RPM at the stripe??

Posted By: hemi-itis

RPM at the stripe?? - 04/02/14 07:35 PM

I'm going over the finish line at 7300 and would like to see it around 66-6700 rpm.Could this be done by going from a 31 inch tall tire to a 33 inch tall tire??
Would also like to loosen the stall but that would increase the RPM at the stripe.
Now have a Dana with 4:10 & 31 inch tall tire. Peak Tq is around 5000 RPM and HP is 6200

Posted By: Thumperdart

Re: RPM at the stripe?? - 04/02/14 08:23 PM

Watcha worried bout, that thing should be happy there..........

Posted By: MR_P_BODY

Re: RPM at the stripe?? - 04/02/14 08:35 PM

Figure the percentage of change in the tire dia..
then use that on the rpm

Posted By: pittsburghracer

Re: RPM at the stripe?? - 04/02/14 09:14 PM

http://www.wallaceracing.com/Calculators.htm

Posted By: oldiron

Re: RPM at the stripe?? - 04/02/14 09:20 PM

(31/33)*7300 = 6857

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/02/14 09:22 PM

I think I see a set of 10.5w X 33 in my future

OR,,,would a set of 3:73's with a looser converter be better???

Posted By: 68LAR

Re: RPM at the stripe?? - 04/02/14 11:27 PM

Because of tire clearance, I was looking at dropping down to a 4.30 or 4.10 gear. I'm going thru the traps at close to 6500 with 4.56 and a 29" tall tire. My concern is what affect this would have on my short times. Remember, I've got a heavy stick car. Don''t mean to hi-jack this post. Just thinking out loud on the web.

Posted By: MR_P_BODY

Re: RPM at the stripe?? - 04/02/14 11:39 PM

Quote:

Because of tire clearance, I was looking at dropping down to a 4.30 or 4.10 gear. I'm going thru the traps at close to 6500 with 4.56 and a 29" tall tire. My concern is what affect this would have on my short times. Remember, I've got a heavy stick car. Don''t mean to hi-jack this post. Just thinking out loud on the web.

Your gonna loose torque due to ratio... but with a stick
you can jack up the revs... will you see the change...
maybe not(on the torque) but your revs will drop

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/03/14 12:18 AM

Quote:

Because of tire clearance, I was looking at dropping down to a 4.30 or 4.10 gear. I'm going thru the traps at close to 6500 with 4.56 and a 29" tall tire. My concern is what affect this would have on my short times. Remember, I've got a heavy stick car. Don''t mean to hi-jack this post. Just thinking out loud on the web.

NOT a hi-jack,we have a similar situation.We both need to lower the RPM at the stripe

Posted By: dvw

Re: RPM at the stripe?? - 04/03/14 02:07 AM

Quote:

I'm going over the finish line at 7300 and would like to see it around 66-6700 rpm.Could this be done by going from a 31 inch tall tire to a 33 inch tall tire??
Would also like to loosen the stall but that would increase the RPM at the stripe.
Now have a Dana with 4:10 & 31 inch tall tire. Peak Tq is around 5000 RPM and HP is 6200

Al, that must be a inefficient converter. I go through at 6900 with 4.10/10.5x31W/147 mph. Flash stall is 5700 rpm
Doug

Posted By: J_BODY

Re: RPM at the stripe?? - 04/03/14 02:27 AM

I'm no expert.... but I was thinking the same thing dvw brought up. I wasn't making a ton of hp with my Mirada (high 9s), but with a 29.5 slick and 4.10 gear I was trapping in the 6200-6400 range.

Posted By: Thumperdart

Re: RPM at the stripe?? - 04/03/14 02:43 AM

I`m crossing the line at around 7200+ w/an 8" 5000+ vert and a 29" tire w/4.11`s..............

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/03/14 04:21 AM

I'm pulling the trans out this weekend

Something ain't right

This converter is 1 year old

Posted By: rickraw

Re: RPM at the stripe?? - 04/03/14 05:00 AM

Check the stator, should lockup spinning one way & freewheel the other way. Easy check.

Posted By: cudaman1969

Re: RPM at the stripe?? - 04/03/14 05:35 AM

I would say it all depends what mph you'r going thru the traps, to many variables to compare with different cars. What is the mph? My engine was turning 7000 but drive shaft was 5600 -a lot of slippage, still went 125 mph in eigth. Sent vert back two more times to tighten up, check that first.

