Hi All,

I have been seriously considering a Subaru EE20 (Turbo diesel) conversion for my Karmann Ghia, but am concerned about the extra weight, hanging off the rear. From what I can gather the EE20 is about 20kg heavier in total than an EJ22.

I like the idea of a powerful and torquey engine, but not if it results in "1950's American style" handling (ie good in a straight line, but tip toe around corners).

What are people's experiences with the heavier engine? Are there any handling "eccentricities" and if so, how did you combat them. By the way, I'd prefer real world experiences rather than theoretical views.

(or if there is already a thread about this, smack me about the head and point me in the right direction)

Thanks in advance.

Timbo, great question mate. It's a question more people should ask.

In terms of an answer, let's start with reality.

REALITY; aircooled VWs are chronic understeerers in stock form.

This is the mark of rear-engined cars. ACVWs mask these tendencies by being chronically underpowered and having chronically soft suspension. Linkpins and swingaxle are even worse in this regard giving neutral camber up front and negative camber out back. However, most of this can be easily improved via some simple mods that have kept FVees fast for many years.

What happens when you add a heavier motor to the back? Well 2 things. Like you imagine, the understeer gets worse. However, beyond the understeer with all that extra power, you then get snap-oversteer. In other words you go; plough, plough, plough, SNAP, totally sideways and fighting to stop it pointing the opposite direction. So to go fast it means driving the car with the handbrake and the throttle for the most part.

How to fix that?
1. move everything you can to the very front of the car; battery, fuel tank, radiator, spare tyre, tools, etc.
2. cut off every thing you don't need in the engine bay, lighten the back of the car via speed holes, use lightweight fibreglass panels on the back of the car, get rid of the back bumper, use ali/composites/plastic instead of steel for everything in the back of the car, etc.
3. move the engine and trans as far forward as humanly possible.

This last step is the hardest and means you need IRS. It's major surgery and not for the faint hearted, but lots of people have done it.

If you do all this and get it all right, you can end up with a car that has a 50:50 front rear weight setup. I spoke to a porsche rally car owner years ago and he said they managed the 50:50 weight split without too many dramas. It just means thinking hard about everything you put on the back of the car. Of course if you manage 50:50, the car will handle amazingly.

Your trying this with a ghia will be much easier than my struggles with a buggy. Even still, the buggy showed a marked improvement as I removed weight from the rear, stiffen the rear chassis and moved heavy things forward.

Hope that answers your question.

^^^^^EVERYONE with a rear-engined car should read this.^^^^^

mate dont waste your money on a Turbo diesel.

Quote:

Originally posted by ian.mezz mate dont waste your money on a Turbo diesel.

Hi

I'm pretty sure that the Subaru engine uses a CAN BUS system to run the motor.

I think http://www.alldrivesubaroo.com.au/  are working on a system for late motors like that to work in earlier cars.

Good explanation Peter, you cant drive all differently configured cars the same way. No matter what sort of rear engine you have you will have understeer on tight low speed corners, it all comes down to the nut behind the wheel.

Steve

All drive Subaroo have finished defeating the CAN bus on late model ECU's - petrol or diesel. It's just a matter of getting the ECU flashed. You can also get a stand-alone ECU for the EE20 diesel - made by Hurricane. I hear that Bosch ECU's work on the diesel's as well. Lots of options really.

For handling - battery, radiator in the front for a start.

in the current economic climate its not economical to put a diesel motor in a petrol car the cost far out way the returns.

.
.
sand bags

I have always found our Beetle to handle heaps better when there are three slabs of beer in the front

Vlad,
Got Zelda completely 180 degrees in the wet the other day.
Definitely a lot difficult to handle than a FR car.

As soon as an RR car builds up momentum in the rear, all hell breaks loose.
Especially in the freaking wet and no tread on the rear tires!

Will definitely be looking into getting the weight distribution better and what not.

Dubster's 1303 has a consistant desire for oversteer in the wet and hasn't nabbed either of us in loosing it.

Even without trying, the rear end loves to go out before any sign of understeer is present. I guess the strut front and IRS helps massively, but the front is also lowered with some pretty beastly sway bars at the front too. It has stock tyres/wheels. Different kettle of fish compared to old swingaxle/beam front.

