Saturn TDI

[Craig]

The drivetrain came out of a '97 Jetta TDI, complete with electronics. Making the swap happen took two years and a LOT of fabrication to make it work/fit/look like it came that way. Definitely not for the faint of heart!

I'm currently getting 64 mpg out of it, although I just started experimenting with injector pump timing in the ECU after someone on the TDI forums told me about it. From what I have read, most people are seeing another 3-4 mpg out of their cars, and apparently the European-spec cars run more timing than the ones we got here. It's pretty neat to be able to plug my laptop in and run diagnostics or change tuning parameters.

I still have some aerodynamic experiments to try, but I've been too pressed for time to do much...

[Varn]

That is interesting to read about diesel fuel timing.

My old diesel (86 Jetta) has a lever (I believe advances the fuel timing) that is used for starting. I have inadvertently left it pulled out with no apparent issues.

Any opinions on leaving the start lever out, or partially out would be appreciated.

[oldbeaver]

Dear Graig and others,

I did my own diesel swap about 5 years ago, and the car and engine is still working in my son´s hands.

However, it was a aspirated and non electronics diesel, which is a lot easier to manage. It took me 2 months with an experienced mechanic, and about 6 months more with my Mercedes mechanic to fix details.

I made a website of the swap:

https://sites.google.com/site/rd28engineswap/home

All details in costs, performance, difficulties are there.

You should document yr swap as it will be very useful to others.

Best,

Old Beaver

[cbpldc]

Cool swap! I love the Saturns, as they are a blast to drive. I have a hard time fathoming what one of those would feel like with some torque.

Chris

[Craig]

Quick update here: a few weeks ago I plugged in my laptop and advanced the injector pump timing after someone on the TDI forums told me about it. I bumped it up from 2.6 to 4.6 degrees. The last couple of tanks I got 67.49 and just grazed past the 68 mpg mark, so I'm really happy about those figures! Anxious to find out what I get when I fill it up again - I think 70 mpg is within reach with a little more work...

[oldbeaver]

Originally Posted by Craig

Quick update here: a few weeks ago I plugged in my laptop and advanced the injector pump timing after someone on the TDI forums told me about it. I bumped it up from 2.6 to 4.6 degrees. The last couple of tanks I got 67.49 and just grazed past the 68 mpg mark, so I'm really happy about those figures! Anxious to find out what I get when I fill it up again - I think 70 mpg is within reach with a little more work...

How did you that? Very impressive! Please share how you measure and advanced the timing. Plus, give more details about yr engine and control system to see if others may take advantage of yr experience.

By the way, where did you get that advice or suggestion?

Congratulations and thanks to share.

Oldbeaver

[ixlr8]

Originally Posted by oldbeaver

How did you that? Very impressive! Please share how you measure and advanced the timing. Plus, give more details about yr engine and control system to see if others may take advantage of yr experience.

Oldbeaver

The info is in the post "Results are in 3-4 MPG increase" on the TDIclub.com web site, in the VW MKIV-A4 forum. Using a scanner like VCDS you can access different engine parameters and make adjustments. I tried this on my 02 TDI and the tone of the engine changed, the engine warmed up faster, but I didn't see any change in fuel economy. For TDI's, the VCDS scan tool from Ross-Tech is very powerful, and is relatively safe to use. There are other scanners out there that let you access and control more... but they let you access deep into the programming and for novice programmers, unrecoverable errors are easy to make. The Ross-Tech scanner doesn't give you access deep into the programming and recommends limits for a parameter and gives a warning if you are going to do something real stupid. Just right for me.

PS- Craig, I have been following your project on TDIclub since you started, very interesting... good work. Good luck on hitting 70mpg.. I am trying for 60mpg in my Golf.

[Craig]

Thanks for the props, always nice to hear from people who have followed my project!

As the title says, I got 71.05 mpg out of it today! Wow! I went 374.6 miles, and took 5.272 gallons of B5 ($20.45)...I was floored when I crunched the numbers in my calculator, had to run them a couple more times to be sure I was doing it correctly. I'm really excited about this figure, and now I'm hoping to repeat it on this tank. A lot of this has to do with careful driving technique, and that timing advance sure did help, too! I also swapped to steel wheels a couple weeks ago, since I want to make a set of smooth wheel covers in hopes of edging the mpg figure up a little more. The steel wheels are a bit heavier, but I think they help maintain the momentum of the car going up a grade on the highway, which is where I do most of my driving.

[Craig]

I filled up yesterday, and this time around I got 72.77 mpg, so the results are repeatable - and beating my previous figure was a nice bonus, too! Now I'm looking at getting into the mid-70s with it. I really need to make those smooth wheel covers, and do some underbody aero...

[Craig]

Just a quick update; my last fillup netted "only" 68.98 mpg...a few errands in town, road construction, and sitting in traffic after seeing The Glenn Miller Orchestra brought my fuel mileage down a bit.