496ci revamped

You have a 4L80E I recall.
What torque converter ?
Recall stall not real high.
May have damaged it.
Low stalls they do not put good parts in typical.
Just Turbo 400 HD models like Coan and Hughes.

Need to call a Pro Converter builder.
$900 ready to spend.

Making Power Torque Yes.
I get a discount from Coan still , I worked their in the machine shop in high school part time while going to vocational school for machine trades.
It appears a 265mm pn# 100310-3-3 is probably the ticket, I will find out tomorrow, I get a 10% discount
 

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I can tell you from being around modern power,added cars what I call high speed torque not all Dyno Operators are the same.
Thier predictions are often way off.

My 2nd 455 I had it on a,Superflow water brake dyno.
The 1st Full Pull with a Full Bore Comp Cams Racing Cam it made way more torque down low than predicted.
It was September 1997.
Good Old Ted Borowski was working the Dyno himself.
A Chevy Shop and they specialized in Big Chevys 900 -1400 Hp Normal Aspirated.
Jokes were cracked.
Ted was mocking me.
Engine running.
Thumping away.
He hit the Throttle WOT and worked the Dyno Brake by hand.
Was not computer automated back then.
The Engine Raced away and on the Tachometer it Read 9,000 RPMs on the huge 18 inch face tachometer.
Sounded Great but was not to exceed 6500 rpm I told him.
Ted shut my RAIV 455 down.
I looked at him and he got real nervous.
Valve covers pulled and checked the Valve lash myself.
No Tuilped stretched valves.
Valves did not float.
Best parts available used at the time.

Like I said you can not have HP without TORQUE.

Made around 20 more pulls and I tuned the ignition and SD455 Q-jet to get best results.
Okay just going by basics
Torque comes in a 4200 not 2600
780 lbs of torque x4200 ÷ 5252 is 623hp at the wheel.
Not the greatest data yet new torque converter will fix most of the issue. hopefully I can get another crack at it next week and see.
 
Okay just going by basics
Torque comes in a 4200 not 2600
780 lbs of torque x4200 ÷ 5252 is 623hp at the wheel.
Not the greatest data yet new torque converter will fix most of the issue. hopefully I can get another crack at it next week and see.
Data may have badly SKEWED.
DO NOT HAVE A CLEAN BASELINE LIKELY.
JUST KNOW IT'S MAKING POWER.
 
I get a discount from Coan still , I worked their in the machine shop in high school part time while going to vocational school for machine trades.
It appears a 265mm pn# 100310-3-3 is probably the ticket, I will find out tomorrow, I get a 10% discount
Go with COAN Then.
I never ever have seen A COAN Torque converter Fail.
 
I get a discount from Coan still , I worked their in the machine shop in high school part time while going to vocational school for machine trades.
It appears a 265mm pn# 100310-3-3 is probably the ticket, I will find out tomorrow, I get a 10% discount
Your the Very 1st in my time here at Grumpys since 2011-2012 to build one his 496 Combos.
We debated torque converters for 4L80E a few times.
Budget torque converters I Figured always no good for 4L80E.
It has been proven by You.
Need The Best.

Very Good Reason only a Turbo 400, Powerglide, & 4L80E only used today for Fast Cars.
 
Okay just going by basics
Torque comes in a 4200 not 2600
780 lbs of torque x4200 ÷ 5252 is 623hp at the wheel.
Not the greatest data yet new torque converter will fix most of the issue. hopefully I can get another crack at it next week and see.
Don't let those guys at the Race Shop with thier Chassis Dyno Exceed Safe Zone RPM.
A 4L80E is a Turbo 400 with overdrive.
Internal Geartrain is same parts as Turbo 400 but with an Overdrive gearset.
DO NOT want spin above 7K rpm.
Unless COAN Titanium Drums installed.
Stock TH400 & 4L80E Drums take Power but High Rpms cause them to fail..

Muncie 4 speed no worries.
Made For 7-8-9 k rpm shifts.
 

