Dick Dobson

Excuse me if this subject has already been discussed. I have a good set of 968 connecting rods that I want to use in a 2.5l Turbo build with knife edged crank. Any pros or cons? Would this be an advantage (lighter weight)? Would it be reliable? Thanks

blown 944

I would ditch them in favor of the 951 rods the turbo rods are much beefier

FRporscheman

968 rods are rarely ever used in turbo builds. Everyone is afraid they will fail, and they either go for the more robust 951 rods, or aftermarket.

I have never heard of a 968 rod failing, but that's probably because they're rarely used! I guess you could trust the 968 rod to 290hp since (being generous) that's the most anyone has pumped out of their 968. The supercharged 968 puts out more, with stock rods, but it hasn't been around long enough to prove the rods are OK.

I'd say with something like a connecting rod, you should play it safe and use the 951 rods. If you want lighter weight, go aftermarket.

theedge

I would go with 951 rods. Proven to some high numbers.

Or aftermarket, depending on your wallet.

931guru

I believe that the 968 rods are different dimensions, since they came out of a car with a 3 liter crankshaft.

That may be the reason that they are not used in 2.5 liter turbo builds...

Van

That's my thought... either the beam length or crank journal diameter might be different. (With a longer stroke, you either need to relocate the wrist pin hole in the piston or shorten the rod - otherwise the piston will hit the head.)

blown 944

pretty sure it is a piston pin relocation

Crank journal should be the same considering you can drop the 3.0 crank in the 2.5 using either relocated pins or shorter after market rods.

Oddjob

I thought that S2s use 944 N/A cast rods. So the 968 rods should be the same dimensionally as the S2 (and therefore N/A and Turbo rods).

V2Rocket

how much of a difference is there between turbo forged rods and NA forged rods?

blown 944

Not much that I could see.
I did not have them side by side but the early rods are pretty stout IMO

FRporscheman

From what I was told by someone who used both forged NA and turbo forged rods in separate build, both rods are fairly equally stout, and the forged NA rods are a little lighter.

All 944/968 rods are the same dimensions. On all 3.0L engines the piston wrist pins are located higher.

DANNiE

Some Rod info from last week...

https://rennlist.com/forums/924-931-...-for-sale.html