Seat Cordoba Vario 1.9 TDI

[Vekke]

Hi,

I bought Seat Cordoba because it has a very economic VAG 1.9 tdi engine. EPA is aroud 5 litres and that was the main point why I bought this car. I drive around 50k kilometers per year so i save a lot by using diesel.

Well i drove the car for two months and then found this ecomodder website. Well it lead to differend driving techingues, which was soon followed by some light modifications egr delete and higher tyre pressures etc...

Then I did a full front bumber block ( intercooler has its own hole), and the last mod is rear fender skirts. This weeks project is full flat lower engine cover. I use glassfibre and polyester resin for the mods.

At the moment my consumption is aroud 4.2 litres but the trend is downwards. My target for next summer is below 3.5 litres, so lots of mods are still ahead.

Pictures will follow soon

[tasdrouille]

Hi and welcome!

I am afraid deleting the EGR is detrimental to FE. You are also putting more NOx out.

I increased the EGR rates at light loads in my car and it helped fuel economy, especially in the winter.

[Deezler]

Tas, how did you increase the egr rates at only light load? Will you revert to standard programming for summer time?
How long have you had your A4 TDI? Why is the A3 retired?


Vekke, good choice on a TDI powered ride! Show us some pics!

[MetroMPG]

Originally Posted by Deezler

Tas, Why is the A3 retired?

http://ecomodder.com/forum/showthrea...come-5929.html

[tasdrouille]

I used VCDS (Vag-Com) to adjust the EGR rate to the maximum idle value within specs. At WOT (figuratively speaking) the EGR duty cycle is 0% anyway, so I should have said I increased EGR at all loads but when I need max torque/power.

Increased EGR helps the car warm up faster, which is especiall useful in the winter. Also, since increased EGR rate increase ignition delay, I advanced timing by 2 degrees at idle (again through VCDS), else I would have been leaving some FE on the table.

I don't know if I will revert in the summer. I haven't had the chance to play with EGR settings last summer.

I've had my A4 for close to 2 months now. Injectors nozzles were clogged so swapped them for a set of .216 I had laying around. The only problem is that I can't get my IQ adjusted properly in VCDS so I smoke a little at high rpm or high load and I waste fuel at idle. I'll need to mechanically adjust the pump, but it's way to cold for now, I don't have access to a garage. I could increase boost to compensate, but I haven't installed a boost gauge yet, and I won't touch boost till I can monitor it.

The A3 was sold because of rust issues. It was my car for my daily commute or trips I was doing alone. We always used the Elantra for family travel as my wife did not trust/like the A3. She likes the A4 look and this one is rust free so we use it in place of the Elantra most of the time.

[Deezler]

0.216 is a pretty big nozzle...
With extra fuel and increased egr, plus gentle driving style (I assume), I would worry that your intake manifold is going to clog up - fast.

[tasdrouille]

Extra fuel for now. My IQ is at 4.6 mg/stroke, max adaptation setting I can get through VCDS for now. After I hammer the pump I'll crank it up to 7-8 mg/stroke so I won't have extra fuel much, just a shorter injection period.

I give it a good punch on on ramps once or twice a day. ULSD helps a lot preventing intake clogging. I removed the IC hose to the EGR valve to peak inside 2 weeks ago and it was so far so good. I'll just monitor it more closely now that I increased EGR. Worst case I clean the manifold in the spring.

[Vekke]

Yes I know the egr helps the engine warm up, but it also uses more fuel when engine uses it mostly when engine is cold... With full front (heater block) my engine warms up almost as fast in normally condition on summer. The egr delete drops your fuel comsumption 0.1-0.2 litres. So if my engine warms as fast in winter i dont need it. After the delete my sg2 proved this to be right. Oh I also bought the SG when I started doing these mods. Also when you have blokked your egr your intake will stay much cleaner! Yes its more harmus for the enviroment but better for purse .

[tasdrouille]

Wierd, I've come to the opposite conclusion when tuning my car and logging consumption with VCDS. What is your idle timing? Stock timing on those cars is retarded from optimal timing for FE. By deleting the EGR, you are removing the ignition delay and decreased flame speed associated with it. Which have an effect analog to advancing timing. That might be the reason you saw improved FE. It doesn't mean it's optimal when considering other variables working in conjunction with the EGR rate.

When I increased the EGR rate, it also increased the ignition delay and reduced flame speed somewhat. In order to see an improvement in FE I had to advance the timing to compensate so ignition happens at the optimal time and all the fuel is burnt during the appropriate period. I am hoping that my .216 nozzles will help inject all the fuel in a shorter period to compensate even more for reduced flame speed. But until I get the IQ physically corrected at the pump, I can't tune further.

I've got an SAE paper where they tested fuel conversion efficiency of a DI diesel engine at various EGR rate and SOI timing at 1500 rpm. Best fuel conversion efficiency happened at 14% O2 and 5 degrees BTDC.

[Vekke]

No I have just mecanichally blocked the egr hose. I havent used yet the computer to program anything. I know you can do some fuelpump settings to get even better fuel economy, but i dont have the program on my laptop