Horsepwraddict

iTrader: (12)

I have spent the entire summer tuning my 5.3 regal. I have a quickfuel HR650 on top of the edelbrock performer RPM with a 216/220 Trick flow cam and the car drives awesome. After much time spent with air bleeds, jets, powervalves and IFR's this is what I have come up with and I think its damn good. Do you guys think I can do better?

Idle: 13.4:1 (I want leaner but don't have the IFR I need right now)
Flat ground steady cruise: 15.4-16:1
Light throttle acceleration 13.5-14:1
WOT: dips to 10.5 on the hit from the squirters and flattens right out to 12.5:1 almost instantly.

Carb setup as follows

9.5 power valve
70 primary main jet
74 secondary main jet
High speed air bleeds- 36 all around
Primary IAB- 75
Secondary IAB-70
Mixture screws 1/2 turn out
31 squirters front and back
blue cam up front
pink in back

I would like to try a smaller pump nozzle in the rear to eliminate how rich it goes on initial WOT, I know you want a slight rich surge but id like it more around 11.5. The primary side is dead nuts at all throttle positions when I stand on it.

speedtigger

iTrader: (16)

Sure sounds pretty good to me. And, I like the idea you are going to experiment with the squirters too. Your "flat ground" cruise is leaner than I have ever tried. My car is tuned to range between 14.0-15.0 at cruise. Not many take the time to achieve what you have. Great work.

Horsepwraddict

iTrader: (12)

I was hoping you would step in Tigger.

My one concern is how lean it goes if I just barely crack the throttle, like a 100rpm increase, it can go as lean as 17 sometimes if its a cool dry day and occasionally it will start to break up. It is never an issue driving around as it is such a short window that it wont even register on the wideband or make the motor hesitate. The only time its an issue is if you are trying to creep forward in a parking spot or something and I notice it.

I would like to continue dropping the IFR AND the idle air bleeds to clean up the idle a little AND bring the transition in a little sooner. I would also hope it might allow me to bring my mixture screws out a little more. What do you think?

speedtigger

iTrader: (16)

Going too small on the IFR can cause a lean tip in. Or, if you get the IFR and the LSB out of balance ( too large of an LSB for your IFR). If you were in a scenario where everything was perfect except for the tip in, I might say increase the IFR. However, since your cruise is slightly lean, you might try going to a smaller LSB first just to see if you get an improvement in both areas.

Horsepwraddict

iTrader: (12)

Ok. So what do you think about this. Dropping primary idle air bleeds to bring cruise a little richer and hopefully helping my lean tip In. Then leaning out my
Idle with the secondaries. Should I use the screws, bleeds or idle feeds? Should I worry much about getting the carb too out of balance from front to back? That's what I have been afraid of which is why I haven't tried it.

speedtigger

iTrader: (16)

It may not like the idle leaned out. You will just have to experiment to see. I typically do not stagger my idle screw settings, but if it works, it works.