Ideas ? ? ?

[doonboggle]

Before I forget about it again, SURE IS GOOD to see the forum back online again.  I was having serious withdrawal pangs....

Would like some ideas with this.  I 'just' got my 81 pickup 1.6L diesel back from the VW shop in Carson City ... not dealer ... that's Lithia in Reno ... and DEFINITELY WOULD NEVER USE THEM FOR ANYTHING !!!

Anyway, reason for having George do the work was primarily the timing aspect.  While I have the tools ... gauge, etc ... have not yet done it ... yet ... on my own; am a bit skittish.

Before taking it to him, I had removed the IP so that could remove defunct a/c unit items, and also to replace the alternator so that I could install the tachometer ... which by the way, is working WONDERFUL !  George ... rabbit guy for last 40 years ... said he had never seen a tach in a diesel 81-84 rabbit.  YAHOO !!

Prior to hauling it in, I had tested the mpg and was getting a good 52 mpg for a 26 mile r/t ... 2 times.  Recall, as best I can, that I likely was in the 55 mph range ... but not certain.  Anyway, that's when I had the brakes sieze up ... and wound up replacing many of the parts ... and rebuilding the system as best I could.

BUTTTTT .... now, on way home from shop, at a range of 55-60 ... rpm in the upper teens (per tach) ... and 'mostly' 60 mph ... with 2 notable hills of about a 5% grade ... average mpg was little less than 40mpg ... in 5th gear most of the way.  Roadway, other than the hills mentioned ... mostly level and flat.

BUMMER !!!  Was in hopes to be closer to the 50 range.  What I had done, when I reinstalled the IP and timing belt, etc., simply used the 3 marks on the pump, mount and sprocket as timing; thus the 52 mpg ... and a bit of rough running.

Sooooooo ..... to try and avoid the 'rough running', but to try and get a better mpg reading, what should I consider.  $$$ are difficult to spend, am on SSI retirement ... so hopefully simple 'dummie' things ... for this 'dummie'.
doon

[Henchman]

Little off topic, but are you sure your RPM gauge is running right?  Less than 2k rpm at 60mph seems low.  How tall is your 5th, or are you running bigger tires?  At that speed I would be at least 2500 rpm, and I have a .75 5th.  Have you gps'd your speedo to see how far off it is?

Ian

[doonboggle]

Well ... you got me there.  Did no adjustment to the DSL-l ... when saw idle was in the 800 range.  Also, floorboarded ... when getting close to 3,500 rpm ... really struggling.  Less than 2000 was more in the 55 range ... if I said 60 ... sorry.  Tires same as what was there before ... and do not look oversized.

No to the gps ... but did clock it in our 06 Jetta, which is adjusted for 5mph. ... slow side.

Little off topic, but are you sure your RPM gauge is running right?  Less than 2k rpm at 60mph seems low.  How tall is your 5th, or are you running bigger tires?  At that speed I would be at least 2500 rpm, and I have a .75 5th.  Have you gps'd your speedo to see how far off it is?

Ian

[R.O.R-2.0]

floor boarded it should turn like 4800 free revving. and you prolly gotta tune the  DSL-1 for your particular setup..

[doonboggle]

I'm hesitant to try and change it any at this point. 
Why ?
With the nearly 3500 rpm as mentioned ... (as I recall), ... in the 65mph range, it appeared to be starting to stress the engine somewhat ... so backed off to avoid harming the engine.
Plus, not being near the top of the speedometer ... am not sure it is off that much.

Am wondering what others with the 1.6L engine, who have tachometers, are getting at specific mph readings.  That would give me a bit more guidance.
TIA

floor boarded it should turn like 4800 free revving. and you prolly gotta tune the  DSL-1 for your particular setup..

[8v-of-fury]

floor boarded it should turn like 4800 free revving. and you prolly gotta tune the  DSL-1 for your particular setup..

To the floor in neutral with absolutely no sort of governor mod done, the engine will spin 5350 +/- 50 RPMS on stock pump.

I drove my 1.6 n/a hard, and was rewarded with outstanding numbers. 45+ for hard highway jaunts... like 140km/h avg speed.. which woulda had me cruising at 3460 RPMS.

I also have one of the tallest geared 020 transmissions. FF/FN, the next highest being only 200rpms taller.. and under 2000 rpm for me in 5th is 50mph and less.. No way you were doing 55-60 and under 2000..

[Vincent Waldon]

Yup, your DSL-1 most likely requires calibration... the factory will have had no idea of your particular alternator pole structure, pulley diameters, etc.  Because it's a linear line it may look OK around idle but can be way off at highway RPMs.

You can figure it out with math:  RPM = (MPH X Gear Ratio X 336) / tire diameter

This chart has the VW gear ratios and also the required calculator built-in:

http://www.scirocco.org/gears/

[doonboggle]

Thanks.  That helps.

Do you know what rpm is at speeds of 40 mph and 60 mph in 4th gear of a 5-speed tranny?

If I knew that ... as the DSL-1 guide mentions ... would like to give it a try on the road, rather than in garage.  They provide a guide that hopefully I can decipher ... which so far seems to be written in Dutch for me ... a simpleton.

And yes, the pickup is a solid non-altered version; with the 1.6L and the 5-speed.

TIA

floor boarded it should turn like 4800 free revving. and you prolly gotta tune the  DSL-1 for your particular setup..

To the floor in neutral with absolutely no sort of governor mod done, the engine will spin 5350 +/- 50 RPMS on stock pump.

I drove my 1.6 n/a hard, and was rewarded with outstanding numbers. 45+ for hard highway jaunts... like 140km/h avg speed.. which woulda had me cruising at 3460 RPMS.

