Series One and a Half (Discovery 1.5)

So... I bought my first Disco 300tdi in August last year and fell in love with it. After three months of putting money into it, I have decided there was no point as the back of it started rotting badly. So, I kept thinking and thinking about a new one that will last forever... (I know, I know...)

I wanted to do some overland and planning to go through Mongolian steppes into Siberia at some point in my life, so I kept thinking what would be the best vehicle.

One night I had a dream about a 300Tdi meat and a comfy, rot free D2 box. And the very next day I found it on facebook! I bought my "oneandahalver" project and pumped a lot of cash since then. I am nearly done but still have few unanswered questions and I wonder if you could help me and give some advice.
My rig has a D1 chassis, axles, gearbox, 300TDI engine and a D2 body.

Suspension/tyres
I have read in most of the product descriptions for the coil springs (terrafirma, bearmach) that those may/will not give a full 2" lift. How is this going to work with D1 chassis/axles and a D2 body? Do I need to consider 1" spacers to compensate for that?
I don't really want to lift it too high but yet again, I bought a 275/65/16, which work out at some 31.6" and I know I will have to cut... but will this be enough to accommodate such a tyre size? I had a problem with those tyres on a D1 at the rear, whilst the front was absolutely fine. Is having 3" at the back and 2" at the front a good idea?

Painting
What do you recommend for painting the chassis (currently brand new galv) and underbody? And what to do the box?

Miscellaneous
I know there are quite a few surprises along the way, so if someone has the experience of similar builds, I would appreciate any advice, tips or tricks
I know that this is a bit heresy, but I am also thinking of putting a VW 1.9TDI in. Has anyone ever done that?


I do apologise, if those questions were already asked, but other than the paint, I don't seem to be able to find the right threads. Links would be very welcome

Interesting mix... Any issues registering that with the DVLA? Guessing as the chassis and engine are currently from the same vehicle you got away with it? Not sure whether adding a VW engine might cause more problems! I'm also not sure i'd want a little 1.9 litre engine in a car that heavy!

How is the back end supported? From memory the chassis for a D1 is shorter than that of a D2!

No probs with DVLA.
Box almost fits onto a chassis but the two rear mounts had to be custom built.

1.9tdi can be tuned up quite easily and is quite popular in US where they fit them to jeeps. It will provide more power and greater fuel economy.

Tis upto you, but I think a 1.9 VAG unit is a heck of a lot of work for very little gains. Sure they are popular and can be tuned, but doesn't mean they are immune from issues. I can't see it being any more reliable or economical than the Tdi is.

Personally not really heard of any going into Jeeps either, not saying they don't, but it really can't be that common. Also not sure what other issues you'll encounter converting a transverse engine to longitudinal.

As for power... meh. I know you get sill claims with the VAG stuff, but reality is 150-180hp is about the most you'll be looking at for any sort of road use. And the extra power will come at the expense of low end grunt. Making it less suitable for a 4x4.

I'm not saying you won't be able to slightly out perform a tuned 300Tdi, just it's going to cost you a shed load in money, time, R&D and bespoke parts to get an almost next to no point gain.

A Td5 would be a much better swap, or if you really want a more modern engine the 2.2/2.4 Puma, at least that will mostly bolt together and allow you to run lots of off the shelf parts.

T-wash the chassis first so paint will stick.

Then use something like this -> http://www.arc-rite.co.uk/fast-dry-tractor-and-machinery-enamel-choose-size-colour-165-p

I used their red oxide and tractor enamel to do my axles and they are still lovely 1 year and a winter of harsh road salting later.

300bhp/ton said:

Tis upto you, but I think a 1.9 VAG unit is a heck of a lot of work for very little gains. Sure they are popular and can be tuned, but doesn't mean they are immune from issues. I can't see it being any more reliable or economical than the Tdi is.

