16v Digfant II FAQ

[cdn20VALVE]

oil pressure sender is in the back of the 16v head. I like to know what the pressure is in the head, rather than the oil flange anyways.

[MBRACKLIFFE]

This is a good point made by cdn20valve so I thought I would elaborate further.

If you are using an oil pressure guage your best bet is to mount the sensor in the head since this will be the first place that signs of an oil pressure problem will surface.

If you are relying on the oil pressure warning light on the dash than I suggest moving your low oil pressure switch which is normally mounted on the oil filter flange up to the head so you will have more time to pull over and shut the car off.

I think there is a sensor that can function for both setups at the same time as well and this of course should be mounted in the head.

also of note is that sometimes an oil temp sensor is mounted in the head and the low pressure sensor is mounted on the flange so it would be a good idea to switch them.

[BOOFWAH]

So IIRC there are two, high and low, oil pressure switches (for the dash light and wonderful sounding buzzer), an oil pressure sender (for the gauge), and oil temp sender (for the gauge) that have to be carried over from my 2H motor to the 9A. The oil pressure gauge sender is large and is in the side of the 2H head. Am I going to be sacrificing a feature here such as oil temp or gauge pressure to keep the buzzer and warning light from flashing? If a cabby owner could be specific about where all these little bits go I would appreciate it.


Modified by BOOFWAH at 8:21 AM 11-10-2004

[rychas1]

i just noticed something very odd. my gas mileage sux stinkin rocks! i mean, i burned a quarter tank in 50 miles? and no, i was not racing nor driving fast. i know manuals get better mileage than autos, but my god. my o2 sensor is good as far as i know, so what else could it be. or am i just SOL (trading speed for economy)? wouldnt my digi2 still gimme good mileage?

[cdn20VALVE]

Yes. The biggest culprit for gas mileage depreciation on digi2 would be and is the 02 sensor.

Test it out, and if it is not per specs replace it.

[CharlieBaltimore]

Hey this is a great thread very helpfull I'm doing a swap 1.8l 16v into a 8v 89 GL just got the 16v from a friend with the tranny and i was wondering if anyonehad (I have an 89 gl swapping 85 GLI 16v)

done the 16v 1.8l swap?

had any advice on swaping trannys?

know any good threads that had advice or info on tranny swaps (from 8v tranny to 16v tranny?

Any help apreciated keep on dubin

[cdn20VALVE]

8v tranny to 16v tranny? Just make sure you use the 16v clutch disk, as the 8v clutch disk won't fit the input shaft.

Of course 16v pressure plate is highly recommended.

[Killingcivics]

Now heres is a big question, my setup is in works great idles at 830 rpm smooth and fine, but what can I do now to modify it. what are my options? bigger mass air flow,cams? I need more bang for my bucks . Its fast now but its gotta be faster

[MBRACKLIFFE]

One of the things that I have found during this swap and driving the car with this setup is that the 16v in general runs much hotter than my 8v ever did so this led me to thinking about the Digi2 system and how it would react to these higher temperatures.

As we all know the Digi2 ECU is heavily reliant on the Coolant Temp Sensor.
In fact the Digi2 ECU makes most of its fueling decisions based on the input from the CTS, (as well as the VAM and intake air temp sensor ).

The Ignition is also is influenced by the CTS which brings me to what i wanted to talk about.

Think of this... when your motor is hot then so is your cylinder head and combustions chamber's. When the motor is hot their is more chance of preignition and pinging. The CTS senses this heat and tell's the computer and ignition to retard the timing to prevent this, as well as leaning out the fuel mixture.

Another way to think of it is that when the knock box hear's something bad it retards the timing.

So in conclusion: Hot motor equals retarded timing and lean running.

I highly recommend the use of a lower temperature thermostat and lower temp radiator fan switch to keep the motor cool and running strong. Another often overlooked sensor is the fan afterrun switch which tells the fan to come on when the car is turned off and the underhood temperatures are high. If this switch is not working it can cause hot start problems caused by heat soak.

I have heard that redline water wetter destroys VW water pump seals however I have never tried it so I can not say if that is true.

On another note I have been toying with a device for Digi2 that will control the signal from the CTS and give us some adjustability in terms of the air fuel ratio. I have tried adjusting the VAM spring but I am more interested in something that can be more easily adjusted for tuning purposes.

I will update you when I have tried a few of my ideas.

[cdn20VALVE]

I find that my 16v set up runs colder than my 8v.

I do have a colder thermostat and the factory oil cooler installed.

I am anxious to hear about your results, however, I had my car on a emmision testing machine, and with stock settings on digi2, I was getting an average of 14.9:1 AFR at idle. Not bad at all.

