Con rods upgrade

[GreenRL]

Actaully it was on a 'Balt, all the info's on the cobaltss.net forum...

I want it in a Kappa, damn drivetrain loss

[mkriebs]

Originally Posted by 1WhiteSSTC

530whp? which engine?

.........i want 530whp

ZZP did it in their LNF Balt.

[greaseyjockey]

i thought zzps rpds bent somewhere between 400 and 500, they didnt know where...mine also bent somewhere between 400 and 500. i sent a rod to k1 in dec, should be getting a set soon.

[cmiller8006]

Originally Posted by greaseyjockey

i thought zzps rpds bent somewhere between 400 and 500, they didnt know where...mine also bent somewhere between 400 and 500. i sent a rod to k1 in dec, should be getting a set soon.

I don't think they would bend at 430 and still take 530 and not be broke. I think they are good till close to 500whp

[mkriebs]

Originally Posted by greaseyjockey

i thought zzps rpds bent somewhere between 400 and 500, they didnt know where...mine also bent somewhere between 400 and 500. i sent a rod to k1 in dec, should be getting a set soon.

Well, when you look at it, its not hard to figure out where they bent. First, then bent, not broke, that points ti it happening in the higher power range that they ran. Second, they didn't spend a whole lot of time in the lower 400's, they shot right up to the upper 400's (475+). The reason I state that they bent, and not broke is... they were JUST being pushed to their limit. Obviously metal is going to bend before it breaks. The limit was not far surpassed, otherwise they would have broken. I would suspect if they would have pushed 600whp, we would have seen a broken rod.

The amount of time that they spent under 475whp, I would deem about 10% of the total run time of the car. Sure, they ran it on the street, and that was probably around 400whp, but I am referring to situations with high cylinder pressure, and the subsequent high stress (dyno and strip mainly).

Now, for the remaining 90%... I remember one of their big plateau's being 486whp. I don't remember, however, how long they ended up being there. But, within the month, they were over 500whp. The amount of time on the dyno to eek the remaining power out of the car would most likely be the cause of the damage. These are the high pressure, high stress situations.

So, my best hypothesis is that our rods are good til 475whp. Just from the deductions I made above, I think I am in the ballpark. Of course, its always good to fair on the side of caution, and play it a bit safe, so I usually say 450whp.

Hope this makes sense.

[Gimpster]

Dynoing a car is usually one of the most brutal things you'll do to it, and correct me if I'm wrong they own a Mustang dyno. If they were doing any kind of load cell tuning on it, even more brutal.

In the old LSJ performance manuals they replace the stock connecting rods with basically the same dimension rod except forged and full floating pin. We got that same basic rod stock. With that rod they claimed the car was "safe to 400hp" (I think thats the #, been awhile since I read the book) and you know theres some fudge factor in there to cover their ass. I'm sure they were quoting crank horsepower though.

So 450-475 seems reasonable to me, just don't detonate it and such

[mkriebs]

Yeah, I mean, ZZP was running 109 octane race fuel too, so I am sure that they had very little detonation to deal with, unless they were running some insane timing numbers.

Of course, any time you increase cyl pressure, you are dancing with the devil.