I have a 72 GS bored 30 with TA 10 to 1 forged pistons,GSCA popular mechanics cam, B4B with 850 double pumper mech. secondaries,stage1 heads angle milled 90 thou. and ported, MSD 6A ignition,switch pitch convertor, 3.08 gears, 400 turbo with a shift kit, South Side lower control arms 2 in. hooker headers 3 in. exhaust with an X pipe. The carb. is the way it came out of the box and the timing is set at 8 degrees in. and 34 degrees @2500 rpm. I bring it to 1500 on the tach and when i launch it , it flashes at about 3300. I shifted into 2nd. at 6000rpm and into 3rd. at 5600 rpm. My 60 ft time was 1.78 sec, and my 1/4 mile was 12.44 sec. @ 107.77 miles per hour. and reving 4800 going across the line. I would appreciate any help on how to go faster as there is only one race day left here in Nova Scotia this year.sept.10 thanks Billy A bill.arseneau@simplyforlife.com
Jet extensions for your 850 if you dont have them already. Timing 35-36, and try shifting around 5600. Thats my thoughts.
billy it seems to me that your car is running very good for what you have in it but im a believer in tuning//trail and error system the best thing is to get to the track early//change one thing at a time log it in a book//cause you wount remenber///try coming out harder the easist way to improve e.t. is 60 ft time ///if it smokes the tires you know you have to back off your laurch rpm etc then go to your timing///less timing give you more torque but hurts you on the higher rpms but play with it you car might like 36 or 38 you wount know till you try it hope that helps let us knoww luck pete
combo I would install 3:73 gears and lose the switch pitch,install a regular TH400 with a -2 shift kit and 10 inch torque that stalls around 3400. I use to run a switch pitch 15 years ago,I found it worked the best by running the power wire to the brake light switch so when I was on the line it would lock up when I launched (let off the brake pedal) . Neat for playing on the street but I found it too inefficient for drag racing.........Chris
Faster 1/4 mile Thanks for the responses, I have lots of low end and run out at the end and my total advance is at 34 degrees, so i will advance it and try it. A friend of mine saw me run and said i didn't heat up the tires enough so i will do that also and i bring the revs up to 1500 rpm's to take off. what do other people bring it to as it launches at about 3300 thanks for the hepl Billy A
Also try short shifting the 1-2 shift, then run out the 2-3. Say around 5400 for 1-2 and 5600 for the 2-3. Buicks seem to like having the motor lugged down just a little after the 1-2. This is all just trial and error though. Good luck.
1/4 mile Thanks fellows, when you say launch as hard as i can do you mean to bring the rvs up higher than the 1500? with the switch pitch it hooks around 3300 Bill
Billy 1.78 is very good for street tires. I have 275/60-15 TA Radials and about the best I can do is 1.81 60'. I typically bring the rev's up to 2000 rpm's to launch. I have a TCI Breakaway torque converter, has an advertised stall of 2800 rpm's or so. Since you have 3.08 gear you should be able to stall it higher than 1500 rpms, the secret is to gradually press the pedal to the floor in a controlled manner as you launch. When you increase your power, through tuning or new parts, you will need to re-learn how to launch the car. More power does not mean better 60' times. :Smarty:
switch pitch Billy do you run on the high stall or the low stall all the way to the finish line.Chris
1/4 mile iI'm sorry, it was in another email and i should have read this one closer, i am running MT ET Slicks 26x 8.5 x14 in. They are 25 in. tall on the car. When i tryed it 2 years ago with TA Drag Radials 275x15 in. 60 series my 60 ft time was 1.85 sec. These tires are 28 in. tall on the car. I had 1970 non stage 1 heads on my car then and now stage1 heads ported and done by Bill Bayliss in New England. When i put it on the dyno before it had 335 hp and 415 ft lbs of torq. at the rear wheels and with the stage1 heads it reads about 350 hp and the torque was better but it started to rain and i didn't get a proper reading. I tryed it at the track twice with the same TA Drag Radials and the power was that much better with the new heads it spun every run and my 60 ft. time was from 2.0 to 2.2 sec. turning 13.0 to 13.3 @ 103 mph Now my 60 ft is 1.78 and 12.44sec, so i'm just trying to get a couple of tenths better thanks for the imput Bill Arseneau I just ram it to the floor, so i should feed it easier ?
1/4 mile Good morning, Thanks for the suggestions, next weekend i am going back to try the car again. I will bring up the revs to 2200 and see if i can launch it harder , also i will advance the timing from the 34 degrees it is at now shift from 1-2 at 5500 rpm and from 2-3 at 5600rpm. If i can shave a bit off my time i will be a happy camper thanks again Bill Arseneau
brake light switch Billy, you might want to try running a wire from the brake light switch so that when you stage the car with the foot brake you will have the high stall to get you out of the hole. When you launch it will switch to low stall right away and it will feel like a 1-2 shift. You only want the hi-stall for launching. When it is in hi-stall the torque convertor is inefficient and creates a lot of heat in the trans, and when you run it off the foot brake it's consistent and one less thing for you to worry about as a driver. I used to run a n2o button on the shifter along with running it to the brake light switch with a toggle in between so I could run it either way. I can't stress enough, you need to get it in low stall as soon as possible to be efficient and get better ET's. A friend of mine runs the TA drag radials on his 3675lb 69GS400 with a 494 stage3 street car (he really does drive this thing on the street) thru the exhaust with TA drag radials he ran 10.20's first time out with them, with drag radials and open headers this car runs low 9.90's. The first time he used them he had the air pressure set at 15psi and it just blew the tires off, he then bumped the pressure up to 20psi and that eliminated most of the tire spin. The more runs he put on them the better they seem to hook. Hope this is helpful....Chris.
