBs and built a bus trans just like should have been done in the beginning...... You can still haul things in later buses and theres no RGBs on them. You just don't look as good doing it :lol: |
Gear oil is not as thick as CV joint grease. |
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BUS_AV8TOR
Samba Member
Joined: May 21, 2005
Posts: 177
Location: Kansas
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| Posted: Sat Apr 14, 2007 11:11 pm Post subject: Re: Speed and RGB's |
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| truckersmike wrote: |
| reduction boxes suck. |
You're right they do suck horsepower  I hate anything that's a waste of horsepower! That comes from growing up around race cars where we would spend a ton just to pick up a few horsepower or shave a few pounds off. How many less RPM are you turning with your FF Trans ? Doesn't the FF trans basically give you about the same gear ratio as not having the RGBs ? And you still have the horsepower drag of the RGBs. You're just not turning as many RPM as you did at the same speed as you did with RGBs...which is saving a ton of wear on your motor..... With a stock 1600, I'd keep the RGBs. With a big motor you're just throwing away horsepower. I'd dump the RGBs in a heartbeat if I didn't have to lower the bus to do it .... I'll be doing a set up close to yours with a big motor and a FF trans and RGBs.
| campingbox wrote: |
| Gear oil is not as thick as CV joint grease. |
You're right about that... But what does that have to do with the difference between horsepower lost with RGBs and CV Joints ??? |
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Clara
Samba Member
Joined: June 14, 2003
Posts: 12400
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| Posted: Sun Apr 15, 2007 7:08 am Post subject: Re: Speed and RGB's |
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| BUS_AV8TOR wrote: |
| truckersmike wrote: |
| reduction boxes suck. |
You're right they do suck horsepower I hate anything that's a waste of horsepower! That comes from growing up around race cars where we would spend a ton just to pick up a few horsepower or shave a few pounds off. How many less RPM are you turning with your FF Trans ? Doesn't the FF trans basically give you about the same gear ratio as not having the RGBs ? And you still have the horsepower drag of the RGBs. You're just not turning as many RPM as you did at the same speed as you did with RGBs...which is saving a ton of wear on your motor..... With a stock 1600, I'd keep the RGBs. With a big motor you're just throwing away horsepower. I'd dump the RGBs in a heartbeat if I didn't have to lower the bus to do it .... I'll be doing a set up close to yours with a big motor and a FF trans and RGBs. |
Are you really bothered by the lower gearing w/ RGBs.... if so say so. That is not the same as robbing horsepower.
The way VW did if worked fine. Think about the purpose of the bus.
Read a little European history if you don't know why they used kubelwagon and beetle parts when they buildt the bus.
If you read some back posts about gearing... there is a lot of info there.
| Quote: |
| BUS_AV8TOR wrote: |
| Anytime you're turning gears submerged in thick gear oil, it takes horsepower to turn those gears... so RGBs COST you horsepower... thats simple physics ...... |
| campingbox wrote: |
| Gear oil is not as thick as CV joint grease. |
You're right about that... But what does that have to do with the difference between horsepower lost with RGBs and CV Joints ??? |
The CV joint grease would be robbing more horsepower than the gear oil in the RGBs.
So the IRS is more of a horsepower thief than the RGBs
You've just got it ass backwards, racer boy.
And... quoting people out of context is lame.
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Clara
Samba Member
Joined: June 14, 2003
Posts: 12400
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| Posted: Sun Apr 15, 2007 7:26 am Post subject: |
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| sharpstick wrote: |
| I just installed a tach and got it hooked up properly this evening. In fourth gear, 55mph is about 3500 rpm. It also turn out my 1600 is actually a 1641 from what the previous owner told me. |
I think you do not have '67 gearing in your transmission.
The info from VW gives their recommended top speed at 3600-4,000 rpms. the engine will last longer if you keep your top speed at about 3K rpms. The best cooling is at 2600-2800 rpms.
There's a gearing calculator URL in my sig... you can use that technique to figure what gearing is in there now.
Do you have big or little nuts? (rear axle nut size .... 46mm or 36mm)
What size rims and tires are you running?
What speed are you wanting to drive? if it's 3500rpms at 55mph, I'd say don't drive 65. Are you okay staying at 55?
The engine size does not affect what RPMs it'll do at what speed... but tire size does. Small tires make you rev higher at the same speed (or go slower at the same rev) and make your speedo read high.
