Well, assuming I'd run it to about 6000 rpm in third, as that's all I'd be comfortable doing, combined with my 27 in. tires and about 8% converter slip, it'd be in the 160-165mph neighborhood. Now, that's not taking into account the aerodynamics of my 43 year old Skylark. Anyone got any ideas, just for fun? The only time I've had it going that fast was on a dyno, and just seeing the tires (which at the time were rated to 90mph) warp, was plenty scary. I believe BillyBoy can attest to that. I should dig up that video...
Jon, I like the theory, but I seriously doubt you'd see anything close to 165 mph. I think, as you say, that the aerodynamics would be the limiting factor, so I doubt you'd ever see 6000 rpm in top gear. Sort of like pushing a brick through the air. I think my estimate is closer to reality but, hey, we're just playing, so I wonder if there are guys out there with real-world experiences in this regard? Best, Ranger Aiken, SC
Yes, quite scary. I have never before or since seen a standing wave form on the sidewall of a tire. To quote Douglas Adams.... "R17 is not a fixed velocity, but it is clearly far too fast."
I have gone 145mph in a 1987 firebird (one of the most aerodynamic GM cars built to that point). Its steering components were a little more advanced than the skylark's and it still felt very "wavy" on the steering. The reason i had to lift off the gas was because it felt like the front end was about to "take off". The car is a bottom breather, and the hood was basically just a giant parachute. This was with a 250 rwhp engine and a T56 6spd transmission. At 145 it felt like it had lots left in it (only at 3300 rpm and not full throttle). I imagine you COULD probably get to 165 if you were brave enough, just not safely. The buick engine probably has enough power to push the body close to 170 but i doubt the body would be stable past 140. EDIT: Speaking of 140. We have some pretty stock appearing quick 1/4 mile cars on the board right? How do these cars feel at 130 at the traps?
Well my friends, it's time to return to the track. My spring upgrades were: 12 Bolt 3.42 posi rear with Yukon Gears, rebuilt Eaton style unit, and aluminum girdle cover along with all new brake hardware. I've also rejetted the carb and richened my a/f ratio from 13.7/1 to ~12.5/1. Finally, I've pulled a little more unnecessary weight from the car, but that should only reduce me bout ~25 lbs. since the 12 bolt weighs a bit more. I'll make sure to weigh her again at the track. Last time she weighed 3660 with a half tank of gas. Hopefully that, along with dumping the 2.76 peg leg will net me some good results. Best run with that setup was 12.96 at 108. I'll be leaving for a track rental at Great Lakes Dragaway in Wisconsin in about an hour. I will now let the ET and Trap Speed estimates commence, assuming any of you have this Friday off. :3gears: Also, for research purposed, I am planning on installing a set of LS1 electric fans I have. To see what I can get over and above my current flex fan, which many claim to be a power hog, I'll try and pull the fan for a pass and see what kind of difference I get from the car.
I just watched your video. Im inspired. If you can run 12's with your combo with an open rear your doing great. I got hopes of getting there myself someday but pushing about another 500 lbs.
Your car is almost identical to my old setup. Mine is in a 70 and weighs about 3900#. Differences are I run a 200-4r with 3:73 gears, with 275/60/15's so the tire is a little taller. Best run was 12.42 @109 mph. So you are really close to what I was running. Put it on a chassis dyno once and it only showed 295HP but that just shows what dyno numbers mean. Main thing for me was that it was blowing through the slightly modified D5 converter and getting over 15% slip going through the lights. In my opinion a good converter could get you into the 11's. Hope to get mine to the track this year and see where the supercharger takes it.
Heat up the stickies real good, push it tight against the converter, mash the go pedal and hang the left front a little bit...I'm seeing a 12.30 up on the board!!
Good luck! My set up is similar to yours, have you done anything to the fuel supply like the fuel lines and pump?
Great Thread! You have a great touch to get off the line like you do. Your car looks GREAT! and its fast.
I'm betting right at 12.5 also, plus or minus depending on the weather. Don't forget to pump up the right airbag even with the posi. If it hooks well the 60' will drop nicely. 325 RWHP has put my car into the <12.5 range around 106 and 390 RWHP has gotten me to 11.90's/112, all at 4250 lbs. That HP was measured with what would be considered a tight converter. A loose one can really throw off the actual numbers low. I wouldn't rely on the 3rd calculator down. That thing was made by Dr. Feelgood. The first one comes up with realistic flywheel HP. The 3rd calc claimed 640 hp/490 hp. If a cam with 226/238 degrees duration can do that then I must be a magician mechanic. I can see where your distorted tires would lower your HP at that MPH. I'm suprised they ran it to that speed with those tires. It may have been more accurate to just run it through in 2nd gear. The dyno computer will compensate. I've already tried the electric fan vs a thermal clutch fan and it was worth zip at the track. It was a cool night so that favored the thermal clutch fan because it would be effectively uncoupled. On a hot summer day another story. I've also run a rpm only type clutch fan on the dyno because it only decouples as rpm goes up and doesn't couple tighter as temp goes up so it keeps results consistant. Removing it completely was only worth 9 hp on the chassis dyno but it doesn't cool as good as the thermal clutch type on hot days. Good luck at the track. If you're hookin', it'll be bookin'.
Thanks for all of the input and suggestions guys. Well, I made 10 passes, good weather, mildly good track prep. My best time was 12.42@109.2 As for the flex fan, taking it off gave me about .3 mph and .05 seconds. I would understand that it's difficult to measure such a small amount, although that was my fastest pass of the day with those given increases. All of the runs were in the low 12.5 to high 12.4 range. I do still have two issues. A slight traction issue and a bit of a bog off idle. I'll post a video tonight or tomorrow morning to give you a reference on the bog. As for traction, I began at 28 lbs. in my M/T ET Street Radials (255/60/15) and worked my way down to 20 lbs., which seemed to work the best. I also kept 25 psi in the passenger air bag. What do you all run in your drag radials? Even with all of this and bringing the car up against the converter, I had issues with my launch, some more than others. The best 60 foot was a 1.81 with most being in the high 1.8s and low 1.9s. I know the car has more in it than that. I could foot brake it to 2200 rpms before I started pushing through the brakes. The converter seemed to flash to ~2600-2800 rpm, at which point I encountered the slight bog and wheel spin to varying degrees. One last point to address is shift points. I started off shifting about 5700 but realized that I could pick up another 1 mph by shifting at 5400. Does this mean I'm making peak hp at ~5000. I ask because when I installed my TA413 a few years back, I advanced it to about 6* advanced in order to give me back a bit more bottom end. Was this unnecessary and am I losing top end hp? I've got iron stage 1 heads with a healthy port job by an unnamed Buick merchant (some of you know who I'm referring to...) Looking forward to your thoughts and I'll have some video of a run or two up shortly.
Here is the video. I unhook my headers at the track. It's worth about .5 mph, so I mostly just do it for the fun factor. I included an in car run at the end to give you better audio of the bog at launch, though the camera is just on the seat as it kept flying around when I put it anywhere else. http://www.youtube.com/watch?v=YZArbHGEMjE
3140 race weight novick,430bbb shifted at 6000/6200 come through the traps at 7500 @118mph went 11.17 gear bound with 4.56 gears gona swap in some 4.10s hopen to get a 10.50 out of it i think its posible to get in the mid 10s thats my goal anyhowthis motor realy pulls hard on top end even with the 4.56s gears.
