G-Teched my 1.6TD - Part 2

[malone]

I found the 16 PSI boost level quite interesting. When the NA pump was first swapped in and untouched (fueling not adjusted), I boosted in the 13-14 PSI range. That's even higher than what a stock 1.6TD can boost with a standard 1.6TD pump :shock:

I suspect that my GT20's turbine was customized (aside from cermachroming) as it was originally marketed for diesel engines, TDIs in particular. I also found that my EGT climbs very quickly during high RPM. It's likely due to a lot of backpressure with the turbine. My air/water IC wasn't functional either, but the EGT sure climbed quick anyway.

That said, with a larger turbo setup, race cam, intercooling, and constant fueling my torque peak may be way up there   not 4,000 RPM like last time. The peak HP (currently 5,100 RPM right where the fuel-cut off was) could very easily be somewhere in between 6,000 RPM and 7,000 RPM.

[fspGTD]

So what part of your mods are giving you basically twice the amount of torque right from low rpms too high rpms? Down at 2400 your boost cant be making too much of a differance. Maybe your larger exhaust and better flowing head? Curious as to what you think.

neverdieidi - Just thought I'd point out that it looks like the black G-tech run you are pointing out was done in 2nd gear but the red run was in 3rd gear.  That could definitely throw off the results, and make them not very useful for direct comparison.

[malone]

You're right, I did a full 1/4 mile run in the stock 1.6TD (black line) and I forgot that Gtech automatically chose to plot 2nd gear.

I assume the lower 2nd gear will inflate numbers because of the extra g-force felt vs. a 3rd gear pull. If that is true, then re-doing the black Gtech run in 3rd gear will likely not close the gap with the red line.

The more recent Gtech plot I posted above are both 3rd gear pulls, done on the same stretch of road, with the same car & Gtech calibration. That to me is a more useful comparision.

I may come across another stock 1.6TD with really low mileage - I'll do a 3rd gear Gtech run in it if anyone cares.

Seeing as I'm not the only Gtech user, I wonder if anyone else has a Gtech file of a stock 1.6TD running 3rd gear?

[neverdieidi]

Ill see if I can get some stock third gear runs, if nothing else ill put mine back to stock and run her.

[malone]

Ok.

Hey guys, I finally took a video of my cold start smoke while leaving home for work this morning I may post it tonight.

[zagarus]

any chance of having or making a video of the full power of your diesel malone? like acceleration and such.

[malone]

any chance of having or making a video of the full power of your diesel malone? like acceleration and such.

Yeah I'll take a video for sure , need to get the TD pump back in there first.

I had 11mm and 12mm parts that were in Alberta and they were supposed to be returned to me, but they're now considered stolen (I haven't seen them since 2004). The guy mentioned several times over several months that he'd ship the parts back to me and then he stopped responding.

I may go with a 10mm from Brett's Ford Ranger TD pump as I don't feel like shelling out another $200 USD for the third time for 12mm parts :evil: Damn thieves. There are a few 12mm for sale for a decent price but they are aftermarket (may not be OEM quality) and they need to be shipped as well. I'd rather waste no time: Its been months with the NA pump so I want the pump + 10mm rebuild to commence soon.

With Bosch 10mm I can be assured that it will spin 3,500 RPM (7K RPM) reliably. That paired with fspGTD's custom nozzles that flow 64% more than stock should provide nice fueling. Then eventually if I do NEED more fuel I may buy 11mm or 12mm and send a spare TD pump to Giles. That'll be great for compound turbos, but it will be nice to see how much HP we can get with the single GT20 turbo for now. We have yet to see full potential with the GT20. If I start smoking and the EGT is starting to push the limit then I'll be done with the turbo :twisted:

[fspGTD]

Sounds like things are moving along nicely, Mark!  Thanks for the update.  

Regarding 2nd gear versus 3rd gear G-tech results, keep in mind that the G-tech knows how fast you are going by integrating acceleration versus time, so it really is not a factor that the g-forces are bigger in 2nd gear than 3rd because that would be expected.  The G-tech should be able to perfectly compensate for that, assuming the road is flat so it is getting accurate readings.

