Turbo 4.3 Dyno Numbers

JT's03

Registered User
Drove the car 2hr's to the dyno today and the car performed flawlessly. ect stayed between 166-174* and the car ran perfect to and from. Willie Lynch from Dirty Dirty Racing tweaked some of the part throttle issues I was having and dialed in the upper maf curve for me. Ended up pushing the car to 13.8psi but had an issue with wg opening causing boost to fall off in the upper rpm down to 13.1psi. didn't have time to give it anymore timing so it stayed at 14* through all the runs and af was 11.5 and under according to my wideband. The af readings on the chart are from a tail pipe sniffer and it does fall off to 11.8, about the time the wg dump opens fully. Car made 445/504 on this setting. Boost comes on instant with this turbo. It would probably pick up quite a bit more with more timing and a bigger turbine. Over all happy with what we accomplished today. Will post a video shortly.
 

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13.8psi falling off to 13.1 psi, 14* timing, 11.5 af the car put down 445/504 sae on a loaded dyno. 93oct pump gas only. 3400rpm converter so the numbers are a little lower. car feels like a beast.
 

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13.8psi falling off to 13.1 psi, 14* timing, 11.5 af the car put down 445/504 sae on a loaded dyno. 93oct pump gas only. 3400rpm converter so the numbers are a little lower. car feels like a beast.

Damn! 445 huh, that's pretty impressive sir! Make a YouTube video instead of Facebook? Not all of us do the Facebook stuff....
 
What RPM were they lifting? Is this motor built to stay below 6k?

When boost falls off, don't forget as RPM goes up more is consumed. So you may not be leaking it, you're just eating it up. Boost needs to scale at least 1 for 1 as rpm goes up just to maintain the pressure. Easier for crank driven compressors since they are indexed directly to rpm. For turbos it takes tuning for the particular motor combination (cam/heads/exhaust/intake). Looks like you have some good data to do some tweaks.

I love the efficiency of the combination. That same pressure ratio doesn't crack 400rwph (corrected) for a crank driven compressor due to the power stolen required to turn the compressor.
 
What RPM were they lifting? Is this motor built to stay below 6k?

When boost falls off, don't forget as RPM goes up more is consumed. So you may not be leaking it, you're just eating it up. Boost needs to scale at least 1 for 1 as rpm goes up just to maintain the pressure. Easier for crank driven compressors since they are indexed directly to rpm. For turbos it takes tuning for the particular motor combination (cam/heads/exhaust/intake). Looks like you have some good data to do some tweaks.

I love the efficiency of the combination. That same pressure ratio doesn't crack 400rwph (corrected) for a crank driven compressor due to the power stolen required to turn the compressor.

Was lifting at 6k according to my stock tach. I think the reason for the boost drop are from a few different reasons. Low timing had some effect, another is the load on the dyno was lower than I'd see on the street, and this 6262 turbo has a .63ar. Have not logged back pressure but I'd bet it's up there. Wastegate is probably leaking due to bp.

My intentions were to crank it up to 16psi and see if it liked more timing but my time run out. I have a real good base tune from Willie Lynch at dirty dirty racing that I can tweak here at my local dyno or track. These were basically shake down runs getting use to what this motor is capable of. Dave Dalke put together a real nice combo with this engine. As much as it loves boost cant wait to see how it likes more timing.

Video should be working now and will work on a youtube video. Thank you for all the comments guys!
 
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Very impressive indeed!:D The question is will you settle for 16lbs of boost or do you plan on a higher number!:rolleyes:

I can only imagine what you will have then.:eek:
 
Numbers are just that - numbers and while I am very happy that Johnny's motor and turbo are both working out nicely, a little perspective is probably in order. ;)

The first thing that caught my eye is the correction factor listed. 1.10? Really? A quick check with wunderground.com for some history for that location and the following is revealed, which doesn't match the weather station of the dyno.

2:54 PM 79.0 °F 64.9 °F 62% 30.04 in 10.0 mi South 4.6 mph - N/A Partly Cloudy
3:54 PM 78.1 °F 64.0 °F 62% 30.03 in 10.0 mi Calm Calm - N/A Clear

Biggest deviation I see is pressure was actually just over 30. instead of the 28.5 recorded by the dyno's weather station. This is a common problem with dyno hardware and tends to wreak havoc on correction #'s.

Since in the video the car is facing an open door, I tend to think that "weather" conditions probably match the NWS more closely than whatever the dyno was recording and the above #'s are actually very close to the SAE standard. That means you can probably deduct most of 44rwhp from the total, so more like 400rwhp actual.

Considering this is a 4.2 rather than a 3.8, and the fact that the split port heads flow more like 240cfm compared to 210 for a typical ported SC cylinder head, the boost # at similar cylinder pressure compared to an SC you'd be looking at more like 16-17psi.

An SC 4.2 with a blower making 16-17psi would give you about 30-40rwhp to the turbo under the same conditions so still good numbers, and should definitely like another 4-5 deg timing. Glad to hear it's running good after all this time though. Now it should be track time!
 
I think the numbers are real close to what they should be. Sae numbers were 432/488. Reason I say this is that a 3.8l with 5spd, 6262 .68ar turbo, comp max cam made 447/431 std with 13-14psi on a dynojet. Mine has more cam and displacement and probably better heads which imo makes up the difference in drive train loss through my auto. But you are right Dave, dyno numbers are fun and all but the real test is what it does on the track. And yes sir it is track time! Hoping to make it to my local 1/8th mile this Friday if the weather holds out.
 
RPM is probably off on the graph because we were using wheel speed to figure RPM , and with the auto trans sometimes that can make it look like the RPM is reading a little lower on top end , but the #s are always close to every other dyno its been compared to , had a guy go to a dynojet in NC and SAE to SAE was only off by 1 HP on exact same car with no changes within a weeks time
 
Good numbers, man! It feels good to have a car running so well. Take it to the track and see how it does!

Just for reference, my car made 530rwhp at 12.1 psi.
 
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