Water/**** Dyno

[mntngts99]

I got to tune my water/**** tonight, I found 48 rwhp and 47 rwtq out of my 8 lb pulley. Then went to the 10 lb and gained another 10 rwhp and 30 rwtq across the board. With only filters, tubes and a cat-back are these #'s about right, 634 rwhp and 691 rwtq with the 10 lb water/**** ?

Thanks

 

[Bob D]

With the 10 lb pully my best dyno was 668/ 729. In the summer heat I did 652/ 720. Maybe your a little rich. I shoot for .81 lamda or around 11.8 afr depending on fuel.

Bob

 

[Bob D]

I fogot to add that is with stock heads, Jesel's.

 

[99 R/T 10]

I pulled a 640/704 water/**** summer day. 8 lb pulley, A/F 12.0.

 

[plumcrazy]

what kinda heads are ya running?

 

[VIPER D]

the question is


what brand dyno's are they???????




vd..

 

[mntngts99]

This was the first time I have dynoed with the 3.07 gears. My base #'s were off by 20+ rwhp from when I had in the 3.55's. Is it the gears or just a different day on the dyno ? First Dyno Sheet is with 3.55's and the second with 3.07's while working with the Water/****

 

[Cris]

That is some wild run to run variation. That is runs 1, 9 and 28. How did the other runs fare? 28 runs in one setting is a ton, If that is true I would expect some heat related effects.

 

[utahviper]

YOur runs are looking like they are in the 12.5 a/f range. That is too lean if you don't make any adjustments on the street. Your a/f will probably be leaner on the street. Did you advance your timing?

 

[mntngts99]

Todd

My a/f is at 12.3 and that's with my engine temp at 185 degrees. I made several back to back run's and with the engine getting hotter the a/f went to 11.8. I added six degrees of timing in the mid-range and pulled out 2 degrees above 5750 rpm . With the 8 lb I saw little if any boost creep and with the 10 lb I saw about one pound of creep. There is definitely a point were more timing and more fuel don't show any more gains.

My car was on the dyno from 3:00 pm to 11:30 pm. I made 28 pulls total but after a certain point it just keep drawing lines on top of lines with no gains. I saved each file as I went so I could go back to the one at which point I saw no further gains.

Thank you for all your help.

 

[1TONY1]

YOur runs are looking like they are in the 12.5 a/f range. That is too lean if you don't make any adjustments on the street. Your a/f will probably be leaner on the street. Did you advance your timing?

Holy crap...look what the dog drug in !!!!!

 

[Schulmann]

mntngts99,

I think you viper is too hot this is why you don't get any gain.

It is useless to do more that 3-4 pulls in sequence.
Your Viper gets too hot and you will even loose HP.
The supercharger gets as hot as 140F on the dyno.
I did the same as you 10-15 pulls within 3 hours.
One day we decided to stop for an hour for our lunch.
The next pull gave 8% more HP and my engin was still HOT.

The best is to get a reference benchmark on the dyno for a given program while the engin is not to hot. Then you can test on a track or an empty highway. Sometimes I test 2 hours on the hwy from 5am to 7am and my best results are often during the last runs. When I finish the "track" testing my supercharger is only 90F.

 

[mntngts99]

Schulmann
I understand where your coming from. Between making changes, reading the sheets and log files and all that other stuff I tried to maintain my engine temp at 190*. There were four times in which I had to run the car for a bit just to get up to temp. I can't see trying to get a Big # that is not usable in real world conditions. My biggest question was the 10 lb pulley. should it have made more power on a stock motor.

Thanks

 

[99 R/T 10]

There is another option. Contact David Weaver over on the Alley, he has made a new larger crank pulley which will add a couple of pounds and adds power throughout the power band. I plan on buying it and stay with my 8 lb pulley.

 

[DEADEYE]

My car was just tuned by Sean Roe with a 12 lb pully, water/****, Belanger headers, cat delete, Corsa catback and 3:73 gears. It only put down 604 rwhp and 663 rwtq. Dave told me that according to his calculations it would have dyno'd about 652/ 716 on the stock gear ratio. Time for a stock ratio now!

 

[1TONY1]

It only put down 604 rwhp and 663 rwtq. Dave told me that according to his calculations it would have dyno'd about 652/ 716 on the stock gear ratio. Time for a stock ratio now!

Maybe I will install a 2.50 in mine so I can pick up a 100 rwhp. I don't know that a 3.73 is the best gear for your setup but I sure would like to hear the numbers if you go back to a 3.07 with no other changes. I will be surprised if you pick up that much.
What kind of fuel system do you have running the 12lb pulley ?

 

[mntngts99]

So what kind of 60' are you looking for with 2.50 Tony ???

 

[DEADEYE]

I have the fuel pump voltage booster the Roe sells.

 

[1TONY1]

I have the fuel pump voltage booster the Roe sells.

You also have the 10lb pulley....the 12 is just boost creep.

 

[1TONY1]

So what kind of 60' are you looking for with 2.50 Tony ???

I doubt it will help the sixty foot at all being traction limited anyway.