street edge, tire psi, track question

[Mustangless]

I posted this in talk but it is getting technical

1st run

60 foot 2.909 I was spinning all the way through first.
I2 7.688
1/8th 11.378
MPH 68.323
e.t 17.104
MPH 86.052


I was really angry about this run. I knew i could improve my 60 foot. I just floored it on that run. I had 33psi in my tires. I let them down to 25 for the next one. I also had my timing on 12 but I was pinging all the way. I turned it back down to 10.

2nd run
60 foot 2.327
I2 6.500
1/8th 9.948
MPH 72.265
E.T 15.405
MPH 90.157

I stalled it to about 1800 but I let off of the gas some after going. I know with another run I could have gotten it lower. I also forgot to turn on od

Mods include

street edge 3k
gutted mac h-pipe
flowmasters
K&N
stock 3.27s
sumitomo 315s


I thought that mph on the last run was pretty good. How does it sound for my mods? What do you think I could get with a better 60 foot?

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How should I be launcing with my converter and street tires? Should I stall it a little then go half throttle then full?

Also what is a good psi for my tires? Is 25 too low?

 

[94MustangGT5.0]

Well, by the first 60' time you put up, it is obvious that you melted the tires from the start. With stock converter and stock gears, i was cutting 2.30-2.4 60's (no spin). Now, with 4.10's, I can cut 2.1xx's with a good launch. I think that with your converter, there is some room for improvement with more practice. You'll have to go to the track on a night where you can get more than two runs in. Next time you go, try to get as many runs as possible, trying all different launches. I would say with street tires, try to find a launch RPM that won't blow the tires off and then just mash it after that. You could also try stalling all the way to your peak stall, then feathering the thottle to avoid excessive spinning out of the hole. What size rim are you running your 315's on also? Overall, I think your times are decent, your trap speed is fairly good, and with more practice, your 60' will get better and you could run in the high 14.xx's fairly easy.

 

[Mustangless]

The tires are 315/35/17s. I am almost certain I could have done better if I got in another run. I'm trying to get tips about tire psi for my street tires. I almost thing I have mine too low but it could be too much.

 

[Swarzkopf]

It's tough launching on regular tires with a high stall.

Try stalling at the line, coming off the brake, and slowly going full throttle...

 

[gcomfx.com]

Sweet... another edge stall!

What are you doing in the water box? All street tires are different. Many do not like much heat. My Essenza's need heat. Also, are you driving around the water box with your front tires? Or are you driving straight through it putting water right back in front of your rear tires?

I get a better ET and 60ft on my tires letting them spin a little by flash stalling from a dead idle and feathering the throttle a bit. If I stall up, the car dead hooks and bogs a tad when N/A and I lose a tenth or so.

I run about 22 psi in my street tires. But mine are narrower and on 9 inch wide rims. To figure out YOUR best tire pressure, I recommend going out and trying a few launches in a parking lot after close or closed street. You want to see the best "footprint" on the road you can get. If you are leaving tracks in the middle, you have too much air. If you are leaving tracks from the outside of the tires (sidewall) then you have too low of air pressure.

BTW - I "usually" get a 2.1 60ft.... but have cut a 1.95 before on the same tires when the track was really sticky. One out of 5 runs I get a 2.0 on a normal night.

 

[Mustangless]

I go around the water box. I will check my tire pressure and play around with it. I will also practice on my launching techniques. I am going to try to video tape next time I am at the track so I can see what I am doing.

 

[gcomfx.com]

Does your launch now look like the "after" in this video I made?

http://www.100mphclub.com/movies/edgestall.mov

Video taping at the track sounds like a great idea.

An in car setup helps too. Here is what bad tire pressure will do to you. :?

http://www.100mphclub.com/movies/gcomfx_incar1.mov

My buddy in the Rx7 spanked me hard that round as I almost lost it in second.

 

[Mustangless]

I don't think it was quite that bad, but I did go a little sideways and it was all the way through 1st. The people watching me said my tires were smoking. On the second run I think I did a little burnout but not big. I was "zoned" into racing or something, because I don't notice anything till I see my 1/8th mile times. That is why I want to video tape.

Was someone riding with you, or how did you have the camera mounted?

 

[gcomfx.com]

The camera is mounted with a suction cup type mount on the passenger window. A friend built it for me. Works pretty good for being "free".

How much track time do you have? Are the above two runs your first trip? If so, you will make up a lot of time with just practice. Every car is a bit different. With any car you don't want to spin too much, but with an auto, you do want to spin some when you have close to stock hp. Even with the stall you need to keep your rpms up there. I've bogged my car on the launch before with my converter by stalling it up with the brake before a run.

Please note: I'm also no where near an expert. I only have like 3-400 or so runs under my belt and my car is the ONLY car I've taken down the track. I do have the benefit of owning a car club that rents the track each year and I used to live within 15 minutes of it. :wink:

 

[Mustangless]

Yea, those were my first 2 runs ever. I know with practice I will get better, just wanted to get some tips. I also have adjustable shocks that were set on 3. I am going to adjust those to the softest next time. I might also take off my front sway bar.

 

[gcomfx.com]

Sweet... keep us updated next time you go out. I've got some drag launch springs to try on my stock suspension, we'll see where that gets me.

 

[SN95StangMan]

hi paul. good to see that you are still around.

i still love watching that burnout video, lol.

Before i got my converter in, i was also hitting 2.4 60' times. after it was in, i got it down to about 2.0 my first time at the track. I played with the psi a little and found out that the best for me was 25psi. I was getting pretty consistent 1.8's when i would go, although i havent been to the track in quite a while. The trick for me was getting a good solid burnout, then launching at about 1800rpm.
good luck.