355 wheel horsepower (stock)?

Every car is going to be a tad different, no two the exact same. I would guess actual rear wheel HP in the 290-320 range on a stock car.... But that's just my guess....

 

What dyno are you using?

Depending on the brand it will read anywhere from 280-320rwhp.

If you tell me the brand I can give you a more accurate figure.

 

+1 ...........that is about right ...........

though ................ one can do it on different days even weeks months apart as long as a correction 'standard' is used (such as SAE) ........ but ideally one should do B4 and after dyno on the 'same car' using the 'same dyno' .............. as others have mentioned cars and dynos vary .......

 

About what is the drivetrain loss with the 348 and 355? A good healthy stock 348 engine will dyno at about 240ish right? A x-ost will push that figure up about 10rwbhp from what I have read..... That about correct?

 

As RWHP varies depending on dyno and day conditions - assuming no engine mods - so does power train loss. I'd like to think it was a constant, like it took so many ponies to grind through the crank, tranny, dif and axles. In fact I was told by a product manager from Dynojet that it is more of a ratio. Our cars have a higher ratio of loss than others, which is weird since I always thought that the layout was more efficient. It's in the 25% range is my guess based on observation.

 

308 owners always operated under the assumption that 17-18% is the norm due to the 3 tranfer gears from the flywheel to the transmission and ultimately the differential. 25% does not surprise me, but it used to until I read an article a couple years ago.

I read an article in a hot rod magazine a while ago (wish I could recall which one) called, "the painful truth" or something to that effect. The technicians who assisted in this article flywheel dyno'd two engines and noted average bhp at the flywheel and ambient temperatures. One engine was attached to an automatic transmission and the other to a manual. Both were placed in chassis and then dyno'd accordingly. Both cars and drivetrains were some late 60s muscle car set-up. IIR, the automatic transmission power loss at the wheels was a figure around 30%. The manual transmission loss at the wheels was around 25-27%. I cannot recall the exact numbers, but they were staggering and were certainly higher than anyone expected.

The only car I have ever had where the power loss was around 15% was that of my '86 Porsche 911 with a 915 tranny. It flywheel dyno'd at 230bhp and pulled 199bhp at the rear wheels. The rest seem to have been much higher.