dyno question

[jimchris]

There is a local dyno day event next week and thought it might be fun to go over but have a couple of questions. Is ok to dyno a car with only 300 miles on it? What gear should it be ran in?

 

[ViperGeorge]

I'm not an expert but if it were my car I would wait until the car was broken in. It probably won't hurt the car if you just do one run or so but remember the dyno is running the car full out under load, not something you generally do until the engine is broken in.

You always do the dyno run in whatever gear is 1:1, in the Viper and most cars that's fourth. If you run in other gears the readings will be distorted by the torque multiplying effect of the gear ratio. The dyno operator will tell you this and they will most likely do the run for you.

 

[ViperGeorge]

Oh, one other thing. Until the car is broken in the engine can be "tight". This will reduce the readings you will get on the dyno.

 

[adamlotus]

put some miles on that car.go for a nice long drive

 

[Richie7]

On a dyno they will run the car up to redline in 4th gear. I would hesistate to do this if it was not broken in yet, but some people do break-in their cars really hard.

 

[SquadX]

I think you will get mixed feedback as I spoken with a couple well known viper tuners on this and some say dont run to redline unil 1000 miles and others say they dyno a new or rebuilt engine from jump. I personally see no reason to not wait until 1000 miles as it wont hurt but anything before that "might". When I had my engine rebuilt, I did the break in process outlined by my builder which is the same as dodge, 200 miles 3k and for every additional 200 miles you put on it, up the rpms 500 until you get to 1000 miles and have at it.

 

[plumcrazy]

ditto for me

 

[ZDigital1]

What can you expect in terms of horsepower increase for a motor that is not broken in. I have recently had Snake Pit Performance do a complete rebuild of the block and heads etc. and it dynoed at 782 RWHP. Can I expect an increase after about 2000K break in miles? When the motor was first dynoed, the weather conditions were not ideal either.