how to increase maximum speed?

[carrizog60]

get a tach

[arsenicpants]

From a safety standpoint this isn't a good idea for driving down the road at 120 kph, but If you could run it off a container of fuel instead of the tank that would work to rule it out.. Does the engine seem to rev up to a certain point then poop out at the speeds mentioned, or can you push it any further(even though it sounds like it's screaming already at that point)

I might try that, just hooking up an auxiliary can to it and see how it runs, that's a good idea
It does seem to just hit a wall at 120, and I can accelerate from 90 to 120 very quickly, but as soon as I get there it's like "aaaaaghhh!! Ok that's enough no more!!" I 'can' push it to a higher rom and maybe to 130, but it gets there very very slowly and at that point it just sounds and feels like the engine is really working waaaaay too hard and it's going to poop a brick or something

Since it has been 2 different pumps, I kinda *suspect* that isn't your problem. 2 difference engines can sort of rule out timing too, but it can't hurt to check..  Timing retarded would make it start like crap too..

It starts instantly every time, and only shudders a little after starting if it's been sitting outside in te cold for a long time

Are you absolutely sure you have a 7a trans??  Another thought, although incredibly rare and odd, how's the exhaust look?  Does the muffler have anything rattling around inside?

The old transmission was a 7A, that's what the case said
I was almost positive that the 5th gear had been swapped out for something much worse at some point in it's life, but this new FN is exactly the same thing, Only a slight bit better, so I've kind of ruled that out
The exhaust is brand new 2.5" straight back with no muffler and a TT downpipe

get a tach

I've got a CE1 diesel cluster with a tach sitting on my shelf, but I think it's worth more to someone in the states than to me, so I haven't cracked it open yet
I may get brave, or stupid, one of these days

I'm away from home now but will try the suggestions when I get back monday
Thanks

[VW Smokr]

Check your IP timing & make sure the cam hasn't slipped back / retarded a bit, due to cranking on the tensioner pulley or something during the final tightening process. That could definitely have a negative effect on higher-RPM power output.

Rumor has it that the wider tires also really add a lot of friction.

[With 195/60-14, my 1.6n.a. Dasher wagon (2400lbs) hits 4000rpm (110MPH) in 5th gear (0.60 ratio), and it's still pulling very strongly, with quite a bit of travel left on the go-pedal. Unfortunately that's just running with the maniacs in morning commuter traffic, not on a closed course, so IDK what the actual top speed really is. I normally cruise @ 65MPH in 4th gear (0.77 ratio) for better fuel efficiency, safety, and less chance of police intervention, jail time, etc.]


J.R.
SoCal

[macka]

I can easily surpass the 110 KM mark, I'd say timing was the issue. When I first purchased my jetta it was really sluggish, turned out timing and a pinched tail pipe were the culprits.

[burn_your_money]

Are you getting full throttle on the pump when your foot is to the floor?

[ShoulderMan]

I had this same problem,  but mine kept getting worse,  I went from good, to wheres my power, to... i can only go 65mph? 

  My problem was the throttle cable, it somehow managed to loose a clip or re adjust its self. (on the injection pump) I was only getting maybe 3/4 pedal,  This afternoon it went to maybe 1/4 pedal, and by then (only able to go 55mph) I had had enough, thats when i could see the throttle cable pull out of its place with the hood up. I bought a crimp and crimped one side down, and re clipped the threaded side

Try adjusting it and see if that helps,  only takes half a minute to do, and it might give you that extra inch of adjustment that you need to increase the fueling on your IP.

It made mine blow smoke and peg the boost guage at 20psi, I had to turn my smoke screw back to stock, and it still hits 15+psi on a hard pull.

