I am very aware of the importance of the converter. I currently have a 4000 stall, switch-pitch unit in my car. It is 10+ years old, and probably due to be replaced. My car has been out of service for some time but is very close to operational again. I am going to see how it works before I make any changes/upgrades to anything. Whatever is in need of attention will get first priority. I have a "future" transmission upgrade planned as well. So, if it is satisfactorily operational as is, it will wait. Keep in mind, this is not a full-race application. I am interested in best compromises for street/strip duty. As evidenced by my selection of a 3.42 rear gear. Thanks guys. :TU: P.S. Sorry Gary, I did not mean to "hi-jack" your thread. :error:
sounds crazy but I haven't read the forum lately. Please forgive the late question. But, from a strip only/g-body perspective; has anyone simply made their rear shocks rigid? Drilled and pinned a set of shocks just for the track? I wanted to try it last season and never did. This would take the place of an air bag and any an anti-sway bar, it would keep the rear level on launch, and it would eliminate the squat tendency of the g-body's rear. I assume the a-body is similar? Straight line accel on a level track might be fine.
Two words - "Tire Spin" With a solid rear suspension you get no initial "hit" on the tire, then no weight transfer, and you spin the tires. It might work on a 14 sec car, but not anything with any real horsepower. Believe me, if it would work better, somebody would have tried it! Have fun.
I think a very important part of any car street or strip has been over looked, the front end. Springs, shocks, remove front sway bar, remove bushings from under upper control arms. Chris
My car is about 5 parts street and 5 parts race. I drive it a lot and I race A LOT too. Here is my set-up... 3.73 gear and a CHEAP E-bay converter ($268 shipped, and even new) I won't pour a lot of money in a converter when I really want a kick-ass clutch instead, but this cheap-o seems to work ok. Front: QA1 coil overs...4click from zero on street and zero clicks at track. No sway bar and f-body spindles. Rear: QA1 Stocker Stars...3 clicks from zero on street and 9 clicks from zero on drivers side and 4 from zero on pass for the track. Stock springs w/ 1 coil cut-off, boxed lowers with poly bushings, No Hop Bars and double adjustable uppers w/ 1.5* neg pinion angle and no pre-load. 28x12.5 E-T Streets on 7" wheels w/ 15.5# in them. This is what it all gets me. 12.27 @ 108 1.62 60 ft and 7.72 @ 87.2 in 1/8th You need your front end to jump first on your leave, it is very important and can only be seen well on film. I know a lot of guys hate-on no hops, but they work really well if you can control them with your shocks. I need a rear sway bar pretty bad, then I could take a couple of clicks out on my drivers rear shock. You can tell by my numbers that my car leaves pretty well, but is not all that great down track. I have a B4B and iron heads, so it is a very mild motor, not enough cam to get the job done on the big end. As far as driveability, great anywhere! Drove Drag Week no problem! Randy
Hooking on the street is all about the converter and geometry of the suspension. Front= Looose, looose, loose. Weight transfer is the name of the game. 90/10 or adjustable shocks and no sway bar. Drag springs or QA1 coilover setup would be even better. Rear= Buick 4 speed nailed it. Rear control arm level with the ground. Takes the IC and moves it rearwards and down below the CG since the upper control arm is shorter than the lower. The upper will move the IC alot more than trying to do it with the lower. Still plants the tires but allows a teeny bit of squat before the hit and a slow input of said "hit", which you need on the street. Basically like tuning for a greasy, crap, track. A rear sway bar(even stock) is a must. Airbag in RR corner is a nice addition. I ran mine at 5psi only. I ran 15 dollar gas shocks on the rear, stock boxed lowers and rubber bushings in my 70 Stage1. I ran this exact setup on my 70 Stage1 with an 11inch switch pitch 3500stall. I used 28x12.5 MT ET Streets at 11psi in the right and 12psi in the left. Car ran low11's/high10's on a 150shot of spray at 4000lbs with me in it. Car was completely uncut and all steel. Factory Stage1 pocket ported heads and stock shortblock with 10.75 to 1 compression. Lunati 253/266 cam on a 110 lobe separation angle. 60footed in the 1.55-1.6 range. Sprayed it halfway through first gear and ran out of gear at 1100feet due to 3.90 gears and a hard redline of 6000rpm I set for the motor's health. 126mph by 1100 feet and hold it right there thru the lights. Relevance of all this was that on a good concrete street anywhere I wanted I could launch it the exact same way as I did on the track and dangle both front tires 6 to 10 inches off the ground on the leave. If the pavement was iffy I'd very lightly haze the tires out of the gate and the only discernable difference to the outside spectator was that I didn't pull tire on the launch. It got out hard even then, just didn't wheelie. Don't ask me if I streetraced ALOT for 15 years to come to that setup as I will give you the standard line of "Streetracing is dangerous. Racing should be done on a track." o No:
UPDATE- 4 years ago I started this thread (see the date!). I went from spinning the M&H's all through low gear, to getting a perfect hook occasionally or slipping a few feet at most; ALL ON THE STREET WITH NO BURNOUT- THIS MY GOAL. I installed QA1 upper adjustable arms & Edelbrock lowers. Still spun. I installed El Camino springs on front - gained a lot of grip. I installed skylark springs on rear- almost perfect grip now. Things to do: (especially if I ditch my switch pitch and get a JW 9.5 converter) Back off front shock nuts for about 1" clearance for test and tune. Remove front swaybar. Add HR antiroll bar Thanks everyone for your input. Gary B.
