I just placed third in at the local dragstrip with my car, first off let me say awwwweeeesooommmmeee, first time at a track. next my issuses that kept me from winning was traction and wheel hop, and a saleen. i'm not a nube to drags but just this track. on the street i launch at around 2500-2700 so my first launch was at 2500, spin n hop 1-2-3 second launch was at 2200 spin n hop plus squirley sideways 1-2-3, ( it's kinda fun watching the other guy go down the track beside you out of your windshield) the track wasn't preped very well and almost everybody had traction issues, except for big fat slickers. after 11 rounds i was "launching" at 1000 rpm! i just ordered adjustable J&M extreme joint uca and solid lca's from american muscle i 've read the post's so no fan boys preaching please, question is what should my pinion angle be? and what tire pressure should i run all stock in the rear (tires,springs, etc..) its a hot lap heads up bracket race, i ate the hell out tire so a rotation is in order just fyi. thanks
o and is a new adj. panhard bar as great as it seems?
The adjustable panhard is to recenter your rear axle. You can try setting you pinion angle at -4* but this is typically for cars that really hook up. You may want to look into a set of LCA relocation brakets. Even though your car is not lowered, it will allow you to set more positive angle into your LCA. The stock setup is rather neutral. A good shock/spring combo to allow for better weight transfer is also a good idea.
does the panhard help with anything beside turning, or does it have an application in drag racing?
An adjustable panhard bar really isn't needed unless you have lowered (or raised) your car more than an inch or so and honestly wouldn't benefit you for drag racing.
The control arms will make a noticeable difference on launch and if you can get a set of relocation brackets that helps also. As for pinion angle I wouldn't get to far away from the stock setting on a dd. Remember to check the angle with the suspension loaded.
For tires you can drop the pressure a little say 5-8 psi but anymore than that you just end up cupping them and riding on the outside edges.
You most likely know this but stay out of the water box. If you can't go around it then spin em off a little after just to get the water off them. Burnouts really won't make much of a difference in traction with street tires.
The stock suspension is capable of handling hard launches with sticky tires. I've done 1.67 60ft with just upper and lower control arms and a set of 10' Mickey's. Of course that was side stepping the clutch with the engine against the rev limiter......I don't endorse that kind of behavior though.
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so what you are telling me is to crawl under the car get the angle under load while stock suspension is still on? do i make a reference line or do go off the drive shaft regarding angle? or should i just measure the oem uca?s center to center and adjust after some testing?
so what you are telling me is to crawl under the car get the angle under load while stock suspension is still on? do i make a reference line or do go off the drive shaft regarding angle? or should i just measure the oem uca?s center to center and adjust after some testing?
Jack the rear of the car up and set the axle housing on jack stands, that loads the suspension so you can still get under the car. OR use a set of ramps and back the car onto them. OR use a drive on shop lift. The car does not have to be level as long as the suspension is loaded.
Put a dial level on the pinion housing and read it, then put the dial level on the drive shaft and read that. The difference is your pinion angle.
You should have -1 to -2 degrees for an automatic and -2 to -3 degrees for a manual.
Jack the rear of the car up and set the axle housing on jack stands, that loads the suspension so you can still get under the car. OR use a set of ramps and back the car onto them. OR use a drive on shop lift. The car does not have to be level as long as the suspension is loaded.
Put a dial level on the pinion housing and read it, then put the dial level on the drive shaft and read that. The difference is your pinion angle.
You should have -1 to -2 degrees for an automatic and -2 to -3 degrees for a manual.
A few things you suggested are vague, some are to simplistic and a few are just plain dead wrong.
You can use jackstands to support the axle, ramps or a drive on lift which is best. The first thing you need to do is measure your rear ride height though. Measure the distance from the tire to the fender lift (vertically). This is your ride height. You HAVE TO check/set pinion angle at this ride height or you are wasting your time. You will find it is very hard to replicate the cars ride height if you are not using a drive on lift. I ended up using ramps with 48-lb of sandbags in the trunk to replicate mine. So there is your first challenge. You don’t do it right you are wasting the rest of your time.
The biggest misconception is what “negative” pinion angle is. Negative minion angle is an angle less than where you would set the driveline angles at in an ideal world where the axle doesn’t “wind up” under launch. If you are going for a -2* angle it needs to be X-2*, X being what the perfect driveline angle is. The perfect driveline angle is when the pinion angle and the transmission tailshaft angle are in “phase”. You need to set, or at least figure out then do the math based on the driveshaft being in “phase”. Here is a link that explains it in detail. Like ride height if you do not figure out what your driveline angles need to be set at to be in phase before you go adjusting for a negative pinion angle you are wasting your time. The angle of your driveline while in “phase” should be considers “zero”. If you do not find that zero you have on basis for any math from that point on.
