MK1 GTI Throttle body upgrade

I've heard that using the throttle body of an old audi 80 2.2litre will improve engine response on mk1 gti's. Is this true??? If so is a simple enough job to do? And also which would be the best throttle body to use? Also would it just bolt straight on? Would appreciate any help. Thank

 

You will need to enlarge the plenum chamber.
You should also fit the Audi's WUR at the same time because it has vacuum based fuel enrichment to cope with the larger butterfly when you bang the throttle down.

 

there is a how to thread on www.vwgolfmk1.org.uk

Amit

 

Audi 80 one will look like this in the mk1:



You will need to grind out behind it to match up the original (now to small) hole with the larger butterfly.

Only slight pain is the idle adjustment screw is then facing the bulkhead (just above silver clip at the back in pic) so it can be tighter to reach (i had a bolt put in mine instead of the screw head).

 

Your engine looks a longway/tilted forward Mike?

My throttle body sits under the bulkhead rather than so clearly in front like yours

 

That was during the strip down so maybe it was moved slightly?

 

I see it not as easy a job as I thought!!! Will the change be so much to really justify it doing??? I had no idea about having to grind parts!!! How about if i were to use a mk2 gti throttle body? Would that be better? I'm assuming no grinding will have to be done - lol!!!

 

When you put a larger TB on you get a slightly better response but along with a good air filter & freeing up airflow into the box you might get about 4-bhp.

The whole idea about changing it is that it has a bigger opening, so the inlet manifold must be opened up otherwise there is a big lip & it will be pointless?

You can get one from a scrappy cheap so just take yours off & use some paper to draw around the hole & see the difference between the old one & the new one & that's what will have to be removed from the inlet when it's off.

 

I always thought the audi WUR mod is only necessary for 16v cars....???, Is it really necessary for mk1 8v???

 

I am not talking about the "WUR" mod but complementing the increase in throttle body second butterfly size with its companion WUR.

The "WUR" mod is something that Vince and Stealth does, he drills out the little brass plug on the back of 16V and Audi WUR's and turns the allen headed screw to alter the fueling, often making the k-jet run a little richer, they tend to run lean at higher revs by default.

The 16V and Audi WUR's have a vacuum pipe that allows for a momentary increase in fueling when the throttle is opened up quickly. The plenum chamber experiences a -ve pressure on hard acceleration which then causes the WUR control pressure to drop which in turn allows the metering head plunger to rise higher for the same volume of air demanded by the engine - hence a richer mixture. The -ve pressure disappears and the fueling drops back to the normal air/fuel ratio.

So you don't need to do the WUR as well but it will help on hard acceleration.

Alternatively you could use a k-star if you can find a working one !!

 

Is the audi 2.2 throttle body and vw mk2 8v and 16v the only/best throttle body to upgrade to or are there any other ones that are better?

 

Your not going to free up air much more with anything else.

 

How much would i expect to pay for an audi 2.2litre or mk2 throttle body????

 

Mine is i think? an audi80 one & i have had it for years now so tbh i ain't got a clue mate.

 

10-15

 

I've seen 2 types of throttle body's on ebay recently ones an 'AUDI VW THROTTLE BODY New genuine B1 078 034 063 DC VAG - http://cgi.ebay.co.uk/ws/eBayISAPI....MEWA:IT&viewitem=&item=220087909167&rd=1&rd=1
an the other is a 'VW GOLF GTI - SPORT THROTTLE BODY - AUDI 2.0 8v MK2 MK3 - http://cgi.ebay.co.uk/ws/eBayISAPI....MEWA:IT&viewitem=&item=330093113665&rd=1&rd=1
i'm pretty sure that the audi one is of a v6 - would this fit also? and the others of a mk2 golf 2.0l 8v what would i have to grind down on either throttle body to make them fit or would it be better to wait and get an audi 2.2? Thanks

 

you don't grind any thing off the throttle body, you grind the mani just behind it to match it up to the larger hole in the new TB.