So, there's a plethora of gearing reduction options available for the Samurais which makes sense due to the total lack of power from the 1.3 but with the ease and availability of engine swaps to overcome this obstacle where are the corresponding gear sets to improve fuel economy and lower rpm at highway speed?

I have a VW 1.6 NA and will be building my tintop to be used as a daily driver, I'm looking forward to the 40~ mpg I'll get but would like to do better than 60mph.  Given the power band differences between the VW 1.6 and the 1.3 I wouldn't be surprised if I actually sacrifice some top speed with the current gearing.  

Obviously I'm looking at the easiest solution of taller tires but as primarily a street vehicle the amount of lift I'm willing to apply is a limiting factor plus I prefer to keep my Sami as stock looking as possible.  I intend to put a set of OME springs and shocks on to provide the necessary safe lift for oil pan clearance but the lift stops there.

Okay, I'm starting to wander off topic... Question, does anyone know of either transfer case or ring & pinion gears to increase rather than decrease?  I haven't been able to find any and call on the collective knowledge of the forum.

Thanks,
J.T.

I'm not aware of any such gearing available in the US.  I guess if you lived where the Suzuki Jimny was sold, you could get a t-case from one of those as I believe it has a 1:1 hi range ratio.

A quick search on the internet says the 1.6NA puts out 52hp and 72lbs of torque.  The good thing is a lot of that torque is available right off idle (chugability is awesome), but still, it is putting out less power than the stock 1.3 engine.  I don't think the 1.6NA could handle too much taller gearing and still cruise at hwy speeds as the power output to the stock 1.3 engine-the power curve is just a little lower.  

Also, the VW Rabbit was a much more aerodynamic vehicle and had less rolling resistance with the little 13" tires compared to the Samurai.  The 1.6NA Rabbit still took about 50 secs to get up to 60mph and that was pretty much the top speed.  Something to consider.  I know this same engine was installed in VW Vans (German market) in the late 70's-early 80s.  When I was in the Army and stationed in Germany, I rode in a few of these vans.  They were painfully slow.

I've heard that the 1.6 NAs are pretty awesome on the trail, but not so good on the highway-they can't handle the continued high revs and tend to overheat.  I would first try the stock t-case gearing and an early .795 fifth gear with 29" tires.

To digress, there is a guy that is somewhat local to me that had 1.9 TD in Samurai.  He was SPOA, 31" tires with stock gearing and he stated that the gearing was pretty good all around.  Although, I don't think he actually did much trail riding-just street cruising.    I think he said he got around 30mpg.  I've only seen him once on the road in the past 5 years too.

Too bad we never got this option in the US.  1.9 Peugot TD.

Few cars get 40mpg, even the new TD diesels with a lot more power you may see mid 40's going 60 all day.

Yes you cannot argue with the torque of a diesel and the crawling ability, but you will probably see mid 30's if you are lucky.

I would keep the stock gearing and run street tires for the best mileage.

I think the realistic mpg will be mid 30s at best with a 60mph top cruising speed. 

If you keep it under 60mph, a Samurai with stock sized tires/1300cc engine will get close to 30mpg.  MPG drops off pretty quickly thereafter due to the unaerodynamic properties of the Samurai. 

Thank you for your thoughts, order of operations will be to install my OME springs & shocks, rebuild my project money, order an ACME kit to install diesel, rebuild project money and then buy tires.  I'll have plenty of time to drive on the current 215/70 set and get a feel for things with the new engine before making any final decisions.  It's unfortunate that there are not more ring and pinion gear options available for the Sami, a 3.07 set with original tires would give me 65mph at 3k rpm and I think the engine could do it.  

Oh well, what will be will be.  I may just put a set of 235/75 on my old CJ wagon wheels and see how that rides with the diesel, I was really hoping to keep the stock 5.5 wheels though.

J.T.

JT,
How do I put this....it really sounds like you don't really have a lot of experience with Samurais-especially with you comment on changing the ring and pinion gears to lower the gearing ratio 17% for an engine with less power than the stock Samurai engine.

I've been driving Samurais for over 20 years.  I learned by working on them and have seen a lot of things done with them.  I still have my very first one too-since 1988.  That being said, I just don't think that the VW Diesel swap is a good choice.  It was somewhat viable 10 years ago when diesel was less costly than gas, but now....Nearly $1,000 for the kit/parts and $500+ for an engine and then more expensive fuel     The 1.6 Sidekick engines are a much better choice for an engine swap.

I also do not think you will be able to cruise at 65|removethispart|@3000rpm with just the 1.6NA.  Here are the specs on that engine:
Max. Power Output
 52hp |removethispart|@ 4,800rpm
 
Max. Torque
 71.5 ft.-lb. |removethispart|@ 3,000rpm

The stock Samurai engine is
64hp |removethispart|@ 5,500 rpm

73.5 ft-lb |removethispart|@ 3,500 rpm

The 1.6na is pretty close to the Samurai engine, a little less torque, but 10 less hp, which means it will be slower than a stock Samurai.  The stock engine can do 65mph with the later .865 fifth gear, but is near top cruising speed with the earlier .795 fifth.  This is with 205/75 tires too.  The 1.6NA, even if it has optimum gearing, probably will not be able to push a Samurai past 60mph.  I also have a 1981 VW Rabbit convertible with a 1.7 gas engine.  That thing is so much more aerodynamic than a Samurai, there is no comparision.  If a 1.6NA diesel barely pushed the Rabbit down the highway at 60mph, it certainly cannot push the Samurai at the same speed.

If the Samurai is not running now, which it kind of sounds like it is not, I would first focus on that.  The 1.3 engine, while not a powerhouse, is a great little engine and has enough power/torque for offroading.  I still run them in most of my Samurais.  You can also install the 235/75 tires on the 5.5 rims.  Heck, I even have some 31" tires on the stock rims.

I think this video says it all about 1.6na VW Diesel performance.

Updated 0-60 in the VW rabbit Diesel

It would be a great little engine for chugging around offroad, but it's not a highway friendly engine.

He really revs the snot out of the Samurai engine, but the acceleration sure does seem a lot less effortless than the VW Rabbit diesel.

Suzuki Samurai Acceleration 10-60 MPH

50 seconds for a 0-60 time in the Rabbit?  That doesn't seem right...  Only 20 for the SJ, must have been on it!

Very new to Samurais but that has little bearing on the topic at hand.  I have up until now had no reason to consider gearing ratios and so am in the process of learning. My reasoning was simple, if swaping engines of comparable power but with considerably different power curves ( the diesel producing its power at lower rpm ranges vs. the gas) it would be logical to adjust gearing to compensate.  I have no doubt that a 1.6na would not perform well at all  in a gearing environment engineered for a small gas engine, who in their right mind would rev a diesel above 4k?  I dont even like to run the existing 1.3 above 3.5 for long.  My approach may be off but my logic is sound, I'll do more homework to view the problem from a more informed vantage. 

On the topic of diesel not making sense anymore due to the shift in cost, well this is a common assumption but false. 
The fuel economy specs for a new 87 Sami were 23 city 27 hwy 25 combined.
A new 84 Rabbit were 33 city 40 hwy 36 combined.
People like to claim that they get 25-30 mpg from their Samis but in a world of mandated ethanol blends you're only kidding yourself, for arguments sake lets give use 25mpg.  I doubt anyone will argue 35 mpg in the 1.6na when some claim up to 45, which I find just as suspect.

The local station I drove by on my way to work had gas for $3.29 and Diesel for $3.69 today:
25 Mpg / 3.29 = .1316 cents per mile
35 Mpg / 3.69 = .1054 cents per mile

The Samurai in question is currently running and I have it tuned for optimal performance. However it's days are numbered.  It recently jumped time and when I opened it up I found the crank timing pully had spun its key, the pully was toast but the crank while damaged wasn't so bad that replacing the key and pully was out of the question.  I know it's only a matter of time before it spins again and I suspect the crank will have to be replaced when it does.

I at first was planning to buy a 1.3 to rebuild in preparation for this eventuality but quickly realized that to do so with performance cam, flat tops and header to squeeze every horse I could out of it would run up around 2 grand.  It became a matter of personal preference to spend my time and cash perusing a diesel replacement instead.  Fuel economy aside I prefer the simplicity and reliability of a diesel.

I hope my points were clear and the writing did not suffer flow problems if so I apologize, I'm writing this on my phone in a parking lot while I kill time in between service calls.

