Gunone

I was able to pick up 1 mph and a full tenth in the quarter mile. Very happy with that! FAST meter also showed a richer mix on topend, where as before it was getting a little lean.

Gunone

Best time of the night was 10.848@125.32. She actually ran four 10.8x@125.x and I am now very satisfied with the tune. Thanks again guys for the "up-jet" suggestion.

Z284thgen

iTrader: (46)

no bump a lil more timing in it mine took fuel and timing I think I ended up best at 36* @3200

06X6spdGTO

iTrader: (6)

Demon 1000cfm 4150 Carb, Vic Jr, 240/244 613 598 109LSA cam...

06X6spdGTO

iTrader: (6)

Your backwards on the Power valve... You run Square jets WITH a Powervalve... Staggered Jets with the POWER VALVE BLOCKED!

The power valve adds the extra fuel so you so can run the jets square.

ZONES89RS

iTrader: (25)

Power valve adds fuel. So you run a smaller jet that will lean out cruise and step up in size at wide open throttle.

speedtigger

iTrader: (16)

No. This is not correct.

There are two passages that feed the booster in the carburetors venturi. The main jet passage that is regulated by the main jet and the power valve enrichment circuit that is regulated by the power valve through the power valve restrictor orifices.

So, the power valve adds fuel through its own circuit, it cannot restrict fuel through the main jet circuit.

Furthermore, to avoid confusion, it is important to state that all Holley 4150 mechanical secondary carburetors (model 4779) have a power valve in the primary metering block. However, only some models have power valves in the secondary metering block. Most, but not all models have the secondary power valve port plugged from the factory. This is why you will see most 750 mechanical secondary holleys about a 71 jet in the front and a 80 jet in the rear.

http://www.holley.com/data/TechServi...%20Listing.pdf

It is only advisable to eliminate the power valve on the primary side in race only situation as the part throttle fuel mixture will be extremely rich. So much so that it is likely to foul the spark plugs during normal driving. The power valves purpose is to lean the mixture in part throttle situations, however it's actual function is to add fuel under heavy throttle and full throttle situations.

Gunone

Badass video dude, I can appreciate a video like that I know how long it takes to edit something like that. All I can say is WOW! I may need to step up on carb cfm because I'm only running a Holley 750cfm. Well the Motor tune is good according to the FAST and the MPH gains and losses. I have the cold plugs in NGK3346 BF7EFs gaped at .035 for the 100 shot and 28* TT all in at 2K. I know and feel that this is a safe tune for my setup but would like to hear more input. Thanks guys I'm headed out tomorrow night for TNT at Thunder Road Raceway Park Gilliam La if anyone is in the area would love to meet them.
Bryan

06X6spdGTO

iTrader: (6)

So how did it do on the spray???

speedtigger

iTrader: (16)

Did you have to flycut the pistons for that cam?

06X6spdGTO

iTrader: (6)

Nope, but I'm using TFS heads with the smaller "LS1" series setup instead of the LS2 2.04/1.60 valves

Gunone

She ran pretty good on just the 100 shot, I am happy with results. I am going to try next time to run the TR6s because she was really rich and fouled all plugs last pass. FAST read 9.5-10.5 at WOT last pass. First pass was 10.57@130 second was 10.30@133 third was 10.28@133 and last pass was 10.38@133. What a ride, all over the place out to 60'. Happy, happy, happy!

Gunone

http://youtu.be/-lV1plMKSRg

speedtigger

iTrader: (16)

Great pass! Starting to feel fast?

As for the running rich, plug selection and timing, lets talk that through.

In regards to the plugs, don't go hotter while running nitrous. I understand your thinking that a hotter play would stay cleaner, but that is not the right way to go about it. The hotter plug could spell doom for your expensive stroker motor. Let's fix the problem, which is a rich mixture.

What jets are in your nitrous plate?

Also, you had said previously that you're best N/A ETs are at 36 degrees timing, correct? You said above that you ran the nitrous at 28 degrees timing? If this is correct that it 8 degrees pulled for a 100 shot. That is way too much. The general rule of thumb is 2 degrees per 50 HP. You are leaving a ton on the table.

If you get that plate jetting cleaned up and get more timing in that thing, you just might run 9s without upping the nitrous jet.

Gunone

I agree totally, 34* is where it ran the best on motor so I pulled 4* plus 2* to be safe. Also i checked the fuel pressure to the nitrous plate and it was 1/2 pound high so I think i have the richness figured out. Next time out I will adjust the fuel pressure to the plate and and give her 2* timing with brand new plugs, 7s.

speedtigger

iTrader: (16)

What jets are in your plate? 1/2 pound of fuel pressure is not going to make a good tune foul your plugs.

dogsballs

great work.

just to clarify the power valve, it will introduce fuel based on vaccuum thru 2 small opening called power valve channel restrictors (drilled in basic blocks or tapped in custom metering blocks). generally jets would be staggered if power valve is right size ie engine vac /2; 13 /2 = 6.5 pv. only time i would guess if restrictors are too small or pv not right size.

dogsballs

glad its not just my new motor. mine is the same, on dyno makes more hp and way more torque in that high 12 region.

last motor was 11.9, but that was efi

Gunone

Nitrous jet 57, fuel jet 57. Edelbrock

speedtigger

iTrader: (16)

That right there is the biggest part of your problem. That is old school fat. Most guys are finding that their plugs don't start to clean up until they get in the neighborhood of a 10 jet-size spread on 5 1/2# to 6# of fuel pressure.

I have my 125 hp "street" jet tune in right now and that is 55n/43f on 6 1/4# of fuel pressure pulling 6 degrees (I could pull less). It yields a very clean plug and GREAT performance (1 full second and 10+MPH in the 1/4).

I am usually around 925# - 950# of bottle pressure.