Wheels, Tires, and Gearing For the Strip

[M3hta1]

Went to the strip tonight. Stock Tires

#378

[BFASTNOTLAST]

Originally Posted by M3hta1

Went to the strip tonight. Stock Tires

#378

I'd say something is way off, that mph is way low for the power you made. That is a mph for a stock car.

[Pro Stock John]

Yeah keep track of where you are shifting, might be low?

I run 89/90 in the 1/8 in my auto shifting at 6000.

[Bad70supreme]

John you shift at 6000? Seems low, I shifted mine at 6300-6400 stock cam, maybe I was over reving?

Ya I agree, MPH is low. Work on that tune!

[07-SRT]

what was the DA ? Something doesn't seem right... Your 1/8th mile time would equate to a high 12- 13 flat et... Even on stock tires (2.0 60')- with the power your making, you should be capable of mid to low 12's..... JMO

[M3hta1]

Yeah I need to definitely work on my shift points. Also my tune seems a little out of wack. Engine power cut at launch rpm goes down to 1500rpm then catches back up after a fraction of a second.

I need to work on my tree, launch, and shifting.

[Pro Stock John]

Mike you are LS3, has different cam. Stock L99 cam is done at an lower rpm.

OP if you make peak HP at say 6500 you would want to start by shifting around there. I'm thinking you should be going for like 94MPH in the 1/9th... no?

[M3hta1]

Originally Posted by Pro Stock John

OP if you make peak HP at say 6500 you would want to start by shifting around there. I'm thinking you should be going for like 94MPH in the 1/9th... no?

Yes you are right. From the dyno between 6000-6500 is my powerband. So should be shifting at 6500 right before limiter?

I may need a light to help me with this cause the way my wheel is it is kind of hard to see the tac. Also switched to the tac / mph on the HUD but in all honesty it isn't big enough....

I just have to keep practicing.

[M3hta1]

Originally Posted by 07-SRT

what was the DA ? Something doesn't seem right... Your 1/8th mile time would equate to a high 12- 13 flat et... Even on stock tires (2.0 60')- with the power your making, you should be capable of mid to low 12's..... JMO

Can you explain DA? And how to calculate it?

[07-SRT]

Originally Posted by M3hta1

Can you explain DA? And how to calculate it?

Density altitude...it puts everyone on a level playing field and what your car is capable of at sea level under certain conditions, just like dyno correction factors do...here is a calculator below.

http://www.dragtimes.com/da-density-...e=Calculate+DA

[Pro Stock John]

Maybe adjust the column to see better?

[BFASTNOTLAST]

Originally Posted by M3hta1

Yes you are right. From the dyno between 6000-6500 is my powerband. So should be shifting at 6500 right before limiter?

I may need a light to help me with this cause the way my wheel is it is kind of hard to see the tac. Also switched to the tac / mph on the HUD but in all honesty it isn't big enough....

I just have to keep practicing.

Soon enough you will be able to teach yourself when to shift by the sound, with enough practice over the years you will know when you messed it up. I very rarely look at the tach anymore. Once in a blue moon I will bounce off the limiter in 1st but its so short with the gear I have you must be ready to row the shifter.
You will get it, keep at it.

[BFASTNOTLAST]

BTW, I switched to a smaller tire today (275-35-20) to get the same result of adding more gear. I now mathematically have a 4.10 or so final drive. Stick cars need a 4.10 IMO!!! The tire is over an inch smaller. Don't let the internet jockeys fool you saying 4.10's are too much, not true at all. However, I would get a GM 3.91 gear set and do the smaller tire, to many horror stories of the 4.10 ring and pinion not lasting. I have yet to hear of a 3.91 breaking. Than again there is always a first.

[M3hta1]

Thanks for the info BFASTNOTLAST. I plan to keep at it.