Tune Up

What do you think?
125" Jerry Fritz Altered
406" Alloy Rodeck SBC
Glide, 10" converter, 5000 flash, 4 11 rear gear
8;71 Mooneyham standard helix
Bird hat
110 pump
Hat nozzles 48, 46, 46, 44
Port nozzles 34, 34 ,32, 30
Super Mag 111 4 amp
Pump saver 150 psi
Idle check 7psi
High speed 60 psi
Port check 15 psi
Barrel leak 75%
Race usually at above 1000 ft
How 'bout some imput?

 

What blower o/drive or boost. Are you running a pump loop.What size pill on h/s.

 

20% over on the blower,
No pump loop,
Main pill 95,
Hi speed 65.

 

I think you should be pulling fuel out.It seems tooo rich.
I have done a 370 ci SB/C with 23° heads
871 @ 28% over with a worn blower making 24 lbs @ 7600
110 pump with loop -15lbs & .110"pill
hat .042's @ .044's
ports .032's
Main .100"
H/S .065 @ 64 lbs
static comp was 10.6:1
B/V 65%
Idle check 3-4 lbs
Have you run your combo yet & does it seem fat & lazy?

 

I actually thought that it may be a touch lean. I have had the car out for a burnout and a launch and thought l may take a couple of degrees of lead out of it to keep it safe. We will be looking to run 7.0- 7.1 around 190, but don't want to burn the thing up.

 

Assuming a typical 110 flowing 13.1 GPM, and assuming your nozzles/jets are flowed.

I'm showing you're about 10 main sizes too lean as well.

 

WJ, if your saying that SCO1035 is lean , then what does it tell you about our tune.It seems to me that we are way leaner & we use a 6 amp mag as well. I guess we should be having some serious meltdown problems but the thing still goes round & round , lap after lap, 1 1/2 km per lap , 4 laps per race.How can both tunes be so different?

 

My tune that I posted was based on air of:

75F
29.92 hg
50% humidity

I was also looking for a 'safe' a/f ratio of 3:1, based on a blower CID of 436 and 100% efficiency.

Many factors can change a tune up. It all comes down to opinion, and no tune up, unless everything is identical in 2 motors is going to be perfect. Only the motor and data logger can tell you what the motor needs to make the most power without destroying parts.

 

WJ,I agree with you totally, but there is a major difference between the 2 tunes. The motors aren't all that different to have the 2 tunes with that much GPM flowing through the engine.

 

Well look at it this way...

A little fat, you can always lean it down. A little lean, and you can always rebuild it.

Which is cheaper?

 

You got it WJ, my thoughts exactly. I'm trying to err on the side of caution as l don't have a bottomless pit of cash. Thanks for everyones imput.

 

Seems to me you will need a bottomless pit of cash just to pay for the extra fuel you'll be putting in & just to run slower. Good luck!

 

Can you post your combo and tune for us then?

Thanks

 

http://www.insidetopalcohol.com/showthread.php?t=18101

Based on this thread, he doesn't have one, which is why he's asking for help.

He's also wanting to add more fuel to the hat nozzles, which is uncontrolled, versus the ports that can be controlled to keep EGT's in balance at WFO.

 

Will is right, unless you know exactly what your pump is putting out you are just stabbing in the dark.

 

If I was to increase all hat nozzles by say 6-8%, would that make my fuel distribution any different than it is now apart from the engine getting more fuel?
If I was to change all the port nozzles the same %age, would all my EGT's stay same or as even as they were?
I also agree with what Will stated. Even the experts who know what they are talking about can only give you a baseline tune.

 

Hey buddy, understand that if you have 10 different people answer the same question on here, you will more than likely get 10 different answers. If people don't necessarily think that yours is the right one, thats ok too, obviously to everyone except you. Just remember that it was just put up for comment, pure and simple, to see what you guys thought.
Great site Will!

 

Having your fuel system flowed by someone may at first seem a bit expensive to some people . When you figure in wasted trips to the track and normal wear and tear on all pieces that move not to mention fuel nowadays it really makes sense to pay it now instead of paying it later . Sounds like a good candidate for Billy at ODDY'S automotive , I doubt anyone has built more blown chevy's than that shop . It's worth a call .