2002z28ssconv

My buddy and I are autocrossing his 85 GSL SE. We dropped a RB intake on the 6 port 13B. It called for a 600cfm Holley but we think they sent us a 650 double pumper. It already has whistles and side floats but the carb is flooding out in the corners even after we lowered the float levels. Anyone have anymore tips?



Also he put in 2nd gen spark plugs. Could that be causing it?

2002z28ssconv

I was in a hurry typing that at work. Here's the rest of the details...



We did the distributor bypass mod where you connect two MSD coils directly to the leading plugs with a third for the trailing going through the distributor. I adjusted the throttle squirter pumps (double pumper) so that they don't give as much of a squirt when you hit the pedal. That helped a lot. At first we were getting too much fuel and sputtering while just cornering due to fuel slosh. That's pretty good now but if we feed it any gas pedal at all while cornering or if we are to quick on hammering the pedal to the medal it floods out and sputters for a couple seconds.



When this things hits it really screams though. Out of 100+ cars at our event on Sunday I was 14th overall and less than 2 seconds out of the top 5. This is with full interior, original bushings, old shocks and stock front sway bar (rear bar disconnected). The only weight we have removed was the AC and fuel injection components. So we should be contending for top time trophies if I can get this thing to run in the corners.



I'm thinking thta the 650 carb might be just a bit too big and we need to change the jets. Our A/F guage reads very rich too. I'm also not convinced that we don't still have a little bit of a fuel slosh problem too. Then my friend remembered the spark plugs that he put in it. We think that the fuel might be pooling up inside the plugs or something. Maybe the 2nd gen coils had higher output to be able to burn through the extra fuel.



Those are our thoughts. Perhaps some of you have already been there and done that. I tried to search but didn't have any luck.

2002z28ssconv

Also (again), I saw a Racing Beat 13B carb intake one time that a guy had ported. It came to a point in the center and all 4 runners were open to the base of the carb instead of having two runners for primaries and two runners for secondaries, all sealed to the base of the carb and kept seperate from one another like they come from Racing Beat. Is this advisable?

RONIN FC

You may not be flooding, look into jet extensions.



In a nut shell, Racing beat fucked up and assumed that design would work on the late closing 6 port like it did on the 4 ports.



Get a 1" 4 hole phenolic spacer for a holley and bore the 2 secondary "runners" of the spacer together. This provides a relief for a pulse wave coming up the aux port/secondary side to go down the opposing rotors runner instead of back through the carb. This will greatly smooth the vac signal to the venturi



For more driveability, try an open plenum spacer under the carb



After you experimented, work the runner mouth round and smooth with some sanding drums.

2002z28ssconv

Wow! I had to sit and let that sink in a little bit. It seems to make sense now. How 'bout the spark plug question? Has anybody run 2nd gen spark plugs in a 1st gen 13B 6 port?



This is what style used to be in it before the carb install:





This is what is in there right now:

RONIN FC

No, but I run a 1st gen distributor with 2nd gen plugs in my fc 6 port 13b. Its fine so long as you run high energy coils equivalent to the fc.



But that shouldn't stop you from experimenting with the original plugs.