Another 2260 Build

[IndigoBlueWagon]

Why would a 2260 making 30 PSI with an engine at 18.5:1 compression make less power than the same turbo running 35 or 40 PSI on an engine with 16.5:1 compression? Isn't it about how much charge you get into the chamber and how much you compress it? My numbers may be wrong, but I'm sure you understand the question. Even if you're not running it at the edge of its efficiency curve (or beyond) it may still keep the air charge and EGTs cooler, which will also help power.

I'm not arguing here, this is just something I've tried for a long time to understand and haven't gotten a good explanation.

 

[TDIJetta99]

18.5:1 IS lower compression on an ALH.. stock they are 19.5:1.. 16.5:1 is excessively low for a Rotary and to make the most out of that you would need a compound setup at 50+psi..

I'm not sure the technical details of why, but typically you lower the CR when you go over a certain power/boost level... It's my understanding that peak cylinder pressure will be lower, but overall average cylinder pressure will be higher, resulting in more power.. You would absolutely get more power with a higher CR, but the hardware will likely fail before long..

 

[Whitbread]

25cc of air at 30psi < 35cc of air at 50psi. Greater mass of air = more fuel can be injected for same A/F ratio = more power.

A couple cummins guys have experimented with raising from 17:1 to 20:1 and had really big changes in spool time and midrange power. However, keeping the head sealed is a challenge even with studs and o rings on anything over 50-60psi. Keep in mind that's an iron head with 6 bolts/cyl where we only have 4.

With CR you can lower compression and maintain driveability/mileage. If someone can make the electronic side work, I'll be all over a CR ALH with crafter pistons like white on rice.

 

[mrchill]

With compression...you dont need big boost. One can make excellent power with lower boost if one has the correct compression ratio for the task. Of course...for big boost, lower compression is safer.

 

[loudspl]

Why can't you run a 2260 with stock compression?

Insane PCP resulting in spun bearings in my experience

Fed a steady diet of M1 TDT or T6. Never applied high load at low rpm...didn't matter.

I'm not sure even a 50-60wt. oil or sputter or coated bearings would save you. I think it's simply a physical limitation with these undersized bearings.
Not really designed for such loads

 

[mrchill]

1.8t bearings are even smaller...and can handle the same and higher torque loads. With the correct boost\cr combination, pcp isnt excessive.

 

[TDIJetta99]

Can a 1.8T make 350-400ft-lbs under 3000rpm?

 

[IndigoBlueWagon]

I think they can. I was at Lime Rock a few weeks ago and there was a 1.8T GTI there that made 450 torque. I'm betting at least 350 of it was available below 3000 RPM. It was quick.

 

[TDIJetta99]

interesting.. The faster ones will usually rev to 7000+ though so it's harder to tell where they come on.. I've driven a 550hp 1.8T and it came alive around 3400 and pulled to 7500 where the fuel cut was.. I'm sure the ones that make a little less power do come on sooner..

I wonder how peak cylinder pressure in a gasser compares to a tdi at similar power levels..

 

[scubagli]

http://www.google.com/url?sa=i&sour...=1371920155125836OmbZk1A&ust=1371920155125836
these are both K04, doesn't look like a k03 would come anywhere near these #...gt28's will make torque like a diesel but 1500rpm later...
http://www.google.com/url?sa=i&sour...L4VHiqGzQABoHlayWluiBoZg&ust=1371920580567947

 

[ryanp]

I don’t think the GTB2260 makes much more power past 35psi or so, not at the expense of higher EMP's than one would call reasonable anyway.

I'll have a nice graph of an ALH with a GTB2260, I have one of my 1Z and obviously 8v + 16v PD's with the same turbo so can try to overlay them all on one graph for comparison.

We are not looking to lower the compression on the projects we are just working on as cold starting and idle smoke always seem to be the most commented 'problem' with big power builds and lower compression wont help either of those issues. Holding the head down and stopping the rods bending is a better fix IMO. Careful mapping makes it acceptable but not 'stock'

the 16v PD's don’t seem to suffer as badly, without glow plugs my van started fine through a cold winter (-5 or so) and now with 100%+ injectors is still fine although we are a little warmer (+15) so I’ll be looking to go down to 17-1 compression.

I suppose everyone wants their cake and eat it, something has to give. Power, Economy, Drivability, Smoke, Cold start, NVH......

 

[TDIJetta99]

http://www.google.com/url?sa=i&sour...=1371920155125836OmbZk1A&ust=1371920155125836
these are both K04, doesn't look like a k03 would come anywhere near these #...gt28's will make torque like a diesel but 1500rpm later...
http://www.google.com/url?sa=i&sour...L4VHiqGzQABoHlayWluiBoZg&ust=1371920580567947

Looks like both of those are under 300ft-lbs, and they come alive between 2500-3000rpm

 

[brnsgrbr]

I don&#146;t think the GTB2260 makes much more power past 35psi or so, not at the expense of higher EMP's than one would call reasonable anyway.

I'll have a nice graph of an ALH with a GTB2260, I have one of my 1Z and obviously 8v + 16v PD's with the same turbo so can try to overlay them all on one graph for comparison.

I want to see this as I am starting my ALH build using your GTB2260VK kit.

http://forums.tdiclub.com/showthread.php?t=387940



Sent from my iPad using Tapatalk HD

 

[mrchill]

Well built 1,8t's can make 300 under about 3200 rpm. The point was...that the bearings are smaller than Tdi and survive the same power and more. The bearings arent the problem.

 

[ChippedNotBroken]

Okay, Jason has everything put back together, got 52mpg@75 on a long trip with the car.

