Torque stall too high?
Thread Starter
|
Freshman User
Joined: Aug 2014
Posts: 39
Likes: 0
Torque stall too high?
Got my 390 built and running. Built for low end torque and hauling *** around town. I put a B&M converter with a 2,400 stall. Sounds awesome and feels like there is a lot power in the pedal. When I gun it off the line it's like I'm driving a manual with the clutch half way in or slipping until mid to high range rpms. I hate it and want it to react to throttle right way. So my question is.....is my lackluster launch and slipping feel from poor converter selection? If so, how much lower in stall do I go? Thanks for the help!
Thread Starter
|
Freshman User
Joined: Aug 2014
Posts: 39
Likes: 0
Lunati62002 cam. Compression close to 9.5:1. When testing by holding brake I get all the way up to about 3500 before motor overpowers brakes. When I put it to the floor from the start it feels like it is slipping until around 4000. It shudders a little under acceleration between 20-40 mph. I filled the converter up with fluid and installed it. It was a little over a year before I actually fired up the motor and drove it. It's almost like I got a junk converter. Trans showed no signs of problems before I rebuilt the motor. Any help is appreciated.
FTE Leadership Emeritus
Joined: Jul 2002
Posts: 42,561
Likes: 423
From: Long Island USA
From what I've read, the stall speed of the converter changes based on how much torque you're actually putting into it - with a torquey 390, that might be exactly what you're feeling.
https://www.lunatipower.com/PDF/Lunati-Catalog.pdf
Looking at the 352-428 list, the 62003 (one step up from yours) says to use a 2200-2400 stall converter. So you're not THAT far off.
Are you sure the tranny's not slipping? Is there a band adjustment?
https://www.lunatipower.com/PDF/Lunati-Catalog.pdf
Looking at the 352-428 list, the 62003 (one step up from yours) says to use a 2200-2400 stall converter. So you're not THAT far off.
Are you sure the tranny's not slipping? Is there a band adjustment?
Thread Starter
|
Freshman User
Joined: Aug 2014
Posts: 39
Likes: 0
I talked to B&M and another torque converter manufacturer and they both said it sounds like a bad converter although it is unusual but not unheard of for a new one to fail so quickly. I really don't think it is the trans. It held fine before I pulled the motor. I could be wrong though, the old 360 had maybe 200 ft/lbs and the new 390 is between 450-550 ft/lbs. I ordered a new one with a 2,000 stall. Hopefully it works, if not I guess I have a couple hundred dollar paperweight and will be going to the trans shop. I'd just take it to the trans shop, but the closest performance shop is an hour away and I'd have to trailer it, time is money. Thanks for the input!
Logistics Pro
Joined: Jan 2011
Posts: 4,762
Likes: 54
From: Antelope Valley ,CA
same cam here with stock converter /trans . no issues
so maybe bad converter ?
what fluid you using good old type F or ?
so maybe bad converter ?
what fluid you using good old type F or ?
Trending Topics
Moderator
Joined: Aug 2002
Posts: 6,104
Likes: 384
From: Southern California
IMHO, it is very important that you speak with the torque converter builder (not a saleperson)....there are many factors that effect the actual rpm stall and they have the specific data to determine what you need....you can have a converter that is rated at 10" 1800 & a 12" rated at 1800 as well but the actual stall will be different (by several hundred RPM in the same car) and is based upon the specific design of the converter vs, vehicle weight, gearing, HP/TQ.....and only, and I want to reinforce only the mfg will know what that is.....
Typically in a street car, a stall in the range of 1400-1800 is appropriate, although you can bump this up a few hundred RPM.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Thread Starter
|
Freshman User
Joined: Aug 2014
Posts: 39
Likes: 0
The transmission is a c6. Using type F trans fluid. The B&M tech told me the stall should be 2,000 after giving my rear gears, trans, vehicle weight and cam specs. He also said 2,400 was a little high but shouldn't be seeing the issues I'm having.
Thread
Thread Starter
Forum
Replies
Last Post
alstieg
1999 - 2003 7.3L Power Stroke Diesel
3
Apr 4, 2009 10:28 PM
Busa01
Performance & General Engine Building
27
Oct 9, 2003 08:51 PM
Sunny_in_hollister
1967 - 1972 F-100 & Larger F-Series Trucks
5
Nov 14, 2002 08:59 AM