Hey guys,

Yesterday I did some race gas tunning at Godspeed on their dynapack AWD dyno while adjusting my GM boost control solenoid (controled by the AEM EMS). After some pump gas tuning I poured in the C-16 and continued to slowly raise the boost level. With the big cams, the stock compressor just can't keep up after about 6000 RPM and boost drops down to around 18 psi with the WG totaly shut. My power peak was 411 HP at 6000 RPM. The uncorrected torque was 370 spike and 360 platau pretty much flat from 4000RPM to 5500RPM. When you apply SAE correction to the torque you get 394 lb-ft of torque at the spike and 389 in that platau range.

This is all with the stock 16G compressor, with titanium exhaust wheel and shaft and a 10.5 hot side housing. I will post up the dyno sheet this Sunday.

Keith

 

NIce numbers!

 

Highly unlikely the WG is totally shut. That would mean that your boost would go higher then youd like. I think someone should investigate into getting a new WG actuator and see what would happen with much stronger ones.... kinda like what the SRT4 guys doing with the WGA mod(which is just a strong spring attached to the actuator.)

 

Believe what you like, the WG is shut. The 16G compressor can't push enough CFM to make big boost with the large overlap of the HKS 272 cams.

Here is the chart I said I would post

Keith

 

I knew the stock turbo was capable of 400hp with the 10.5 housing. Now I want to see if 400hp is obtainable with completely stock turbo.

 

I'm not sure if that's a mistake or not, but according to that sheet, that is crank HP not whp

 

See where the graph says "tcf 1.00" at the bottom? With the Dynapack you have the option of inputing a "fudge factor" to give you an estimated crank HP based on the wheel hp. When it is set to 1.00 the output on the graph is what you made at the wheels

Keith

 

Gotcha. Thanks for clearing that up! I'm not too familiar with Dynapak's

 

That's some serious power! Nice job fourdoor!

 

Probably so, but just like the 10.5t, you won't do it on pump fuel. C16 makes a big difference.

 

Oops my response sounded a little harsh didn’t intend it to sound condescending. Anyways you think that the WGA is having trouble staying close meaning that it might need a stronger actuator?

 

Hey Yellw,

It takes 12 psi of boost on the diaphrame of the WG actuator in addition to the force of the exhaust gases pushing against the WG flapper valve itself to open the valve normally, so when all boost pressure is cut off from the diaphram I am pretty sure that exhaust pressure isn't forcing the WG flapper open all on it's own. I could be wrong, but I am confident

Bishiboy:

From my experiance the 10.5t housing helps out mostly in the mid range, since the compressor side can't keep up with the demands of the motor with the big cams, I don't think my PEAK numbers are any higher now than they would have been with a stock turbo with 9.8 housing. Better mid range torque, but not a higher peak power. I have no doubt someone running C-16 and a good engine management can make 400+ on the bone stock turbo.

Keith

PS: Those C-16 numbers are made on the same timing map as I use on 93 octane. I ran out of dyno time before I could start tweaking on the timing map. I have no doubt that I could have gotten more power by playing with the timing..... how much do you guys estimate I missed out on by running out of dyno time for timming adjustments?

 

C16 will deliver more power all else being equal just based upon the fact that it contains significantly more energy per mass unit.

I'd be surprised if you could get much better peak numbers with timing adjustments so long as the turbo is the limiting factor. Should be able to fatten up the midrange though.