1.8 JH-engine tips?

[kapsu]

GTX,

so the 4-1 exhaust manifold of the JH is a bottle neck? what can be done?
Different manifolds available?
here seems to be one with dual outlets:
http://www.techtonicstuning.com/viewpar ... um=251.101
and matching downpipes as well..

Or just get rid of the whole original front section and get a decent manifold&downpipe and change to high flow cat at same time.. as they wont fit the original cat anyway. hmm, not cheap :/ well, nothing is..

ps. how can I make actual links here?

[Angel]

hi,
why don't you replace your Jh with an PL? Isn't that allowed in finnland? That's the easyest/cheapest way to get more horsepower.

there are two ways to put links in here:

Link1: http://www.rowi.net (url)http://www.rowi.net(/url)
Link2: RoWiTech (url=http://www.rowi.net)RoWiTech(/url)

you must replace the parenthesis () with brackets [] than it will work.

greetz angel

[Tempest]

>the lower compression is due different pistons

This is correct (even have a nifty picture in a book here showing the 2 pistons, the JH one has a deeper mould in the top of the piston).

The effort in changing the pistons is still considerable given that as Angel has already said, you may very well be better off starting with a 16V block.

This is very unusal for me to say, as I normally am a big fan of the JH engine, well mine at least, as prior to me buying my Rocco with the JH, some other person had already kindly invested bucket loads of money and time in modding that engine (increased the compression by skimming the head, now back up to 10:1 again). So my JH is quite a different story in terms of tuning. But if yours is still totally standard, then even I would have to agree that unless you really want to stick a lot of time and effort into that engine, you are better off getting a DX (probably very difficult in Finland), or some 16V block.

Tempest

[GTX]

It even makes sense instead of buying a complete DX/EV(from Gollef2) getting an EX(90hp carb enginge) oder an 2H(Gollef1 Cabrio)-Block and put the JH Head on it. Then u will even have the 10:1

[kapsu]

about the Audi throttle body.. which models have the compatible part?

[kapsu]

I just checked the throttle body and the holes measured about 36mm and 45mm.. what size is it in the Audi body? It can't be much bigger if it will fit the original manifold & mounting?

While measuring I noticed that the cable was a bit loose and the throttle flap didn't open all the way to the max from the pedal.. and it didn't hit the full throttle microswitch. What does the switch do anyway? (couldn't even find it on some older technical pics..)
Well, adjusting the cable was cheap

EDT: picture attached



Post Edited (07-18-05 12:50)

[Tempest]

>It can't be much bigger if it will fit the original manifold & mounting?

The Audi throttle body does have bigger butterfly valves, which hit the opening of the original manifold when you're trying to fully open them. That's why using a Dremel you will have to grind some material away at the opening of the original manifold to make room for the valves to fylly open.

>What does the switch do anyway?

It signals the Lambda control unit to ignore the Lambda sensor readings and enrich the mixture.

Tempest

[kapsu]

Tempest wrote:

> you will have to grind some material away at the opening of the original
> manifold to make room for the valves to fylly open.

Ok, that is not a problem. It can be attached directly to the original screw holes on the manifold?

What is the correlation between the throttle body and the warm-up regulator, why change both (mentioned above)?

I noticed many 5E units in the eBay.de, have to check the local VAG forums first ;)

> It signals the Lambda control unit to ignore the Lambda sensor
> readings and enrich the mixture.

thanks for the info!

[Tempest]

>Ok, that is not a problem. It can be attached directly to the original screw holes on the manifold?

Yes, but you just need the extra clearance on the manifold for the larger butterfly valves to fully open.

>What is the correlation between the throttle body and the warm-up regulator,

The Audi throttlebody has an extra vacuum connection that goes to the warm up regulator to further enrich the mixture on demand. Although some people have used the throttle body without the Audi warm-up regulator, the results weren't that satisfying (guzzling fuel etc.).

Tempest

[GTX]

I think the exhaust manifold from the G1 Cabrio Enginge 2H 98HP will fit, is is a little bigger than the JH one.