Max bhp, torque for an aby

[cquattropower]

Does anyone know the limits of the aby engine as standard, what can the pistons, rods take etc, also is there any difference between a s2 head gasket and a rs2 head gasket. I have heard that the first thing to go on a s2 engine is usually the rods. Is that right.

[Ross]

Best to decide what you want to achieve and then work with that? Do some searches and you'll find lots of discussions and project threads that will give you answers. I think the generally accepted answer for an ABY is yes, the rods are the first to go. Torque is the killer - over 550Nm is considered getting into the dangerzone and 600Nm+ is risky. But there's some people running more. With the right turbo you'll have 450hp on the stock rods. The pistons are good for circa. 600hp.

The 3B engine is a little different, came with weaker big end bearings and a paper head gasket that shouldn't be pushed beyond 300hp. Usually replaced with the S2/RS2 head gasket, which i believe are the same.

[GazzaG60]

to be safe id opt for the rods and gasket around the 350lbsft area. some rods will be stronger than others.

[Jamo]

474 NM way below the torque an RS2 would generate with a good chipset.

MRC and S2central all say 550-600 NM is the rod limit

[EspenW]

Eternal discussion this

I've seen 350hp engines kill rods.
On the other hand, 16VT (same rods) has been taken to 500hp at the wheels. That is 125whp per rod, so equivalent of 625whp on 20vt, or 700+hp at the flywheel.
With clean, nondetonating combustion, the limit is way up there, but the risk of not so clean combustion and misfire increases with increasing output.

[GazzaG60]

in general the 16vt has less torque though. but i agree with Espen its all on the rods in a particular engine being better than others.

why push them to the limit where they break or presume a high limit. fitting uprated rods is a lot easier and cheaper than a bore/sleeve/new block.

[EspenW]

Overall torque will be lower on 16vt, but torque per cylinder will be similar, which is what defines the torque load on the rod.
Still, agreed on the advice to uprate them if opening the engine, or planning to push the limits.