Drag Racing Tech - What is killing my 60'?

You can see my 60' times in my sig. On street tires I am getting them really hot, stalling between 1500 and 2000, and just nailing it off the line. It hooks good almost no tire spin and pulls high 1.8 60' times. Even on drag radials it hardly any better. Gears are 3.23, converter is 3600, timing is around 20 degrees when I hit it then quickly ramps up to 28. No knock, log files look clean.

I know I can make it launch harder with different gears, converter, etc. But what I want to know is are the 60' times I am running "normal" for my setup?

You have a few issues.....

Weight- I dont see any weight reduction, this car is a pig, and you can only make it leave so hard given the setup. Weight is a big issue with these cars, especially with the cam, you run.

Stall- you gotta man up and look for something in the 4k range.

Gears- again, depending on the tire size, 3.73's at a minimum

Suspension- An auto car hits softer but that doesnt mean it cannot benefit from a shock that holds the power and transfers it correctly and evenly to the rear tires.

Cam- your running a MS3, which is a marshmellow cam, it doesnt hit hard off the line and unless you do some of the above mentioned things, dont expect it to hit like a monster.

I had a Hotcammed 383 LT1 ported heads, full bolt ons, Nittos (245/50-16), 2000 stall, no suspension, 3.23's on a 10 bolt 3700 race weight. I managed n/a to do 1.7's all day on realy shitty track prep, and if I knew then what I know now, id be dangerous.

Since my cam is not a top end cam, and the power curve of the motor, allows for it to leave good, and did a best of 12.08 @113, and that was 4 years ago.

If a auto goes into this car it will have a yank 4400, 4L80e, trans brake, leaving the 4.10's in there and QA1's all around w/ a Spohn drag bar. Going balls to the wall.

Nothing wrong with that stall, you can go much faster with it. I've never tried or needed to stall mine past 1200. I've went 1.51 60' a few times with it, but all of them in the 1.5s on 275-50-15s.

Maybe some more gear for the MS3 would help, but I'd think you could go low 1.7s or high 1.6s as it is.

Nothing wrong with that stall, you can go much faster with it. I've never tried or needed to stall mine past 1200. I've went 1.51 60' a few times with it, but all of them in the 1.5s on 275-50-15s.

Maybe some more gear for the MS3 would help, but I'd think you could go low 1.7s or high 1.6s as it is.

I disagree.

But then again I would like to see a posted race weight.

That gear/stall/weight combo is all wrong for that cam. based on provided information.

Gears is a definite possibility, probably 3.73s because this is my DD car. I'm a little hesitant to bump the stall up much because I dont want it to flash too high on the bottle. From what I am hearing tho, my 60' is in-line with where it should be on the setup??? As long as I am running times typical to others I am good, I just would be wondering wtf is going on if ten guys got on here saying they run 1.6s with the same setup. Oh and there is no weight reduction and I have no clue what it weighs.

I should add that I chose the cam partially because I know it wont hit really hardbut will pick up on the bottle moreso than some others. I don't want to have serious traction problems or issues breaking shit from hard launches, I dont care about wheelies. My car leaves soft and thats okay, but I think its a little too soft, considering I give it all I can on Nittos and it doesn't spin a lick.

Someone on my local forum mentioned LCAs, how much would these help?

They help alot, but get the relocation brackets (weld in) with them, do it one shot.

Someone on my local forum mentioned LCAs, how much would these help?

Lower control arms are one of the best improvements that you can make to your rear suspension. Not only are they a stronger piece but your car will become more consistant due to the bushings being a high durometer urethane. The factory bushings are a soft rubber, our bushings are a very hard urethane. As others have stated lca relocation brackets will also be a huge help. The allow you to change the instant center of your car and that will definetly help you get your 60' down. We have several different versions of lca's. Here is a link to our page, look it over and if you have any question give me a call.

http://www.bmrfabrication.com/F4.htm

You definately need gears. For optimal results you could go with a bigger stall, but it's not totally killing you, you need to remove weight from that car, and get some suspension work done. Lots of people preach about stock suspension ftmfw..... blah blah, every car I have seen do suspension work, lca's, torque arm, front shocks has always benefitted. Most cars wont ever cut a 1.5 or better 60's on a stock torque arm/shock/spring/lca... it's been done, or so some people say, but I have never experienced it, nor witnessed it.