[MAFGTI]

Here is my setup but for next summer i'll be running some DCOE 45

I Was using an BMW535i MAF

Modified by MAFGTI at 4:53 PM 11-27-2004


Modified by MAFGTI at 5:04 PM 11-27-2004

[Fast929]

Very interesting. Looking like the cross section is a good bit larger. Wonder how that would work with the digi2 setup? Not sure how it would calibrate with the stock ecu...??? Maybe something SNS could work into their prom.

Have to let us know how it works out. Working on the same setup....

[MBRACKLIFFE]

There has been an extensive posting on the BMW VAM swap so I thought I would post the link.

http://forums.vwvortex.com/zerothread?id=1052915

There is also some more info on the swap in the 8V FAQ, look for the post by digiracer.

http://forums.vwvortex.com/zerothread?id=1019859

[CSDis4lovers]

just curious here as to the right ecu to use for the setup. I do not know if it matters, or i have overlooked this on a previous post. I was always led to believe digifant cars with dual outlet downpipes, and the three wire 02 sensor, such as the 1990-1992 8v GTI had different ecu's then say the same year gl jetta's and golfs with the single downpipe. Even if this is the case, I am wondering if it has any barring on the swap.

Great thread, I have really enjoyed this. Always wanted to venture into the world of a 16v digifant equipped car. And bump for being local

[veedubinit]

awesome question, i wasnt aware of a different part number for dual downpipe applications. actually, we were swapping parts between a single downpipe 1990 golf and a 1992 gti. part numbers matched at least the comp did. Bump for more info.

[CSDis4lovers]

i could be wrong. but as memory serves me correctly. i have had numerous 8v digifant vw's. one was a 90 coupe that i installed with a dual outlet downpipe, manifold and three wire 02 sensor. car acted totally different, so much i had to unplug the new 02 sensor, which led me to believe the ecu was different as to one with the freer-flow exhaust system and the more retrictive version. again, i could be wrong, but curious if someone could answer this.

[veedubinit]

Interesting, we noticed no difference. Bump for answers

[CSDis4lovers]

also a couple more questions. again forgive me if i missed these in previous posts. the injectors. I know the stock digifant ones can flow a fair amount of fuel, but wondering if the corrado ones gave any sort of advantage, (if people have used these with the digifant 2 setup). and as to the cooling issues with digifant. I assume a lower thermostat, if not simply a lower temp fan switch may help these problems.

My ultimate question would be the idea of tuneability, as in squeezing as much hp, and torque out of the 16v with digifant 2. being that their is a plethora of digifant 2 jetta's and golf's in the junkyards, this is obviously a plus, but wondering if on a longterm hp/torque goal with: a free flow exhaust, mild-upgrade cams (maybe a set of 260/268), simply intake mods, and of course a boast through the ecu(you have talked about vw_pilot, what about the AMS digiprom?)

again, cheers for a great topic being discussed here! tempting to try a "junkyard resurrection" with a salvage vw (namely a 4 door golf) and maybe a passat 9a block and head.

[E60]

Quote, originally posted by mrkrad »

This part isn't completely required.

I fabbed up one of these and threw it on and it was leaking a bit. I just shaved a little corner of my harness plug off and it works perfectly.(you have to remove one of the unused sensors on the head.)

Modified by E60 at 12:14 AM 12-16-2004


Modified by E60 at 2:12 AM 12-23-2004

[rychas1]

Quote, originally posted by tibz23 »

also a couple more questions. again forgive me if i missed these in previous posts. the injectors. I know the stock digifant ones can flow a fair amount of fuel, but wondering if the corrado ones gave any sort of advantage, (if people have used these with the digifant 2 setup). and as to the cooling issues with digifant. I assume a lower thermostat, if not simply a lower temp fan switch may help these problems. My ultimate question would be the idea of tuneability, as in squeezing as much hp, and torque out of the 16v with digifant 2. being that their is a plethora of digifant 2 jetta's and golf's in the junkyards, this is obviously a plus, but wondering if on a longterm hp/torque goal with: a free flow exhaust, mild-upgrade cams (maybe a set of 260/268), simply intake mods, and of course a boast through the ecu(you have talked about vw_pilot, what about the AMS digiprom?) again, cheers for a great topic being discussed here! tempting to try a "junkyard resurrection" with a salvage vw (namely a 4 door golf) and maybe a passat 9a block and head.

i can only talk from experience, as im sure others will add on their wisdom. i didnt pick digi2 b/c i wanted to put down 500hp, it was already in the car (8v) so a natural choice. stock injectors work fine (sure bigger is better, to a degree) but the porsche 3.5 fpr is what really make them cook! having that fuel ready to explode into the chamber when needed is a great sound and feeling. digi2 keeps the car cool, as it doesnt seem to run as hot as CIS cars. all these are stock on my car, no overheating obviously, im not putting down as much tq as others (PL) so i dont get an orgasm until about 3500rpm and this has been discussed repeatedly, but the 2.0 (or aba tall block) and pl 16v head seems to give the best numbers all around. chips (csw, sns, ams, etc.) are all must! it will simply bring the beast even more alive! now, this is mostly a stock engine, so adding cams, exhaust, ignition, bmw maf, injectors, etc...all will simply put u in the back seat. but remember, in the end, digi2 is still economy, so its cheaper, fun, simple, but 500hp maybe outa reach. enjoy!!! (psss...when ppl ask 'hey whats under ur hood, just say sorry economy 8v management system, sux! then...smile and look in ur rearview mirror )

[CSDis4lovers]

thanx for the info. and no, never wanted to put down 500 hp, never wrote it. I understand the cheapness/economy of digifant II, which is why it sounds enticing. I was hoping 180 would be reasonable, and seems so. thanx again for the help.

