Oettinger, Graf, KR and ABF heads - How much do they flow?

VW Motorsport, and Seat Sport, with some TBs of unknown origin to this day:

 

Oh blimey, look at that. Awesome. I wonder how it went? Would a manufacturer (e.g Jenvey) be able to produce something like this on a one-off basis?

 

There's no way any manufacturer would - doesn't make economic sense.

 

This suprises me. Let me explain.

A high spec Pug 205 8V will manage about 175hp - thats an 83 bore and 88mm stroke (1904cc) with 43mm inlets and around 11.5 CR. bhp/l = 91.91.

The VW 8V with a standard bottom end is 82.5mm bore and 92.8mm stroke (1984cc) and the TSR Pack D head had 40.5mm inlets and 35mm exhausts. You ran less CR at 11:1. So with less CR, less valve, you managed 97.78 bhp/l.

Full on race pintos with massive 45mm and over valves dont do much better than 100hp/l.

Now I'm not saying you didn't get the power that you claim, I know the car was very successful so respect where respect is due etc, but I dont think it was as easy as you make out.

Whats interesting as far as this thread is concerned is the increased valve area possible with a 16V over an 8V - inlet valve area for a TSR pack D head = 5153mm2 whereas for a std 16V (32mm inlet) = 6434mm2, a 20% increase in flow area.

Found some flow diagrams for 8V (regular and big valve) and 16V heads:

http://www.cncheads.co.uk/vw_1800_16v.html
http://www.cncheads.co.uk/vw_golf_8v.html
http://www.cncheads.co.uk/vw_golf_8v_bv.html

says it all really

 

Why would you need a one-off set of ITB's?

If you want to get an extra injector in there, that could be done in a custom manifold (e.g. one based on the bottom half of the VW 16v one.) with one in the ITB itself.

 

I'm looking at going 8 injectors, just going to machine up some bosses and tig them in to the trumpets, just something i'm interested in trying as Dave Walker allways raves about it and It's a cheep way to flow enougth fuel for a possible bioethanol map.

 

Like your thinking....E85 is the future

 

Why not do a F1 style and dangle them inside the trumpets, in sure with some bracketry you could hang a fuel rail and injectors so they stick inside the bell mouths. Would this ensure better fuel atomising? I assume that is why they are dangled in F1 engines

Would the injectors cause much of a reduction in the air flow?

 

The word "dangle" with regard to car engines makes me nervous...

Adding them into the trumpets sounds like it could be an idea. Has anyone tried this successfully?

 

surely adding them in the airbox pointing into the trumpets for really high rev work would be pretty easy

or if using bike bodies you already get the injectors integrated near the trumpets

Tramp ran 8 injectors on his super/turbocharged ITB'd thingamy

 

I am sure you are aware that actual bhp is not just a factor of valve size, CR and bore/stroke relationships. Maximum potential bhp is dependant on these factors...but also many others.

Oh and you mean 20% more valve area....not flow area.

Probably worth mentioning that the BTCC sciroccos were 183bhp from a 1600cc bottom end...pretty special engines granted, but goes to show that the airflow is available to generate that sort of BHP.

 

Would this not result in the butterfly being a long way from the head, having an adverse affect on throttle response?

 

the further away the injectors are from the head is for high revs the closer set are for low revs, then its a matter of staging the switch over in the software

 

Those SEAT ITBs look very similar to ones I had to do as bit of work on a couple of years back. Machined by an Aviation Co in Portsmouth. 8 injector bosses and a straight shot into the head. Thats all I'm saying.

 

Interesting. The pic is actually from a Mk3 Golf kitcar...but I suspect the hardware was similar if not the same on the Seat Ibiza kitcars.


A few Portsmouth aviation companies....

http://www.google.co.uk/search?hl=en&q=aviation+portsmouth&meta=

Why an aviation co would be near that sort of componentry... I have no idea

 

I have just been on the Jenvey website, would any of their twin injector bodies fit a vw head I wonder?

Also on a slight change of tack, has anyone used a motec m800? And does anyone know of someone good who could make up a loom and map it?

 

Various Motec dealers around - Dialynx springs to mind.

 

Thanks Chris. Checking them out now.

 

Motec (UK?) are based just south of Banbury - Adderbury if I recall.

 

Good to hear, I am just outside Reading so either of these places are reasonably close. Always handy, I will pop in and see them shortly.