Personally not really heard of any going into Jeeps either, not saying they don't, but it really can't be that common. Also not sure what other issues you'll encounter converting a transverse engine to longitudinal.

As for power... meh. I know you get sill claims with the VAG stuff, but reality is 150-180hp is about the most you'll be looking at for any sort of road use....
A Td5 would be a much better swap, or if you really want a more modern engine the 2.2/2.4 Puma, at least that will mostly bolt together and allow you to run lots of off the shelf parts.

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Allegedly with a turbo mod and a good remap they can squeeze out around 200bhp and nearly 600nm. Plus the fuel economy of 40mpg plus... allegedly...

But you are right, this would require a lot of work and even more money, which I don't happen to have atm. Plus a lot of custom built parts for the conversion and the reliability would be a big question mark.
It would be good to have some power but what matters to me most is the range and such fuel consumption would almost double the one of 300tdi.

Bennehboy said:

T-wash the chassis first so paint will stick.

Then use something like this -> http://www.arc-rite.co.uk/fast-dry-tractor-and-machinery-enamel-choose-size-colour-165-p

I used their red oxide and tractor enamel to do my axles and they are still lovely 1 year and a winter of harsh road salting later.

Click to expand...

Thanks a lot!

VW engine, with a heavfy vehicle like the d1.5!!!!!!!

Stick with what you have, 300 is pretty reliable.

If you wanted get up and go, a full D2 would be better with the TD5.

Puma engines, not that reliable

Mackie4 said:

Allegedly with a turbo mod and a good remap they can squeeze out around 200bhp and nearly 600nm. Plus the fuel economy of 40mpg plus... allegedly...

But you are right, this would require a lot of work and even more money, which I don't happen to have atm. Plus a lot of custom built parts for the conversion and the reliability would be a big question mark.
It would be good to have some power but what matters to me most is the range and such fuel consumption would almost double the one of 300tdi.

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I'm no expert on the VAG Tdi's, but I've been around quite a forums and seen lots of stuff. Suspect a map alone is not really going to get you to that power and not reliably on the road. With a diesel you can probably get headline figures on a dyno, but it'd run way to hot EGT wise on the road or for any sort of extended use. So you'd likely need a propane kit and maybe even a power adder like Nitrous Oxide.

Don't get me wrong, I'm all for tuning cars. But seriously, if it's so easy to get 200hp, loads of torque and 40mpg from a 1.9 Turbo Direct Injection 4 cylinder engine. Why would PSA have gone to all the effort to make the 2.7 V6 diesel and only return 190hp and less mpg?

Simply put they wouldn't.

BTW - like all engines, getting more power means moving the power curve to the right, i.e. make more torque higher in the rpm band. A bigger turbo will do this, but will also induce far more turbo lag and won't make boost as low in the rev range. Off road driving you'll be at tickover and just over. The Tdi makes boost shortly after tickover, suspect a tuned 1.9 wouldn't.

300bhp/ton said:

I'm no expert on the VAG Tdi's, but I've been around quite a forums and seen lots of stuff. Suspect a map alone is not really going to get you to that power ... a tuned 1.9 wouldn't.

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Thank you for that. I think as with everything like this there is always a catch.

Going a bit off the track, I have read your post about lifting D2.
I am currently at the stage of thinking and thinking and thinking over, which direction to go with lifting my 1.5.
I want to use it for overland trips, but I know for a fact that there will be off roading/laning weekends in Wales throughout the summer and would really like to improve the vehicle handling off the road. I also travel with the family, so lots and lots of stuff to pack into a disco, plus an additional 300ish kg's of mods (front/rear bumpers, winch, rock sliders, guards, etc.). We usually camp somewhere and then go laning without the extra bags.

I was thinking of lifting it but no more than 2" (I don't want to roll it and modify the props) as I would like to fit my 31.6" MT's but the more I think and read about it the more this size becomes unrealistic to fit. Could I ask for your point of view on the above?

