Scottish Diesel Rocco

[danster]

Hello to you all from Scotland. I have been aware of this forum for a while now and thought it was time I signed up.

I have been into VWs for a long time. A serious case of Dubitus if ever there was one. I have had far too many cars to list here, but my current road car is a red 1992 Scirocco GT2, which is now a GTD with an AAZ in it. I picked up 27k mile running gear from a Seat Toledo that an old chap no longer needed.  

Here is the car.


Here is the engine bay. (just after install so things have been tidied since)


The idea was to tweak it up a little to liven things up. However the ever increasing fuel costs, and the fact I hardly do any great mileage has made me consider tuning for MPG rather than power. I have another Rocco for track use if I want to go fast, and that way I will not get caught speeding on the highway and lose my license.
With this in mind I am considering changing out the engine for a non turbo one!  
I have 1.9 1Y IDI, 1.6GTD and 1.6D engines. And a 1.9 1Z TDI and a 1.9 SDI if I am allowed to mention this in the IDI section.
So does anyone have any real world experience of MPG figures that these engines could obtain in a mk1 platform vehicle when optimised?
I like to keep things simple and am put off by all the electronic and complexity nonsense that seems to cause and regularly gives faults. So M-TDI or M-SDI may be considered too.

[dodger21]

I have a 85 Golf 2dr 5spd 1.6 IDI NA. (WOW! That's a lot of abbreviations!!!) The previous owner put on slightly larger tires on the aluminum 14" wheel. Around town is a dismal 35 US mpgs. But on the highway I net around 52mpgs.  If it had the right size tires, I could see 40/48 mpg. Now, a friends of mine in the Cummins diesel world, put a diesel pusher pump on inline with a regulator set at 12psi and he nets 45/55mpg. I do believe that a pusher pump will help as there is less load on the VE vane pump, gets rid of air leak problems, and helps at higher RPM's from the pump running dry and losing power.

Just what I have experienced and heard

[danster]

Jeepers, now I have to get my head around the US gallons thing. 

A quick google suggest that there are 3.785 litres to a US gallon.
We have 4.546 litres to a UK gallon.

  On the upside though, our pints of beer are larger over here.

I take it your miles are the same?

[Bugsy_malone 666]

Just drive slower :lol:

Realistically the turbo motors do better MPG.

I have a 72 baywindow camper van with a 1600TD out of a golf CL and previously I had a 1600D in it, it was fairly sluggish/on par with the petrol engine and gave 40mpg driving at 55mph in my lard brick of a van, with the 1600TD its alot quicker 45-48mpg. An intercooler would actually make the engine slightly more effiecent and may improve economy further.

I have a mk6 golf diesel and because it has an MPG gauge I watch that alot which made me drive alot slower than with my 1.8 petrol mk3 golf, my g/f would agree but probably says I dont drive that much slower!

I am thinking of putting a 1.6NA in that but to be honest its such a sluggish lump a turbo is going to be fitted just to help with joining the motorway!

Have you considered maybe looking into a waste veg oil conversion to lower fuel costs rather than fun? Its what I am doing as when theres an offer on at Tesco/Asda/Morrisons/Sainsbury sometimes fresh veg oil can be as low as 90p a litre rather than the £1.30 we pay for diesel.

[danster]

I only do short journeys, so the installation costs of going to a twin tank setup / heating the veg oil are probably not worth the effort.
I would be having to start the purge back to diesel about halfway through my average journey. I only do about 3K miles a year.
It is just the ever increasing costs of fuel, road tax etc that are making me think of ways to reduce the cost per mile.
Sad as it is, probably buying a newer car with lower road tax would make the most significant reduction in yearly running costs.

Sooner they put the road tax on fuel the better IMO. Fairer in so many ways. Drive a big thirsty car = pay more. Drive loads of needless miles = pay more. And that ties in with environmental issues too.

[Bugsy_malone 666]

I only do short journeys, so the installation costs of going to a twin tank setup / heating the veg oil are probably not worth the effort.
I would be having to start the purge back to diesel about halfway through my average journey. I only do about 3K miles a year.
It is just the ever increasing costs of fuel, road tax etc that are making me think of ways to reduce the cost per mile.
Sad as it is, probably buying a newer car with lower road tax would make the most significant reduction in yearly running costs.

Sooner they put the road tax on fuel the better IMO. Fairer in so many ways. Drive a big thirsty car = pay more. Drive loads of needless miles = pay more. And that ties in with environmental issues too.

I drive 10k a year myself, i'd rarther they stopped buggering about with taxing the motorist and just aim at taxing the rich, not who drives what! as I want a hotrod with a massive engine and it would just end up costing to much to enjoy

I think really if your journey are that short then its probably not worth changing anything now your diesel, as you rightly point out the warm up time for going over to veg wouldnt be worth it. I bought a mk6 golf TDi 1600 which was on a massive deal because I had a petrol 1.8 mk3 that was a bit of a drinker(plus £205 road tax!) and while for the most part my mon-fri I only do about 50-60 miles total, I do 70-100 miles each weekend seeing my g/f. its on the weekend trip that I would make use of veg oil.

