improvement on performance??

[philO 0]

is there anything i should do to improve the proformance of my 1.8 16v while i've got the head off, that won't break the bank and send the insurance rocketing?

phil

[cheesy 0]

Don't know fully about prices but gas flowing and porting is the way to go on head inlet and outlet manifolds

[Rossco 0]

get a mk2 golf inlet manifold its got a 50mm diameter instead of the corrados 42mm and i does make a difference, not too expensive either

 

Ross

[Rpmayne 0]

I thought I read somewhere that some 16v golf owners changed the 50mm diameter manifold for the 42mm to increase low down torque. Just wondering whether they did that because the corrado is heavier and needs it to pull away better.

[CaiosG60 PWR 0]

I think I'm right in saying, get a 2.0 16v passat bottom end from a scrap yard and just bolt it onto your 1.8L head to give your engine a conversion to 2.0L. There is a bit more to this conversion but not a huge amount. Also go for the 50mm inlet manifold of a Golf MK2. Keep your VW exhaust manifold but get it matched to the head along with your inlet manifold. Along with the other usual bits and bobs, exhaust, filter, leads, plugs, etc you should have a car with plenty of grunt!!!!!!

 

 

My mate spent money on a TSR 16V manifold and it was no better than the standard VW one! :(

[cheesy 0]

I think i was told that on C's around the 90/91 yr had the 50mm inlets as standard

[dav 0]

I have heard that swapping the cams with the ones from Golf GTI 16v helps, and a funny one this, but I have also heard that if you use an exhaust cam on the inlet it will also help gain a few bhp up the mid to top end.

 

Apparently all you have to do is chop the end off and get a slot machined in it for woodrush pin and fit it. I think that it has something to do with the slightly wilder profile. The chap the was talking to about said that it goes a bit mad after 4500 rpm with this mod. He said the he got Stealth Racing to machine the Cam for him.

Also you can up the fuel pressure, by opening and adjusting the Fuel Pressure Regulator, but this would only be worth while of you already made mod's that require the extra fuel.

 

HTH

[Scott 0]

I think i was told that on C's around the 90/91 yr had the 50mm inlets as standard

 

Correct.... my 91 had a 50mm inlet as standard.......

[philO 0]

arr ha!! my 1990 1.8 16v does have a 42mm inlet manifold! are the holes in the head going to need enlarging as well?

philo

[sc16v 0]

The cost of gas flowing ahead on a 16v head is not worth it... if your only stripping it down for that (ie if its running ok) on the other if its off for a reason then it's worth getting gasflowed. Chaning cams improves perfromance does make idle very rough indeed on KR engines though,

But the only way to see big improvements is to put the 9A 2l engine in and fit KR cams to it 165BHP (with exhaust, filter etc) But trying to find 9A lump is very tricky indeed, they cost about £400 at the mo :D

[philO 0]

thanks for that, the reason the head is off is cos the gasket blew! if i was to get it gas flowed, how much bhp would i gain roughly and what would the cost be?

phil

[sc16v 0]

You could do it yourself save money but gains might be smaller, than if pro did it.

You can see gains around 15BHP but expect 10BHP, Cost should be couple of hundred depending who you use.

[Mike Edwards 0]

1. Fitting the larger diameter inlet will improve the top end, but at the expense of losing even more low and midrange.

2. Gasflowing and porting is worth doing, but costs~£500+ (unless you know someone who will do a good job for very little...)

3. Kent Cams will regrind your existing camshafts to GF1602R speck for less than £200 all in to give 15-20bhp extra and a lot more torque across the rev range.

 

Needless to say I recommend going for No.3 and have had this done to my 16v.

 

At the VWCCGB Rolling Road Day at Stealth Racing earlier this year it managed 155BHP (well, okay...154.8BHP...)

 

Next to come is a K&N panel filter and some adjustment of the mixture to see if I can get it into G60 territory while keeping it driveable.

[sc16v 0]

Mike Edwards. Whats your idle like with those cams in. Ive seen and heard about some KR running rough and this is why its always put me off, I have few hundred quid at the mo so would consider this again :)

[Mike Edwards 0]

Very stable.

 

They are a fairly mild set, so not that surprising.

 

I imagine you'd have to try something a bit more radical to mess up the idle, or maybe you could get the same effect by going overboard on the gas-flowing and porting, leading to rough running at low engine speeds.

[Dirtysouth 0]

How about skimming the head? i dne this on my nova to increase pressure, not to sure if it helps on 16v? just a thought? :roll:

[cheesy 0]

when the head goes 99% of the time u have to have the head skimmed so when its put back together it seals right.

I think i'm right in saying this, someone please correct me if wrong

[CaiosG60 PWR 0]

cheesy, I recon your right about getting the head skimmed. If its a aluminum head that is usually the case. I know 8v have aluminum heads but not sure about 16v's. The problem is that when you skim a head you mess with the compresion or something!? As the area inside the head becomes slightly smaller. This can be counter acted buy fitting a thicker head gasket. Such as a metal performance one.

[cheesy 0]

I had mine skimmed cos the gasket went, mine was only very slightly pitted

[iceman 0]

we took a 50mm intake manifold at school and bored that sucker out to about 55mm. i don't know how much it costs at a machine shop it was free at school.

[sc16v 0]

There is a tolerance on heads, when skimming so there is a limit it can be skimmed to before it starts to alter the compression.

As a rule its is adviseable to skim the head before refit to enusre to flat surfaces. (head and block) :D