DYNO results - got questions

[MikeLT4]

Put my LT4 on dynojet yesterday. Looking for some clarifications.

Dyno'd at 315.4 rwhp. Factory is 330 which is crank/flywheel hp. (right ???) Been told that manuals on average lose 15% from crank to wheels. That would mean that my bhp (???) is now about 370 hp.

My HP peaked at 5900 rpm. My AFR averaged around 13, was told that is about right.

Dyno'd at 315.0 rwtq. Factory is 340. Is this also a 15% conversion like the HP?

I'd appreciate your expert critique.

It was cool seeing my speedo reach 140mph.

 

[SlowRide]

Mike, here is my understanding of Dyno's. The other guys here can clarify even further.........

There are many kinds of HP. Below are just a few of the more commonly used:

SAE: The computer will adjust your pull to a 90 degree temperature and high humidity conditions.

STD: The computer will adjust your computer to a 70 degree temperature and low humidity.

UC: Uncorrected, means you get whatever it pulls.

I do believe a 15-17% difference between flywheel and rearwheel is correct.

Like I said, some of the other guys can be more detailed than I.

Hope this helps....Nick

 

[MikeLT4]

It was SAE.

Other info - I'm in Clearwater FL so we're almost at 0 elevation. Temp was in the low 70's and it was one of those all-day drizzle rains. Don't know what barometer was reading.

List of mods -

SLP Triple Threat w/3 K&N's
Holley 52mm TB (new TPS and IAC)
Holley AFPR
B&B 3in catback
160 stat w/fans adjusted
MSD 8.5 (installed about 1 yr ago, changed plugs also with stock ACDelco plugs.)
TB bypass done
MAF screens removed
IAT relocated

 

[Edmond]

Put my LT4 on dynojet yesterday. Looking for some clarifications.

Dyno'd at 315.4 rwhp. Factory is 330 which is crank/flywheel hp. (right ???) Been told that manuals on average lose 15% from crank to wheels. That would mean that my bhp (???) is now about 370 hp.

My HP peaked at 5900 rpm. My AFR averaged around 13, was told that is about right.

Dyno'd at 315.0 rwtq. Factory is 340. Is this also a 15% conversion like the HP?

I'd appreciate your expert critique.

It was cool seeing my speedo reach 140mph.

Mike, those are pretty strong numbers!

 

[Skant]

Check out the info in the model center about the LT4 engines. As far as I can tell, it's not kidding. The LT4 was significantly underrated by GM.

Your numbers are on the higher side of the norm, but still within the expected range. Most LT4's land around 360 or so.

- Skant

 

[Flynbanjo]

I really don't have any answers to your questions. I am however curious where you had the test performed. I would like to see what my car would do on a dyno.

 

[MikeLT4]

In Largo FL, a place called Race Related. They specialize in Vets and Mustangs. They have a DynoJet. A group of about 25 CorvetteForum members, called the Florida Misfits got together and made a day of it.

 

[Vettelt193]

With the mods you have, your power is right about where I expect it should be. 15% is a solid number to use as a drivetrain loss. I expect you could gain another 10 HP with a good computer tuner, to further adjust for your mods.

 

[Flynbanjo]

Thanks for the info. I will have to look them up the next time I am home.

 

[CKA_Racing]

Check out the info in the model center about the LT4 engines. As far as I can tell, it's not kidding. The LT4 was significantly underrated by GM.

Your numbers are on the higher side of the norm, but still within the expected range. Most LT4's land around 360 or so.

- Skant

Not really. It's not 100% stock. He has some mods. With those mods 315 is about right.

 

[CKA_Racing]

What kind of Dyno was it. A Mustang Dyno? Or the other one. I'll assume it was the other since the numbers are about right for that type of dyno. The torq conversion you did is correct.

 

[Skant]

Then I'm curious what the mods are.

- Skant

 

[CKA_Racing]

Then I'm curious what the mods are.

- Skant

He has it listed in his sig.

SLP Triple Threat w/3 K&N's
Holley 52mm TB (new TPS and IAC)
Holley AFPR
B&B 3in catback
160 stat w/fans adjusted
MSD 8.5 (installed about 1 yr ago, changed plugs also with stock ACDelco plugs.)
TB bypass done
MAF screens removed
IAT relocated