Puppan

The sound you hear is my manual boost controller in the car.. when the boost comes it leaks out thru the incar valve making that crazy snake sound :-)

Thanks by the way, I hope to be able to share some more videos this summer with the evolved TurbocUp :-)


/Pete

LtReid

ok, so are you the one driving the car, or.... the white boy jumping up and down?

Puppan

Actually I´m the crazy dude jumping up and down ;-)
At that time my car was the fastest 2wd car ever in that track on road legal tires, that´s the reason for my happy expresions.. It´s a test track for a car magazine and it´s always the same driver a old WRC pilot named Gullabo..
After I was there they laid a complete new asfalt so my car will forever be the fastest on the old track..

Here you can see some other wild cars that been raced on the track unfortunally they haven´t separated the old and new track but anyway it´s a cool list with many awesome cars..

http://rejsa.nu/superstage/

/pete

tedesco

@Puppan:
Nice machining done on the block but why did you sleeve it? Do you fear cylinder walls to crack or is it due to bore change? The rigidity of the block will not be improved by sleevs but certainly higher cylinder pressures will be possible. Did you experience the limits of the stock cylinder walls?

Puppan

Well I sleeved it because of the problems you mentioned above, one cylinder cracked in 4 places. So I indeed experienced the limitations of the cylinders walls ;-). Can you explain what you mean with "rigidity"? English aint my native language as you proberbly allready seen..

/pete

sweanders

Rigid = hållfast, stabil.

Raceboy

Puppan, what is the bore size now?

Puppan

Then actually I think the block will be much more "rigid" because of the contruction were all the the darton sleeves are interconnected and stabelised in the top.. Why shoulden´t it be??

If you do an ordinary "dry" sleeve change then I could understand your arguments?! But the Darton sleeves is complete different thing!

/pete

Puppan

Still 104mm..

/Pete

tedesco

So you realy had some cracks in the cylinder wall, that certainly was over the limit! Did not think that this would realy become a problem if you stay away from the wild things.

I think with the sleeing block stiffness will be affected in a negative way because allthough with Dartons "integrated deck" sleeves (I think this is how they call it) the bores in the bottom of the block to fit the sleeves will have to be enlarged. I do not belive that you get this back by having the top of the cylinders toughing each other. As far as I understand the assembly the cylinders are not realy connected but just in contact with each other. This should not incerase tosional stiffness or bending stiffness as the cylinders would be still able "to move" when the block deflects.

What was the maximum boost (and intake themperature) you run to get cracks in the cylinder walls. They are 8mm alu and should stand some seriouse pressure I thought. Which cylinder got the cracks and how did the others look like? (I am realy a curiouse guy...)

Puppan

I have to disagree :-)
I think the problem with the older Porsche blocks are that they are made in Alusil wich makes them really hard but not that good with movement.. In a turbo tuned 3l block car like mine the block has to deal with much more movement because of the higher cylinder pressure that comes from the turbocharging it then suffers more "pain" then it was consructed for and because of its alusil compond it cracks.. Another part is that because of the aluminium cylinder movement expansion and decreasing in every piston stroke the coolant near the cylinders walls are pushed away making a vacuum and that have a result of heatspots and kavitiation that increases the chance of a crack even higher...

This is a theory of mine and for the moment i can´t prove it in the 944 engine but I know that other kind of vehicles with aluminium cylinders with high cylinder pressures can have this kind of problems, for example turbocharged trucks ..


/Pete

ztnedman1

117mph trap speed!!! That thing would be nasty on the street from a roll. Too bad 951's cant launch worth a crap or this would be a low 12 maybe really high 11 sec car.

Chris White

You guys are thinking about two different areas of strength.
The Darton MID sleeves will not stiffen (or lessen) the torsional rigidity of the block as a whole – what they will do is eliminate the individual (free standing) cylinder flexing and create a more stable and stronger deck – good for head gasket longevity!

Chris White

lart951

Puppan, awesome video, great car keep the good work.

tedesco

Chris got the point. I was reffering to BLOCK stiffness and Puppan taked about cylinder integrity. About the cylinders beeing stronger after sleeving I do not have the slightest doubt but I belive that the bore increase you need to do on any block just to get the sleeve in (wet, dry or MID) will not help to strengthen the block. To which diameter did you need to bore to get the sleeves in? Are you both colaborating toget the block sleeved (Chris is doing the same as far as I know...).