Posted By: 572charger

Re: RPM at the stripe?? - 04/03/14 11:51 AM

i,m with doug check the convertor , ive got 4.30 gear 31.50 tall et streets and i shift at 6800 go thu traps at 7000 on a good pass with good air runnin 9.60s -9.70s ati convertor slip is only 8% it pulls like a frieght train in high gear 142mph !!! 3900lbs ,

Posted By: dennismopar73

Re: RPM at the stripe?? - 04/03/14 12:18 PM

Quote:

I'm going over the finish line at 7300 and would like to see it around 66-6700 rpm.Could this be done by going from a 31 inch tall tire to a 33 inch tall tire??
Would also like to loosen the stall but that would increase the RPM at the stripe.
Now have a Dana with 4:10 & 31 inch tall tire. Peak Tq is around 5000 RPM and HP is 6200

WOW! That's a ton rpms if that's correct wit 410 gear !
I think the vert you got is in need of repairs

Posted By: SSDAcuda

Re: RPM at the stripe?? - 04/03/14 12:59 PM

Quote:

Quote:

I'm going over the finish line at 7300 and would like to see it around 66-6700 rpm.Could this be done by going from a 31 inch tall tire to a 33 inch tall tire??
Would also like to loosen the stall but that would increase the RPM at the stripe.
Now have a Dana with 4:10 & 31 inch tall tire. Peak Tq is around 5000 RPM and HP is 6200

Al, that must be a inefficient converter. I go through at 6900 with 4.10/10.5x31W/147 mph. Flash stall is 5700 rpm
Doug

Exactly. Al sometimes the weight of the car and the gear have opposite effects. I thought you bought a racepak, and if you hook it up you can see converter slippage at the stripe. Will tell you facts. With that said, I would try a 4.30 and the car will tell you the answer...

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/03/14 03:00 PM

Quote:

Quote:

Quote:

I'm going over the finish line at 7300 and would like to see it around 66-6700 rpm.Could this be done by going from a 31 inch tall tire to a 33 inch tall tire??
Would also like to loosen the stall but that would increase the RPM at the stripe.
Now have a Dana with 4:10 & 31 inch tall tire. Peak Tq is around 5000 RPM and HP is 6200

Al, that must be a inefficient converter. I go through at 6900 with 4.10/10.5x31W/147 mph. Flash stall is 5700 rpm
Doug

Exactly. Al sometimes the weight of the car and the gear have opposite effects. I thought you bought a racepak, and if you hook it up you can see converter slippage at the stripe. Will tell you facts. With that said, I would try a 4.30 and the car will tell you the answer...

Almost finished installing the Racepak,that was one of my winter upgrades.Still have a week or so before I get into the chassis shop for those upgrades.Car won't make a pass until I get this stuff squared away

Posted By: Whompin_Wedge

Re: RPM at the stripe?? - 04/03/14 06:09 PM

Yea I agree on converter. We are 29.5 tires with a 4.56 and go through at 7200..

Casey

Posted By: MR_P_BODY

Re: RPM at the stripe?? - 04/03/14 06:18 PM

To be honest I wouldnt change anything till you get
the racepac installed and see if your tack is just off
which very well could be your issue

Posted By: dvw

Re: RPM at the stripe?? - 04/03/14 10:15 PM

All these RPM/gear/stripe numbers are useless without the MPH. If I have the car slowed to run 9.50@143 it only turns 6700 instead of 6900 at 147.
Doug

Posted By: 383man

Re: RPM at the stripe?? - 04/03/14 11:06 PM

Wow some of you guys really twist them. I shift about 6200 and trap about 6400 at 10.70's and almost 125. But my mild 493 seems to like that rpm range. Ron

Posted By: cudaman1969

Re: RPM at the stripe?? - 04/04/14 03:31 AM

Quote:

All these RPM/gear/stripe numbers are useless without the MPH. If I have the car slowed to run [Email]9.50@143[/Email] it only turns 6700 instead of 6900 at 147.
Doug

like i said et means nothing mph determines trap rpms. watched some old films of 1964 super stockers, they ran 11.60s at 130 mph. a lot of difference then and now. today some cars run FAST out the back door.

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/04/14 03:48 AM

Quote:

To be honest I wouldnt change anything till you get
the racepac installed and see if your tack is just off
which very well could be your issue

That would be a hoot!!

Posted By: hemi-itis

Re: RPM at the stripe?? - 04/08/14 06:34 AM

Pulled the trans tonight.Found the new max lug gearset scored the stater causing a pressure bleed off,Gotta do some measuring to figure out why it got scored