View Full Version : torque converter help


fast81
01-09-2005, 10:38:00 AM
This is actually fast79. Could not find my password so I used my brothers name.

79 camaro
454
3700lbs
oval port heads
solid roller cam
duration at 50
intake 255 exha 265
lift 650 675
victor jr intake
holley 850 dp
1.75" headers
3" exhaust
350 turbo trans
4.33 gear
footbrake
26X10 tire
shift at 6800-7000rpm
previously had a trans specialties 10" 3500 stall.

Between shifts engine rpm would fall 900rpm.
car run a 7.16et at 96mph in the 1/8 mile with a 1.56 60' time.
Rear wheel dyno showed 448hp at 7000rpm
528ft lbs at 3800 rpm

Was told I need more converter. So I installed an Art Carr 9.5" 4500 stall. Between shifts, the motor does not drop any rpm. If I floor it in third while moving slow it seems to flash to 5000rpm. Is this a good choice for converter stall?
My goal is to run a 6.90et. Caltracs are next.

Problem 2-The Art Carr makes a whistling sound around 6500rpm. What could this be?

Mwilson
01-09-2005, 11:31:00 AM
Is it street driven or strip only?
If its street driven you'll probrably have to make a sacrifice on converter for some manners. On the dyno what were the torque /HP numbers throughout the range?
That kind of power i would think you could get on down in the high six? im not much on big block power though post a dyno sheet.

[This message has been edited by Mwilson (edited January 09, 2005).]

fast81
01-09-2005, 12:30:00 PM
rear wheel dyno with the 10" 3500 stall-

RPM Torque Hp
3800 537 390
4000 530 420
4200 520 420
4400 510 425
4600 475 425
4800 460 420
5000 440 425
5200 430 430
5400 420 435
5600 410 435
5800 390 440
6000 380 440
6200 370 440
6400 360 445
6600 350 445
6800 340 448
7000 330 445
HP curve is very flat after you get to 4200 rpm.
This is as close as I could read the graph. This is on a WinPEP Dynojet rear wheel dyno. Air Fuel ratio remained constant between 12.8 to 13 at WOT.

fast81
01-09-2005, 12:31:00 PM
I want the converter that will get me to the 6.90et range (if possible). 90% strip 10% street.

onovakind67
01-09-2005, 12:40:00 PM
I guess the big question would be:

How did the new converter compare to the old one? I also think your 60' should be considerably quicker - like 1.45 or so.
If you try to determine the peak torque on a chassis dyno you need to remove the effect of the converter. The 3800 peak torque is probably the result of the torque multiplication of the converter. It seems very unusual that the torque peak is at 3800 and the power peak is at 7000.
I notice that you have a 255/265 cam in the big block and shift it at 6800. I wonder what the shift points would be with a small block with a 255/265 cam?

[This message has been edited by onovakind67 (edited January 09, 2005).]

Mwilson
01-09-2005, 01:21:00 PM
Yeah i thought about that the numbers hes posting are with that converter

fast81
01-10-2005, 04:22:00 PM
I spoke with ATI today and they want me to get a 8" treemaster that falshes between 4800-5200 rpm. I think this is alot like Ed's chevelle. Any comments?

Rick WI
01-10-2005, 06:19:00 PM
It sounds like you are overpowering the converter, re: RPM doesn't drop between shifts. Guess would be the converter is too loose. Why don't you call Art Carr and see if they can restall your current converter to dial it in a bit better? Usually this is a free sevice at least once on a new converter.

I assume you rounded the dyno numbers off? Would be odd to have all the numbers end with a zero or a five except for the eight.

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70 SS 454 CI Dynoed 684 HP, 702 TQ All Aluminium Fuel Injected Small Block , plus 200 - 500 HP NX nitrous system.