Torque Converter for 272" Stage 2

[Eticket]

Wondering what stall torque converters everyone is using for 272-274 inch motors with Ported Champion heads and T76 or close turbos?

I'm going to be foot braking so I don't want to screw up and go too tight.

Thanks,
John

[Kip]

What tranny are you running?
See ya, Kip

[FreddieWilliams]

Eticket,

A few local Brutal 6 members (Neal Steward and Jason Hall) are running a Vigilante multi-disc lockup (#6 pump) converter with good results. I believe the #6 pump is rated around 3600-3800 rpm stall but don't quote me on that.

Neal runs a 250ci stage motor and Jason runs a 262ci stage motor. They both run a T76 BB with a Q-trim exhaust wheel.
Maybe they'll chime in here soon.

HTH,

[JayC]

If youre running a non lockup 200 or a 400, I would call Billy Anderson at Anderson Performance about buying one of the ATI converters he is selling. IMO they are some of the best out there for what we're doing and Billy seems to have them dialed in.

Maybe if you're fortunate, he will actually return your phone call.

[EightSecV6]

Did you call?? Damn I must be getting like the "other" guys!!!HAHAHAHA. I will try to give you a call today....

[Reggie West]

I will offer a counterpoint here at my own peril.

From the type of motor you are building I will assume ( you know what they say about assumption ) you are looking to run 10 flat and mid 9's.

Neal and Jason are both using 2004Rs with a Precision lock up converter.
Their transmissions are holding up to the beating and Neal has run a best of approximately 10.20 ( Neal jump in here and correct me if I am wrong.)

My Dad has a similar combo, he is using a 72 turbo, TH 400 with an Art Carr 9 inch non lock converter. Now Dad just changed the stall on his converter because it was slipping so bad that he was bouncing off of the rev limiter at half track. His new stall is a 3200, builds about 4 psi at 3500 and now the car pulls steadily thoughout the run. We will find out for sure tomorrow night when he takes it to Palmdale. The best time he has run so far is a 10.50 with some problems( burnt pistons you know the usual bugs )

So there are two schools of thought here. I think it would depend on how the car will be used.

If you are using this on the street primarily and race on the weekends, I would use a lock up converter. Now from those who build these things, they will tell you to use all the billet pieces for the trans and it will hold up to 9.50 in the quarter.

If this will be a car that you trailer in and it is a race car, you may want to try a TH 400 and a non lock converter. Dads car does not use a trans brake and it is very responsive with the stall speed he has now.

One more thougt here too. I am starting to believe that we Buick guys get a little carried away with stall speeds on the converters. I think that a stall speed for your combo of around 3200 to 3500 at the most will work nicely and not have a lot of slippage. Any more than that is just a waste. Of course this just my 2 cents.

Good luck

[Eticket]

Thanks Guys. I think I'll go with a 3500-3700 stall. I'll get some more opinions about driveability from some locals who have big stalls.

John

[ChrisCairns]

Originally posted by Reggie West
One more thougt here too. I am starting to believe that we Buick guys get a little carried away with stall speeds on the converters. I think that a stall speed for your combo of around 3200 to 3500 at the most will work nicely and not have a lot of slippage. Any more than that is just a waste. Of course this just my 2 cents.

Good luck

Well said Reggie. And I totally agree that too much slippage is wasted horsies.

I have a 400 with 10" converter. Brand new it stalled right at 2600 at zero boost. I went through the traps at 5700.

Over the winter I had the stall raised....I told AC I wanted max stall out of the 10" without negative fin angle. He told me at the time that I would probably get around 3200 maxing it out. It did exactly that. It now stalls at 3200 at zero boost and at 4000 at 5 psi. I go through the traps at 6300 and I "think" it's too high...i.e. slipping too much. I think going through the traps around 6000 will be better with my cam so I'll ship it back to AC later this summer and hopefully he's kept the "figgurin's" and can put it back to what I want THIS TIME--lol...such as 2900 at zero boost.

Don't over stall it. What is nice slippage on the bottom end is perhaps too much slippage on the top end.

[9SECVSIX]

Am using a AC9"Turbo 400, It stalls 0 boost@3200. With 3.42 gears, 29" tire the Fel-Pro is shows 6450 rpm over the line at 145mph. Am well pleased with it. FWIT the same convertor on a milder combo showed 6050rpm at 136mph.

Brent

[Reggie West]

Just as info, Dads car ran a best of 10.40 @ 130 mph.

This was at Palmdale but it is still not where it should be.

I dont know if it is still slippage or a tuning problem.

We are starting to think a lock up converter may be the solution.

Can anyone tell me what EGTs you should be seeing using C16? That would be of some help.

[Chuck Leeper]

Reg, I go 10.20's at 132.. See the egt in the LOW 1600*F
BUT!! I am at 400' altitude too. Isn't Palmdale higher than that??
Could make a bit of difference... I run 20# boost during these runs..
HTH

[Reggie West]

Yeah Palmdale is at 3200 feet above sea level.

With the altitude correction the run comes out to a 10.1 at 134 so we may not be far off.

The EGT's are in the 1650 range right now, is there any room to go higher or will I be just frying pistons trying to push it?

The real difference is that we are running 26 psi doing this and that is as fast as she will go.

[Chuck Leeper]

I see alot of stage engines operating as high as 18-1900!! SCARES ME!! I plan to stay at/below 1700. I drive my car on the street 99%, so I keep the tuneup kinda fat and low on the timing.
Is the turbo the limiting factor in your performance?? I'd guees that at 3200", you would want to step up a bit w/ the turbo size to compensate for the lower O2 content and lighter air.??

[Reggie West]

The turbo is a 72 but I am not seeing any difference in performance from 26 to 30 psi.

Now with a 70 I know there is a noticable difference but that does not seem to apply with a 72.

I am starting to wonder about the one and only thing that has not been touched with this car and that is the intercooler. It is a Duttweiler front mount but it seems pretty small to me.


BGNRA is doing their get together out at Palmdale this weekend so we will test and tune a little bit more. I remain vigilant for the 9.90 time slip!!

[lazaris]

What Exh wheel are you using on that 72?

[Reggie West]

Q trim or the bigger housing, I cant remember which was which.

[lazaris]

"Now with a 70 I know there is a noticable difference but that does not seem to apply with a 72. "

Well if its a P trim that could be your problem. What size is the exh housing? 3 or 4 bolt?

[Reggie West]

Its a 4 bolt housing.

There is something else not quite right here and I am still looking at the converter.

It is a mystery that Sherlock Holmes would love.

[John Wilde]

Reggie,

What are your Air Inlet Temps?
You can tell if your intercooler is effective
by those numbers. I can tell you that the
core you are using is quality, but pretty
small for a 272 with a 72 turbo. When
that intercooler was produced a te-44
was a scary street turbo not for the faint
on heart!!! LMAO =) You can either purchase
a new unit or stack another core like precision
does with their race unit.

[Reggie West]

I have no way of telling what the inlet and outlet temps are.

This is just a guess at this point. We are going to fiddle around some more at palmdale this weekend and go from there.


I just might try one the Ford intercoolers just for the hell of it. It is cheap and if it does not work I will modify it to fit in my stock car. HMMMM the wheels are turning..........


Any other ideas would be appreciated here guys, thanks.