FWIW, just the addition of qa1 front shocks/275 lb springs brought me from consistant 1.67-1.69's to a 1.57, 1.58. And there is much more in it, as I was having tire press issue's...

Point being, try removing some weight and some suspension work... Perhaps disconnect the front sway bar at the track... I dont even run one, but I dont want the sway bar nazi's to crawl over me for telling you to pull it out...

I will look into some weight reduction, but I don't want to do anything thats going to sacrifice too much. Things that are replacable, like the spare tire, jack, etc I leave out, but I am not interested in puling the ABS for a mere 20 lbs, removing safety / crashworthiness features like bumper supports, side impact beams. Probably the biggest single weight mod I can do is a set of drag wheels.

Question about the LCAs is I am launching as hard as the car can. I have tried launching off idle, all the way up to about 2000 rpms and I just floor it instantly. The car doesnt spin, it hook, it just doesn't go. So are LCAs gonna do any good there? I could see that theyd be useful if I was having traction issues, but I'm just not.

Another point that was made to me is just because my RPO code says the car has 3.23s doesnt mean it actually does, they could have been swapped out in the past 145k miles. So I'm gonna get under there and find out for certain it has 3.23s and not 2.73s.

I tried the off idle launch my last time at the track, against my better judgement. The 60 time was the same as stalling it to around 1500. I'd rather have the "slack" out of the driveline. :D

Tom, I think Gears/LCA+relo brackets will do wonders for your car.

Gears first...and then I bet you'll find that you need the LCA+relo brackets :thumb:

Just verified they are 3.23s. I have no problem moving to 3.73s or 4.10s, but my concern is if I am slower than most on 3.23s, I will probably be slower than most on any other gear ratio.

I am looking at my logs and just wondering how come the engine RPMs dont have a steep climb to about 3600 (my stall speed). I guess I assumed that the engine would rev up really fast to that and then not as fast afterwards. Instead that transition seems to take place around 2600. This converter was bought used and I guess its possible its not a 3600.

Well I guess I have my answer, I locked the tranny in 3rd gear and hit WOT from 15mph and from 0 mph. I attached the log file, it stalls to about 2600 from a stop and maybe 3000 from the 15 roll. Wonderful :( I guess now it makes sense, put an MS3 cam in your car with a 2600 stall and you get worthless 60' times.

Well I guess I have my answer, I locked the tranny in 3rd gear and hit WOT from 15mph and from 0 mph. I attached the log file, it stalls to about 2600 from a stop and maybe 3000 from the 15 roll. Wonderful :( I guess now it makes sense, put an MS3 cam in your car with a 2600 stall and you get worthless 60' times.


Makes sense, that sucks!

There is something wrong somewhere, it stalled exactly 3600 in my car n/a. For one, try launching lower. I always 60'd better launching with it rev'd just enough to take the slack out of the rear end (actually off idle did best, btu I was scared doing that too often :D). Stalling it up high always hurt my times. You make more power than me, I don't see how it's only stalling to 2600 unless it's from the lower torque down low. I don't know what it could be, but something is wrong somewhere. Like I said in the PM, I cut 1.70s on it all day long and even broke into the 1.6s

I was still running 3.23s and I had a 28" tire on it. All I can think it that your cam makes less torque down low and it can't pull the flash up as high as my smaller cam with more bottom end did. It takes low end torque to push a stall to it's flash point. Under 2600 your makes doesn't make much torque at all

Are your nitrous passes on this stall too? That stall on a 75 shot took my car down to a 1.50s 60ft, and I pulled 1,41 twice in a row spraying from a dead stop with it stalled JUST enough to have the slack out of the rear end