The '2 ton bugswatter' - back for a gentle stroke

[JP]

Linky?

[chaloux]

http://forums.quattroworld.com/s4s6/msgs/234741.phtml

[JP]

Cheers made for an interesting chasing myths read.

Will clear a couple of things up.

The 7A cams are like vw's kr cams for the 16v in terms of duration but with greater lift. It was common practice to fit two exhaust cams to the 16v's by chopping the nose of so it would fit inside the head like an intake cam.

These where subsequently timed up as an exact duplicate of the exh. Eg (fictitious figures) 236/218 and 218/236 with regards to opening and closing events. This makes for a great na cam based on centre lobe configuration compared to stock.

Exactly the same applies to the 7A cams. However now we want a lobe seperation suited to turbo use so a vernier is required to dial in the relationship between int and exh. A further vernier is then required on the belt to tweak the relationship to the crank.

I spend a long time playing with timing settings on a virtual dyno simulater running a cam iterator to simulate 100,000+ variations based on the opening closing data of the 7A exhaust cam specifying peak power as my end target. Running the end configuration back to back against catcams hydraulic I5 turbo cams it came to light that they both produced near identical peak power on the simulater using flow data personally aquired on my flowbench. With the added bonus of improved midrange power delivery with the twin 7A's.

Using my dialling in config power delivery in the midrange is equivalent of stock AAN intake with 7A exhaust. But peak power is broader and higher not tailing of as quick as can be seen from my dynoplot. Achieving 1bar of boost at 4000, 2bar @ 4200 and 2.5bar peak @ 4400 on the stroker 3586 combo.

Hth JP

*edit as reference if you specify max torque under the curve the program gives you the exact spec of the rs2 cams

[diesel des]

Jp can you point me in the direction of where to get a vernier cam pulley that has the pickup for motronic. Cheers des

[JP]

I picked mine up from 034. Ordering my flywheel clutch from them so could add it to order when time comes and safe you some shipping _

[diesel des]

I see they sell two jp. Can you link the one that's needed to work with tye cam sensor. Sounds like a plan on the adding to your order. Cheers des

[JP]

Scrap that they don't sell it anymore

[diesel des]

Dohh. Any alternatives?

[Billman]

I got mine from Rosten.

[diesel des]

His website seems dead...

[JP]

Tiny little update going to start over the weekend to get the car up and running again as I've taken delivery of some goodies.

[prj]

Sorry for too much torque

[Rocco]

Very sweet items

[Pat D]

Out of curiosity, what piston to head clearance (squish) did you end up having?

I've been reading a lot and there are mixed theories, but the majority of online info is saying that 40thou or under is claimed to be beneficial for better combustion and ignition doesn't have to be advanced as far when compared to a quench that is somewhat greater than 40thou.

[JP]

of the top of my head it came in at 50thou. Although there is no real quench anymore as the JE pistons just have a dish unlike the oem pistons which have a shelf for the quench. So I tweaked the combustion chamber to compensate.