Went out to the track to try out my new 75 shot and it sucked horribly.I tried spraying in 1st and the other runs i sprayed from 2nd until 4th.
Run #1 r/t: .121 60ft: 2.176 1/4: 13.836 miles per hour: 105.21
Run #2 r/t: .293 60ft: 2.269 1/4: 13.994 miles per hour: 104.95
Run #3 r/t: .215 60ft: 2.425 1/4: 14.182 miles per hour: 105.32
Run #4 r/t: .454 60ft: 2.174 1/4: 13.883 miles per hour: 105.12

I am running MT et streets 26x11.5 on the stock 17's. I had them at 18 psi and was launching at about roughly 3k slippin it out the clutch quickly instead of popping it and my times still sucked. I had minimal tire spin. I was running 14.0 and 14.2s on just motor and with a 75 shot my best whats a 13.8 whats up with that. Anybody have any idea on what am doing wrong or how to improve my times? My rear end is stock except for lowering springs and 3.73s. I am just about to give up on my mustang all this money gone into it and only a .2 second improvement not very contemplating. Any tips or tricks or advice on what it looks like am doing wrong??

 

Try letting some more pressure out of the tires.. to me it sounds like you're just spinning tires..

at what rpm were you launching ect

 

Launching at about 3k rpms and i had them at 18 but near the traps the rear end would shake feeling like it was going to fish tail so thats why I decided not to drop it more...

 

If those are the same ET Streets I was running I had them down to 10PSI...its the slick right?

 

Yup thats the one they look just like slicks... didnt u feel the rear end shake at around 90 or so?

 

No. I think your psi was just up too high. Lower the pressure to about 13 and go from there. I ran pretty well at 10psi.. after you warm up the tires they'll gain a little pressure..

 

I remember i tried running them at 16 psi and the rear felt shaky towards the end of the track and a friend told me i was running them too low and thats why i felt that so you dont feel that shaky rear end feeling? My tires arent balanced though bcuz the tire shop said it would require way too much weights to balance them...

 

they should be able to balance them.. friggin lames.. find a diff tire shop lol. no it didn't feel shaky to me..and i ran them at 10psi. thats too much air in those tires..

 

Your 60' is terrible for those tires. You can cut better 60' times on street tires. You need to go out there and just practice more and see what works with your car. With those tires you should be spraying in first gear every time. The mph is decent for this hot weather and a only a 75hit.

 

I run 17-18 PSI in my Hoosier DR's & launch at 4k-5k RPM and dead hook just about every time. I wouldn't be very comfortable running much less pressure than that, maybe 14-15lbs at the lowest. You definitely need to have them balanced, they should be easier to balance than a treaded street tire, so the shop you took it to needs some help.

The only thing that I can think of that would probably help you out would be LCA's and SFC's, other than that all I can recommend is the driver mod..

What is odd to me is the fact that you are only trapping @ 105... I was trapping right at 100 in the 1/4, it seems like you should be picking up more MPH than that.. Something is definitely not right..

 

If he is only spraying in 2nd and launching soft the mph seems not to bad for this hot weather. Its not gonna trap 110mph on a 75hit.

 

I guess I should feel pretty good about my car then. 13.595 @ 99.96 N/A and the weather was about 80-85*

 

I trapped 101mph with just an H-pipe,dumps,CAI,drag radials, and a shifter. I do powershift the car which helped me get another mph out of the car.

 

Yeah i cut a 2.01 60' foot on streets.

Practice!

 

seat time is where it going to be man.

 

Dunno but on that ET Street (which is a slick..) 11psi is fine. I had zero issues with it launching off a 100 shot, minus the fact i couldn't heat them up very well. If it were a drag radial, yea, higher psi.. but not on that tire if you're going to be at the strip..

Just from my personal experience, and going with advice from a good friend of mine whos been doing this for quite some time with zero issues. Even with nitrous, a vortech, and now a hellion turbo on his GT..

 

So do you think I should be launching above 3k rpm?

 

Because you have a stock rear end its kinda hard to leave hard and not worry about breaking an axle. Me I always rev to atleast 3,500rpms at the line, but usually 4k-4,500rpms and once I see the 3rd amber light I start letting the clutch out and start going to WOT. By the time I'm say 5-8 feet out I am at WOT and the nitrous kit hits and off we go.

Its gonna be hard like I said to launch hard with stock axles and not worry about breaking them. Just keep working on it as no one gets their best 60' the first time out with a new setup. I also think the air pressure is a bit high. But I can't say without seeing the contact patch. What I do is go out to a place do a hard launch see the tire marks and work on it till the entire tire is leaving marks, no lighter inside or outside marks. That will get you damn near where you wanna be.