Dual Quad Owners...Question on tuning (Now w/ PICS)

Posted By: Pyper70

Dual Quad Owners...Question on tuning (Now w/ PICS) - 09/01/10 11:34 AM

How the heck do you get in between the two carbs to adjust the rear A/F screws? Luckily my vacuum ports will be blocked off because I have a Mech Adv. dizzy. My A/F screws hav a torx inset. I was thinking to cut the tip off of a torx screw driver, set it at an angle, and weld it back in place...

What are your tips for that?

Also, next question is I assume the 500cfm Eddy's are set to run by themselves OOTB, but should I change some metering rods or jets because they will be running in sync with each other. Is there a baseline I should start from with alternate parts or go from how it is OOTB?

This setup is going in on Thursday/Friday most likely. I got the Bouchillon kickdown & throttle linkage.

Posted By: quickd100

Re: Dual Quad Owners...Question on tuning - 09/01/10 11:54 AM

I just use my fingers on the screws, they're just spring loaded. Start with the box stock settings with your Eddies, they will probably be very close as is. Dave

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/01/10 11:44 PM

Are you running a progressive linkage or a straight link where both carbs idle circuit is involved. I never liked that and always run a progressive like the Hemi. Anyway on my edelbrock 2X4 intake running dual Carter Competition carbs I'm able to get a small screwdriver in there, like it was mentioned they are springloaded and there's no real resistance on them. I have two complete strip kits plus extra springs, jets, and metering rods to tune my carbs. I also have an autometer 02 sensor in the car to monitor my air fuel mixture. I also run a 1 inch spacer plate under each carb. A lot of work to make it work, and when it does its awsome.

Posted By: Pyper70

Re: Dual Quad Owners...Question on tuning - 09/02/10 12:55 AM

Running the progressive linkage that came in the box with the Edelbrock. I have the Autometer O2 sensor as well...I have 1/2" phenolic spacers between the carbs and the Manifold. I milled down one of the billet spacers to make two 1/4", and two 1/2" air cleaner spacers to clear the linkage and fuel line. So I should be in the clear there.

Posted By: DJVCuda

Re: Dual Quad Owners...Question on tuning - 09/02/10 02:36 AM

Thats the beauty of the holley's ( 390's) the screws were all on the sides ( front to back )

Altho - now I just adjust it all from the drivers seat in the tuner.

Posted By: JAKE68

Re: Dual Quad Owners...Question on tuning - 09/02/10 01:14 PM

If you just bought a new edelbrock inline intake they have their jetting recomondations included in the package. Having a senior moment and can,t remember if the jets where included or if there was just their recomondation.But did do the jetting and when I threw it on the dyno they where right on.For a duel quad set up those carbs are on the fat side otb.

Posted By: Den300

Re: Dual Quad Owners...Question on tuning - 09/02/10 03:05 PM

Quote:

But did do the jetting and when I threw it on the dyno they where right on.For a duel quad set up those carbs are on the fat side otb.

when i jetted my two 600s like recommended the engine
where running way to lean. the spark plugs where totaly white.
as they nearly burned

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/02/10 07:33 PM

I notice you still have the choke linkage on the secondary carb, ditch it, you don't need it there. I also pulled all the linkage that works off it to make sure they didn't affect the tune. You'll have to pull all that aircleaner stuff off there to adjust the idle circuits. On my secondary carb I have the idle screws turned all the way in so they don't affect the idle. Make sure the blades on the primary side of the secondary carb are completely closed. On mine I use the first hole (closest to the plunger) on the accelerator pump, and the second or middle hole on the secondary carb, it works for me. On the secondary carb make sure to plug the powerbrake vacuum hole at the back, I plug the vacuum lines on the front of the primary carb and use the vacuum ports on the secondary carb dizzy or whatever (I have a vacuum gage running off there). I run my power brake vacuum off the primary carb. I also have a fuel pressure gage mounted on my fuel lines to the carbs. Mine like between 5.5 an 6 lbs pressure. I also rin the .110 needle and seats in both carbs fed by a 1/2 inch fuel line with a return to tank line off the fuel filter (like the Hemi's came with). The 02 sensor is a great tuning aid, just takes time to get it all together. Hope that helps.

