Gains over my Freak Converter?

[Justin Kirkham]

Ok, I was looking to get a streetable converter (2800-3000) because my car will be my daily driver for the next 7 years or so, but then I was out and I noticed something... My car stalls to almost 2600. Now,I know that our tach's aren't that good, but assuming that my car does stall to 2600, what gains would I see from a 2800/2900/3000 stall? Thanks!

-Justin

[Justin Kirkham]

ttt

[Magnus]

Many of the newer cars are able to stall that high. On my stock 97 I was only able to stall up to 1800 or so.

You'll still see a gain with an aftermarket verter. Your converter still only flashes at 2200 or so, whatever it is stock.

[Justin Kirkham]

<blockquote>quote:</font><hr>Your converter still only flashes at 2200 or so, whatever it is stock.<hr></blockquote>

Huh?

-Justin

[Magnus]

I'm assuming your achieving this 2600 # by holding the brake in and giving it gas correct? IE: testing brake stall.

[Justin Kirkham]

yeah, so is it actually only stalling at 2200?

-Justin

[Magnus]

It still only flashes to 2200 or so. Brake stall is a test of so much more.

[Pro Built Automatics]

Real stall is when you can hold the brakes and it stabilizes (if the brakes hold). Flash is when you stand on the throttle from a stand still, you will see it jump to a certain rpm momentarily. If you can get 2,600 rpm, and have the brakes hold, then this is the true stall for "your" motor. Problem is that most drivers can get their brakes to hold to do this test. Another reason is that if you have 3.73's, compared to 2.73's in the rear, it will be harder to get it to stall because of numerical torque multiplication. I hope this helps.

[Justin Kirkham]

See, at sea level I started spinning at 2200rpm or so, but up here at 4,500 feet above sea level, I cna hold 2600rpm for as long as I want to. I have once held it for 10 seconds at the beginning of a race.... his 3 honks took FOREVER.... So given that my motor has a true stall of 2600, would a 2800 or 2900 stall converter still help my performance a good amount?

-Justin

[jmorgan]

hrmm you dont have a freak converter


I DO though [img]smile.gif[/img]

[Pro Built Automatics]

I can't figure why altitude would give you more stall?, it doesn't make sense, if anything it should be less rpm stall due to less torque. The 9.5" should still give you an increase in performance, depending on what stall you wind up with. What diameter torque converter are you running now?, and what's the rated stall of it?

[Justin Kirkham]

I have a stock converter. What I meant about altitude is that with my lack of power, I can rev it up and my tires don't spin on me. At ground level, if I got to 2200, my tires would start spinning and I just did a burnout if I revved any higher. At 4500 feet, I can simply hold my rpms at 2600 and I get no slipping.

-Justin

[Andre@Edge]

Its not uncommon for the O.E. 245mm converter to slip or flash to the rpm your stating Justin.
Its a "good news", "Bad news" situation.... The good news is that this will make for a more aggressive launch.
The bad news is that you will suffer by the loss of coupling due to the excessive clearance of the converter.
The stock (max) stall on your stock motor was 2060rpm in the 2000 year (depending on gearing you had 2060, 1895, 1865rpm). This was "true stall" but due to the excess clearance of the OE converter many can see well above the "true stall" numbers on the foot brake. This is caused by only two things. Increased torque input, or excess clearance. The converter made for some fairly big variences between exact, side by side built fbodys. One may be set for total slippage of 6% and another for 9% or 11. One set with .090 total clearance and the other with a impeller to turbine clearance of .125...or greater.
Its no secrect why they were set to excess. Make a sloppy converter and you have less warranty issue with the performance minded drivers who purchased this car. More slippage equaled less repairs. Set up with the efficient converter many of you can light the tires with no effort. No extra HP, no tire changes, just STR and corrected efficiency.
If you have a converter that came factory that gets you to 2600 on the tach, you have a poor converter, or you are badly in need of a fluid change. The transmission fluid breaks down from the excess heat and the lower viscosity couples more like water then ATF.

No mystery why the converter was set at excess, but the order to the converter manufacture should have require a constant to say the least.
Early transmission failure, transmission heat, lack of power, eratic shifts, roaming into and out of lock up, even the chatter, or the popular 1870 code can be kicked straight from the production line.
The performance manufacture corrects this. The converter is reconfigured to use math for stall and STR and the slippage is greatly reduced.
P.S.
Before this thread goes bad....., YANK and PI do this very thing to increase efficiency and any reputable performance converter maker is aware of this problem with the OE product.
Not a freak.... its genuine GM.

[ March 12, 2003: Message edited by: Andre@Edge ]</p>

[Justin Kirkham]

Ok, I think that I get the idea now. Thanks all for the input. Bottom line, after I get my intake done, a 2800-3000 stall torque converter will be next. Thanks!

-Justin