Has anyone dynoed their V8?

[nuck]

What does the stock car make at the rear wheels?

[cross-eyed-twit]

I think 350 hp but with the new 2002 (?) code about 358 hp.

[nuck]

350 is the flywheel hp. I am interested in the actual dyno reading for baseline stock, to see what the driveline parasitic loss is and to compare modded dyno results. Not a lot of people bother doing a baseline before mods though.

[superdave]

I did a dyno run recently and was pretty much stock. It ran 298-300 at the wheels which equates to 350 at the fly.
I then tried another run with one or two tweeks and it ran 311 at the wheels which is 365 at the fly.
Hope this helps,


Dave

[nuck]

Interesting Dave. I know you can expect to get different numbers on different days based on the tempreture and humidity, not to mention the operator but 300 hp is about what one would expect based on the weight and straght line performance. I drive a Z06 Corvette and pretty well all the stock dynos of the 405 hp version of the Z are between 350 and 360hp at the rear wheels. From this we assume about 50hp in drivetrain loss. This isn't expressed as a percentage since the rotational mass of the flywheel, transmission, driveshaft, and rear wheel/tire combo which are almost all of the parasitic loss don't change as the power goes up.
I would have thought the mid engine would have a bit lower loss than the front engine layout but the numbers I have seen mentioned elsewhere for the V8 are also 295-300rwhp. For comparison, the 350hp Corvettes are also putting down around 315 with a manual transmission, but I suspect this is due to the engine being slight under rated.
Maybe I will do some snooping on a 911 board to see what they are putting to the ground. A carbon fibre driveshaft will save a rear drive 300hp car over 10hp compared to a steel one due to the rotational weight savings so I assumed a mid engine layout would benefit by at least this amount. Perhaps the reduced mid or rear engine power loss is just an urban legend. Thanks for the responses.

[anonymous-user]

Yup, Corvette stated outputs tend to be conservative. Dyno is amusing but it's performance on the road/track that really counts. Standard 350 bhp Corvettes will do the quarter mile under 13 sec with automatic transmission so 400 bhp cars should do better in the right conditions. Mid-engined cars have plenty of grip off the line which the dyno doesn't reflect. There's some very quick real world Porsche's out there which show what can be done with limited power.

[quik S4]

we just had an 03 with the tubi exhaust on our rollers... 296 at the rear wheels... sounded great.

cheers

[superdave]

I was told is dyno terms that the Esprit mid engine because it's in line, it's considered similar to a front engined rear wheel drive car. Unlike a front or rear engine transverse configeration like the Elise for example. I am not a techy so please forgive my ignorance.
BTW, I have my Esprit do two runs on the same day with standard and tweeked so I knew the conditions were the same.

[cross-eyed-twit]

what did you tweek?


db

[ccmdoc]

Well, not stock - P.U.K Red Race chipset and Claudius' twin intercooler setup, but here are a couple of my runs. Best run was actually the last and 358RWHP. Don't know watht eh HP and torque at the flywheel might be, though.

[superdave]

Emailed you Dom. Happy New Year BTW, I didn't realise it was you!!!!


Dave

cross-eyed-twit said:

what did you tweek? db