7.0L SBC finally Chassis dyno tuned

[Blue Max]

Just got the Truck tuned on chassis dyno (Dynojet 224X) . 290Ftlbs @ 2750, 308 @3800, 290@4500. Atmos. loss @ SAE30 that day. I was told Drive train could be upto 20% additional loss. So I guess that a 616 Ftlbs Tq at the crank. Going on a mountain drive this weekend to see what the loaded (2200lb camper) grunt feels like. Should be sweet! AFR's and EGT's look perfect in local driving.

 

[GoToGuy]

What block did you use to get 427 cubes?

 

[Blue Max]

What block did you use to get 427 cubes?

DART SHP 4.125" Bore with 4.0" stroke, and 6.0" rods

 

[L31MaxExpress]

Just got the Truck tuned on chassis dyno (Dynojet 224X) . 290Ftlbs @ 2750, 308 @3800, 290@4500. Atmos. loss @ SAE30 that day. I was told Drive train could be upto 20% additional loss. So I guess that a 616 Ftlbs Tq at the crank. Going on a mountain drive this weekend to see what the loaded (2200lb camper) grunt feels like. Should be sweet! AFR's and EGT's look perfect in local driving.

Something is way off. 308 ft/lbs would be 385 at the crank. My 350 made 340 wtq @ 3,700 rpm with a Lunati 218/228 @ 0.050 roller cam, marine intake and thorley tri-ys. With the GM 6395' 196/206 cam it made 304 tq @ 3,400 on pump gas and 330 tq @ 2,900 on E85. My 383 made 430 wtq @ 3,600 on E85.

 

[sntrym]

I agree with L31MaxExpress. That's not enough power for a 7.0l. When you had it dyno'd did you have it locked in 3rd gear? If not, your numbers will not be accurate. Which cam and intake are you running?

 

[0xDEADBEEF]

He is in Colorado. Maybe the numbers aren't corrected.

 

[L31MaxExpress]

I agree with L31MaxExpress. That's not enough power for a 7.0l. When you had it dyno'd did you have it locked in 3rd gear? If not, your numbers will not be accurate. Which cam and intake are you running?

The numbers are accurate regardless of a 2nd or 3rd gear pull within a few percent as long as the dyno was calibrated for the overall gear ratio. 2nd gear will read a little lower because of the transmission geartrain loss but is all I will pull a truck in. I was well over 100 mph in 2nd gear at the 6,200 rpm fuel kill anyway.

 

[L31MaxExpress]

He is in Colorado. Maybe the numbers aren't corrected.

Perhaps but why would one not use the weather station corrections? Here in Texas during winter I have actually seen gross un-corrected numbers higher than the SAE corrected dyno numbers reported due to negative correction values.

 

[0xDEADBEEF]

Perhaps but why would one not use the weather station corrections? Here in Texas during winter I have actually seen gross un-corrected numbers higher than the SAE corrected dyno numbers reported due to negative correction values.

Gotta love those negative DA days.

 

[L31MaxExpress]

Gotta love those negative DA days.

They are really fun at the track if you can put the added power down. 50-60F, sun to warm the track and good prep on the surface. Those kind of days on the street are usually just a spin fest though. In winter I have seen -3,500 DA.