what is "blowing through the converter"
Thread Starter
Launching!
iTrader: (3)
Joined: Jan 2007
Posts: 204
Likes: 1
From: Jacksonville, Florida
what is "blowing through the converter" 92 Fox-3200lbs with driver
4.8- TU1 cam-TC78 turbo
557whp
3.08 gears
okay this is my first automatic
its a TH400 and a billet cover 245mm 3k stall converter with a FMVB and no brake.
built by a 1 man local shop that only does performance transmissions/converters and been in business 30 years.
it was spec'd for my build and I bought it new from them.
whats happening is when i bump the 6200 rev limit in 2nd at WOT and shift to 3rd it will only fall about 500-700rpm and get right back on the rev limiter BUT IT STILL ACCELERATES decently but stays on the rev limiter.
if I do the same at about 3/4 throttle im able to keep it off the rev limiter on the upshift a lil longer.
the car deff shifts into drive fine driving around town.
if i roll into boost while cruising in 3rd it pulls hard to 6200 and bounces off the rev limiter but still accelerates.
the builder is supposed to come drive it this weekend as well as im having the rev limiter moved up but there is deff something going on.
any help is appreciated.
4.8- TU1 cam-TC78 turbo
557whp
3.08 gears
okay this is my first automatic
its a TH400 and a billet cover 245mm 3k stall converter with a FMVB and no brake.
built by a 1 man local shop that only does performance transmissions/converters and been in business 30 years.
it was spec'd for my build and I bought it new from them.
whats happening is when i bump the 6200 rev limit in 2nd at WOT and shift to 3rd it will only fall about 500-700rpm and get right back on the rev limiter BUT IT STILL ACCELERATES decently but stays on the rev limiter.
if I do the same at about 3/4 throttle im able to keep it off the rev limiter on the upshift a lil longer.
the car deff shifts into drive fine driving around town.
if i roll into boost while cruising in 3rd it pulls hard to 6200 and bounces off the rev limiter but still accelerates.
the builder is supposed to come drive it this weekend as well as im having the rev limiter moved up but there is deff something going on.
any help is appreciated.
It means you're probably making more torque than the converter is designed to handle. Gearing and weight have a big impact, but in your case not likely. All that additional torque is being converted into transmission destroying heat, rather than accelerating the vehicle.
One of the most important factors in how well a converter performs in a given combo is what the RPM drop is on the high gear shift. Turbos typically like a bigger RPM drop or pull down to make them work better. The term "blow through" is when a converter is stalled to high or to inefficient up top for a given torque curve. Which sounds like what you are experiencing.
Chris
Chris
Thread Starter
Launching!
iTrader: (3)
Joined: Jan 2007
Posts: 204
Likes: 1
From: Jacksonville, Florida
One of the most important factors in how well a converter performs in a given combo is what the RPM drop is on the high gear shift. Turbos typically like a bigger RPM drop or pull down to make them work better. The term "blow through" is when a converter is stalled to high or to inefficient up top for a given torque curve. Which sounds like what you are experiencing.
Chris
Chris
Thanks Chris- I actually talked to you a while back and you were my first choice but the local guy gave me a great price on a TH400/Converter package and has a superb reputation locally so I went that way.
The converter and trans were spec'd for me- the converter doesnt flash to high on start up and I told him to err on the side of too tight versus to loose as this is just a fun street car for me.
Is it common to "miss" on the converter spec/looseness ?
Im actually 140whp shy of what I had him spec the converter for.
Thanks Chris- I actually talked to you a while back and you were my first choice but the local guy gave me a great price on a TH400/Converter package and has a superb reputation locally so I went that way.
The converter and trans were spec'd for me- the converter doesnt flash to high on start up and I told him to err on the side of too tight versus to loose as this is just a fun street car for me.
Is it common to "miss" on the converter spec/looseness ?
Im actually 140whp shy of what I had him spec the converter for.
The converter and trans were spec'd for me- the converter doesnt flash to high on start up and I told him to err on the side of too tight versus to loose as this is just a fun street car for me.
Is it common to "miss" on the converter spec/looseness ?
Im actually 140whp shy of what I had him spec the converter for.
Chris