Posted By: Pyper70

Re: Dual Quad Owners...Question on tuning - 09/02/10 08:14 PM

Quote:

I notice you still have the choke linkage on the secondary carb, ditch it, you don't need it there. I also pulled all the linkage that works off it to make sure they didn't affect the tune. You'll have to pull all that aircleaner stuff off there to adjust the idle circuits. On my secondary carb I have the idle screws turned all the way in so they don't affect the idle. Make sure the blades on the primary side of the secondary carb are completely closed. On mine I use the first hole (closest to the plunger) on the accelerator pump, and the second or middle hole on the secondary carb, it works for me. On the secondary carb make sure to plug the powerbrake vacuum hole at the back, I plug the vacuum lines on the front of the primary carb and use the vacuum ports on the secondary carb dizzy or whatever (I have a vacuum gage running off there). I run my power brake vacuum off the primary carb. I also have a fuel pressure gage mounted on my fuel lines to the carbs. Mine like between 5.5 an 6 lbs pressure. I also rin the .110 needle and seats in both carbs fed by a 1/2 inch fuel line with a return to tank line off the fuel filter (like the Hemi's came with). The 02 sensor is a great tuning aid, just takes time to get it all together. Hope that helps.

Jon...I notice from the pics on your site that you have both chokes disconnected on the setup....How does your car warm up? Do you have any close up shot of the dual setup on yours? I guess I have to do some tweaking on the carbs before they go in.

When speaking of dual quad terms...the primary carb is on the rear? and the Secondary is the front?

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/03/10 01:46 AM

I run a pull choke, I don't rely on the electrical ones. And yes its connected to the Primary (rear) carb. Your progressive linkage looks ok, mine is reversed from yours I think. I'll try and take a recent pic and post it.

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/03/10 02:16 AM

OK Try these.

Engine 1

Egine 2

Engine 3

At the drags

Had to throw the last one in for kix, I'm turning 11:70's at 120 with Goodrich drag radials.

Posted By: CrAzYMoPaRGuY

Re: Dual Quad Owners...Question on tuning - 09/04/10 01:00 AM

My Interceptor has a CH28 and Edelbrocks. I don't run chokes at all, takes about one minute to warm up before I drive away... starts up no problem.

I don't run progressive linkage. I have two Edelbrock 500s.
I just use my fingers on the A/F screws too.
Pretty danged close together!

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/04/10 03:38 PM

I've tried several engines w/progressive and w/o. On the street I really prefer the Progressive, it is milder mannered. However, I'll run either way at the track depending on air/heat/traction. If its all good I run a straight linkage. Takes me about 5 min to change.

Posted By: quickd100

Re: Dual Quad Owners...Question on tuning - 09/05/10 02:17 AM

I run a Weiand tunnel ram with 2 modded 850 thermoquads on my 528 Hemi. I don't use a progressive linkage and it runs VERY WELL on both sets of primaries. Before I installed a 8" convertor I had a TA 10", I had the carbs tuned so they ran 14.5-15/1 A/F ratio at cruise I checked the MPG once driving it real nice. (Very hard to keep my foot out of it too) I got 13.8 mpg.
Since then I said screw the economy the carbs are tuned for power, the convertor stalls at 6200.Dave

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/05/10 03:11 AM

I followed the thread when you did that. I really like the idea. On a tunnel ram or cross ram straight linkage is the only way to go, however, on a dual plane you can run progessive and it'll do just fine. I bet that engine of yours howls when you wot.

Posted By: Pyper70

Re: Dual Quad Owners...Question on tuning - 09/05/10 08:10 PM

So I installed it up until the point of needing to make the fuel line as well as installing the Buchillion kickdown.

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/05/10 10:23 PM

Lookin good. You will need to install a spring on the secondary carb or it will hang open for sure.

Posted By: Pyper70

Re: Dual Quad Owners...Question on tuning - 09/05/10 10:26 PM

Quote:

Lookin good. You will need to install a spring on the secondary carb or it will hang open for sure.

Yeah...I need to make two small aluminum brackets and attach them like you have yours, that long spring will fail for sure.

Posted By: Cudajon

Re: Dual Quad Owners...Question on tuning - 09/06/10 12:42 AM

I bought those brackets, but I've slept since then and can't remember where I got them.