Since im new to working on my car and driving in general i will need some help guessing the ammount of power my motor should have. I have a 94' m6 z-28 with a motor that was just rebuilt, .030 over, new roataing assembely, fully balanced, heads re built with exhaust ports smoothed, k&n filter, recently rebuilt transmission with new clutch, flowmaster cat-back american thunder exhaust, hollowed cat. Basically that is the extent of mods a have gone to. I live at sea level and have had the redline moved to 6000 beacuse of the balancing. Please give me an estimate on horsepower beacuse insurance company is nagging me.
Thanx,
Brian Kaiser

BTW i dont think .030 made it a 383...sorry

 

.030" over makes it a 355.

 

Thanx for the correction. As i said im pretty new with these cars and im just looking for a close estimate of power my car should produce. If you can take a min please help guestimate what final hp i should be close to?

 

I would say you are making around 290-300 rwhp. I think you will notice a bigger difference with aftermarket headers and a bigger cam.

 

I was looking to get new injectors(stock ones have 120+k on them). I would like to go up in size a few notches. Would that help improve HP by balancing out all the air i can supply with the k&n and exhaust? How much would i loose in gas milage?(If any)

 

The only things that are really adding hp to your set up are
polished heads
Cat back exhaust
Hollow cat
KN Filter

your car has 275hp stock and 315 ft lbs of torque. The mods listed do more for hp than torque
I'd say your at 295hp and 325 ft lbs of torque
Calculate a 12.5% drivetrain loss
so 295*12.5%= 258wrhp.. Could be more depending how much material was taken off the ports of the heads, if the intake was port matched etc...

Oh and injectors will give u 0 gain. You may have a choppy idle with bigger ones too, without a tune.
Do a search to see what mods people recommend...

Long tubes, 3inch ypipe, cold air is a good start.

 

Why in the world are you telling your insurance company?

 

Exactly, that's the real point in question here. They'll have the stock 350ci numbers on record, so the fact that your engine was R&R shouldn't matter to the insurance company. They won't insure it beyond its FMV to cover the mods anyway. Why are they asking for this? I'm guessing they paid for the R&R? Just tell them it is within 2% (355 vs 350) of the factory Z28 specifications of that year.

 

Beacuse its insured with a rare/collector car company beacuse our family has many cars.....65 shelby cobra, 68 rs/ss camaro 396...ect cars on that policy and those engines came out with a variety of different power variances. So basically i gotta let them know how fast the car is/will be. Seems alright to me. BTW will my car be slow beacuse of only 295 rwh? Seems low.(or are most cars and ricers these days measuring crank Hp) ???