However, actual results don't match in different gears for the following reasons:
1.  aerodynamic drag isn't linear with speed - since this drag increases exponentially as speed increases, it causes the higher gear results to be artificially lower.  At lower speeds (and therefore lower gears), aerodynamics make much less of a difference.
2.  engine-speed rotational inertia - heavy flywheels and engine-speed rotating components take more of the engine's available % of power at lower gears, which require a greater % change in engine RPM for a given change in road speed, than in higher gears.  In my experience, this factor overwhelms aerodyanmic drag differences in the very low gears: 2nd gear and especially 1st gear.  It is especially noticeably when you lighten a flywheel, because you will see your G-tech net horsepower figures increase in the lower gears significantly, (2nd gear significantly but even more dramatic difference in 1st gear!) but the difference it makes becomes less noticeable the higher the gear being tested, to the point where you might not notice of measure on the G-tech much difference resulting from a lightened flywheel in the higher gears.

So what I find is that there is a "sweet spot" gear where the G-tech reports highest horsepower numbers.  In my Rabbit GTD autocrosser's case it's 3rd gear, but that could vary by a lot of factors like: gear ratios, aerodynamics of the car, relation of overall mass to engine-speed rotational mass, etc.  What happens I belive is at too low of a gear, the net horsepower will be less than the optimized gear because of too much engine-speed rotational inertia causing high resistances to the the quick-changing engine RPMs.  At too high of a gear, net horsepower will be less than at the optimized gear results because of excessive aerodynamic drag.

[zagarus]

i wish i knew as much about diesels as you do, geez, all the fine details you guys look at, im happy just knowing about how to increase fueling and boost!  ill be paying a few visits to passenger performance this summer

[malone]

Speaking of compound turbos, I don't recall having posted these images earlier in this thread:





The smaller turbo is an OEM T3 and the larger one is a T3/T4.

935racer is fabricating a better setup; tubular equal length exhaust manifold and a custom intake manifold with radiuses that are approximately twice as large in the 90 degree bend that attaches to the head. The turbos may be a T3 with .48 A/R turbine / .42 A/R compressor, and a standard Holset HY35.

edit: Thanks for the info Jake

[zagarus]

:shock:  :shock:  :shock:  Pulling up beside a diesel with that would be nuts!  Can we say, "smoked ya!"  :lol:

[malone]

:shock:  :shock:  :shock:  Pulling up beside a diesel with that would be nuts!  Can we say, "smoked ya!"  :lol:

I would strongly suggest not pulling up to my right or you will be staring straight into an exhaust pipe in my front fender


(not my car, but similar idea)

The last turbo in the compound setup will sit towards the passenger side with its turbine outlet facing directly to the fender, so a short & straight exhaust pipe through the fender is ideal.

The car will still be street legal however. I'm thinking of reinstalling the stock exhaust system (under 2") that fits easily with no rattle and then teeing its downpipe to the big exhaust pipe, which is controlled by a valve. The valve will be wired together with my max. fuel & boost switch. Wiring will be extremely simple, about 30 minutes to complete.

Leaving the switch off inside the car uses stock fully muffled exhaust that is quiet and street legal. Flick the switch to "on" and the LDA, boost valve, & big exhaust opens up more within a couple seconds. More boost, fuel, and exhaust flow all at once.

Stock exhaust = bolts right on. Fender exit exhaust pipe = straight pipe, no bends.. also very easy. The main challenge is fabricating a 2" downpipe to connect the stock exhaust system to the main pipe, and there's lots of clearance with 2". All this may actually be easier than fabricating a complete turboback 2.5" or 3" exhaust system that is rattle-free on a lowered car.

Pros of the dual exhaust system:

* Easy to install
* Less prone to rattling
* Street legal with no compromises between regular driving and racing
* Cheaper in pipe costs. I.e. one big straight pipe and a few 2" bends for downpipe instead of a complete mandrel bent 2.5" or 3.0" system + aftermarket muffler.

Cons:

* Might be more expensive overall (only due to a good quality electronically actuated exhaust valve).
* Valve may become stuck due to soot build-up in the long run. However, the car will still be driveable should this happen and the valve is easily accessed or removed for cleaning.

Switch "off":



On:



I typed this in detail so 935racer can comprehend this idea, seeing as he's the welder.. what do ya think?

Am I crazy or is this actually viable? I'm open to discussions..

[zagarus]

my God this will ne awesome!  What is your goal with this car anyways? just a really fast powerful IDI, racecar, mechanical show car? or just one plain sick jetta!?

[wyldman]

I'd go through the hood,with a small stack.That would really turn some heads !

[andy2]

I vote for through hood not fender :lol: