Date: Mon, 29 Oct 2001 00:54:33 -0800
Reply-To: Robert S Keezer <warmerwagen@JUNO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Robert S Keezer <warmerwagen@JUNO.COM>
Subject: Re: Transmission Ratios, Diesels, Conversions
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If i may enter this discussion to comment I am much obliged.
Wow-I know the inline four can do the high rpm but I don't like holding
that tune too long because it's an expensive song in terms of fuel
economy.
I take similar trips in my 2.0 Golf powered 82 Westy (with 81 trans)and
with an average speed of 70 mph I get about 20 mpg. On a trip where speed
limits are 75 have been getting 19 mpg.
From looking at your results, Mpg /-Km/h is one major advantage to using
the .457 or .483 transmission.
Power is there with the 115 hp motor. The 5 speed trans which I would
like to have is a perfect match for this motor because it lowers the
gearing some(in Frank's direction) and gives you a 5th which is taller
than the standard WBX fourth for best economy.
A Diesel trans really slows the beast down unless you floor the
accellerator and like the high octaves .
I feel the two best gears of the five speed is 4th-5th gears. Think of
the fourth as a tall third and the fifth as a tall fourth.
The fourth in the four speed is still a little too tall even for 115 hp
unless you are on level ground. Hills slow it down on fourth.
Now of course, dropping down into third i can go over the pass at sixty
@4,500 rpm. If i had a five-speed , I could turn a few hundred less revs
in tall third(fourth). Third would really pull up in the Rockies!
The standard Diesel trans has no problem bogging down on these passes,
the final drive gives it the torque it needs here, but to go fast, you
have to drive at higher than average rpm which will shorten engine life.
My first i-4 engine was a RV 1.8 Jetta, and it lived to be 160,000 miles
before it burned up a rod bearing.
I do believe we can blow these things-towing a 4,000 lb trailer hammered
out all by crank end thrust washer.
These motors are'nt indestructible. The Diesel clutch is not that heavy
duty-just towing a Vanagon Westfalia and the trailer showed me this.
So, though I realize the egine is capable of high rpm, I think that the
design is intended to be a "Burst" mode as opposed to being "Full Auto".
Of course, if you are a rocket scientist who's other car has a rotary
engine then Frank's rpms are low.
I was heavily persuaded to once put a rotary engine in my Vanagon.
but that would'nt have sat well with this list.
With the five speed trans-we can have the best of both-low end torque and
the best top end cruising rpm.
If you have a 1.8 engine, (100 hp or less), the 5-speed trans is a must.
Or something to wish for.
Robert K
1982 Westfalia
On Mon, 29 Oct 2001 01:48:48 EST Frank Grunthaner <FrankGRUN@AOL.COM>
writes:
> I've chosen to reply in reverse order to Mark's comments. I've placed
> my
> comments in bold hoping to avoid even more confusion:
>
> In a message dated 10/27/01 1:23:27 PM, drillock@EARTHLINK.NET
> writes:
>
> << And yes, if a mere 60 mph is your intended highway cruising speed
> then
>
> the diesel r+p ratios are useable. I just got back from a 1200 mile
>
> interstate trip in my 4.57 r+p TD Vanagon. I did not see any
> passenger
>
> vehicles traveling at such a low speed except uphill. Who in God's
> name
>
> would install a Tiico conversion and then drive at such
> obstructionist
>
> speeds on long trips? Only a masochist would hold 60 mph for hours
> on I5
>
> with semis constantly running up their butts at 70 mph. "The most
>
> efficient utilization of an engine" is not always the primary
>
> consideration. Sometimes real world factors interrupt the dreaming.
>
> Unbelievable! Real World my posterior! Most efficient and optimal
> gearing
> choices refer to a reasonable midband operation - that is, a
> condition where
> sufficient power reserves remain so as to exceed that velocity, and
> lower
> speed power remains such that the engine is not devoid of the torque
> needed
> to fend off small inclines. I never suggested a speed governor
> holding the
> damn thing at 60.
>
> As for velocity chest pounding, I just returned from a trip from LA
> to
> Monterey, then Santa Cruz and back. 830 miles. The run to and from
> 152 was on
> I5. In my abused Westfalia with DZ transmission (5.86 r&p) I ran
> between 75
> and 85 most of the way. The exceptions were the Grapevine which I
> cleared at
> 62 full throttle in third, and one semi where I had to push it up to
> 90. I
> averaged 17.9 mpg for the trip as I was in a hurry. I had a maximum
> oil
> temperature of 235 F (113 C), minimum oil pressure of 34 psi with
> Mobil 1
> 15W-50, and a maximum EGT reading of 740 C (1365 F) running at 85 mph
> in the
> closed loop mode. (These numbers refer to 215/75x15 tires, so the
> actual
> speed is around 3 to 4% higher). This was done with AC on. I am
> pleased to
> say that I was not passed by passenger car or semi. As I have
> indicated many
> times in the past, this engine/transmission package can wind beyond
> 6100 in
> fourth (around 98) on a straight and level. The chip redline is 6700
> rpm. I
> often spin up to 6500 rpm in 3rd to pass on hills (70 mph).
>
> 60 mph my sensitized hemorrhoids!
>
> I guess it all depends on which set of engineers you have an
>
> affinity for. Look at the gearing choices of the VW engineers who
>
> actually were responsible for putting the gas inline 4 engine into
>
> production Vanagons. Don't expect to see 4 speeds with diesel r+p
> ratios
>
> (5.83, 5.43). They did NOT choose such low gearing. I believe 4.83
> is
>
> what they mostly used, a waterboxer ratio. Also offered 4.57 AFAIK.
> Were
>
> they brushing aside their own engineering data?
>
> OK, now this is a valid point. Going through Helmut's transmission
> ratio page
> and assuming its veracity, several points are clear:
>
> The 67 horse, A/C engine pulls an overall gear of 3.89 (top) and
> 17.28 in
> 1st. For the 1.9 WB 82 HP engine the values are 4.11 and 18.26. For
> the
> diesels with 5.86 r&p, the numbers are 4.89 and 22.17; with the 5.43
> gears,
> they are 4.62 and 20.54. The Euro TD runs 4.29 and 20.79. For the 5
> speed
> diesels, the numbers are 4.18 and 22.31, or 4.45 and 22.31, or 4.51
> and
> 22.31, and for the most recent 3.96 and 19.84. For the SA
> transmissions, the
> 93.8 HP engine and the 162 HP engine run a 4.833 r&p with an overall
> ratio of
> 4.11 and 18.26 for first. Same as the 1.9 and 2.1L WB power trains.
> The SA 5
> speeds run an overall top gear ratio of 3.94 and 3.73, with 1st gear
> numbers
> of 19.86 and 18.76. For the automatics, 68 hp engine runs a 4.09 in
> top gear
> as do the 76 to 88 HP 1.9L WB engines and the 93.4 and 109.9 HP 2.1L
> engines.
> I assume the 3.74 R&P was a short run fluke.
>
> From these ratios, some observations:
>
> 1. The engineers are running the same gearbox for a wide variety of
> engine
> power outputs. If you include the A/C, the WBs and the SA I4 and
> I5's in the
> group, the final drive top gear ratios run from 3.73 to 4.11. In
> this group,
> the strongest engine pulls a 4.11 and the weakest pulls the 3.89.
> The range
> in power is a factor of 2.4x! Of course, the old A/C engine makes
> its torque
> max at 3000 rpm, while the SA I5 makes its max at 4500 rpm. Of
> course these
> gear ratios don't begin to relate to the differences.
>
> 1a. Two possibilities - A). These are the same engineers that placed
> the
> heater fan in the observed relationship to the dash. or B). They are
> running
> at cruise with nearly the maximum load the engine can pull.
>
> 2. All the gear ratios give a first gear pull of about 20 to 1. It
> is hard to
> start this box from a standstill.
>
> 3. Typical engine and gearing practice is to engineer a 4 speed gear
> box with
> upper ratios such that you can shift from 4th to third and hit the
> torque max
> at speeds around 60 mph so there is strong thrust for passing. Not
> possible
> with these gearboxes which give a 50 percent rpm drop from 4th to
> 3rd (4
> speed) or 35 percent for 5th to 4th.
>
> So, I return to my former statements:
>
> 1. The wheel thrust values are as I have given them in the previous
> post.
>
> 2. Acceleration from any speed is a direct function of the number of
> pounds
> of thrust you have available above and beyond the amount you expend
> to
> maintain the current speed.
>
> 3. Lifting the vehicle up and over any grade encountered will come
> out of
> your thrust reserve. High reserve, climb a 5 percent incline without
> slowing
> at your chosen velocity. Low reserve, make that a 0.5 percent
> incline, or
> drop a gear.
>
> 4. Major impact on longevity is load, not rpm in this range of
> piston speeds.
>
> 5. Fuel consumption is function of load, not just rpm. 8 percent
> less fuel
> for 40 percent lower rpm.
>
> 6. For modest power/torque conversions the DZ is good, the DZ with
> 215/75x15
> wheels or the DM is a fair alternative. The 1.8L I4 engines with a
> DK trans
> will be about as swift as the 1.9L WB when not running on
> water/glycol vapor
> mixtures, the TIICo with the 4.83 r&p will go like the 2.1 wb it
> replaced.
> Put those I4's in the DZ, DZ and 15's or the DM and you will have
> substantially more thrust available than the running 2.1.
>
> 7. Thrust is fun.
>
> 8. Spending money on overpriced conversions is painful.
>
> 9. Assuage pain with pleasure (er fun)!
>
> 10. Masochists convert and go slow as stock.
>
> 11. With higher power and torque reserves, go for the 4.11 overall
> or the
> 3.89.
>
> 12. Frankly, I took the maximum speed I wanted (100 mph), divided by
> the
> engine redline (6300 for the normal I4), the tire revs per mile
> value, and
> the gear ratio in fourth to determine the best ratio for me.
>
> 13. To each, his own view of the real world!
>
>
>
> Mark >>
>
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