Hope this helps

-Ron
 

[DieselBalz]

185/60/14
AVX
Pump good timing set less than 3000 miles ago with new belt
Throttle cable good, pulls good for the Eco (from what I gather)
Tire pressures checked, rolls well (40 psi all around)

I do not like to drive over 65 as it is rolling at 4900/5000rpm at that point.(I cringe at the thought of all the times I ran it at 70mph on the interstate before I got the tach) I have been reading about the different types of transmissions and have located a turbo diesel way down here in FLA sitting in a quiet corner of a junkyard. I am actually going to check the trans code tomorrow. (Crossing fingers for ASF)

Using the Scirocco rpm calculator, I ran the numbers and they are not matching what I am running. Plugging in my tire size and the 4.25/.75 final and fifth, the calculator says I should be running at 3062 rpm and I am almost 2000 rpm above that. Than I played around with the final and fifths that were on the similar trans codes and when I matched 4.25 to the 1.26 of the 16v motorsport I came within a hundred revs of what I am actually doing.

Could something else in the drivetrain, say maybe a worn clutch or smaller diameter flywheel, cause my numbers to be so off? Or did I happen to get the uber 16v motorsport tranny by sheer luck?

(Also hoping this helps OP in some way)

[Vincent Waldon]

2000 extra RPM sounds well beyond the range of normal differences in tires etc..where did your tach come from... and how was it calibrated?  

[DieselBalz]

VDO Vision from summit on the W terminal. Timing light. (Its awesome having a friend who drives a SnapOn truck) and your post on a thread about the switches which was spot on btw.

[Vincent Waldon]

Hmmmmm...there goes that theory. 

[DieselBalz]

I was hoping Obi VWan would theorize a little more than just the tach! 

You thought I got a Sunpro and winged it didnt ya?

[theman53]

Do you have any other trans to try? Flywheel would make no difference. A slipping clutch would, but it wouldn't be consistant. The AVX is probably the worst trans to have and maybe someone messed with the gears in it.
Does it pick up amazingly fast? If you are running that low of gear I would get another trans and keep that as spare.

[R.O.R-2.0]

Do you have any other trans to try? Flywheel would make no difference. A slipping clutch would, but it wouldn't be consistant. The AVX is probably the worst trans to have and maybe someone messed with the gears in it.
Does it pick up amazingly fast? If you are running that low of gear I would get another trans and keep that as spare.

OH YEA! that thing should take off like an 8th mile drag car with an AVX in it..

[DieselBalz]

I dunno about a drag car but it revs up fast, I am shifting outta first before the speedo reads 10 mph. 3rd comes at 30, 4th at 40 and I can run fourth up to 50/55, and than top out at 70 max rev. But I hold off at 60-ish.

I found an ACH and an ACN at the junkyard I hit today. Now I just need some time off to pull it. Looking at the Gear Up site I think I am gonna snag the ACN.

This junkyard is awesome. Hundreds of air cooled of all types, Ghias, 412, Sambas, couple of "Things". Also has a good amount of water cooled Mk1-3. Jettas, rabbits, golfs, quantums, vanagons a few passats. I took a bunch of pictures. Ill be posting it up soon. It has a Diesel Jetta Coupe sittin there motor and all!

[arsenicpants]

i built and tried out a little fuel tank for the jetta today to bypass the regular tank & hard lines
at first it seemed that it made all the difference; in the first block of driving i could take it farther in all gears (60k in 2nd!) but as i drove it it seemed to go right back to the way it was before. i took it out onto the freeway after a few minutes of street driving and it still stopped short at 120km/h, pushing it
but really, i did notice a difference at first
also, the engine seemed quieter, and the turbo didn't seem to be working as hard all the time

I had just the fuel inlet to the pump hooked up to the extra tank, not the return (the return still went to the stock tank), and i had the extra tank venting from the top
could this be why? somehow? is the tank pressurized by the return?
i looked under the car at the lines and it looks like one of them is smushed a little. i remember driving over a giant rock ages ago, that must have been when it happened
the tank looks fine, clean and dry, although i realise the inside could still be gross. I'll have to pull off the cover and have a look inside
i've decided i'm going to buy new hard lines and redo them, even if that's not the problem. it's cheap enough to do

i haven't tested the timing yet, although it starts up easily even when it's a little cold, could it be too far advanced?

thanks for the help