Project Potential... variable vane turbo on 1.6l

[TDIMeister]

If it's got an otherwise stock 1.6 TD pump, I'll start the wager at around 70 hp

[fspGTD]

OK guys - the initial test results are in!

Brendan - yeah this thing is a sleeper.  No outside hints distinguish it from a lowly 52 crank hosepower 1.6l NA!  

TDIMeister - if your 70hp guesstimate is wheel horsepower, I'd say you are right on.

To start off, I weighed the car at the local dump: 2140 lbs w/ driver and 2/3 tank of fuel.  Since I weigh about 150lbs, the car without anything inside it and a dry fuel tank is definitely less than a ton.

I G-tech'ed five HP and torque curve test runs.  I threw out one where the power was "off" (I think it may be something heat related - either hot fuel, or air intake)  The other 4 results are plotted below.  Note that these results are uncorrected, although I figure that the dyno correction factor during the tests was .997 (very close to 1).


Keep in mind these are G-tech figures - different from chassis dyno results in that there are aero drag losses.  These figures are not bad at all!  To compare with a stock 1.6lTD, check out the fist post on this thread (thanks malone!): http://www.vwdiesel.net/phpBB/viewtopic.php?t=1352

The peak hp of the 2nd gear runs was 61.6-64.3 hp @ 4250-4300 RPM.  Peak Torque of the 2nd gear runs was 88-91 ft-lbs @ 2600-2700 RPM.

All the runs were done in 2nd gear except for the blue plot, which was in 3rd gear.  I kept mainly to 2nd gear because the speed range was much safer for the zone (25mph) I was doing the tests in.  4500 RPM is 42mph in 2nd gear, but it is 70mph in third!  :lol:  Anyway the extra aerodynamic drag in 3rd explains why the horsepower figures for the blue plot are lower.  But also notice on the 3rd gear run because I shifted straight from 1st to 3rd the engine was tested in a lower RPM range, and also with the extra load you can see the turbo had more of a chance to spool up making more torque right above 1500 RPMs.

Although the VNT is already putting out a beefy torque band noticeably extended into the lower RPMs versus say a stock 1.6lTD, I think it is capable of being tuned for even more torque down low, since on this iteration of how it is set up, it starts closing the vanes probably as early as only 3 or so PSI.

I also did one quarter-mile acceleration test on a long flat stretch.  For whatever reason, subjectively, I wasn't happy with how the power felt on this test, IE: engine power seemed "off".  I think since I was idling it for a while at a stop before I launched, it might have heat soaked a bit.  Also I got a little excited and chirped the tires both at launch and on the 1-2 shift.  :oops:  Probably doesn't help that these are only 5" wide rims!  :lol:  So anyway it definitely has more potential at current state of engine tune, but the results should at least be "ballpark" of where the car is at right now:
  1/4 mi: 17.2s @ 77.7mph (OK, not stellar though...)
  60 ft: 2.52s (this probably isn't too great...)
  0-60: 9.85s (under 10 seconds...    Cool!)

[TDIMeister]

TDIMeister - if your 70hp guesstimate is wheel horsepower, I'd say you are right on.

Yes, my assumption was based on whp    realizing that the method of testing would be either a G-tech or a chassis dyno, and I am not a fan of correction factors and driveline loss calculations, which I feel are often applied too liberally.

That is a beatiful torque curve, Jake.  What impresses me is the so-called 80%-rule, which looks at the RPM spectrum at which 80% of peak torque and 80% of peak HP are produced, and the RPM ratio relationship of the two peaks.  By eyeballing your graphs, it appears to me that you have at least 80% of peak torque between 1500 RPM all the way to redline, and 80% of peak HP from 3000 RPM onwards, and the RPM spread from peak HP to peak torque is 1700 RPM or a ratio of 1.65 (4300/2600).  From an engine benchmark standpoint, those are AWESOME numbers!!!

Congrats on the pioneering work!  I look forward to seeing what your next plans are for this engine!

[lord_verminaard]

TDIMeister - if your 70hp guesstimate is wheel horsepower, I'd say you are right on.

Yes, my assumption was based on whp    realizing that the method of testing would be either a G-tech or a chassis dyno, and I am not a fan of correction factors and driveline loss calculations, which I feel are often applied too liberally.

That is a beatiful torque curve, Jake.  What impresses me is the so-called 80%-rule, which looks at the RPM spectrum at which 80% of peak torque and 80% of peak HP are produced, and the RPM ratio relationship of the two peaks.  By eyeballing your graphs, it appears to me that you have at least 80% of peak torque between 1500 RPM all the way to redline, and 80% of peak HP from 3000 RPM onwards, and the RPM spread from peak HP to peak torque is 1700 RPM or a ratio of 1.65 (4300/2600).  From an engine benchmark standpoint, those are AWESOME numbers!!!

Congrats on the pioneering work!  I look forward to seeing what your next plans are for this engine!