Oh one more thing, just because you can mount 235/75 tires on a 5.5 in rim doesn't mean you should. I can remove 10mm bolts with vice grips but I don't   kidding aside thank you for your thoughts, you've given me many valid points to consider and as a result I will approach this problem much more informed and prepared.

J.T.

How large of tires would you need to go with to get the gearing you want?

Your logic isn't flawed, but the differences in power requirements between a VW Rabbit and a Samurai are quite immense.  They weigh a similar amount, but that's about it.  The Samurai simply needs more power to move it down the road than the Rabbit. Since I grew up driving both vehicle types, (familiy has owned the Rabbit since '81 and the Samurai since '88), I think I can say that with some conviction.  

For a cheap engine, pull a 1.3 8-valve from a Geo Metro Sedan/Suzuki Swift at the pull it yard.  Same block/head as the Samurai engine and you can likely get them for around $100.  Swap over the Samurai stuff on the outside of the engine and you have a cheap engine.  Been there, done that.

If you want more power, pull a 1600 8-valve from Kick/Tracker, but you will also need an adapter kit but it's still a lot less than a diesel kit which starts at $400.  The 1600 8-valve has considerable more torque (93 ft lbs) and hp (80) than the 1.6 NA VW Diesel.  A much better engine choice for a vehicle that will see road use.  

Everything I've ever been told or read about the VW diesels is that they were great offroad, but were downright horrible on the highway.  The local guy with the 1.9 TD spent a lot of time, I would guess at least 50 hours doing the swap.  If I recall correctly, he still had some cooling problems.    

I'd hate to point you towards another board, but this BBS has a great diesel section:
http://bbs.zuwharrie.com/content?board=48.0

After reading all the stuff on this board years ago, I wrote off the diesel as a viable option.  Seem like it needs constant tinkering.  I was really considering a diesel swap at one time (and I might eventually do it for the novelty aspect), but it seemed like the 1.3/1.6 Suzuki engine was a much better choice all around.

Anyways, if you keep the speed below 60mph, a Samurai will consistently get high 20s on 205/70 tires.  Before the EPA ratings were recently revised, the Samurai had 28/29 city/hwy ratings which is actually pretty close to a stock Samurai mpg.  The new EPA rating were supposed to take into account faster acceleration, higher highway speeds, a/c, ps etc, none of which really applies to a stock Samurai...which is still very slow and has no creature comforts.  Again, they didn't actually retest the Samurai, they just did some funky math to come up with the new number from the old.

As far as the stock rims, many people run relatively wide tires on the small rims because it makes it much less likely to blow a bead when you're offroading.  You can really drop the air pressure in them.  235/75 isn't exactly pushing it on the stock rims either.

50 seconds for a 0-60 time in the Rabbit?  That doesn't seem right...  Only 20 for the SJ, must have been on it!

I remember one of the car mags around 10-15 years ago showing off some stats on cars that they had tested over the years.  The VW Rabbit Diesel was the slowest car that they had ever tested.  0-60 in something like 50 seconds. They joked that only VW would sell a car slower than the old VW Beetle.

Here is a picture of my "farm worker" Samurai with 31x10.5 TSL on the stock rims (reversed, new stem location) with 1" wheel spacers.   

How large of tires would you need to go with to get the gearing you want?

From the trolling I've done it looks like 31s are the rule of thumb to make up for the lower rpm range of the diesel, however.  I went back to the gearing calculator and used 31s as a point of ref to find that it provides a 16% decrease, scarily close to my guesstimate of 3.07 gears being optimal for the diesel with stock tires and a connection I had not previously made.  So it looks like I was right on track but the caveat is as Rash so passionately points out POWER and I'm starting to agree.  The common variable between increasing to 31" tires to regain cruising speed with the 1.6 is a turbo which I have been avoiding.

Although it may seem crazy I prefer to stick with the na and look for the optimal gearing to make a comfortable ride but I may end up having to move up to the turbo in the end.  Upshot is that upgrading to the turbo will be relatively simple after having already fitted an na under the hood.

For now, until I find new information that will change my thoughts I plan to run 235s on stock gears(like I have a choice) which will provide a 10% overall decrease.  Maybe it'll be a happy medium.  One thing to keep in mind is that when I say I want to be able to do hwy speed I actually mean hwy and not interstate, if I can't do 80 I won't even consider getting on an interstate.  So if I can hit 55 without feeling like I'm spinning the engine to an early grave that will be acceptable.

J.T.