Stock Gran Sport air cleaner with the baffle removed, and a K&N filter. Leaves an open ring around the lid, must be good for more air flow and looks kinda cool. I got Kitabel's spreadsheets, and now realize how much I dont know. The fact that the rod/jet changes I made made the car run faster was sheer dumb luck. I realize I'm looking to calculate % of area change around rod/jet conbinations, and I can punch all the numbers in to show those changes, but the basic question remains: Do I go leaner than stock for hot weather, richer when cold? The basic tuning thing is new to me....
re-reading the post, I see Kitabel had answered my question about going leaner in warm weather (80 degrees or better?) <TABLE class=tborder style="BORDER-TOP-WIDTH: 0px" cellSpacing=1 cellPadding=6 width="100%" align=center border=0><TBODY><TR title="Post 1746493" vAlign=top><TD class=alt2>For warm weather I'd just drop 2 sizes primary, 1 secondary, leave the rods alone, and try it out.</TD></TR><TR><TD class=thead colSpan=2>11-14-2010 10:15 AM</TD></TR></TBODY></TABLE> I dont know where Carmen came up with these funky tri stepped rods, but I used them on the primary as opposed to going with bigger jets to account for cooler weather, using the rods as the primary tuning device. I went up one size on the secondaries to account for the greater airflow. I figured I could change the rods to lean out the primary circuit under power, and would just call the secondary jets a wash when using this manifold. By that logic, I could put the original rods back in, or even go thicker in hot weather and that would have almost the same effect as going to a smaller primary jet size- I still have to do the math, but am I way off?
Rhett, what I did to gain traction was install a set of airlift air bags inside the rear springs and then preload the left side with 5 psi and the rt side with 10 psi.... it helped a bunch.....
Good to hear from you! Did the same, but going by an old article ( " Great Scat, Look who's at the Dragstrip" Car Life, 8/65 - Great article! reads like a cookbook for getting the 65 Gran Sport into the 13's. I'll e-mail it to anyone who wants it) I use 50(!) on the Rt and 10 on the left. The bags definitely helped alot - I couldnt pull down these ET's on an open rear without them. I'm working up a chart of the mods I made and average ET's (G-Tech0 right now....
Rhett, I'd like a copy of that article please. Thank you for the great thread. Learning to properly adjust my carb is one of the next things on my list.
Silver Bullet - thanks for the feedback, good luck with your carb! Having made the offer to send the Car Life article, I've found I don't have it on my laptop as a .PDF anymore. However, I do have a very similar article from a '66 issue of Hot Rod caled "Blueprinting Buicks for Action" I'll send that now, and it's VERY similar in the mods recommended. I'll try to load the Car Life article back in the next day or so...
Finally figured out how to save my Test and Tune file as a .pdf file to attach here. This gives a rundown of every significant thing I've done to the Gran Sport, and the effect that it's had on ET and MPH. It's an interesting view, because I've always looked at the work I've done in terms of best ET, not average ET...looking from an average standpoint some of the mods didnt have the overall effect I thought, and some were more significant than I thought... PS - Silver Bullet, send me your e-mail address for that article...
your best runs are with 6 degrees timing, do you know what your total timing is when your at 6 degrees, i am guessing 34 total?
I noticed that too - I took old distributor out, but Carmen set this one to go in at 10, for a total of 34. Installed like that, it would ping at the top end of the run, so I just kept dialing it back until the pinging came out. Did that twice, back in September and again this month and both times the car was faster, but until I charted this all out I didnt realize it was so closely related to retarding the timing...so I guess I'm at about 30 total now...
Wonder how it would run with some better gas and timing at 34 degrees? If you have wheelspin problems, try launching it in low stall.
I ran that way at Lebanon Valley, with 8 or 10 degrees and 108 octane... Didn't ping, launched good but that was before the recurve and Doc mod manifold..60 fts were all 2.2 or so Funny, because my best 0-60s are with the timing retarded. Still feels strong enough to break loose if I really nail it, but all in all I think easier to launch.