 
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My old neighbor I grew up next to 20 feet away Mike was an Avid Drag Racer.
Street Racer also.
Entire Family are Street Racers.
All Mike ever used was COAN Torque converters.
Said all others were JUNK.
But said Hughes was Good too.
Fastest he had was a 7-second Door Slammer 3rd Gen Camaro.
Scott Shafferoff 540 BBC.
Methanol Alcohol Rons 5 inch Flying Toliet, Hilborn Belt drive Fuel pump.
Powerglide that car.
All others were TH400 cars prior.
Used COAN always.
Never a converter or Trans failure.
Loan Pontiac guy with my 70 TA.
Come 2007 I bought an 87 Corvette Convertible.
Always a Chevy guy too me.
 
Don't let those guys at the Race Shop with thier Chassis Dyno Exceed Safe Zone RPM.
A 4L80E is a Turbo 400 with overdrive.
Internal Geartrain is same parts as Turbo 400 but with an Overdrive gearset.
DO NOT want spin above 7K rpm.
Unless COAN Titanium Drums installed.
Stock TH400 & 4L80E Drums take Power but High Rpms cause them to fail..

Muncie 4 speed no worries.
Made For 7-8-9 k rpm shifts.
6k was the limit starter out at 5500
Just wanted to make sure there were no noticeable issues.
 
My old neighbor I grew up next to 20 feet away Mike was an Avid Drag Racer.
Street Racer also.
Entire Family are Street Racers.
All Mike ever used was COAN Torque converters.
Said all others were JUNK.
But said Hughes was Good too.
Fastest he had was a 7-second Door Slammer 3rd Gen Camaro.
Scott Shafferoff 540 BBC.
Methanol Alcohol Rons 5 inch Flying Toliet, Hilborn Belt drive Fuel pump.
Powerglide that car.
All others were TH400 cars prior.
Used COAN always.
Never a converter or Trans failure.
Loan Pontiac guy with my 70 TA.
Come 2007 I bought an 87 Corvette Convertible.
Always a Chevy guy too me.
A lot of the internals are TCI and Sonnax
Input shaft is TCI clutch kit is Sonnax
Valve body as you know is Transgo
 
6k was the limit starter out at 5500
Just wanted to make sure there were no noticeable issues.
I know TH400 Aluminium Drums are $900 .
Coan Titanium Drums likely $3500.
I know what Titanium valves cost.
Bought them for TA.
Ti is expensive.
Noticed many 4L80E builders use stock drums.
Take Hp like I said.
High Rpms 7k + Not so good.
Explosion and through the floorpan .
Unless Trans shield, SFI Race Bell, & Kevlar blanket in place.
All that stuff ignored in Pro Tour world.
Those Guys are dumb and all slow.

You have RACECAR.
Play it smart and safe.
 
To me it's backwards
Dyno are like computers and internet.
Garbage In Garbage out.
Some Read 50 Hp Low.
Some Read 100 Hp High.

Mainly a Tuning tool.
Nice for results and bragging rights.
If falls short not really a big deal.
Much more involved in setting the car up and using all the power.
It takes just 500 Hp in a 3200-3400 lb car to run 10s.
Granted it takes low diff gears 3.90-4.88.
Sticky tires and chassis that gets the power down clean.
 
Well found out a few minutes ago
I can put a lockup converter in View attachment 10837
I think he is talking about the Converter fill and Trans Cooler Flow rates.
On a Turbo 400 it's done with drilled Orfices.
It's a complicated topic.
I know alot but not all.
4L80E I have never rebuilt yet.
None of us have but one guy from Sweden that comes around time to time.

In real high horsepower cars you usually have to eliminate torque converter lockup.
But I think it has changed lockup ok Again.
Be an expensive $2,000 - $10,000 Race converter.
Too expensive for most.
Be like a Drag Week Race Car.
Need Sponsor to help pay the bills and parts.
To get them you have to compete on National Level and Win Races.

Coan Racing your best Bet.
You worked there in the past.

RPM Transmission so so.
Really I see them as C5- C7 Corvette Race trans conversion suppliers.
Insane expensive.
$20,000 -30,000 needed.
Take a New C7 2018.
Toss the 8 speed auto .
They install a Turbo 400 or 2speed Powerglide mated direct drive to the Independent Rear Suspension Differential.
Drag Race use .
Also do 4L80E Race swaps in Vettes.
 
But not the Torque converter.
Where your at.

Hopefully the 4L80E is ok.
Hard to tell.
Usually a teardown inspection required.
 
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