Now that you have your driveline running in “phase” its time to set your driveline angle for dragstrip launches. If you are not doing drag launches you don’t need or want ay negative pinion angle as log as you have quality control arms. The pinion changes angle very, very little if you have quality control arms. I have tested this with my data acquisition system and potentiometer hooked up to the pinion. Unless you are running drag radials and have at least 350hp leave your driveline set in “phase” or zero. Your pinion barely deflects when you drop the clutch with under 350hp or you are running real radials.
If you are putting down some pony’s and running sticky rubber the pinion will deflect when the clutch is dropped, but not much and not for long. -2* is pretty extreme and I would only run it for a car that was at the track a lot and getting 60ft times under 1.8sec. The reason being that if you are just driving down the road at -2* you are putting a lot of strain on your U-joints (they are out of phase) and the car will have less rear wheel horsepower. And lastly you will get a high speed vibration. For a car that has good control arms, goes to the track but also drives around on the street I would set it up at -1*.
Ok, back on point. So you are under your car and you have already set the driveshaft up “in phase”. If you want to set the pinion at -1* all you need to do is take the current pinion angle that you just set, which could be just about anything depending on if the car is level, etc. ad adjust the pinion 1* down from there. A -1* pinion angle is simply your in “phase” pinion angle minus one. It is irrelevant what the in phase number is.
Get a good digital angle finder.
Have a few pieces of angle aluminum (the kind you can get at Home Depot) to use as a “base” for the gauge.
Get the car in the air.
Exactly replicate the rear ride height
Put jack stands under where the K-member meets the floorpan then put your jack under the K-member right under the motor. Jack the jack up until the weight of the car is just coming off of the front jackstands. This is to remove the droop that the front end of the car has when supported by the “tub” and the wheels are not loaded. It’s a lot more than you would imagine and it changes the transmissions output shaft angle considerably. And unless your Trans output shaft is at the angle that it is while the car is on the ground you will not calculate your “in phase” angles correctly and everything after that will be wrong.
Take your time
Measure everything a BILLION times. There are a ton of variables. You will find that you will not get repeatable measurements unless you start to eliminate them. Only after you can take all of the measurements 3-4 times in a row with no changes have you eliminated all the variables.
Keep in mind, 1* is very, very small. This is not a rough adjustment. It is therefore very easy to be 3* off just because of how you are placing the angle finder. This is where repeatability comes into play. If it does not repeat, you don’t know what you have.
Good luck.
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+1 sqidd. Very accurate explanation of one of the most misunderstood subjects out there
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350 at the wheels or crank? all i have is a jlt cai and 93 performance tune done to the engine, it s pretty close to that at the crank now for the most part, so Zero Phase or -1* i plan on sticky's and a supercharger down the road thats why i got the adj. upper.
350 at the wheels or crank? all i have is a jlt cai and 93 performance tune done to the engine, it s pretty close to that at the crank now for the most part, so Zero Phase or -1* i plan on sticky's and a supercharger down the road thats why i got the adj. upper.
I have over 450 at the wheels and the stickiest "radrace" rubber you will find on a street driven car and I set mine at zero
If I were to bolt up some drag radials and launch it on the sreet I would probably go -.5*
If I were running drag radials or slicks at the track I would go -2*
If I were you and had quality controll arms I would set it at zero no matter what tires I had or where I was running.
And when I said 350hp I mean at the wheels. Its the only real HP there is. Crank HP is for people that like to talk big
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pinion angle??? 
was traction and wheel hop, and a saleen. i'm not a nube to drags but just this track. on the street i launch at around 2500-2700 so my first launch was at 2500, spin n hop 1-2-3 second launch was at 2200 spin n hop plus squirley sideways 1-2-3, ( it's kinda fun watching the other guy go down the track beside you out of your windshield) 
the track wasn't preped very well and almost everybody had traction issues, except for big fat slickers. after 11 rounds i was "launching" at 1000 rpm!
i just ordered adjustable J&M extreme joint uca and solid lca's from american muscle 
i 've read the post's so no fan boys preaching please, question is what should my pinion angle be? and what tire pressure should i run 
all stock in the rear (tires,springs, etc..) its a hot lap heads up bracket race, i ate the hell out tire so a rotation is in order just fyi. thanks 
