Ironically, it's my electrical engineering background which makes me such a proponent of headers. The propagation and reflection of exhaust pulses running through tubes is completely analogous to the propagation and reflection of electrical pulses running down wires. Rusty, you and I would run real even. I'd get you off the line, then you'd run me down on the top end for an even tie. Best RT would win most races. At 200 lbs more race weight and 2-3 mph faster, you're obviously making more horsepower than me. Maybe you guys are right -- if I put the W&Z manifolds on, I'm sure I'll pick up horsepower. I really respect you for driving your Hurst/Olds such distances for the races. Ever since I swapped my 3.23 gears for 3.90, I can't seem to get excited about driving more than an hour on the highway.
YEP - I must admit .... Your EE knowledge has gotten you this far .... Hopefully there's REALLY 14.3 volts going to the dome light ...... :moonu:
Thanks for the compliment! :beer I agree, most people leave "too many stones unturned" before they start adding aftermarket parts such as headers, Holley carbs, etc. The factory spent a ton of time engineering the total combination of parts. Headers typically show gains when you change the factory cam, port the heads and extend the operating RPM of the engine. If you retain the factory cam there is little to be gained.
Can I get an AMEN!!! I don't know exactly what tweak you shared with Rusty, Jeff, but my favorite Quadrajet tweak is to better control the opening rate of the secondary air valve. I drill out the orifice in the vacuum break so it has no effect, then I insert various precision orifices in line with the hose feeding the vacuum break. Finding just the right one (not too big, not too small) can really improve your 60' time. And I would think this could serve as a traction aid for you pure stock guys and your hard tires. Many people have no idea their carb is actually bogging off the line -- not the fall-on-your-face kind of bog, but going too lean just the same. I've been toying with the idea of selling tuning kits containing maybe 5 different sizes of these precision orifices, but that's another back-burner project I never seem to get to.
Selling tips to go high-13's ..... with headers ? Isn't that kind of like selling round tires to those that didn't realize that they were round already ? p uzzled:
Why bother drilling out the vaccume break when you can disconect the rod and manage your air vane tension? As for traction aids :rant: , leave those to Formula 1! Having excessive power and knowing how to launch is half of the fun running this series! Learning how to back pedal like John Force doesn't hurt either! :TU: By the way Brian, what kind of 60' times are you turning with your 3.91's? I was pulling consistent 2.0 60's with my Eagle GT II radials that are 7 years old!
Casey, are you saying you already knew that the vacuum break orifice size is a great tuning aid? If so, nice of you to share it with everyone like I did. If not, maybe you should try it. Your 12-second brain might learn something from my (mid-)13-second brain. :moonu: Rusty, I've had much better success tuning with the orifice size than the spring wrap. I prefer to set the spring just about as loose as possible then make the adjustments with the orifice. You don't really have to drill out the existing "orifice", because no one makes them like the original Delco units. Those had a very small, precision orifice. The replacements I see today simply form the end of the tube into a crude hole that's much too large. Last time I had street tires (Eagle ST) on my W-30, I also had 3.23 gears like you -- and like you, I had 2.00 60' times. With Drag Radials and 3.90 gears, the 4000 lb beast is pulling 1.85 60s. Probably more if I turned on the A/C.
Yes, I did know that it was a tuning aid. A "great" tuning, aid ..... we could debate that, but you are correct, it is a means of tuning. I do concede that it is not a well known method to the masses, so me comparing it to round tires might have been a bit trite. p Personally, I find it much easier and consistent to dial in the air door and distributor curve to get my results. :TU:
Eaton doesn't make a posi for the "O" axle Olds. Bummer too ..... I'd love to run one. 400# spring kit is plenty for a polyglas equipped car. I've got an 800# kit for the Biscayne with the 12-bolt Chev, should I choose to replace it. But I don't think I'm going to.
Nobody makes anything for the "O" axle. About all you can find is custom made or used (40 year old) parts. That's why I don't run them and prefer to run with the Canadian car Chevy 12 bolts in my cars. Kinda goes along with the Canadian beer motiff.
Headers first and now drag radials! :spank: 2 Strikes against. If you tell me you have a blue bottle in you trunk, I may have to come to MI to steal that car away and give it a good home! :moonu:
I'll be more than happy to blow Casey in the weeds with a "manifolded" W30. :bglasses: :laugh: :3gears:
As much fun as it is to try to launch these cars on street tires, I got sick of my tuning effects getting lost amongst inconsistent 60' times. How can you see a one or two hundredth improvement when your 60' time is varying a tenth or more -- which in turn makes the ET vary a couple more tenths? Sticky tires to the rescue! If you're able to launch consistently on street tires, Rusty, you're more man than me...... The Drag Radials are more fun on the street, too. Less smoke, more balls.
Very good point. I have planned all along to have at least drag radials on my car for tuning. But once you get it tuned up, put some bias plys on it and tune the suspension.
Gee that's funny. I've run M/T Sportsman Pros (same diameter as my G70x14 Polyglas but 10 inches wide), I also ran slicks. Best 60 foot times ever are with the Polyglas. Once the car is set up for it and you learn how to drive it out of the hole, it doesn't make that much difference. Course if you want to take that part of driving out of the equation and just mash and go, that's different. Look at your MPH when you're evaluating changes in tuning, et's are almost meaningless. MPH is a better measure of the hp. Oh yeah, bring along a whole lot of spare Type O rear ends parts if you start launching hard with sticky tires. Careful, Sanchez..........W30's really aren't that much faster than W31's. In fact only the 66, 67 and 70's were faster in factory stock form. They feel a lot faster because of the high low end torque, but look at the numbers. On these tires especially. Anybody can build and race a modified hot rod. Your high water mark is Detweiler's Certified 12.65. Casey's not that far behind that, with a lot of experience driving it. Cutting good lights AND good 60 footers is very tricky in Pure Stock. I can easily get one or the other, but the trick is to get both. Getting better at it, though. Whole different world from drag radials, slicks, etc. Just not as consistent until you get really good. I'm not, he is.
Personally .... I wouldn't tune the car with drag radials and then put Polyglas tires on. Tune the car (engine, suspension, launch, etc.) to the tires you are going to race with. Kinda like tuning the engine with a QJet, and then bolting on a Holley. If you're gonna run a Holley, tune to the Holley. :Smarty:
Sanchez: Is this the Pure Stock engine in your W30? It may run 11's after all! Brian E: Drool over this one................
No Dave, mine is much closer to this; Mine has A/C and power brakes however. Prince, who's car that is, runs headers while I don't. My 70 W30 actually looks closer to stock than yours did. btw-Nice contradiction in your post; "Best 60 foot times ever are with the Polyglas.", then "They feel a lot faster because of the high low end torque, but look at the numbers. On these tires especially." Throw drag radials on Detweiler's W30 and Casey's small block and I bet you'd see more than a couple tenths spread. You guys do it your way, I'll do it mine. Believe it or not, you are not the only guys that have an idea how to make an Olds run. And I wouldn't be getting too cocky considering you are a second behind an auto car Dave. And, if you think you need all that crap to run 11's with an Olds 455 you are sadly mistaken. I'd be embarassed to run 11's with an engine like that. That's all I have to say for now.