I also have one of the tallest geared 020 transmissions. FF/FN, the next highest being only 200rpms taller.. and under 2000 rpm for me in 5th is 50mph and less.. No way you were doing 55-60 and under 2000..

[vanbcguy]

Thanks.  That helps.

Do you know what rpm is at speeds of 40 mph and 60 mph in 4th gear of a 5-speed tranny?

If I knew that ... as the DSL-1 guide mentions ... would like to give it a try on the road, rather than in garage.  They provide a guide that hopefully I can decipher ... which so far seems to be written in Dutch for me ... a simpleton.

And yes, the pickup is a solid non-altered version; with the 1.6L and the 5-speed.

TIA

Problem is there's a gobload of different 5-speed gear ratios.  The final drive ratio has a pretty big range, and there's a ton of different 2nd/3rd/4th/5th ratios.  Pretty much 1st gear is the only thing that's the same across all the 020's.

If you find the code stamped in the bottom of your transmission you can look up the gear ratios on the chart linked to above... That will let you sort out what your RPMs will be.  Without it you could be anywhere - you could have a gasser tranny that's geared really high, something somewhere in the middle or a proper diesel tranny that's geared much lower... Difference in RPMs at highway speed is as much as 2500 RPM.

[doonboggle]

First thing I want to do is to say THANKS to those that are responding.  It is evident that I am a 'dummie' in this venue, and that you fellows are far more sharper than this old 'phart'.  THANKS !!!

Regarding the floor boarding, the RPM gets up just a scoch shy of the 5K level ... which is where I was pretty close to the other day when on the road, and backed off to  not harm the engine.

Next, regarding the tranny, it is a FF version, which is the 3rd item on Vince's chart; FF01-120

Then the tires are 170/70/13.

Soooooooo ... based on one of the advisories of above, with the 5K reading with pedal floored, does that negate my earlier statement that in 5th gear, I was getting something near the 2K at speeds in the 55mph range?

If so, if anyone has the DSL-1 and have adjusted it, sure could use some guidance here.  Looking at Dakota's guide, I get lost...

And finally, how does Vincent's chart come into play if'n the DSL-1 is adjusted?

Thanks.  That helps.
Do you know what rpm is at speeds of 40 mph and 60 mph in 4th gear of a 5-speed tranny?
If I knew that ... as the DSL-1 guide mentions ... would like to give it a try on the road, rather than in garage.  They provide a guide that hopefully I can decipher ... which so far seems to be written in Dutch for me ... a simpleton.
And yes, the pickup is a solid non-altered version; with the 1.6L and the 5-speed.
TIA

Problem is there's a gobload of different 5-speed gear ratios.  The final drive ratio has a pretty big range, and there's a ton of different 2nd/3rd/4th/5th ratios.  Pretty much 1st gear is the only thing that's the same across all the 020's.

If you find the code stamped in the bottom of your transmission you can look up the gear ratios on the chart linked to above... That will let you sort out what your RPMs will be.  Without it you could be anywhere - you could have a gasser tranny that's geared really high, something somewhere in the middle or a proper diesel tranny that's geared much lower... Difference in RPMs at highway speed is as much as 2500 RPM.

[Vincent Waldon]

Do you know what rpm is at speeds of 40 mph and 60 mph in 4th gear of a 5-speed tranny?

That is what the chart is for. 

Plug in your tire size (170, 70, 13), the final drive (3.89) and 4th gear (0.97) ratios of your FF transmission, and the chart tells you that:

40 mph = 2267 RPM
60 mph = 3401 RPM

At 55 mph your tach should read 3118 RPM... so if you were reading in around 2K you can see that your DSL-1's calibration is off quite a bit.

Adjust your DSL-1, per the instruction manual, until your tach reads correspondingly at one of those speeds.  For safety sake obviously it's best to make this a two person job... hopefully the manual is smart enough to recommend that as well.   

[doonboggle]

Vince:  I'm missing something here.
Referring to the calculator link you provided earlier under the scirocco title, here is what I come up with.  the data is laid out following the calculator as presented for the FF 81 tranny code' 5th gear.
WIDTH= 170
SIDEWALL RATIO=60
RIM SIZE=13
FINAL DRIVE=3.89
GEAR RATION=.71
Under option #2
SPEED=55
MPH=2427

Your calculation used a different 5th gear number, and also 4th gear ... but could not fiddle with those numbers to come up with the 3118 you show.  What have I done incorrectly?
TIA

Do you know what rpm is at speeds of 40 mph and 60 mph in 4th gear of a 5-speed tranny?

That is what the chart is for. 

Plug in your tire size (170, 70, 13), the final drive (3.89) and 4th gear (0.97) ratios of your FF transmission, and the chart tells you that:

40 mph = 2267 RPM
60 mph = 3401 RPM

At 55 mph your tach should read 3118 RPM... so if you were reading in around 2K you can see that your DSL-1's calibration is off quite a bit.

Adjust your DSL-1, per the instruction manual, until your tach reads correspondingly at one of those speeds.  For safety sake obviously it's best to make this a two person job... hopefully the manual is smart enough to recommend that as well.   

[Vincent Waldon]

Well, you've used a different tire ratio and are using 5th gear rather than 4th, so the numbers will be different... your initial post said 170/70/13 tires and was asking for speeds in 4th gear at 40 and 60 mph.

If I punch in your most recent numbers I get the RPM you got.. so you're using the tool correctly... carry on!

[R.O.R-2.0]

arent tires like 1X5 (185, 175, something ending in a 5) ive never seen 170/70/13s