Jeff and Jason weren't able to match up so I am hoping to catch up with him at one of the local
GTG to fix the tune.

 

[TDIJetta99]

It was actually 53.4mpg but either way it was impressive considering there was only a few hundred miles on the engine when I did the drive..
Filled up in Milwaukee WI Friday morning and made it all the way to Matamoras PA with one tank.. It was nearly 100 degrees over the last few days so I had the AC blasting for the entire trip.. Most of the drive was done with the cruise control set at 75-80mph (gps speed) with the exception of the work zones and the little bit of traffic near Chicago.. There was about 1/2 hour of dead stop and go and the rest was smooth sailing..


The car didn't drive out there, it was in an inclosed trailer with a race car that I delivered to Road America in Plymouth, WI..

 

[brnsgrbr]

What? Are you saying that the truck got 53mph towing 2 cars in the trailer? I think you segwayed without warning. Lol.


Sent from my iPhone using Tapatalk 2

 

[TDIJetta99]

No the truck got 8.5mpg.... ron's tdi that was in the trailer with the Ferrari got 53mpg on the drive back

Sent from my DROIDX using Tapatalk 2

 

[ChippedNotBroken]

Got a chance to drive my car for the first time since:

The pistons,
Turbo,
Transmission,
Regulator
CPU chip
and
Rear Struts were swapped out.

Since I am using Jason's old tune that was set up for smaller injectors and a different cam there are some surge and smoke issues that still plague the car so I may be jumping the gun making any observations just yet, but here goes.

The car is punchier down in the 1400-2200 RPM range but you quickly realize you have a smaller turbo when you get over 2400 RPM. If I were still looking to do any kind of racing with the car I'd want the 2260vk, but for the sporty daily driver I now want, it is just about perfect when paired with the 6 speed tranny. I might feel differently if I still had the stock 5 speed.

It hits just about every major speed limit @ 1800 -2000 RPM when paired with the correct gear. With the old 5 speed 50MPH was always a pain, too fast for 4th and too slow for 5th.

Hopefully Jeff and Jason will be able to figure out the programming and I will finally have a chance to enjoy the car.

On a side note, the speedometer/odometer is off about 3% and Jason said the computer wouldn't take the fix, not the end of the world but if anyone has a fix we'd like to hear from you.

 

[TDIJetta99]

^^ Ya the impulse number" coding in the instrument cluster refuses to accept a change...

The speedometer is about 10% optimistic and the odometer is 3.5-4% optimistic.. Worst case would be to use a Dakota Digital signal converter to adjust the output..

 

[ChippedNotBroken]

On a side note, the car is a lot quieter now. Not sure, but could the turbo have added that much noise?

 

[ChippedNotBroken]

Well, it's been a year now since the new hardware, but I am still running on the tune from Jason's old Jetta. His tune was for smaller injectors so it's not ideal but the car gets me from one place to another.

I was hoping that I could just get the tune nailed down and put this project to bed, but like everything that has gone on before, it is turning out not to be as simple as one might expect.

 

[ChippedNotBroken]

MOVING ON TO OTHER THINGS. CAR FOR SALE.

I PUT CLOSE TO $20,000 INTO THIS. WILL TAKE FIRST OFFER OF $6500.

The engine and Transmission have about 20K miles.

 

[TDIJetta99]

What should I do with those fenders?

 

[ChippedNotBroken]

What should I do with those fenders?

YOU'RE ALIVE!!!!!!!!!

I sent you a PM.

 

[ChippedNotBroken]

xcdhracer15 just sent me a deposit.

Promises to continue the fun.

 

[ChippedNotBroken]

New Day

The end of one story, the start of another.

I'd like to thank Jason and Matt for the hours of work they put into this project, as well as several other board members who offered their expertise and services.

 

[andy2]

It's unfortunate that you weren't happy with you car's performance after all that.I've been struggling over the years with my 99.5 jetta also.I completely understand and agree with your updated post below.Thanks for posting you experience.

Post dated 11/8/2014

Why I sold the car after a 5 year build:

First let me say, I'd do it again. I got a chance to meet a lot of great people and had some VERY interesting times along the way... That said I have a word of caution for those who might want to venture down this path.

If you are not a mechanic, or love to tinker on mechanical things EVERY weekend and have a real aptitude for it, or have VERY deep pockets then just get a tune, maybe slightly larger injectors and call it a day. In the end I handed this project off to someone more qualified to finish it because the people I needed to make this work became unavailable and with this kind of build, there just aren't that many people out there that can put something like this together and polish it off. So... if you can't finish it yourself, best not to start.

Most people were spoiled with their 90hp ALH when they added some bolt-ons like 17/22,clutch,bigger nozzles and a tune.I think this let others to believe that there was alot more potential if simply stepping it up from the bolt-on crowd.

What have you replaced this car with ?

 

[PeeWee]

Wow thats one long story. Thanks for the big efforts.

 

[ChippedNotBroken]

It's unfortunate that you weren't happy with you car's performance after all that.I've been struggling over the years with my 99.5 jetta also.I completely understand and agree with your updated post below.Thanks for posting you experience.

Most people were spoiled with their 90hp ALH when they added some bolt-ons like 17/22,clutch,bigger nozzles and a tune.I think this let others to believe that there was alot more potential if simply stepping it up from the bolt-on crowd.

What have you replaced this car with ?

I haven't made up my mind yet. Most likely to sell my wife's Mini as well and buy a Subaru Outback. The 2015 model gets pretty good gas mileage and the car is perfect for NE PA winters.

I considered the TDI wagon, but my wife is afraid to let me any where near another Diesel Jetta