car is slower with new trans and convertor why?

[turbo tom]

I was running 12.8 with old trans and old convertor with race gas

 

[BIGPSI]

put a bigger turbo on it! thats easier than changing the stall LOL

 

[NCTURBOS]

Forget the advertised stall rating on the converter, we need to know what pump# the converter is?!?! Oh, and the converter isn't the problem... Just make sure you're locking it at w.o.t., otherwise it might not be the most efficient operating on the big end of the track.

Most importantly, and I'm surprised no one has already asked... What are you using for datalogging? You mention you've made other changes to the car as well, so now there are multiple variables involved.


K.

 

[NCTURBOS]

not utilizing the stock powerband with that converter. unless your going to upgrade to a 60 plus turbo then put a stock 12 inch back in and watch it pull thru the rpm range. a car stock car will pull harder starting out wot at 1800 thru 5200 that starting out at wot at 3200 to 5200 your not using all the power the car has to offer

So when you (or anyone else for that matter) make a w.o.t. pull with your car, and you run the rpm up to 5200, how much does the rpm drop at each shift point? I'm thinking it's probably closer to 3200 rpm instead of 1800 rpm. Putting the effective powerband (rpm range) where?!?! Hhhhmmm


K.

 

[forcefed3.8's]

I can't see a Vigilante being inefficient at that power level. I had under 10% slip running 10.8's@125. The car would pick up 29mph in the last 1/8 uunlocked. We have used 0 pump Vigilante's in 12sec to 9 sec cars, with no complaints, they work great. It is the converter I recommend to anyone wanting to keep lock up and run down into the 10's.
We need alot more info, old times/mph vs. new times/mph, boost, timing, O2's,etc. Just because you open the hood and dump in a bucket of $, doesn't mean it will instantly go faster.

 

[bison]

60 foot were 1.8 to 1.9 and now there 2.0

Thats not the converter or trans

 

[dank GN]

I have a 2600 stall converter with low miles if intrested for a fair price about 3000 miles on it pm me if intrested

 

[Nick Micale]

........stage 2 trans and vig 9.5 lu 3400.......

If the converter was a true 3400 stall, it would give you a much better 60' time than a 2.0?

These Vigilante converters have been a big problem for the cars I have personally tried to work with using them over the years. I do not believe your converter stall is accurate.

On the last GN when I removed the Vigilante, it went from a 13 sec. car to a low 12 with much better 60' times - nothing else was changed.

 

[turbo tom]

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I recently bought a new rebuilt 2004r trans from Extreme Automatics and had it installed. The trans is a stage 2 and I have a lightly modified 1987 Turbo Buick Grand National. The tcc switch was replaced after the install and it seems to be bad again. What could be causing it to go bad? It down shift and jerks as im slowing down just like im driving a manual shift.Thank for any help.
turbo tom
248-390-3345

turbomillwright@sbcglobal.net

 

[turbo nasty]

Did u do the pump mod to the trans for the vig convertor? Makew sure that is done before forcing l/u with that multi disk

 

[turbo tom]

yes pump mod was done by extreme automatics

 

[turbo nasty]

The chip change back to stock due to the KR you spoke of.... that could be it right there.

If you are running a chip with less timing and lees boost or same boost and less timing then yeah its gonna slow down.

Im not real sure whats all you have done.

Thread sayd car slowed............you think its trans and conv. Then you mention the stock chip going back in.

With the car running "slower" what chip do you have?
What psi boost?

 

[turbo tom]

replaced the chip from tt cause i was getting false knock and still getting false knock at 15 lbs

 

[turbo tom]

Anyone know of a good tuner in Michigan?

 

[NCTURBOS]

replaced the chip from tt cause i was getting false knock and still getting false knock at 15 lbs

How do you know it's false? It could be real or something mechanical causing the knock. The issue causing the knock could be why the performance of the car fell off some. Regardless... Most street chips pull the timing back to account for the knock, which would slow the car as well.

If you plan on owning one of these cars for an extended period of time you should invest in a datalogging program...


K.