Any experience on 20v on throttle bodies?

how bout 8v x-flow?

 

don't take the pi55 now - this is done in my own non-existant spare time. i could possibly do in 6-8 months time if someone could supply a head

tt

 

Right, one detail on the sprinting regs regarding engine types allowed, the MSA state that;

"The engine block must be externally identifiable as that fitted to the original model"

So the question, can you guys tell me if the 20v block (turbo and non-turbo) is identical to the KR block. Doesn't matter about the sump, or the head, or any of the contents of the engine apparently...

(thanks for your feedback on these questions so far )

 

dunno if it's identical but it's bloody similar

all derived from the old 8v block

tt

 

same enough for mod prod, not for road mod and std
Edited by: RobT

 

So here goes the $6 million question, do I fit the 20v turbo and move up a class to the over 2.0 (due to the 40% wieghting for turbos), albeit to a lot quieter class with less competitors. Or do I modify the 16v engine and compete with all the stripped out ex-rally cars in the under 2.0 class, which is I'm told a lot more competitive due to the numbers of cars competing.

...what to do...

 

Nice looking manifold..
did'nt know one existed..

where did you get that?

 

The flowbench figures were real and on Vortex. so no doubt a search may reveal them again. (over to someone else to do that who has more time than me)
Flow bench results not neccessarily being directly relating to power tho as we know, but an indicator of potential.
Lumpy 20v cams.. not sure how lumpy they can go...
Cat cams list some fruity ones.. but think mechnical lifters for those and definately pocketed pistons to clear the extra lift.

 

Link from Vortex:

http://forums.vwvortex.com/zerothread?id=1102510

Figures in CFM @ 28" - I assume this pressure for flow but 28" what I'm
not sure - perhaps 28" (700mm) water or mercury above atmosphere
(760mmHg). Also, valve lift measurements in thou, 500 thou = 12.7mm

Top graph is AEB (large port 20V) vs stock 1.8 (KR?) 16V
Intakes show about 20-25% more flow at a given valve lift with 20V

Bottom graph is small port 20V
Not really that different from 16V, especially at higher lifts

Need to examine further - Will put all data into Excel tomorrow andget
nice multicolour overlay

Thoughts and comments from rest of thread:
1. Wonder how flowed heads compare ?
2. Small port has no flow increase above 300 thou lift (7.62mm). This is
sod all lift for a cam - std small port head likely to have little point using
hotter cams
3. Need to overlay std and hot cam lifts on these plots
4. Large port std cams - exhaust 366 thou lift (9.2mm), outer inlet 303
thou and inner inlet 301 thou. And timing on inners is different - valve
clearance issue ? may be difficult to fit hot cams to a large port head thus
without piston mods (and cutouts will reduce CR so may need custom
pistons).

Later

Rob

 

Good find dude.

 

Now then

Dug out some old literature I had from when BRM were developing the 16V heads and found std and after flow figs (with std size valves):

Inlet 87 CFM to 106 CFM (inc. 22%)
Exhaust 66 CFM to 92 CFM (inc. 39%)

These were at 10" WG pressure and no valve lifts were stated. WG=water guage which is pressure above atmospheric, 1"=0.036psi. The vortex figs are thus perhaps 28" WG so higher inlet pressure than BRM figs so this coul;d explain higher flow figs of 16V.

Obviously we need more info but its a start - but right now I would say that 16V race heads are better flowing than std large port 20V heads
Edited by: RobT

 

vortex test at 12.7mm lift, that seems pretty high,

 

12.7mm lift is pretty high but graphs plateau pretty much at 10mm which is std cam lift for a 16V

Have made a composite graph now of all these traces and it makes interesting reading - dont have anyway to post it up here though.......

Rob

 

It'd be nice to see a 9A head with some graphs to.

Looks like the low lift flow figures would be better than the KR from looking at the two heads to me.

 

i guess you can't just look at the head or cams in isolation, meaning that if you have a cam that has a very savage opening ramp then the valve does not spend very long at low lift etc. or if it's only running mild cams then flow over 500 thou is irrelevant.

Surely the 20v was developed as an improvement over the 16v but i guess the aims were mostly emmission related

 

which head was better in the end did we ever find out

 

Give Elton @ Jabba a call as they recently mapped a 20v on t'bodies.

 

what ECU bill? not OEM surely

 

not std no.. cant rememebr is DTA or Haltech

 

any specs of the car