For overland you may want to have a separate setup to use just for that. A friend of mine overlands a 90 often. For 'normal' road use and off road he runs a Terrafirma +2 kit with medium springs. So longer +2" springs and longer shocks.

However loaded up and with the roof tent on, it feels completely unstable on road, way too much lean and body roll. So he swaps on some HD springs (also Terrafirma I believe). This makes it much nicer on the road loaded and works ok off road for the sort of use you'd take a loaded overland rig.

However unloaded and without the roof tent, the HD springs make it sit way too high, a lot higher than the +2 springs, plus it bounces and rides horrid on the road. And off road the springs are too stiff with too little weight to compress them properly, so it lifts wheels off the ground very easily compared to the other springs.

You might also want to consider anti-roll bars. My friends 90 doesn't run them, but would be another option. But anit-roll bars will reduce flex off road. X-Engineering offer their X-Deflex detachable anti-roll bar kit. Something like this might make sense for your use and allow you to run a slightly softer spring, but control body roll better.

Mackie4 said:

Allegedly with a turbo mod and a good remap they can squeeze out around 200bhp and nearly 600nm. Plus the fuel economy of 40mpg plus... allegedly...

But you are right, this would require a lot of work and even more money, which I don't happen to have atm. Plus a lot of custom built parts for the conversion and the reliability would be a big question mark.
It would be good to have some power but what matters to me most is the range and such fuel consumption would almost double the one of 300tdi.

Click to expand...

I can see no reason to take out the 300 tdi you currently have ,just work on getting it reliable by doing all the preventative maintanence

300bhp/ton said:

You might also want to consider anti-roll bars. My friends 90 doesn't run them, but would be another option. But anit-roll bars will reduce flex off road. X-Engineering offer their X-Deflex detachable anti-roll bar kit. Something like this might make sense for your use and allow you to run a slightly softer spring, but control body roll better.

Click to expand...

I managed to get a lot of articulation with roll bars, some D2 ones can allow high amounts, but don't go there!

May be worth just one on the 1.5 if none are fitted, or just disconnecting drop links when you need to, this is very common in America

I am just not sure how this is going to work out with d1 chassis and d2 body. I guess, will have to give it a go and see.

The plan is to go for the medium weight +2" terrafirma for both rear and front (for offroad/greenlane trips) and having a spare set of full HD +2" terrafirma for the back. Thanks for the tip with detachable anti roll bars. My good friend uses them on his jeep and I will do the same for my disco. I am just concerned that I will need to get rid of my 31.6" wheels as I doubt they'll fit... : /

chrisstdt said:

I can see no reason to take out the 300 tdi you currently have ,just work on getting it reliable by doing all the preventative maintanence

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Well, the main reason was to get an extra range on a tank (which will matter a lot, when I eventually set off into a proper overland - i.e. Siberia) and it would be nice to have some power too...
I am pretty sure that 300tdi will prove bullet proof if it is looked after and maintained properly.

Did anyone try modifying 300tdi inlet manifold (equal plenum) to allow a better supply of the air to the engine?

MJI said:

I managed to get a lot of articulation with roll bars, some D2 ones can allow high amounts, but don't go there!

May be worth just one on the 1.5 if none are fitted, or just disconnecting drop links when you need to, this is very common in America

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Yep, I know. I have been driving a D1 without any fitted for about 2 months and it was scary... but then the ability off road was just brilliant. I have never got stuck in those 2 months. As soon as I fitted front anti roll bar it was a game over - had to be dragged out of various places.

I think I will get rid of the rear one and run on the detachable at the front.

Mackie4 said:

Yep, I know. I have been driving a D1 without any fitted for about 2 months and it was scary... but then the ability off road was just brilliant. I have never got stuck in those 2 months. As soon as I fitted front anti roll bar it was a game over - had to be dragged out of various places.

I think I will get rid of the rear one and run on the detachable at the front.

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One reason I like the ACE system