jgporsche

NO LONGER NEEDED.

FRporscheman

This sounds interesting....!

gt37vgt

yeh looks like it would go strait in saw a guy put 2 in a 928 realy not an epic performance difference only worth about 4% think I'll spend them resorces setiing up my varible geometry turbo

jgporsche

no, it's worth 29HP......do a little research.

Jfrahm

Well the 968 has higher CR, bigger valves, shorter piston skits, piston squirters, a MAF... I would guess that it might be worth 5-8% HP-wise but the real value would be better midrange. However If I had an S I would be more inclined to spend the time/money getting an S2 engine and having 20% more displacement.
I feel an S2 long engine would drop into an S with stock ECU, AFM, airbox, etc. and make a bunch more torque and probably 200 HP. There is probably room in the stock S maps to handle that and it would provide a lot more low and midrange. You could mod from there with a MAF, chips, tuning, etc. and find another 20HP in your free time. A variocam swap would cost a lot more than a straight engine swap and involve a lot more custom work (cams, head machining) and variables.

-Joel.

jgporsche

larger intake valves, and the comp bump was only .2 (11.1:1 from 10.9:1)...MAF is more for throttle response.

You are correct about low end HP/TQ on the S....you must've missed the thread where I gained as much as 15WHP/WTQ down low with the 944SMAX chip.

With a custom MAF, headers, full exhaust I was at 180WHP (stock S2's dyno around 180-185WHP). I had a bit less TQ though.

I wasn't planning on a variocam "swap".....just a variocam conversion. Th 944S stock cams only need custom sprockets (I priced them at $495), the cyl. head needs a 3rd mounting point for the 968 cam chain tensioner, 968 wiring harness (bought on ebay for $125), 968 valve cover (bought for $100), 968 DME (bought for $175). I already had the Maxtronic emulator (which would have allowed me to tune a 968 chip with my 944S values, and I would have been able to control the variocam.)

But I sold the car, before I went that far. But I WILL get another 944S and I WILL do this conversion.

Jfrahm

I'd be interesting and those are nice gains with the chip but it's still a ton of work for IMO less than you would get with more displacement, which I think would be cheaper and much easier. The low and midrange from 20% more displacement (over half from a longer stroke) is great. A Variocam setup would be a lot of work for what I suspect would be under 200whp, and I think you'd get pulled by a stock, or at least chipped, S2.

I think the 968's MAF is not just improving throttle response but is part of a better overall engine management system. The piston squirters should allow for more spark advance on pump gas too and there is a lot of power to be had (or lost) there.

Interesting project though.

FRporscheman

There's no replacement for displacement, but it's still fun to go where no one has gone before.

gt37vgt

so seems the 968 used the bigger cams and tired to make them small with the variocam. and you intend to use the smaller S cam and make it a little bigger with the vario cam . I respect your kind of doing it cause you know you can i'm similar . pretty sere when i said it worht 5 % i got that from some one who had just pulled the plug on th vario cam on a 968 and compared . the thing is that unlike other motor these have heaps of head flow and there for respond weak to camchanges . the fact that these motors when chipped still make power at 7000 rpm is evidence of the headflow

gt37vgt

hey do you have some solid numbers on the valve timing of these cams i have some that seem to be rong message me if you have any thanks

jgporsche

they didn't use larger cams. they used larger sprockets.


that statement is not even close to the ballpark. a friend has a dyno gain of over 19WHP with performance cams on his 968. check out RS Barn.

Jfrahm

Bigger sprockets? Smaller sprockets for variocam, I thought. But bigger cams in terms of lift and duration. I think it is better to look at the 968 motor as an engine cammed for high end HP and tamed by variocam, FWIW.

-Joel

jgporsche

well, i am not talking actual size. The 968 cams have 1 more tooth.

Jfrahm

I believe the sprockets have one _less_ tooth on the 968 cams. They use the same chain as the S, s2 and 32v 928 but need more free chain to wiggle it up and down. Sterling's 928 variocam setup needed smaller sprockets to work with the variocam system.