On the other hand.. bigger tires will make the speedo read low and give you more road speed at the same rpms. You could get some 15" bus rims (not bug rims) and run 205 75 15s tires on there, easier than swapping the tranny out, unless you feel the trans needs a rebuildt anyway.
Putting the interior back in will make the bus quieter.
Even just laying a rubber floor mat in will make a difference. Or laying a foam pad/some blankets/sleeping bags over the engine.
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DaBraink
Samba Member
Joined: August 12, 2005
Posts: 172
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| Posted: Sun Apr 15, 2007 8:49 am Post subject: Re: Speed and RGB's |
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| BarryL wrote: |
| RGBs are good: keep them. |
| Quote: |
| I'd love to get rid of my RGBs I just don't want to lower my bus to do it. IMHO RGBs were not one of VW's better idea's |
When VW first designed the bus, there were no 1600 dp engines around, and to pull a fully laden bus through the mountains with 25hp required the use of reduction gears.
Remember there were no super highways so there was no need to do more than 45mph. Reduction gear boxes also gave the bus better ground clearance and ability to hold a larger load.
The original reduction gear boxes were for military use, so the vehicle could creep along at about 2 to 4 mph without stalling, to support soldiers on foot. At that speed you need a decent rpm to cool the engine.
The R & D is already done, why not use what is already in the parts bins to keep costs down. Practical and inexpensive.
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If it ain't broke.................find something else to fix.
There's never enough time to do things right, but always enough time to do them over. |
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sharpstick
Samba Member
Joined: July 27, 2005
Posts: 447
Location: Amarillo, TX
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| Posted: Sun Apr 15, 2007 9:23 am Post subject: |
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| I do have larger than stock tires. The previous owner put them on so I will have to see what size they are. With the larger size tires am I actually going a few mph faster than what my speedo says? |
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DaBraink
Samba Member
Joined: August 12, 2005
Posts: 172
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| Posted: Sun Apr 15, 2007 9:29 am Post subject: |
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The original tire size on my 67 Kombi should be 7.00 -14 which is close to 195/75-14. The PO installed 195/75-15 which is essentially a 1 inch larger diameter. It went from 25.5 to 26.5 and the speedometer should be approx. 3.9% different, that is 60mph speedometer reading is actually around 62.5.
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If it ain't broke.................find something else to fix.
There's never enough time to do things right, but always enough time to do them over. |
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Eric&Barb
Samba Member
Joined: September 19, 2004
Posts: 24736
Location: Olympia Wash Rinse & Repeat
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| Posted: Sun Apr 15, 2007 9:52 am Post subject: |
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| campingbox wrote: |
I disagree, sound louder, sure....but run louder? |
Hi Greg,
To the perspective of the driver and any passengers inside it runs louder. Not only from the vibration from the engine, but tranny, wheel to road contact, wind, weather, nearby traffic, etc.. Plus these vibrations get to bounce around the interior longer/more.
As for RGBs. Sure they do rob a little bit of HP, but this gearing gives one more road clearance, AND add to the much higher wieght load rating on the outer ends of the axles. We have driven through snow so high a Beetle would have long before bellied out in. Plus having the VW Bus with RGBs that can be loaded with 3/4 or 1 ton of weight can be real handy. Partly due to being without RGBs the other pre-1968 VWs have a weight rating ranging from about 600 to 1,200 Lbs.
Yes, when VW went from RGBs to CV joints in 1968 the rate weighting stayed up, but only by using much heavier duty stub axle with two beefier bearings per side than were used in any year of type 1 & 3.
Plus the RGBs are a lot easier to maintain than any CV jointed type. To replace the grease in CV joint suspension you have to take everytthing apart. In the Swing axle suspension you remove tranny drain plugs, drain, reinsert drain plugs, and refill.
If you really want less HP drain between the engine and wheels due to gearing (about 19% going through the type 1 tranny) take a look at electric wheel motors like Porsche devised just before WWI. Today an updated version of these are being tested on Metro Buses.
http://en.wikipedia.org/wiki/User:A-Hrafn/Wheel_motor
Would be cool to try this out on a VW bus and be able to run at a flip of a switch real one, two or four wheel drive. Biggest hurdle would be to design a hybred setup for long distances.
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