Power numbers
#11
Thread Starter
Whistle Truck Guy
Joined: Sep 2005
Posts: 177
Likes: 0
From: The Middle of Nowhere, Oklahoma
I didn't get a printout of the dyno graph, but one of the guys at the shop pulled up another turbo 4.8 dyno graph and laid my graph onto the other one... My power came on sooner but the other guy made more power. He had a c5 Z06 cam and an 88mm Garrett turbo. Other guy made 642hp, but it never really peaked. Dyno graph went to 7k and up till that point, power kept climbing. The last couple hundred rpm, power started to slow its climb, but never started dropping.
Still tho, what makes me wonder is that there are people making way more power than I'm making, with the same turbo. Such as BigBlock90... He made over 600 to the tires with almost the same turbo I have. Only difference is he has the .96 a/r housing and I have the .81 a/r housing. Surely just having the smaller exhaust housing wouldn't make that much difference. Would it?
Still tho, what makes me wonder is that there are people making way more power than I'm making, with the same turbo. Such as BigBlock90... He made over 600 to the tires with almost the same turbo I have. Only difference is he has the .96 a/r housing and I have the .81 a/r housing. Surely just having the smaller exhaust housing wouldn't make that much difference. Would it?
#12
Joined: Jan 2006
Posts: 16,282
Likes: 438
From: Huntsville, AL
The higher the rpm that the turbo can maintain boost (and engine torque) the higher tje power. Power is torque times rpm. That same turbo on a 3liter engine would probably make 900hp at 10,000rpm.
#13
Thread Starter
Whistle Truck Guy
Joined: Sep 2005
Posts: 177
Likes: 0
From: The Middle of Nowhere, Oklahoma
This is true. Still blows my mind that people are making 100+ hp more than me with pretty much the same turbo on the same motor. Only differences would be the exhaust housing and some slight cam differences. Maybe I should have done a Z06 cam instead. Those seem to be pretty killer with boost.
#14
I am still working on some base MAF tuning on my 4.8 with KBR 72mm turbo. Besides the 42lb injectors and exhaust, everything is stock.
Running 7lbs of boost and it doesn't seem very powerful to me. Has anyone ever run a setup like this with the stock cam? What would I expect to produce at the wheels with a stock cam and 7psi?
I have not done anything with the timing. Wondering if that needs to be played with also.
Running 7lbs of boost and it doesn't seem very powerful to me. Has anyone ever run a setup like this with the stock cam? What would I expect to produce at the wheels with a stock cam and 7psi?
I have not done anything with the timing. Wondering if that needs to be played with also.
#15
Thread Starter
Whistle Truck Guy
Joined: Sep 2005
Posts: 177
Likes: 0
From: The Middle of Nowhere, Oklahoma
Well I think I have the problem found on why my numbers are low. Am I going to say? No. Because I don't want anyone knowing what kind of newb mistake I made. Not even newb, more like mistake made by someone that's never seen an engine before. Holy crap I feel stupid.
#17
Thread Starter
Whistle Truck Guy
Joined: Sep 2005
Posts: 177
Likes: 0
From: The Middle of Nowhere, Oklahoma
A gorilla sitting in the passenger seat would be a better excuse. I hope it's as simple a fix as I'm thinking. If it's not... I guess I'll have to live with being the only sumbitch on this planet that managed to only make 508rwhp from a 4.8L with 15 pounds of boost while running on E85. A cammed 4.8 at that... With a good intake.






