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JoePapa · 03-09-2009, 11:02 PM

I recently swapped from an Edelbrock Performer RPM manifold to the Victor. Since the Victor doesn't have a vacuum port, I added a 1" open spacer with the port for my vacuum brakes. Overall the swap was favorable. The car picked up about .4-.5 seconds and dropped from 11.9-12.0 range to 11.5's.

In tuning with my LM-1, I noticed the air fuel ratio tends to be a lot leaner. I've gone up to a 90 / 81 jetting and, depending on air, it may take more because AFR on the last outting was high 12's to very low 13's.

This sounds like a lot of jet to me. I'm wondering if this is normal or if I need to ditch the open spacer and either not use one or go to a 4-hole spacer for better signalling.

What have others found?

Engine Specs:
69 400 bored .030
#62 Iron heads - home port to 275cfm @ .500 lift - heads milled to 10.4 compression with .040 gasket
Bullet Solid cam 260 / 258 duration @.050 - .554 / .586 lift int / exh
Crower Solid lifters with EDM hole
Crower 1.6:1 roller rockers
825 CFM Mighty Demon

Thanks in advance!!

Scott Stoneburg · 03-09-2009, 11:05 PM

a 4 hole tapered spacer was worth the investment on my car, worth almost 1 mph in the 1/4. track tested back to back comparison

shaker455 · 03-10-2009, 12:19 AM

Joe,
Test the well caps on the top of the metering blocks and make sure they are not leaking.

JoePapa · 03-10-2009, 09:22 AM

Scott - thx, was thinking Wilson tapered or straight 4-hole. I've read good things on the tapered.

Shaker455 - guessing take a pass for a baseline then make another pass after I cover the surface with tape or wax or something to prevent air loss?

shaker455 · 03-10-2009, 06:46 PM

How about taking the jet out and blocking the booster feed hole with a finger.

Put some soapy water on the caps and use a rubber air tip were the jet screws in.

Look for the fuzzy pumper barber shop on the caps!...

hal101 · 03-10-2009, 06:52 PM

WOW

how much taller is the victor than the RPM ??

and what rpm are you shifting at ??

Skip Fix · 03-10-2009, 07:38 PM

I've run more jet in my 850 Demon on a couple of intakes T2 and Victor.

ponjohn · 03-10-2009, 09:13 PM

joe - did you pick up any mph?

JoePapa · 03-10-2009, 10:16 PM

Thanks Shaker, good idea.

I'd like to say I'm shifting at 6,000 but by the time I row the gears (stick shift) it's about 64-6500. Sometimes I'll hit the 6k mark but I really need a shift light to help me get consistent there. My ET's are ususally pretty close though.

MPH picked up 4-5 mph. The motor really responded well to the bigger manifold - it's obviously matched to this cam and air flow better. My previous mph was anywhere from 112-115ish depending on the air. I installed the manifold during these winter months so in the cooler air I've ran 119/120 and not sure what it will do in the 100 degree heat yet. I came close to 130 with a 150-175 shot though

Half-Inch Stud · 03-11-2009, 07:50 AM

Picking-up 3MPH not too surprising, but 0.4 0.5 ET is amazing to me.
Did 60foots move down too? (how much?)

84 Jets were to lean in my 1050.
high 90s Jets at all 4 corners might be the right values, but I still need to track-eval that. Feels better that 84s on the Street.

Now that I'm re-cammed, such an eval can LIKELY occur this season.

JoePapa · 03-11-2009, 02:29 PM

60' times went from 1.7-1.8 to 1.6-1.7.

The car has a very stiff suspension and my 60' times aren't very consistent. I can usually hit the high 1.6 to mid/low 1/7's though. So between stiff suspension, stick shift launch, and piss poor clutch that's probably about as good as it's going to get for now.