I sat down and worked out running costs of a new car long and hard to see if it was worth buying and with just £30 road tax and no parts to buy for at least 3 years I worked out I would pay for at least 1/4 of the car with the savings in fuel, which I think is somewhat true. The downside is you cant use biodiesel or veg oil in it.

I suppose it depends on what you use your car for and how long the actual journeys are, because to be honest if most of your journeys were only ever a max of 30mph then you wouldnt need more than a 1600D N/A engine, but as I already mentioned from my experience with my bus that only does about 2-4k a year with shows, the turbo diesel was better on fuel than the N/A by 3-8mpg. Make it more effiecient with a proper intercooler (like found on a renault 5 turbo that has a warm up thermostatic flap inside) may improve results further, depending on your driving.

Being the speed freak I am I'd just probably try and make it faster lol, but seriously though I think its pretty sweet as it is, GTD is probably on par with the old GTi engine that was in there and its a clean car

[nathan_b]

my rabbit pickup with a 1.6/1.9 k14 mild gov mod and fuel tweaks can do 10.5s 0-60mph and gets 42/50 US mpg, and probably 45/55 in the summer. The 42/50 were with snow tires, 13" rims. Oh yeah, and I run it hard, all the time.

[madmedix]

Nice car. Not many nice examples left over here thanks to road salt. I have two cars, both 1.6 (N/A and turbo). I experience the opposite with L/Km with these cars; the N/A gets considerably better economy. My commute is 168Km per day total, and at the same speed (weather and volume dependant) and driving habits the turbo consumes about 12% more fuel (I frequently alternate cars). Granted, the turbo now has ~612,000 on her, and is getting rebuilt when all this snow leaves. The N/A only has 223 on her; but that's a normal mileage spread over the last 20 years of owning these cars. Other than the Jetta being a little heavier and other little differences between the two, I'm fine with it.
Watch out for your 'road tax'; over here it's fuel tax. It's an insidious little bastard

Good luck on whichever route you go...they're both fine engines in my opinion.
Cheers,
l

[dsl_53b]

My 86 Scirocco with 1.6na usually averages 40-42mpg in town. FN trans, 175/70/14 Sumitomo htrt4 tires. Under ideal conditions on the freeway, it gets over 65mpg if I keep it between 55-58mph.

[snakemaster]

mpg 1.9 tdi , i run a MTDi in my mk2 golf 70mpg  and if i change the 5th gear to a longer on then more mpg , i run the tdi box to. nice roco

[danster]

Thanks for the input folks. Just letting the calculator cool down from doing all the maths on US versus UK mpg.

This was a late AAZ, the IP had the flat boost pin, and it still has some other extra solenoid connection on the underside of the pump. I thought this may be some kind of advance / retard control. It is not connected at the moment. The car does feel flat, even with 15psi of boost. I never found any conclusive evidence that this extra connection was ok to leave plugged in or unplugged to a 12v supply. It changes the engine note on tickover but that is about it. Sounds like it is advancing the injection timing as there is a little more crack to the engine.
Could it be for some kind of limiter for when the engine was cold, possibly to prevent full power and possible head cracking if the engine was driven hard before being fully warmed up? The donor car had all sorts of electronic gizmos on it that were removed for the install in my Rocco.
It starts fine with a blast of the glow plugs, even in the minus 15deg C temps we had here in Scotland this winter. Just a pain heating it every time I get in it though.
Maybe the 1Z TDI engine with a mechanical IP could be just a little better on fuel, and will start without glow plugs.
Just waiting for a Landrover Discovery to come my way and grab the IP off before scrapping it.

[snakemaster]

a intercooler would help your mpg

[JGWarner]

Very cool 'rocco. I love seeing TDs where they're not supposed to be, which is why I'm putting one in a Fox (a model you guys didn't get in the UK).

Also, stupid side note: I've played highland bagpipes for 14 years, and now I make trad instruments for a living. www.sweetheartflute.com

[danster]

Very cool 'rocco. I love seeing TDs where they're not supposed to be, which is why I'm putting one in a Fox (a model you guys didn't get in the UK).

Also, stupid side note: I've played highland bagpipes for 14 years, and now I make trad instruments for a living. www.sweetheartflute.com

The car was originally a 1.8 carb model so was terrible on fuel. The diesel engine came along at the right price. I was always looking to convert it to diesel as it is my road car so not too bothered about crazy power and speed.

I have this other Rocco for going fast on the track. 


And my late father used to make bagpipes. It was the reason I got my own place, as I got fed up being woken by him practising his bagpipe music first thing in the morning when I was still sleeping!

[ibizz]

nice car and samoiedo