Any experience on 20v on throttle bodies?

If your 'only' going to get 185 or so, why bother with a 20V ? you can do this is a 2L 16V on Kjet (and have a massive amount of tuning bits available to go further whereas you will find tuning the 20V very difficult, and expensive, given the lack of off the shelf bits)

For all the bother, I would want a damn site more than 185.

Rob

 

That's one of the reasons why I want to find out how much I can reasonably expect from this setup, that and the fact that the engine will be alot newer and hopefully more reliable...

 

stroking an ADR will give a poor rod ratio/angle, but it all depends on how many revs you want to pull,

power depends on cam spec, Bill has sourced some NA 20v cams, but i think the ADR ones are fairly warm as standard

 

2.0 20v ? This thread any use? http://www.clubgti.com/forum/forum_posts.asp?TID=31375&PN=1

Don't know how that will sit with your regs

 

I am starting to have some doubts as to how much power a standard 1.8 20v will give me if just run on throttle bodies. If I have to add the cost of new cams & assorted gubbins to the mix, (allowing for the cost of tbs and DTA ECU) then it starts getting an awful lot more expensive than the 2.0 16v option, or even the 1.8T option and just accepting that I'll run in the higher class.
I've spoken to DD, Badger, and Jenvey, and no one so far can tell me what power the standard 1.8 20v will put out on tbs. Everyone seems to tune these 20v engines with new cams, and increase in capacity. I'm nervous because as standard it's only 125bhp...

 

well the head is supposed to flow better than a race KR head, but it all depends if the cams are lumpy enough to make more power. i think it'd be in the 160-170 bracket, so really about stock abf output, but with less torque. however with more capacity, compression you'd have a good flexible engine.

more power is really going to come from more revs, the head has the flow capacity but the 20v head has some valve weaknesses, a new set of valves and springs is about 250-300, but it'd need some good rod bolts and cams to push it up to 8k revs. overboring with 2.0 pistons [alt?] will obviously help but you have to weigh up the costs compared to tried and tested 2.0 16v methods. ultimately the 20v head has more potential, it's just finding a good compromise with all the other parts.

 

The other thing to consider is what are you going to use for an exhaust manifold for a 20V ? its going to need a custom one.......ker ching. 16V one available off the shelf.

I am still not convinced that the 20V is in any way better at normal states of tune than is available with a 16V - perhaps its better at very high states of tune but where most of us are its very marginal IMO.

Trouble is however, there is very little info out there to base your decision on, the safe bet is the tuned 16V as its a well described beast, people know what works etc, the 20V may have massive potential but are you prepared to take the risk ?

I was seriously considering doing this myself last year but due to the level of uncertainty with this engine and potential high cost if it dont work out or you need to tune further, I decided against it and got a high spec 16V instead which produces well over 200hp and 170ftlb - - and has now eaten my gearbox .

Rob
Edited by: RobT

 

Who says the head flows better than a race KR ? these things get bandied around but are they based on any fact at all ?

Rob

 

note the use of "supposed" in a "have i I got news for you" allegedly styli

i believe it was badger bill that posted some flowbench results from vortex a while ago

can't remember what lift they were recorded at
Edited by: prof

 

I have a MK3 cable change box sitting on the floor of by garage waiting to go into the car... please don't tell me the ratios are going to be much taller than the existing rod change box in the 16v ?

Rob, did you get much power improvement from a 4-2-1 manifold on your 16v (if you use one that is?)

The only thing that holds me back from converting the 16v to 2.0 is the fact that I'm not sure how highly strung it's going to be, ad I need this car be able to get me to the track and back, sometimes a 200 mile round trip on top of thrashing the thing when I'm there!

 

This is exactly what I mean, no-one can remember who said what and legends develop based on no actual fact at all. And I would be more than happy if data does exist to prove me wrong on this point.

Agreed 'to the eye', the large port 20V looks well smart cf. 16V. But as any good tuning book will tell you, the port size is not where its at, its shape etc, and a well ported 16V is actually pretty good.

When you factor in a std off the shelf 2L bottom end for the 16V (cf. 1.8 for the 20V), stronger std valves in the 16V, much more availability of cams, verniers, exhasusts, inlet manifolds etc, the 16V looks a good bet.

180-200hp no problem with the 16V - how much do you want ?

10yrs from now, when the tuning houses have got off their arses and done some tuning with the 20V engine, we will all know the situation. Until then, in the absence of data and experiences, its a very expensibe gamble to make.

Cheers

Rob
Edited by: RobT

 

Obviously Mad20v's engine is a different kettle of fish to a normal ADR , for a start it's got a lot of custom bits inside and cost well over 7k No disputing his is a cracking engine which revs to 8500 which on his engine builders rollers puts out 200+atw, but it didn't come cheap.


Edited by: G_V_K

 

agreed Rob, if you are competing in a race series and need to be competetive then sticking with the tried and tested 16v route is a good move. I'm building a fast road motor using a lot of stock vw parts but in an unusual combination, we'll see how it goes.

Bill did have some graphs tho at one time

 

i'll be able to tell you all very soon - i've already flowed the 8v and 16v head here at work and will do the 20v shortly - it may take a litle while as it is a pain in the ar5e.
this is on an OEM industrial flowbench - a proper serios bit of kit with repeatable results. most of the flow bench results i have seen on vortex use acual flow figures in terms of lb/hr but there can be discrepancies in terms of the pressure drop used across the head, the position of the pressure tapping etc. I'll post my results as flow coefficients which takes all of this out of the equation.
for reference, the 8v vs 16v results were as expected.

cheers,
tt

 

Nice one TT , interested in the results from this.

 

Depends which code 02A box you have - different ones have different ratios. My manifold is a 4-1, off the shelf 4-2-1's I have seen for the 16V VW have a poor design with primaries too short. 2L 16V is a std engine - not highly strung at all.

Rob

 

Agreed, graham's engine is a belter and my comments are not directed his way, more towards more std mods and tuning potential of the 20V

 

TT

Do you have std unmodified flow figs for 8V, 16V and 20V heads ? presumably you took some before starting any flow work ?

 

amazing the resources available in a cardboard box under a flyover

 

all figs will be std. 20v (wide port) to be done shortly.

tt