Swapping manifolds was a very good move for my application. I was just surprised at how much more fuel I had to add but it sounds like it may be a little more common then I expected. Life is good - shooting for 11.4's next.

walterd · 03-11-2009, 08:18 PM

Hey Joe, glad it is working out for you. I don't have a LM-1 or other so all we do is check plugs, running 83/83 - 86/86. Why do you run 90 up front and 81 vs even front/rear, curious?

66bonne · 03-11-2009, 09:50 PM

WOW - that is a remarkable improvement.
I've been running the RPM intake and going to try a Torker 2 but with the improvements you posted I may have to look at the Victor as well.
Thanks for the informative post.

Jim

JoePapa · 03-12-2009, 09:46 AM

Thanks 66bonne - it's worth trying out and made a significant improvement for my application.

Hey Walter. The reason I've got 81 front and 90 rear is because I run the front power valve on my carb. I was trying to keep the street driving to a reasonable AFR but with 81's in the front that's probably shot now. I think the rule of thumb is 6-8 jet sizes variance between front/rear if you run a power valve. If she needs more at the track I'll add more to the front first

BTW - I've heard the car show is now on 183 and 1431 but haven't been out there yet.

BILTIT · 03-12-2009, 10:05 AM

I had to jet up a fair bit when going from an RPM to a TII, gained a couple MPH.

walterd · 03-12-2009, 11:45 AM

Quote:

Originally Posted by JoePapa

Thanks 66bonne - it's worth trying out and made a significant improvement for my application.

Hey Walter. The reason I've got 81 front and 90 rear is because I run the front power valve on my carb. I was trying to keep the street driving to a reasonable AFR but with 81's in the front that's probably shot now. I think the rule of thumb is 6-8 jet sizes variance between front/rear if you run a power valve. If she needs more at the track I'll add more to the front first

BTW - I've heard the car show is now on 183 and 1431 but haven't been out there yet.

Interesting, I run power valves as well, guess I should try this as well if I try it on the street more. We have been to the 183/1431 meet, not a bad showing for such a new location. Will be there when it is warm and we aren't at SAR. If the weather improves we will be there this Saturday Midnight Madness and next friday for the Jackpot race.

Have fun!
Walt

pinballDan · 03-12-2009, 12:21 PM

What carb are you using ? Is this on a 1st gen bird ? If so what hood are you using ?

Thanks Dan

JoePapa · 03-12-2009, 01:52 PM

Thanks everyone for confirming this is normal. I just wasn't sure how much I should have to jet up but it makes sense, more air needs more fuel.

PinballDan - I'm using the 825 cfm Mighty Demon. I was lucky enough to get one before their quality control fell through the toilet. This is a first gen and no it didn't fit. I picked up a used 350 hood and cut it so the air cleaner will fit through. I still need to get a scoop or fiberglass hood to cover the air filter.

You can see it poking through in http://www.youtube.com/watch?v=8GIbp...eature=channel

I have a few videos under out there too under JoePapa69 but don't think there are any recent clips that really show how much higher the air cleaner is then the hood. With the 1" spacer and not milling the manifold, the air filter lid is about 3" above the hood at the front of the filter.

Ron H · 03-12-2009, 03:14 PM

Great deal. I bet you were stoked when you pulled that 11.50 run!! Got a roll bar?
Less restriction = more air flow= more fuel needed = more power. Giddy up.

JoePapa · 03-12-2009, 03:48 PM

Quote:

Originally Posted by Ron H

Great deal. I bet you were stoked when you pulled that 11.50 run!! Got a roll bar?
Less restriction = more air flow= more fuel needed = more power. Giddy up.

No rollbar yet. I need to stop making it faster and fix the rust and cage it but since I already had the manifold I had to try it. I'm going to hate having it down for repairs but it's fast enough now that the new direction will be safety equipment. New sheetmetal and a cage are the next milestones for the car.

PS - I was very stoked on the 11.5's. That night she ran 11.56,7,8,9 - I was very pleased.

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