Chrysler 300C & SRT8 Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
72 Posts
Discussion Starter · #1 · (Edited)
Dyno Results! Need4Speed's 2005 SRT-8

Woohooo!

Just got back from the dyno .....

358.2 WHP & 346.1 WTQ ....

This is also on a Mustang Dynometer, which is known for showing lower numbers than a dynojet .... (the mustang dyno owners say it is more accurate .... they say dynojet reads 10% high)

Here is the graph :



Btw, we also measured the AFR's .... really really rich ... running 11.5-1 at full throttle ...... (as rich as my old Turbo Subaru) Looks like it could use some leaning up .....
 

·
Premium Member
Joined
·
4,071 Posts
need4speed said:
Btw, we also measured the AFR's .... really really rich ... running 11.5-1 at full throttle ...... (as rich as my old Turbo Subaru) Looks like it could use some leaning up .....
Oh hell yeah! Lean that summabitch out and there's more power to be had....That's boost level AFR.....Even at full timing advance w/ 10.5:1 compression that's overkill.
 

·
Registered
Joined
·
30 Posts
Another set of good numbers. Both dyno results are very close.

Chrysler has a habit of underrating their motors. It's certainly a pleasant surprise when you aren't led astray by the mfgr.
 

·
Premium Member
Joined
·
4,071 Posts
rt4 said:
With all that extra fuel, maybe supercharging won't be that tough :)
RT
No...It will take even more fuel. Supercharging the Hemi, IMO seems like a good platform. 2 plugs per cylinder and the hemi combustion chamber loves boost. No hot spots.
 

·
BLOODY ADMENSTRUATOR
Joined
·
7,554 Posts
need4speed said:
Woohooo!

Just got back from the dyno .....

358.2 WHP & 346.1 WTQ ....

This is also on a Mustang Dynometer, which is known for showing lower numbers than a dynojet .... (the mustang dyno owners say it is more accurate .... they say dynojet reads 10% high)

Here is the graph :



Btw, we also measured the AFR's .... really really rich ... running 11.5-1 at full throttle ...... (as rich as my old Turbo Subaru) Looks like it could use some leaning up .....
Whoohooo indeed! Just wait til that engine gets some miles on it!

Very impressive.
 

·
Banned
Joined
·
1,300 Posts
Here's a great article from Car and Driver about modern dyno testing:

Car and Driver: Is your Dyno Lying

Here's a small quote from the article that might help explain the lower horsepower ratings compared to the other dyno run posted in the forums, as well as explaining the richness of the fuel/air ratio you saw:

Dinan's cars are wired with a battery of sensors that report when the airflow over the bumper is too little, when the inlet air is too hot, and when the water temperatures in the block and radiator are too close together (most turbocharged and supercharged cars also "know" when their intercoolers aren't cooling enough). The computer reacts by backing off the spark and turning up the richness—and as a result, turning down the power—to prevent catastrophic engine meltdowns.

To prove his point, Dinan bolts to his Dynopack one of his 2003 Dinan M5s, heavily tweaked to make a claimed 470 horsepower at the crank (he expects about 415 at the wheels). With the hood closed and no external fan blowing air into the radiator, the car wheezes out just 334 horsepower at the wheels. An LCD data logger on the dashboard reveals the air-fuel ratio from the engine computer. Approaching redline, the BMW's computer richens the mixture all the way to 9.5:1 as the underhood temperatures soar.
 

·
Premium Member
Joined
·
4,071 Posts
JMatt said:
Here's a great article from Car and Driver about modern dyno testing:

Car and Driver: Is your Dyno Lying

Here's a small quote from the article that might help explain the lower horsepower ratings compared to the other dyno run posted in the forums, as well as explaining the richness of the fuel/air ratio you saw:
Yes, dyno results for intercooled boosted cars can be considerably lower. Using a squirrel cage fan or the like in front does nothing to simulated the cooling effects of actually driving down the street. You'd need to put the car on a dyno in a wind tunnel to simulate it....Or spray the intercooler with nitrous.
 

·
Registered
Joined
·
29 Posts
vvv90 said:
Yes, dyno results for intercooled boosted cars can be considerably lower. Using a squirrel cage fan or the like in front does nothing to simulated the cooling effects of actually driving down the street. You'd need to put the car on a dyno in a wind tunnel to simulate it....Or spray the intercooler with nitrous.
Or fill the air/water intercooler tank with ice water.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #13 ·
Jamesw said:
You liscence plate is awesome, do you get alot of shit for it?
Funny you mention that ....

Because of some recent "races" I had with some C5 Convertibles ..... the guy at the shop thought it would be funny to put that as my plate # .....

I don't have plates yet ..... (still on the in transit)
 

·
Premium Member
Joined
·
4,071 Posts
need4speed said:
Funny you mention that ....

Because of some recent "races" I had with some C5 Convertibles ..... the guy at the shop thought it would be funny to put that as my plate # .....

I don't have plates yet ..... (still on the in transit)
Ha ha...I didn't notice your plate. That's good, you are bound for a lot more races.
 

·
Registered
Joined
·
72 Posts
Discussion Starter · #15 ·
I'll be taking her out to the drag strip tomorrow ... hopefully, as long as my plans go as planned .....

We'll see what she does ....
 
1 - 15 of 15 Posts
Top