Tom and I have been talking about A/F dial in for a year or so, and he has accces to a Innovate Motorsports set up that we were gonna try this spring. A couple weeks ago I was up at Ken's house (Everyday Performance) and he showed me his Edelbrock 6593 A/F meter. It's only got one o2 sensor lead, but he says he likes it alot and it is fairly cheap. For the money it makes sense to own one, especially with two other cars to dial in after this one....(we never talk about the 455's, it's like a dirty little secret) And if it makes you feel better, I am finally home! Everything worked out just like I'd hoped.
Played with the Governor this morning, making some progress - Taking one spring out did give me a 500 RPM bump...first run it started to break up at the peak so I bumped the rev limiter to 5700 and took another shot to rule it out....Perfect. Now I have to wonder how accurate the console tach is...it's always been FAIRLY accurate against the Sun machine and my cheap chinese diagnostic tach at low RPMs....at this latest shift point it indicates just over 5k, but I might have hit the 5500 rev limiter too (or it might have just not been ready to spin to 5100 at that particular moment) Maybe the Pertronix calibration is off? Either way it pulled STRONG all the way through to the new shift point- it never fell on it's face and I didnt feel like I was overwinding it either. As I understand it, if you overrev a nailhead it will really drop right off, no? And If I REALLY overreved it it would start popping back from floating valves, no? I dont want to lunch this engine, it's old and tired and I understand that revs and most stock Buick engines dont mix well... I have to assume I'm shifting north of 5500 at this point, even tough the tach reads probably 5100-5200 What do you guys shift at? What can I safely get away with? - And GTGSX - The removal of the spring DID mess with part throttle shift points - it's not unpleasant, but again probably 400 RPM higher.
now just back off the modulaor screw to start with 2 turns counter clockwise it will up shift sooner and softer at part throttle.never knew you could run a stock tach with pertronix it never reads right after you take out the points. it makes sense it seems faster, the higher you rev it in first gear the more you will be in your power band when you shift to high.
About the factory tach. I have one and it always seemed like it would not go past about 4700. Thought it was broke. Mabey it was just the petronix?
Ha! It's making it past it now! Like I said, it's always been fairly accurate, or so I thought. Either way, I'm gonna leave it as is and bring it up to Lebanon and see what it does. Just hope I dont scatter it! Maybe with the big bore exhaust, Q-Jet and Doc Mod it likes the revs? I would have swore it would fall on it's face over 5200 One time on a run I accidently took off in 1st and want ready to shift and zinged to way over 5k (way over). All it did was heel over and go "Bwaaaaaaaa" and slow down. No popping or crazy noises or anything
Big pig, how does that Q-jet run on the nailhead? did you say you picked up 2 tenth with the d.d. mod? was wondering how low throttle response is. wish I was closer so I could make the nailhead day you guys are planning:grin:
The first run on the Q-Jet that my buddy drove he came back down the return road and got out and said "Wow - it's never run like that!"....it was that noticable. I'd have to attribute a 10th or more to the carb, but it's more than that - it just feels so much better and my 60 foots stayed at 2.10-2.20. It revs quicker and has great throttle response (but to it's credit, I had good throttle response with the AFB too - no flat spots). My best run ever on the AFB was 14.85, but I was never able to repeat it, I would mostly run 15.0 or so. wiht the Q-jet, I have run a best of 14.77, but I can generally keep it in the 14's. On my non Doc Modded AFB manifold I was generally 15.3 or so. It's hard to quantify, but the Doc Mod helped alot. I've done so much stuff at once, I havent had the time to do one mod at a time. The big 4 have been a fan clutch, Doc Mod, Q-Jet and distributor curve. The car started at 15.6, so could you attribute .2 to each? Pretty close. Strangely, the 3.08 ot 3.23's didnt have a huge bang, and the Eaton diff helped alot too, but it turns out I had the suspension jacked around enough to launch pretty well on the open diff before. I'm launching a little more aggresively, but it'll still spin pretty easy if I go over 1700 rpm off the line. Hopefully a little more suspension work and I can launch harder, maybe launch at 2k And during all this I had electrical issues, so hopefully this season it's easier to tell whats really going on (and dont scatter the block!) I'm gonna try to weld in the o2 bung this afternoon. Looking forward to seeing whats really going on...
