NZ12'S

Installed new stall and the 60' went from 2.01 to 1.82seconds..........but the e.t. stayed about the same 13.07 and the miles per hour about 104-5, which is what it ran before the stall. I'm thinking I have the shift points in second too high and it's turning 6100 across the line which is probably high. Looking at my mods do you think I should back up the shift points and let it go ahead and shift into o.d.. Thanks for any thoughts.
BAWSS
LID, FERNCO, 160 THERMO FTRA PORTED MAF ERG MOD HYPERTECH 3:73 GEARS 2700 MIDWEST CONVERTER HOOSIER QT PROS CUTOUT

Capn Pete

I had almost the same problem when I installed the 3.73's after 2.73's..........my E/T was pretty much identical, and I actually lost 1 mph. My 60' time was improved to 2.0 from 2.1 on a couple runs though. I also wonder if I have the shift points set too high from when I had 2.73's (they were around ~6200 rpm). If you bring them back closer to factory shift points, the engine will spend less time outside its optimal power band, and also it will get into 3rd gear a little sooner and be pulling stronger for the last length of the track. That's what I want to try the next time I go to the track anyway.

What about your traction? A 1.8 60' time is good, but are you running street tires, or some type of drag tire?? There's potential that you could cut the 60' time even more if you're not already running good tires.

NEWBIE T/A

I have a 2800 Vigilante stall in the SS , and the best time is in the sig.

I also have a HPP3, but have never experimented w/ the shift points - the book says that you have to be real consistent at the track to maximize the gains/decide on the best setting - well, I am not too consistent !!

I assume the 3.73's are making the difference as I have the stock 3.23's & run in 3rd thru the 1/4 - never paid attention to the RPM's as I crossed the line.

Why are you singling out 2nd gear ? ( Maybe you meant 3rd ?)

Did you try it w/ the factory points after the converter install ?

More questions than answers - sorry !

I don't believe that a stall will give a greater MPH in the 1/4 than one wihout as you have not increased your HP's, only moved into your torque powerband sooner than without one.

I think experimentation is your best bet - but, only with one variable at a time.

Good Luck !

Britt

NZ12'S

WELL, THE REASON I POINTED OUT 2ND GEAR IS I HAVE FELT IT NOSE OVER RIGHT BEFORE IT SHIFTED. NOW THIRD IS WINDING SLOWER AND I THINK IT MAY HAVE GONE OUT OF THE POWERBAND BEFORE IT CROSSED THE LINE. I DID REPROGRAM IT AND IT DOES FEEL STRONGER ON THE TOP END. I'LL HAVE TO WAIT 3 WEEKS TO FIND OUT IF THAT IS THE ANSWER.
I KNOW THE MPH SHOULDN'T GO UP MUCH AT ALL BUT THE RULE OF THUMB IS FOR EVERY TENTH YOU DROP AT 60' YOU SHOULD DROP TWO TENTHS AT THE END!
BAWSS:
confused:

Capn Pete

I feel your pain.

V6toZ28

When did you make your run before you put the TC in?? I'm assuming it was Famosa, unless you ran up to Sac or Sears ...

As far as the "rule" of a tenth in the 60 equals 2 tenths in ET ... that's really more of wishful thinking ... sometimes it works out that way sometimes it doesn't ... there's a lot of other factors that come into play ...

NZ12'S

YES ALL RUNS WERE AT FAMOSA. WITH ABOUT THE SAME WEATHER. HOWEVER, IF YOU ARE 2 TENTHS FASTER AT 60' YOU SHOULD BE AT LEAST 2 TENTHS FASTER AT THE END. UNLESS THE CONVERTER IS NOT DOING IT'S JOB ON THE TOP END.NO? I STILL THINK I WAS JUST SPIINING IT UP TOO HIGH AND LOSING IT THERE. DOES ANYONE KNOW WHERE THE STOCK HP AND TORQUE CURVES ARE LOCATED FOR THE LS1??
THANKS
BAWSS1@AOL

V6toZ28

Unless you had a weather station ... the weather is not about the same .... barometric pressure and dew point can have dramatic affects on the D/A coupled with just a few of degrees difference in in temperature ... enough to make a difference of 2 or 3 tenths. In the Central Valley you can get those changes hour to hour, much less day to day.

As far as where to set your shift points ... the LS1's curves are all over the place stock ... I've seen them with peak power at 5600 and seen them peak at 6000. The only way you will know for sure is to dyno your car.

The nosing over you experienced at 2nd was likely torque management ... it becomes more noticable with a higher stall converter. In and of itself it does not "cause" anything to happend with a AM TC that wasn't happening stock ... but eliminating it or reducing it can optimize your ETs.

Also ... Midwest TCs are inexpensive, but quite honestly I haven't seen any really dramatic numbers coming from them. IMO they appear to under perform converters from other manufacturers with equal characteristics ...

Last thought ... It takes time, passes and attention to detail to tune in a change, to get the most out of it ... Just out of curosity, did you get any passes in with the gears before you put in the TC or did yo do it at the same time?? ... M

NZ12'S

YES YOU ARE RIGHT ABOUT THE WEATHER IN THIS VALLEY,HOWEVER THE CAR DOEW RUN WITHIN .04 OF ITSELF USUALLY ALL NIGHT. IE 13.05 TO 13.09. AS FAR AS THE TORQUE CONVERTER GOES IT DID ITS JOB. IT TOOK THE TWO TENTS OFF THE 60' AND THAT WAS JUST FLASHING FROM IDLE. I THINK IT CAN DO EVEN BETTER. I STLL THINK CROSSING THELINE AT 62-300 RPMS IN THIRD IS PROBABLY THE BIGGEST PART OF THE MPH AND ET BEING THE SAME.
WE'LL FIND OUT ON JULY 11. ALSO THE CAR WAS NOT LIGHTENED AS USUAL(SPARE AND JACK AND HALF TANK OF GAS)
SO THAT MIGHT HAVE SLOWED IT DOWN SOME. THERE IS LOTS OF VARIABLES.
THE TORQUE MANAGEMENT MIGHT HAVE BEEN THE BIG FACTOR AT THE BIG END?

THANKS FOR THE OINPUTS
BAWSS

AL SS590 M6

I'll just add this. If you are crossing the line in 3rd at 6200-6300 rpms you'd better go and get your tranny rebuilt because it's slipping like heck. 104-5mph should never be anywhere near 6200 rpm with a 3.73 gear. Heck even with a 4.10 you can run 110mph under 6200rpm.

NZ12'S

THE TRANNY WAS JUST REBUILT. AND ARE YOUR REFERING TO A 6SPEED THIRD GEAR OR AUTMATIC?
BAWSS

Capn Pete

Actually, Al is right. With an AUTOMATIC & 3.73's, you can hit almost ~120 mph in 3rd gear (at around ~6000 rpm). If you're only running ~105 mph @ ~6000 in 3rd, that ain't right?! Are you sure they're not 4.56's?!

AL SS590 M6

I am speaking of 3rd gear in an automatic car as your sig talks about a Midwest converter.
And seriously if you are any where near the red line in 3rd at 105 mph with 3.73 rear gears your tranny or torque converter is slipping badly. And that's why your performance is down.