1.5 70HP JB tuning advice?

Hi guys.

Have a 1982 1.5 70HP enginecode: JB. (European model)

I am looking for a mild modification, with the aim of gaining more torque.

It´s a 5speed gearbox, ab werk, and I find that I have to shift down to 4th gear, when I encounter a hill at 80 to 100km/h.

Apart from the lack of torque, I think 70hp is almost adequate for the light car.

I was thinking of the following:

- Race cam
- Exhaust
- switch from Pierburg carb to Weber replacement carb (Not 40mm) - Will it make a difference? If not to power, then just to consumption and driveability?

Which cams would you suggest and do I have to put on a full exhaust system with manifold (Ridiculously expensive)?

And are there any bottle necks on the 1.5 engine that I should know about? Due to th Danish legislation I do not have the option to do an engine swap  

Thank you very much!

Race cam - no dont go that route it will impact on driveability and put the power higher up the rev range at the expense of low down torque.

Weber carb may help if the pierburg carb is past its best.

First thing to do is ensure all the service items are replaced, thats plugs, cap, rotor, leads and filters to ensure theyre at optimum.
Then ensure the timing and fuelling is correct.

If youre intent on swapping parts out to improve the engines performance, then first port of call is a free flowing air filter, followed by a 4-2-1 tubular exhaust manifold ( that will help with torque).
You can then move on to less restrictive exhaust boxes but the noise will likely be greater.

Cylinder head will be a restriction if power and torque are what you want so attention to that would be a next step after youve done all the rest.
I could certainly improve the cylinder head for a reasonable cost if you could get the head to me in england.
Pm me if you wish.

Hope thats useful.

Overboost said

Race cam - no dont go that route it will impact on driveability and put the power higher up the rev range at the expense of low down torque.

Weber carb may help if the pierburg carb is past its best.

First thing to do is ensure all the service items are replaced, thats plugs, cap, rotor, leads and filters to ensure theyre at optimum.
Then ensure the timing and fuelling is correct.

If youre intent on swapping parts out to improve the engines performance, then first port of call is a free flowing air filter, followed by a 4-2-1 tubular exhaust manifold ( that will help with torque).
You can then move on to less restrictive exhaust boxes but the noise will likely be greater.

Cylinder head will be a restriction if power and torque are what you want so attention to that would be a next step after youve done all the rest.
I could certainly improve the cylinder head for a reasonable cost if you could get the head to me in england.
Pm me if you wish.

Hope thats useful.

Thank you for the constructive reply!

I realise that I have posted in the wrong forum. Sorry about that!

The basic engine has only 100.000km on the clock, so it's in quite good condition.

I have replaced plugs, airfilter and rotor recently (Not leads) - I am planning on doing a Dyno test in order to determine how overall condition is.

I will start with a 4-2-1 and an open filter eventhough the manifold is very expensive  8O

Is Peco a good make in exhausts? They have a great value for money solutions from manifold and backwards.

I think I will swap for the Weber as it would do a little bit better in driveability and fuel consumption.

I also plan on getting the ignition adjusted as well as the new Weber on a rolling road after installation of new parts.

How much would the polish and porting of the cylinder head roughly give in terms of HP or NM?

http://www.hottuning.eu/?nav=products&subnav=view&product_id=180

This is a reasonable price, but it only says 8V? Will it fit my 1.5?

Im planning on getting a Simons Sport Exhaust system from manifold and backwards:
http://www.carlab.dk/shop/sportsudstoedning-vw-golf-81565p.html

Pipercross open filter: http://www.carlab.dk/shop/luftfilter-60-x-5458p.html

Don't bother messing around with the 1.5. If you want an upgrade, the first stage I'd do is replace it with a 1.8 from a later cabby or scirocco. It can still be carb but the Weber is a useful aftermarket fitment, if only because the original Piedburgs wear and then cause erratic running. As well as 300cc more, they're high compression. No need to go to 1.8 injection, the hassle of that will be more bother than the gain you'd achieve.

paul_c said

Don't bother messing around with the 1.5. If you want an upgrade, the first stage I'd do is replace it with a 1.8 from a later cabby or scirocco. It can still be carb but the Weber is a useful aftermarket fitment, if only because the original Piedburgs wear and then cause erratic running. As well as 300cc more, they're high compression. No need to go to 1.8 injection, the hassle of that will be more bother than the gain you'd achieve.

Hi Paul.

Because of Danish legislation I am only allowed to do an engine swap if performance do not exceed 20%, which means a maximum of 84HP.

The Scirocco's 112HP, makes it too powerful to get it approved. The Danish laws are unfortunately very strict.

And I also would like to preserve the original engine, as the car is in excellent original shape.

Does anyone know if the manifold will fit my 1.5?

//Mads

That's a shame because the range is structured:

1.5                  70 bhp
1.6                  75 bhp
1.8 carb           90 bhp
1.6 injection     110bhp
1.8 injection     112bhp

So if you're limited to +20%, then the 1.8 carb is 6bhp over. How do they measure this, is it official manufacturer's figures?

