Prochraged LT4 Going to the Dyno... any bets
 

Car has around 50K Miles, Corsa Cat-Back and an Intercooled Procharger. Any guesses on what the RWHP will be? A local shop is having a show/dyno day. Booked a slot for S&G's

I am expecting to see around 400. Who wants to take a stab at a guess?

503?

I think I would have to change my underwear.

483 ......Has a nice ring to it !!!!

Not a lot of info. I'm going to go ahead and assume everything else is stock. So you take a ~305 RWHP engine, add 50% and you end up with ~460 RWHP. My guess is ~460 RWHP.



.

How much boost are you running? 10 lbs should put you close to the 475 rwhp mark.

None other to give, you are correct, the rest is stock. I will be doing quite the happy dance at 460.
I see 10-12PSI on the gage.

If you are getting a solid 10 to 12 PSI in the intake and your tune is good you will be close to 500 HP at the tire.

420, I'm going to guess that the tuner will be conservative on a stock LT bottom end.

I would also be very happy with that number.

Not more info to add to the car, but to give some perspective. I bought the car used. The shop that did the install is out of business so I can't get any additional information on it than I know the person owning the car before the guy I bought it off of paid to have the supercharger installed. Since I have had the car, I had to replace the belt and tensioner.

The is a baseline to see where it is. I am considering a blower grind cam for Lloyd Elliot and Long Tube Headers. Then a full custom tune, but it's a 96 and finding a tuner as I have read on here can be a bit of an issue. We will see, I have an IROC project car right now and the Corvette is more than enjoyable the way it is.

401 Bob.

If you are running 12 lbs boost without a tune on stock pistons, you are flirting with danger. If you have thrashed it for a while I'm guessing that the installer tweaked the stock tune when he put the blower on.

I don't thrash my cars, but yes it has seen a few WOT pulls through 2-3. And, that is just the point. The Previous Owner didn't know, the shops stamp that is on the super charger is out of business so, I have no way to know. This is the beginning of figuring it out and determining what the next steps are. I know it is still running the FMU. Part of the Cam/Headers probably will include Pump/Injectors if I am going to a full tune. The Car has a boost and fuel pressure gage installed. Under boost the Fuel pressure rises and holds steady. Haven't had a chance to really stare the gage down and get a precise number, but it seems to be 45-47PSI. I don't know why they went this route instead of a wide band, but again, this is the first step is determining where to go next.

Since the car has a MAF and it can read the increase in air volume entering the engine and will add fuel as needed. The increase in fuel pressure is to keep the difference accross the injectors the same so the correct amount of fuel is discharged from the injectors under boost. Since I have no idea what is really going on with the tune or even the car this is just my educated guess.

The Procharger installation manual says to install a Wide band or Fuel Pressure gage. I would still rather have a wide band so I would know where the mixture is, but the fuel pressure gage shows the pumps are producing enough volume to maintain requested pressure.

There are a lot of option on the table with this car. Fuel Pump, Injectors, Cam, Meth Injection, Headers, Heads, Tuning or going 383, but to start to formulate a plan, if any... you have to know where you are starting. They dyno won't lie or make guesses. Based off the number I get I should be able to decipher what kind of tune is in it (If any). I would imagine a shop would do some kind of tune after installing a Supercharger if they are worth a crap, but being out of business makes you have to put that into question.

I would first install a wideband and log some runs to make sure you are in the ballpark. I have one in my bracket C4 and record every run. If the afr is way off, cancel the dyno secession and schedule a session with a tuner. You will want to run a wideband anyway so you can keep track of your tune. Things can change with time. They are not that expensive or difficult to install. A welded O2 bung is all you need.

Not sure if I missed it-But which unit do you have? P1-D1-P600B

Looking forward to your results.

Steve

I think it could last a long time if it's a street only car. How long can you really "give'r" on the street, anyway? 5 seconds? You should be able to do a LOT of 5 second hits on the street, IMO, on a decent tune.