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Discussion Starter · #1 ·
my recent dyno after all the headaches with tuning net 387rwhp...

I have heads and cam and that same combo netted on a camaro 484rwhp on an ls1 block... cam is 226/230 113lsa

Any ideas????

afr was from 11.6 to 12.2 at the end

the dyno wb was reading 10.6 to 12.6....

still, tuning will not net 100rwhp.

Stock rockers, stock lifters...

www.roxanette.com/awfuldyno.jpg
Pushrod length is 7.4 IIRC. This was all sent from cartek.

im down about 70rwtq of what should be expected... honestly i expected 440rwhp here on this dyno etc... still i am 60rwhp DOWN!

if only one cylinder would be off the car would have a heavy miss or imbalance.. the car feels overall w/o the power it should have..
Keep in mind that i did on that same dyno with a headers and intake on a 01 ls6 engine 340rwhp....

So with an 04 ls6 block.. ported heads... ported intake... vararam... 226/230 cam i will only gain 47rwhp????? That doesn't sound right.
 

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have you not tuned the car at all? no bigger injectors? no timing changes? i wouldnt be surprised if you dont see the gains youre looking for without a tune. However, if you have done some tuning you should see around 440rwhp as you said. If you suspect the rocker arms are badly adjusted, just pop off the valve covers and have a look. good luck :yeadog:
 

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Was the cam installed by someone who knows what they are doing? Done professionally?

Who ported the heads? Done professionally?

Should have bigger injectors.....I use the GM 36 lbs injectors.

I'm assuming you have headers and a good exhaust system.

You need LS1 Edit or EFI or another program re: timing and a/f ratio's. Tuned on a dyno?

What rear end ratio you using? Any ratio's higher than the 3.42's will show less power on the dyno.

AND, speaking of the dyno, was it adjusted for weather(temp, pressure, etc)?

What octane fuel are you using? Low octane will cause the knock sensors to retard timing in WOT.

Tuning is so critical.....

Just some thoughts.....HTH :thumb:
 

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Discussion Starter · #5 ·
I installed the cam.. The cam is installed correctly... I've done it numerous times... I suspect i chocked the valves a bit or something...

Tuning is done by me... also done a lot of them... Gone crazy a bit with this one though...

Injectors are 30# injectors... Tuning will not net you 100rwhp period.. timing was where it should be... There were some instances of slight knock retard and around 22º total advance in the end...

Octane fuel is 93.

Rear end is stock 3.42.. pull was done on 3rd gear.. should have picked up around 8-10rwhp on 4th.. but i am looking for a ballpark figure only... I don't want to stress the engine that much unless its really needed...

Tuning was done on the street to 12.0AFR... i can pick around 10-15 uptop leaning a bit and fine tuning it.. still.. 15+387 is 402.. where are my other 50-70rwhp?
 

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When you did the tune did you cancel or change the cat over temp feature in the pcm. It controls air/fuel mixture to prevent the catalytic convertors from overheating.

You probably did this..but just thought I'd mention the pcm will dump fuel in to cool off the exhaust temps and it kills power....

Just taking a shot in the dark. Good luck and yes you should be making 440rwhp.
 

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Discussion Starter · #7 ·
JBsZ06 said:
When you did the tune did you cancel or change the cat over temp feature in the pcm. It controls air/fuel mixture to prevent the catalytic convertors from overheating.

You probably did this..but just thought I'd mention the pcm will dump fuel in to cool off the exhaust temps and it kills power....

Just taking a shot in the dark. Good luck and yes you should be making 440rwhp.
yeah i didthis
 

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Here is my .02 .. along with a question:

1. Your dyno shows the car to be a 94 ZR-1 LT5, I assume this was mislabled?

2. You mention a Camaro with the same set-up and an LS1 getting 484 RWHP. On a cam that small? I have seen MANY car's dyno'd, and never anything near that kind of power on a "baby" cam. I run a 228/230 BTW, and with professional tuning, professional porting and assembly by a very good shop (before the 383) I made 420 RWHP, far more realistic IMHO.

3. A/F should be adjusted to 12.8, I would not go any leaner. That will pick up a little power. Did you run Auto-tap, any K/R? What did your LTFT's look like? You say you went a bit wild with the tuning - what did you mean?

Bottom line is that you are for sure down on power, about 40 RWHP though IMHO.

Les


The Highlander said:
my recent dyno after all the headaches with tuning net 387rwhp...

I have heads and cam and that same combo netted on a camaro 484rwhp on an ls1 block... cam is 226/230 113lsa

Any ideas????

afr was from 11.6 to 12.2 at the end

the dyno wb was reading 10.6 to 12.6....

still, tuning will not net 100rwhp.

Stock rockers, stock lifters...

www.roxanette.com/awfuldyno.jpg
Pushrod length is 7.4 IIRC. This was all sent from cartek.

im down about 70rwtq of what should be expected... honestly i expected 440rwhp here on this dyno etc... still i am 60rwhp DOWN!

if only one cylinder would be off the car would have a heavy miss or imbalance.. the car feels overall w/o the power it should have..
Keep in mind that i did on that same dyno with a headers and intake on a 01 ls6 engine 340rwhp....

So with an 04 ls6 block.. ported heads... ported intake... vararam... 226/230 cam i will only gain 47rwhp????? That doesn't sound right.
 

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Discussion Starter · #9 ·
ZO6/Les said:
Here is my .02 .. along with a question:

1. Your dyno shows the car to be a 94 ZR-1 LT5, I assume this was mislabled?

2. You mention a Camaro with the same set-up and an LS1 getting 484 RWHP. On a cam that small? I have seen MANY car's dyno'd, and never anything near that kind of power on a "baby" cam. I run a 228/230 BTW, and with professional tuning, professional porting and assembly by a very good shop (before the 383) I made 420 RWHP, far more realistic IMHO.

3. A/F should be adjusted to 12.8, I would not go any leaner. That will pick up a little power. Did you run Auto-tap, any K/R? What did your LTFT's look like? You say you went a bit wild with the tuning - what did you mean?

Bottom line is that you are for sure down on power, about 40 RWHP though IMHO.

Les
So you are telling me that i should only do 40rwhp more than what 03 z06's do with headers and intake?

I mean I dynoed a header 02 with NO intake and did 375rwhp!....
 

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Why not just pick up the phone and call the pro's at Cartek :thumb:

Let us know what you find once it's sorted out :yeadog:
 

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Discussion Starter · #11 ·
Did that.. they don't know yet... will give another call tommorrow... just looking some ideas...

I did think it was a bad rocker arm adjustment, but didn't know it could be because of too long pushrods due to the base circle be a bit longer maybe.
 
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