AzDave47

Based on my dyno runs with 91, I was 572 uncorrected, 595 SAE smoothing 5 (602 was SAE Smoothing 0) and OEM injectors at 89% duty cycle, which would have a potential of 625 SAE Smoothing 5 at 100% duty cycle on the dyno my engine was tuned on after the HCI work. Keep in mind if the uncorrected numbers which are based on the actual fuel that is going thru are then corrected upward, the injectors may not be able to actually achieve that higher corrected number. Based on my experience I do not know the actual limit of the OEM injectors at SAE conditions or better (I will probably not see better conditions due to temperature and elevation), but I know my build was getting closer to the limit so I hadd Id725s installed 15 months after the original HCI build when I changed the Pfadt 1 7/8" to ARH 2" headers and catted x-pipe.

Now I am at 605 SAE Smoothing 5 on 91, but running ID 725 injectors, not sure of the duty cycle on those.

Here is some dialog with Michael D from my build thread:


Quote:
Originally Posted by Michael_D View Post
I'll leave the agreeing/disagreeing about Nic's comments to someone else. We all have opinions, some are stinkier than others, some smell like a rose garden.

At 90% I wouldn't be that concerned either. 80% was, and still is the recommended DC limit. I've already posted a link that will detail the reasons why. Personally, I use 90% for my cutoff.

At 100%, you have a problem. At 95%, you are essentially already at 100%.

600 rwhp on this car, this engine, straight gas....you usually max the oem injectors out. I'm not going to argue about that either. I've learned that questioning a dyno sheet on this forum is worse than telling a mother her baby is ugly.

Have fun Dave.
Dave
I did read your other posted link on this subject (thanks) and you did get me to ask about the DC and it looks like the flow numbers fit with your current DC range 89%<90%. Thanks for that feedback, too.


As far as dyno numbers go, I agree they can run all over the place, that's why I did the stock before and the HCI after on the same dyno. Before was 469 on this and another dyno. After the 602 was a 133HP gain. While I like the 600 number, I would expect on the normal dynos that get 440 stock that I'd be in the 575 range, which may square with 89% injector duty cycle. I'm not bothered by the HP numbers. We'll see how it does Mojave in October. That will be the meaningful number to me.

rpmextra

despite anyone`s achievements there will always be a pack of wolves looking to tear it apart. The dyno as you know is a tool, and they used it before and after to show what kind of gain they achieved. The dyno may be off on its settings but the improvements to the build show nonetheless. Once the OP starts pushing the car at the track, we will get a real idea of how close those number truly are. Different dynos say different things, don`t get caught up with it so much. It is exactly why I haven`t dyno`d my car since 3 setups ago. The car will run hard if it makes power.

95vettski

This an incredible achievement, congrats!
Can you tell me how much the car weighed? I'm a big fan of doing more with less and was wondering if could share the key factors why your example trapped more with less compared to other combos?

Thanks

rpmextra

There's not much too it really. I'll pm u to refrain from hijacking the thread

jayyyw

I'd love a PM as well. I like to learn new things.

American Heritage

rpmextra:

Just emailed you over some info on the E85 conversion,,,, Plus a few other goodies!!!

http://www.americanheritageperformance.com/
310-326-2399

RobGOV-DCZ

James is already too fast. Don’t give him any ideas

robz

I agree. To support that claim, we've see 139+ from a bolt on c6z setup on bias ply tires which means 140+ on radials IMO.

People underestimate how great driving and great air can significantly affect mph too.

And of course all of us drag racers know it's not about uncorrected peak hp dyno numbers, right?

qwknuf6

I did some checking on this ,if the LS7 has 42lb per hour fuel injectors ,42x8=336 lb per hour x BFSC of .5 = 672 HP (FI @ 100% DC)
Fuel Pressure can also play a role , if you up the Fuel Pressure from 43 psi to 50 psi you would up the stock fuel injectors output to 50lb per hour ,50x8=400 lb per hour x .5 BFSC = 800HP making sure your Fuel Pump can supply that much fuel .

rpmextra

Thanks Rob. And maybe one day people will let go of those dyno sheets just a little. There's so much more to a well setup car than peak numbers.

​​​​​​

Michael_D

OE injector flow rate is 42pph @ 58 psi.

nuke61

Both are good points, but this thread was about "American Heritage Heads 625hp 505tq on 91 pump" - which simply cannot be true without fueling changes.

Nuclear427

Awesome results!

You should come out to Shift Sector/Never Lift Half Mile in April in Coalinga and to No Fly Zone In Bakersfield.

Did you end up making it to The Red List in December? I couldn't make it, but am planning on going next year.

It would be fun to get some races with you

Noimright

American Heritage

Excellent!!!
We have had quite a few customer searching for the 600rwhp+ number get their with our ported heads.

We are some of the best cylinder head men in the business. Our main porter spent the last 25 years porting heads for TRD's Indy car and NASCAR programs and that is just one part of our extremely talented team.

http://www.americanheritageperformance.com/
310-326-2399

nuke61

Dyno graph? What mods?