Opinions on gearing / trans / converter

I am looking for opinions on my trans set up and my converter... My car has some really good times at portions of the track, but seems to lack in a few others. I am thinking it could be due to my converter but I am not sure..

Here are a few numbers for you.

1.09 sixty foot

4.80 in the 1/8th mile at 154 miles per hour

7.60 in the 1/4 at 186 miles per hour



The sixty seems strong, the 1/8th et seems to be a little slow for the MPH, and the 1/4 mile seems to be about right for the speed, but slow for the 60'

This is in a 548" Blown Alcohol BBC, Dart 360's, 14-71 High Helix, 38 pounds of boost... The tuneup is right on...

Car weighs 2800 pounds, runs a 4.30 gear and goes thru the traps at 8300 to 8600 rpm.

Trans is a 1.86 low gear power glide

 

Hi what size tires are you using the rpm seems high and I would say you have quite a bit of converter slip if you are running 7.6 at 8600rpm, I run at a similar weight run 6.5 at 9200rpm with a 34 1/2 inch tire.

 

1/8 mile et seems way low for the 60ft & mph.
We run an outlaw 10.5 car --3000lbs , 496 hemi ,14-71 33over , about 30lbs boost, 3.70 rear gear , 1.80 pg
1.16 60ft
3.15 330
4.80@150 1/8
7.54@160--letting out at 1000ft

 

Hi gt.

What size tyre are you running ? What RPM do you shift at ? What is the stall speed of the converter and do you load up against the transbrake ? Can you post the rest of the incremental times ?
Cheers Jim

 

I would have to dig out a time slip for the rest... But the tires are a 33x17 Mickey Thompson.

Shift the car at 8000, leave the line at 3000.

The car should really run faster for the weight and the motor... I am thinking the converter needs to be tighter. It is a 5500 stall speed. We use the trans brake, but no two step, we run it off the air throttle.

Ignition is a MSD 10 Plus.

 

converter

gt. you are not doing too bad for that weight and a battery type ignition! we ran around 4.60 with our last chevy, but at less than 2500 lbs. best 60 ft. of 1.02 & 4.57 8th. we found that a 9.5" converter worked best. ( w/ 4.57 x 1.80 powerglide)
there is some trade off with using a looser converter with a taller gear( i.e. 4.29 or 4.10) or tighter converter with lower gear ( 4.56)
size of converter definitely matters. too small a surface area (converter) will not load the engine to make max power. bet your converter is less than 9". most converter builders understand this issue. my people (torque converter service, columbia , s.c. ) are excellent and reasonable on costs!
our current set up 2610 lb, 1.80 glide, 4.29 gear, 526 hemi went 4.21 &4.19 @ 170 last week with a 10.4" tcs converter. good luck chuck p.s. with manton pushrods

 

Thanks for the info, it is good to know that I am just about where I should be.... The MPH just always seemed high for the ET in the 1/8th mile compared to some of the other cars I run with... They would run the same ET but less mph with less 60'.... But I guess that could be apples to oranges considering mine is set up for 1/4 mile and theirs are set up for 1/8th
The car was running a mag for years, then I guess right before I got it, they started to have problems with it and went to the MSD 10. We are running a 16 volt system as well

 

like others have said your converter is to loose. at top of 1st you are only doing 100mph, it then drops to 4400 rpm at the shift. check the math if you wish.

 

I was thinking the same thing...

Here is a video of the car going down the track a bunch of years ago... I dont have any new video's. It is still set up exactly the same as it was then, just new parts now.

http://video.google.com/videoplay?docid=-8942364149205447080