pyropete125

Hi,

I am looking into options for my 87 924S track only car. It has a 2.5 NA now and over the winter I am swapping in a 16v 3.0 S2 engine and a microsquirt efi system - no need for the 60-2 flywheel.

240mm vs 225mm disks

It has a 951 LSD already and it still has the NA bell housing and I read that some parts are different but nothing definitive about just putting a 951 flywheel and clutch in it.... so...

Can I just put a 951 flywheel and clutch in a NA bell housing? Same starter?

Is a aluminum flywheel good for a 3.0?

Thanks
Pete

odonnell

Someone correct me if this isn't correct - but I've read on here that the turbo clutch parts won't fit inside the NA bellhousing.

Please share your MS maps for the S2 motor!

pyropete125

I was hoping that you or someone here had something close for a base map that I could start with.... :

odonnell

PM me when you're ready to tune, I have a few VE tables that will start your car but they need fine tuning big time. Luckily once you get the engine started and warmed up, it's something the common guy can do just by seat of the pants driving and common sense.

V2Rocket

951 clutch stuff "shouldn't" fit in an NA/S2 bellhousing.

it's all a liiittttle bit bigger...Lart951 has about a million 951 bellhousings laying around for you.

starter is the same.

FRporscheman

I have done the measurements. It's hard to see by eye, but the holes drilled into the bellhousing for the starter are further out (from the crank axis) on the 951 bellhousing. The starters are the same, though.

Note that the flywheels are the same diameter between NA and turbo, but the PPs are different and thus the starter ring gears are different in diameter.

If you do change to the 951 bellhousing/clutch setup, be sure the gap is set correctly on your speed sensor. (The ref sensor gap should be ok but check it anyway.)

V2Rocket

Arash..951 clutch is 15mm bigger than NA...is the flywheel really the same OD?

asmperformance

Just went through this on a 944S2 E Prod build. We used a small diameter Spec clutch made for the 951 and the 951 bell housing. The 944 bell housing has a different starter mounting offset. The clutch was sourced through Lindsey Racing and after running the car at several events including the runoffs at Daytona it worked very well.

V2Rocket

The Lindsey/Spec twin-disc piece?

asmperformance

Yeah, that's the one. Takes a little fiddling to get everything right but it worked well in the race car and felt like it wouldn't be that hateful on the street.

asmperformance

Here's the dyno sheet from the 3.0L S2 motor that's in front of that Spec clutch.

ramius665

That's for a naturally aspirated S2?!

V2Rocket

LET ME GUESS...
12:1 cr, 951 rods with special bearings, dry sump, custom cams, but stock intake mani and throttle?

FRporscheman

Yes, same O.D. Check out the pic, 951 above, 944 below. You'll notice the difference in the lip right away. Another difference is that the 951 has the friction surface raised up to be flush with the PP mounting surface, so machining is easier, and there is more clearance for the crankshaft bolts.



(I was revisiting the cheap clutch alternatives idea. I found a Ford clutch that fits the 951 setup, thanks to more clearance from the crank bolts, but it looks too weak for the 951's power.)

V2Rocket

What disc?
If it's a Ranger I wonder if there's a ROW diesel version (higher torque) with the same trans...?