Tuning options are limited on the 1.5. You could do a cam swap (to a GTI cam), swap the exhaust manifold and re-jet a Weber carb to suit, but I think after all that effort you'd still be in the region of 75-80bhp (ie, not much gain at all). Really you want higher compression, and the only way to do that is swap the pistons, and the most economical route to that is an engine swap - but the 1.8 carb (which is high compression) is 90bhp. Pistons from a 1.8 won't fit into a 1.5 without a rebore, and then you're into £££ (or Knone in your case).

paul_c said

That's a shame because the range is structured:

1.5                  70 bhp
1.6                  75 bhp
1.8 carb           90 bhp
1.6 injection     110bhp
1.8 injection     112bhp

So if you're limited to +20%, then the 1.8 carb is 6bhp over. How do they measure this, is it official manufacturer's figures?

Tuning options are limited on the 1.5. You could do a cam swap (to a GTI cam), swap the exhaust manifold and re-jet a Weber carb to suit, but I think after all that effort you'd still be in the region of 75-80bhp (ie, not much gain at all). Really you want higher compression, and the only way to do that is swap the pistons, and the most economical route to that is an engine swap - but the 1.8 carb (which is high compression) is 90bhp. Pistons from a 1.8 won't fit into a 1.5 without a rebore, and then you're into £££ (or Knone in your case).

It's such a shame about the remaining 6hp, but that's the way it is - It will trigger a new registration fee, as the car will have a change of "identity".

I am currently talking to a guy who has a spare 1.6L GTI camshaft which would do good on the engine and by putting GTI valves on the 1.5L cylinder head and modifying it to go from the low compression (8.2:1) to a higher one similar to the 1.8 with 10:1.

The standard 8:2:1 is actually just ready for a turbo  :mrgreen:
I have been told that the original (exhaust) manifold has some sort of tube in it which acts as a restriction and that explains the good performance gain from the 4-2-1 manifold.

I have just ordered:

- Stainless Steel 4-2-1 Manifold
- Weber replacement carb
- 1.5 JB cylinder head for modification
- 1.6L GTI Camshaft
- Simons 2" sportexhaust system from manifold and backwords

Missing:
- Rolling road test to determine engine health and HP/NM before project start

 8)

any updates on this? very interested

did this project ever happen?  i'm doing the same to my JB and I'm interested in how it ended up..

Hi guys,

It has been a long time since my visit to this site.
But I have worked quite a bit with my little Mk1

First of all was a complete service:
- New sparkplugs
- New ignition cables
- New rotor
- New rotor cap
- New coil
- New condensator
- New "Platins" (Don't know the English word)
- New rubberflange for Pierburg carburetor
- New vacuum hoses
- New gasoline hoses
- New radiator
- Oilchange, oilfilter, airfilter, gasoline filter, thermostat, fan temp sensor etc.

I started with buying a 4-2-1 stainlees steel manifold:
http://www.hottuning.eu/?nav=products&subnav=view&product_id=180

Great price and fitment was ok - But not 100% bolt on as one or 2 of the flanges for fitment on the engine had to be "massaged" a bit to go on, but a part from that it's great! It gave a lot of torque compared to the original restricted manifold. Also the sound was improved to the better.

Second mod was a 2,5" exhaust from Jetex.
http://www.vwheritage.com/vw_spares_Exhaust-Sys-Jetex-Single-Oval-70-90MM-G1-83-Sci-Mk1-WC253J29H5_act_shop.product_pID_19642143_lang_EN_country_GB.htm
This worked great with the manifold and the car now has a great sound without being to noisy or loud. It sound brilliant standing in the back of the car and hearing the engine idling with a deep throaty sound. The sound when revving is more metallic, but still controlled and full of bass.
If I had to buy an exhaust today I would probably buy one with the german style tailpipe with the upside curl.

Third mod was a Weber Conversion kit from Fastroadcars:
http://www.fastroadcars.co.uk/shop/index.php?act=viewProd&productId=11

I fitted the carb, but had to mod the flange between old manifold and new carburetor.
I wasn't satisfied with this solution and had trouble with the throttle cable mechanism.

Luckily I found a pair of Solex C40 ADDHE (2x40mm) from a 1600 Alfa Romeo Spider.
The set was previously used on a 1.6 GTI which correct jetting manifold and everything at a great price.





The last picture is with new throttle linkage from Fastroadcars.
Also I have ordered new soft mount and airhorn/airfilter, which is also fitted.
The sound is unbelieveable and the performance is much better than expected.
I can only say that this is the best mod I've ever done to a car.

See video here (Danger of great sound ..!)
http://www.bilgalleri.dk/video/tuningprojekter/48871-vw_golf_1___15_jb_med_2x40mm_solex

Next mod is electronic ignition from AccuSpark with complete new Bosch JFU4 distributor:
http://www.mgcenter.dk/pi/Bosch_009_JFU4_str%C3%B8mfordeler_m_AccuSpark_3691_301.aspx

Also I would like to get the head portet and polished and supplemented with the 1.6 GTI camshaft that I got lying under my bed

I love the video! Great noise! I've got a 1.5 gl which am looking at lightly modding…didyou ever get rolling roaded?

Nice video. Lovely sound. Seems to shift a bit as well. Nice work mate.

Shame about the regulations in Demark. I bet sometime soon we will have them here in the UK

Hi,

I am also thinking about putting a double carb into my mk1, i have excatly the same engine as you so i Was thinking if you can help me.
at this moment i am thinking about weber 40 dcoe and my question is what else do i need to make this conversion from pierbirg 1b3 to weber 40dcoe. Manifold? Carbs… What else? Do i need fuel pump?