you know you can set those electric chokes right? you should be able to loosen the screws and turn that large black piece and get it to come of early or stay on longer.

i'd grab an entire proform 750 with electric choke and adjustable airbleeds, or grab a proform 750 with the HP body.

they all have billet metering blocks, and billet baseplates. they are mucho better than the normal holley stuff

 

I am running an electric choke and if I turn the black piece any more to delay, it will not open all the way. Thought about putting in a resistor to slow the heating coil down, but have not gotten to it yet.

Now that it is warm today, I am discovering that the manifold must be loading up with wet fuel during idle in traffic. The AFR is fine at idle, but when I roll into the throttle when the traffic clears, it goes dead rich. I have to clear it like a pro stock car before it will cruise right. It is fine on the highway though and when it is cool, it is not an issue, presumably because the air is more dense. I will see if jetting down some will help. If not, I may have to readjust the butterflies to get some more velocity at idle or drill them...

There is nothing like trying to tune a race engine for the street.

 

try tuning a small displacement motor like my 289 with a 300/300 duration cam in a car with an auto.

fun times

 

Yep...big duration cam with a small stroke and trying to not get run over while it is in gear has got to be a good time!

 

my personal opinion is that the carb is just to big, granted you have a radical cam. i would try a 700 or even a 650cfm. i think most of the fine tuning questiones would be answered....

 

I know and agree...a little late at this point, but I may hit that at some point. At WOT, and cruise, the carb is fine, it is just a bear to get to perform at low velocity too. I think a 650 would kill the top end as this car is probably in the 90s VE, but a 700 might be what the doctor orders...from what I have read, if I had adjustable air bleeds, this would be done already.

 

yeah man i say stick with 750 but get a carb or mainbody that has adjustable air bleeds.

 

Damn. I has an elaborate answer for ya. But here goes the short version
Don't get the Proform, the HP is better quality for the main body.
What ever you do to the front, remember to do to the rear.
If you changed the butterfly angle up front, it changes lots of things. Just the AFR bounce your getting is probably the main circuit juuuuust starting to flow, then not, then flow. Your getting droplets from the boosters. The primaries are probably open just a bit to much. That's when you drill. Same air flow, but the transfer slot is uncovered the correct amount.
the problem at idle you are talking about is probably just the gas heat soaking in the carb. Hot gas takes FOREVER to burn. Sometimes it's bad enough to get a sneeze through the carb because the burn is delayed so much. You reving it is just empying the hot gas through the motor and new cooler gas replaces, and the problem is gone. Phenolic spacers are your best friend. Put one on if you possible can. You'll be amazed at the difference

Race engines are generally much easier to tune. Idle, transition to WOT. Done. Street is much harder. When you master this, you can show your buddy stuff he didn't know about his HP. lol Hope this helps man. -Dustin

 

Thx a bunch! I was just reading about heat soak. Funny you mentioned that too. I am pretty much maxed out on height (Air Gap Intake). A taller plenum would also help my velocity issues, but I am not going to cut the hood up (want to keep it stock looking). The strange thing is it did not do this dead rich after traffic idle when I had the secondaries open more...I am heading to the coast for some R&R and good food. I plan to re-jet Sunday or Monday depending on when my favorite UPS man arrives (it is running too rich at cruise right now anyways). If that does not clean up the dead rich deal after idling, I will try cracking the secondaries an 1/8 turn and see what happens. I will also measure the idle transfer slot on both sides before changing anything (for reference). From what I read, I really don't think the transfer slot is too exposed on the primaries. You can see a definite 14.7 idle and slow cruise and then see it shoot up to 12.5 when the main circuit kicks in. If I hold the throttle very very still, the AFR will creep up to 13, so the accelerator pump should not be causing an issue. I could never really see when the main circuit kicked in before, which is why I adjusted the butterflies (pretty sure I opened the secondaries too much when tinkering six months ago). I can see the change now, so if I drill the butterflies, I would think that would cause me to have to close the butterflies more which is kinda pointless since the idle circuit is working correctly now, right?

Dreaming of air bleeds...not going to cut down my crawfish intake though to pay for a $600 Holley HP!

 

cpr, that's the fisrt negative thing i've heard about the proform bodies. what is bad about them? just purchasing the main body (or the one from holley) would be a cheap route to take.

urban, how tall is your current air cleaner? could you put a shorter filter in it to give you 1/2" or so for a spacer under the carb?