geeting a 1961 impala to be a bit quicker

[grumpyvette]

hey grumpyvette?
I am thinking of changing up my gear ratio to make it a little more fun to drive :evil: . so I am looking for recommendations on this. The car is a 4000 lb 61 impala with a 700r4, 3.89 gears, 3100 rpm stall with lock up in 4th gear and a 27 inch tall rear tire.


Here is the combo specs....

ENGINE
-383 stroker 442hp/470ft lbs of torque )
-Comp Cams Roller Cam Duration-Intake 230deg Exhaust 236deg @ .050 / Lift Int .510 Exh .520 and 110 lobe separation
-Air Flow Research 195cc Heads 74cc chambers
-9.7:1 compression


CHASSIS
-700r4 tranny Bullet proofed
-B+M super cooler tranny cooler
-9 inch ford rear end
-Centre Section With Motive 3.89 Gears And Auburn Pro series limited slip


And the dyno specs....

Intake cener line 105 1/2
jets 76 front 85 rear
vac sec spring short yellow
timing 35 deg
RPM----HP----TQ----A/F--- Vol Eff%

3900 - 328 - 442 - 13.3 - 97
4000 - 340 - 447 - 14.0 - 97
4100 - 356 - 456 - 14.2 - 97.3
4200 - 370 - 462 - 14.0 - 97.5
4300 - 381 - 465 - 13.9 - 97.5
4400 - 390 - 465 - 13.9 - 97.4
4500 - 397 - 463 - 13.8 - 97.4
4600 - 404 - 461 - 13.7 - 97.2
4700 - 410 - 458 - 13.8 - 97.1
4800 - 416 - 465 - 13.8 - 96.9
4900 - 422 - 452 - 13.8 - 96.7
5000 - 427 - 448 - 13.8 - 96.3
5100 - 430 - 443 - 13.8 - 95.8
5200 - 433 - 437 - 13.9 - 95.2
5300 - 435 - 431 - 13.9 - 94.9
5400 - 436 - 424 - 13.8 - 94.6
5500 - 437 - 418 - 13.9 - 94.3
5600 - 439 - 411 - 14.0 - 94.0
5700 - 440 - 406 - 13.9 - 93.5
5800 - 442 - 400 - 13.9 - 92.8
5900 - 442 - 393 - 14.0 - 92.1
6000 - 440 - 385 - 14.0 - 91.5

My current WOT upshifts are at 6000 ish any idea as to where they should be? I have been using the B+M weights and springs to try and set up the shifts. I would asume they might need to be at about 6000, if so should i use the springs to fine tume now or keep trying the weights?

if i calculated right with a 4.56 cruise will be about 2500 locked up in 4th gear running around 60 mph/100 km/h

the car is local city driving, no track, not often on the hwy but every now and then I do go for an hour or so on the hwy at 100-120 km/h to get to the bigger city for some cruising.

Yhanx in advance

 

[grumpyvette]

whats your goal here when you state ,you want the car to be..by "FUN TO DRIVE", are you trying to make the car more street drive friendly or add more hp or acceleration ?, (I'm assuming your goal is to make the car quicker)and obviously your current combo seems to be reasonably well matched, and thought thru.
to make the car faster you either add hp/torque or reduce weight or both, and maximize the engines power curve with the cars gearing, swapping to a 4.56:1 REAR GEAR WILL HAVE ONLY A MARGINAL EFFECT ON THE STREET FROM THE CURRENT 3.89:1 REAR GEARS SIMPLY BECAUSE ON THE STREET YOUR NOT GOING TO GET GREAT LAUNCH TRACTION, without slicks, and once your rolling at about 30 mph or greater the difference (looking at your engines power curve)won,t be huge, because your max torque is in the lower and mid rpm range
swapping to a roller cam like a crane 119571
http://www.cranecams.com/product/cart.p ... il&p=24181

and fiberglass fenders,hood and trunk lid
http://www.vfnfiberglass.com/6270impala.htm

would help. or you might want to consider a nitrous plate kit
http://www.summitracing.com/parts/NOS-07001NOS/


BTW
Your entire FUEL/AIR RATIO range is too lean by at least 1/2 ratio.
keeping it lean at idles better for plug life and mileage but try to get the f/a ratio to fall in the 12.8-13:1 range on a street car above about 3000rpm and youll make better torque, changes to the jets and power valve can usually do that
Assuming the front/rear bias is accurate, you need at least 78/88.

but reading plugs and use of a timing light,vacuum gauge and IR temp gun to read exhaust temps should help

read these threads

viewtopic.php?f=70&t=202

viewtopic.php?f=44&t=773

viewtopic.php?f=4&t=1337&p=2921&hilit=+infrared#p2921

viewtopic.php?f=44&t=777&p=4546&hilit=+power+valve+vacuum#p4546

viewtopic.php?f=44&t=1788

viewtopic.php?f=55&t=1639&p=4545&hilit=+power+valve+vacuum#p4545

 

[grumpyvette]

"Grumpy I am looking for it to be more fun in the way of having the power and torque more for lighting the tires up at will even from a rolling start. But don't want it to be a pain in the but to drive around as well."

instant cure for what your looking to do (providing you can stand all the crying your checking balance and wallet is going to do for MONTHS

http://www.superchargerusa.com/chevy_bk ... _strip.htm

http://www.superchargerusa.com/chevy_bk ... htm#bbc9.8