[rychas1]

i know. i was just using 500hp off top of my head. no prob.

[GTOBB]

new dyno result

power on crank

[rychas1]

ok u cant repazent a digi2 16v like that without specs. please share!!!!

[GTOBB]

1.8 16v , KR intake 50mm and KR intake cam, 245cc injectors, BMW 735 maf , gti 8v PF ECU + chip , stock exhaust with cat. , 190000km on engine.
I still looking for chip binaries (code) with rev limiter up to 7000rpm

[mrkrad]

didn't i tell you to underclock the crystal on the motherboard?

[MBRACKLIFFE]

Underclocking the chip on the board will raise the redline..? Does this have any effect on the speed at which the processor polls the sensor's for information..?

[mrkrad]

maybe or maybe not. go try it and let us know. might have to beef up the fueling since at 7400 the ecu will think its at 6800rpm right? maybe more fuel pressure to offset the gain given a linear rate of flow (i assume if you rev to 7400 you have cams/etc to make use of 7400). Making noise and not power is lame.

try it, you might like it. The fuel chip can always be skewed over a little to compensate. You want a cheap solution i give you an idea.

[rychas1]

i dont get it. stock (8v) exhaust on my PL engine feels bloated, like it needs to fart (for lack of better term) o it pulls, but i know exhaust is necessary for steady creamings. i know i need 2.25 and the 55mm cat, but how can u push those #'s with the stock 8v exhaust (im assuming). will cams alone make for most of this power? your AFM and injectors will make one heck of a combustion, but how does that much spent air/fuel escape??? maybe im missin something if not....cams for me!

[OhioBenz]

a PL (16v) with 8v exhaust???? no way man! we can even tell the diff on our 8v Digi-2 Jetta running the dual outlet mani, 2.0-16v Cat and 2.25" exhaust..... A stock 16v flows more air than a ported VR6!!! Biggest restriction is the exhaust.

[rychas1]

question for the digi2 16v fokes.....maybe this is unique to our hybrids?

cleaned my ISV, it works (been tested and buzzes like a .... ) so i cant figure out how come everytime (now seems like everyday) i havta keep adjusting my idle screw to prevent the car from cutting off from idling so low. i adjust it (to a nice 950, where it should be, when the car is warm and accessories are off, just like bentley suggests. so wtf is making my idle reset itself below where i set it jsut a few hrs ago??? and y? if i turn the idle screw much more, its gonna be out of the throttle body help help before i bend some metal

[rychas1]

on another note mentiond way long ago (concerning my speedo being too fast)...i was actually clocked by a curbside police radar on at least 4 times this week (going down dekalb ave.) and my speedo said 70 exactly, but he radar read 52-53. so, again, is it my cluster (need upgrade to th 140mph one) to read more accurately, or speedo cable to tranny need changing/ upgrading? yes rememeber, its auto, and im sure i just cant buy an 16v auto tranny cable. any ideas???????

[veedubinit]

I had to take off my ISV because it was not working correctly. The sensor itself worked but with no vaccume leak (tested) it was trying to get the comp to over compensate like 1500 then 900 then 2000 then 500 then 2500 then stall. Soi thought i needed to re-route the vaccume system as i had a T off the main break booster vaccume on the intake manafold. soooooo wheni set up the vaccume like a stock 16v it idled at 1300 for some reason. . i couldnt figure it out .. we tried everything .. thats as low as we could adjust it with the screw. So eventatually i just ripped it off and adjusted it cleanly with the screw. . .it stalls sometimes when its cold (it is winter too) but 1 min of driving and it idles like a dream. If anyone has any ideas for me then they are welcome. . .but my advice is to rip it off and go without.

[freeflow90]

Hi,

Im about to start putting together everything I need for my swap so I have a few questions.

1. Can I use all the 8V motor Mounts?

2. Can I use all the 16v pulleys (car has a/c and I plan to keep it)

3. Will the 8V c.v joints work with a 16v transmission?

Im sure Ill have more!

Click for a larger image

P.s The engine came out saturday

[OhioBenz]

1) Motor mounts - yes
2) Pulleys - yes
3) CV joints - 16v are 100mm, 8v are 90mm

you can either swap the 90 mm flanges over to the 16v trans, or buy the 100mm driveshafts