Ya, I was going to comment on that too.  ANY engine builder in the world would kill to have a torque curve like that.  You were right about it matching up with the 4-speed well.  Even with an added intercooler you'd have more peak hp and torque, but with the same long flat curve.  That's killer.  I dont think the TDI's can sustain torque that long!  

Gives me plenty of ideas for my project...

Brendan
84 Scirocco 8v
00 Camaro L36 M49

[TDIMeister]

[...I am not a fan of correction factors and driveline loss calculations, which I feel are often applied too liberally.

I thought there might be interest to discuss a lengthy missive I posted a while back about the prevailing method of applying driveline loss calculations, that is, a fixed 10-15% figure.

http://forums.tdiclub.com/showflat.php?Cat=0&Board=UBB4&Number=708003

I suggest this whole thread be archived

Hope I'm not hijacking your thread, Jake.  :oops:

[fspGTD]

I also find it interesting to compare the 1.6VNTD dyno results to my Rabbit 1.6lTD autocrosser's:

The GTD autocrosser has a bunch of differences... < 1800 lbs, different gearing... but probably most relevant influencers to the dyno plot are it has the factory Garrett 1.6lTD turbo with factory 9-10 psi boost pressure (as required by the racing rules), more fuel injection mods, and an intercooler.

Taking a closer look at the RPMs, the 1.6VNTD has more torque than the 1.6lTD in the 1500-3000 RPM area.  When the factory 1.6lTD Garrett sleeps, the variable nozzle turbo is awake!

-----------------

I originally started this thread to determine whether it would be feasible to adapt a VNT turbo to an IDI VW Diesel to work without an ECU.  I think that is pretty well established now.  Although I don't have any reason to think the fuel economy would be bad, (in fact I think it is actually going to be pretty sweet), the car currently has an odometer in need of repair.  Once that gets fixed and I hear some preliminary fuel economy data, I will relay the numbers up here.

I am also glad to hear that many of you guys have found my postings beneficial.  The benefits have been mutual!  Thanks for all the collaboration work from you guys.

To answer the question of what other future modding plans are in store for this car, look to other threads on this board.  Hopefully in the not too distant future!

[fspGTD]

I think I solved the oil light/buzzer problem.  I found that an '84 1.6lTD used a different high-pressure oil switch on the oil filter stand than the '84 1.6lNA.  It turns out that the TD switch is rated at a lower 1.4 bar pressure, versus the NA switch, which is 1.8 bar.  I swapped the 1.8bar switch for the 1.4bar on the oil filter stand, and on the first start I noticed the oil light went out immediately (it used to require a little revving to go out).  Driving it around, I haven't got it really hot yet, but so far seems to be working properly.

Edit: I also got the odometer repaired.  I performed Roger Brown's trick of drilling out the center of the broken plastic odometer gear slightly so it is not as highly stressed when pressed over the shaft, and I also used plastic epoxy to repair the cracked gear.  The repaired gear seems to be holding up well so far.

[Jetman]

Hello.

Your vnt project looks very nice!!

Here some information about my Vw 1.6d vnt engine and car. whole homepage

[fspGTD]

Jetman - welcome to the GTD forum!  Your car looks awesome, even though I can't read the finnish I enjoyed looking at the pictures.  Thanks for the link and it's good to meet you!

I see you swapped VNT controllers to some pressure-actuated version... looks like a custom mounting bracket?


And impressive custom exhaust manifold - wow! :shock:

Did the long-runner exhaust manifold make a performance difference?

[Audi80]

Finally I got my VNT running. I have followed Jetmans and fspGTDs projects from the beginning. Both have been very intresting and seems to work well.
I still have some learning with the boost controlling. I used the stock vacuum box with flipped internals. I haven`t got boost under 1,6bar (23psi)  I think I have too stiff spring in box.
I have got better gTech results than Jetman, but I don`t think I have even close to 160hv what he has. I have stock and loose suspension, that must give me better results. 0-60 7,5sec, 1/4 mile 15,8 and 141hp by the gTech.
Pics

[Jetman]

..

[fspGTD]

Beautiful install, Audi80!

http://www.kotinet.com/matti.farm/Audi/114-1483_img.jpg
By the way, that is an interesting exhaust tip.  :wink:

[Audi80]

Dynoed today. 151hp/286nm at wheels. That`s ~165 crank hp

http://www.kotinet.com/matti.farm/117-1746_img.jpg

[vwmike]

Dynoed today. 151hp/286nm at wheels. That`s ~165 crank hp

http://www.kotinet.com/matti.farm/117-1746_img.jpg

Could you give us some more details on this car?  

[Audi80]

1.6 CY engine, mechanical head, little porting with bigger valves. VNT20 with tube header, 2,5" exhaust, gasser intake manifold. 10mm pump and 28psi (1,9bar) boost. Pictures are couple posts above.
This is pretty much all you can get with 10mm pump.

By the way, that is an interesting exhaust tip.

Didn`t want to show big exhaust tip, those are for teenagers :wink: