how in the world do you dyno one day with a 62 charger stock injectors.Dyno another day with a 64 charger 1.8 injectors and drop 22 hp.I know some can very.the first time i ran with no air filter bumped the rail pressure up two settings on the smarty,timing 1.this time i ran a flat 9 setting. how can this be with a bigger charger and injectors.does anyone know how to get hp numbers without a dyno?

 

Just to add the guy that did the dyno let out of the throttle early as soon as it hit its peak i thought he should have stayed in it a second or two longer.

 

a dyno is not a true measure just a close guess really not all dynos are the same and when you have different operators you will always get different numbers.

 

If you didn't do the run yourself AND do it exactly the same way AND get the same type of printout from the dyno you will never match.

Dyno runs will basically tell you if the changes you made are heading the right direction, but, all the parameters need to be really close or it is not valid data.

 

I guess im headed in the wrong direction for the life of me i cant figure out how i could get lower numbers with bigger injectors and turbo.Surely with the upgrades i should have picked up at least 40 hp over the 552hp. If there is that much differance from dyno to dyno how do you ever know which way your going.Maybe you just use one dyno to tell the gains never knowing what real hp you have.

 

Whats done to the fuel system? Maybe you're taxing it out on lvl 9 with bigger injectors.

 

Yes one dyno is the best plan as they REALLY do differ from place to place. You have tons of variables that come into play....the machine itself, the way the operator has the machine set up, the weather, the altitude, the temp....well frankly the list just keeps going.....

When making changes I like to baseline on a dyno and then swap the parts and hit it again, same place same day

 

My cp3 is stock, but i thought it could handle up to 1.8 injectors thats why i didnt go bigger.The only thing i can say for sure is in the seat the truck runs way better than it did.Ill probably go back to the same dyno run the exact tune and see what happens.

 

air dog 150 straight to the cp3

 

SW 9 and bigger injectors is going to stretch the stock CP-3 to the limit. That is a LOT of duration. Not sure what the 1.8 injectors are rated at but probably too much for the SW setting. You would need a rail pressure gauge to see what is going on but it is likely the pressure is dropping at the top end.

Like I said before, unless you did the runs and did close to the same way on the same dyno with close to the same conditions the numbers may go either way.

You almost need to start at a lower setting then work up on the runs. Start with SW5 then SW7, then SW9 and compare the numbers. That will tell you a lot about how the fuel system is performing.

 

The 1.8 is a 85 hp injector, the last dyno i started out at lvl 6with a 523hp then lvl 9;2 timing;2 rail.I thought i did my homework on the injectors with a stock cp3 i knew it would be close but you could be right.the truck gets 20 mpg i fear a 4 to 5 mpg drop with a cp3 upgrade.Im paying $160 a tank now if it wouldnt kill my milage i would do the upgrade.

 

Mileage is going to be more about how you drive it than the a higher flowing CP-3. You won't see the extra fuel until higher rpms.

Every truck and every setup reacts differently. You just have to decide whether you want big power and less mpg or err on the sided of conservative. At his rate, when fuel tops $6 per gallon those injectors and 80% over CP-3 isn't going to make life enjoyable.

 

what would be the best way to a moderate cp3 upgrade with out the arsons kit.I mean most bang for the buck but doing it right keeping buget in mind.I use this truck for a d driver pulling 13k 4 or 5 yimes a year. i wouldnt be looking for much more than i got just need to properly fuel it thats it. thanks

 

I wouldn't touch it until I verified an upgraded CP-3 was needed. Get a rail pressure gauge and do some more comparative dyno runs first.

But thats me, my needs don't even dictate an Arson kit as I can pull anything I have faster than I care to drive. I can also break any of the drive train with the power of a stock CP-3.

If I was to do it, I would go with an 80% over to have some head room.

 

Thanks for all the info ill chase down the dyno truth but stay where im at with any additional mods.I got a 96 12 valve project with bigger plans way less money.