This has been some very interesting reading but I have a question that I hope someone can answer even though I have my doubts that it has ever been tried. I have a street car that I take to the strip several times a year. It's mild and runs 8.55-8.60's in the 1/8 and so far my 60ft best has been a 1.82. When I was running the radial ta tires with 3.73's it would hook from time to time depending on the track conditions but when I switched to 4.10's I couldn't get a good hook anymore so I went to BFG drag radials. Now it's good as far as traction but it does this little shudder thing when I first hit it. A friend of mine told me he saw wheel hop so that's probably what is causing that. I have stock boxed lower arms with stock rubber bushings and rear sway bar, a set of medium quality gas shocks and adjustable upper arms with urethane bushings. The driveshaft angle is 1.6 degrees on both ends. Hoping to get rid of that shuddering I recently installed a used set of hop-stops. They have the solid ends with a steel sleeve and no bushing in the ends, although I did drill a hole and put a grease fitting in them. I was going to go to the track last weekend but it rained so I'll be going next week to try them out. Sorry this is so long winded but now for my question: One thing I noticed on the street so far is that it rides much firmer in the rear and I expect this is due to the combination solid/urethane mounting on the upper arms. Do you think I could change the upper bushings to the stock rubber type to soften this ride up a bit without hurting the effect of the hop-stops very much? Bill
Pinion angle should be measured aginst the eng/trans centerline. Driveshaft angles should be equal and opposite on each end. I use transmission mount spacers to fine tune mine. The eng/trans slants down toward the rear. The pinion slants up toward the front. The eng/trans line will run above the pinion line and pinion line will run under the eng/trans line. If those lines are parallel to each other, that is perfect for full throttle moments as it uses up no power, but when OFF the big throttle, you need some negative pinion angle. When cruising, a 4link like our A-bodies will need about 1.5 to 2 degrees down. That means the pinion shaft center line (bottom line) will be lower than parallel by 1.5 to 2 degrees than the eng/trans line. The drive shaft takes care of itself. I know ther are some fine books out there that teach you all about traction and race suspensions BUT GUESS WHAT!!!! THEY SHOW PICTURES OF THE REAR U-JOINT AND ASS END OF THE DRIVESHAFT BEING MEASURED FOR PINION ANGLE.THIS IS TOTALLY USLESS AND CAN CAUSE MAJOR DAMAGE TO YOUR DRIVETRAIN AND MORE. Stick with the parallel lines minus the amount of negitive pinion angle your application requires. The drive shaft should be near equal angles at each end (and opposite angles). Another way to look at this , when you hammer the throttle your pinion tries to nose upward and it will do so about 2 degrees. It is at that moment that the centerline of the trans and the pinion need to be the same angle (parallel) toward each other. They can't share the SAME centerline unless you bolt the axle solid to the frame and throw away your controll arms and coil springs etc; then you would need no drive shaft or u-joints, Just a shaft. That unstable feeling at the rear: Check your arm bushings as they can squirm loose quickly after some hard runs. Boxing the stock arms will help the stop squirming.