Good point modulus.

However, the oversteer is SNAP oversteer and preceeded often by some understeer too.

Something else to remember, MR (mid engined, rear drive) cars are also natural understeerers. That's why they are "slow in, fast out" cars. You brake hard, turn in and then accelerate out. Watch some of the mid engined cars on Topgear and you'll see what I mean. If an MR car gets out of shape, it happens fast is usually very hard to catch. Again some of this comes down to setup, but wherever you put the weight, that's what controls the physics. If you want a well balanced car (rather than a "drivers" car), like an RX8 or MX5 for instance, you go as close to 50:50 balance as possible.

Course there is a way to "drive around" the understeer. It involves lots of chucking the car round and lots of power. It's called "drifting". It's not usually all that fast.

Vlad: "Thankfully the late type 3's are nothing like this"

Sorry to rain on your parade, but they are much the same as every other ACVW. Look where the car suspension sags over the years... that's where the weight is. Lbugs too. The difference being, you can change your front camber easily.

In other areas, what was interesting is that on road or even in mud (low traction conditions) the baja is 95% time was riddled with mass under steer. My thoughts was the light weight of the front (which causes the front brakes to lock very easily too i noticed) would loose traction and just 'plough' in the direction of motion. I guess the 10.5inch wide tyres on the rear is what keeps the oversteer from peeping up.

Mind you with alot of effort, once you do get the rear spinning (in the mud), only then i can get oversteer to come about.

Hi Everyone,

Thanks for your comments. I have read and re-read your comments many times. Pete and Jak, your comments were particularly informative and have influenced my decision to give the turbo diesel conversion a try. I know I have to rethink a couple of things, but I think it should be do-able.

I know that economically it makes limited sense (and the further I get into it, the more extra costs seem to emerge), but if anyone has driven a modern turbo diesel recently, you'll understand that they have great characteristics for the street. Lots of torque down low and deceptively quick. Now, take a couple of hundred kilos from the original vehicle and it should be a lot of fun.

I'll start a build thread soon, once some building actually starts. I'm sure no-one wants to read pages and pages of degreasing and chassis painting, etc. I intend on outsourcing key parts of the project, but want to wait for the right people to be available, rather than paying for work I'm unhappy with. Unfortunately, this means there are already lengthy delays (including this reply, sorry).

Thanks again, Tim

A TDi motor will probably heavier than a subaru NA for a few reasons.
1. the blocks are usually iron to account for much higher compression
2. inline 4s (unless you are going subaru TDi) are longer and hence have the weight further back.

I'd actually advise against going with a TDi motor in KG for your average conversion. Coz unless you plan on building a specially designed tall ratio trans, you're not gonna get the value out of the TDi you would in factory car. To give an idea of the sort of revs, my Pug 307 diesel does only just 2000rpm at 110km/h (70mph) in 6th gear. You'd need a very tall gearset in a beetle box to get close to that. Now if you do LOTS of freeway miles, it might be worth it, but otherwise not. Modern efi EJs are pretty good and if you want better fuel economy you could put an aftermarket ECU on and tune it really carefully.

my EJ 20 bug uses 7.5lt per 100Ks

good luck .

This project is getting a Subie EE20 turbo diesel and a Subarugears 5 speed to suit. Going to be a helluva combo.

don't you think to be moving forward and you want to do something better , you be going electric. Rather then a rattly diesel.
Diesel cars ain't big sellers in Australia.
I guess we have to wait and see if or when you finish it.

Quote:

Originally posted by ian.mezz don't you think to be moving forward and you want to do something better , you be going electric. Rather then a rattly diesel. Diesel cars ain't big sellers in Australia. I guess we have to wait and see if or when you finish it.

Quote:

Originally posted by HappyDaze ^^^^^EVERYONE with a rear-engined car should read this.^^^^^

Ironic, there's talk about moving forward, but in a 60 year old car that has none of the hundreds/thousands of improvements that have been incorporated into cars over that time.

Who's trying to kid who?

Nah, I'm committed. I bought a diesel family car for all these reasons... and besides, they sound cool.