Dissapointing results switching to 7" converter

Kevin Panzino · 07-28-2015, 05:56 PM

Recently bought a new 7" converter from a reputable converter company.

Had run an old tried and true Munsinger 8" for eternity. That converter flashed to ~6,200 RPM with my combo (255/294 HP 350 SBC, powerglide, 2.08 1st gear)

Was looking to try an additional ~500 RPM stall. Converter company stated they would recommend a 7" converter for this application. Put it in the car. No other changes. They got the converter quite close, as it flashes right around 6,600 RPM. So far so good, right... WRONG... Car lost a FULL TENTH in 60' and is down .2 to .25 in 1/4. Car is confirmed to be hooking up with no spin. Big end speed is only 1/2 MPH off when the ET is .25 down, so Engine HP is still there and slip is same as old 8" Munsinger at big end so this tells me the converter is pretty efficient once it gets to overunning the sprag on the big end.

It seems the 7" converter just physically has much less torque multiplication than the 8" at a given stall speed....

Anyone else have similar experience that can chime in?? Feel free to PM me, if you'd rather not discuss in public...

Kevin Panzino

07-28-2015, 05:56 PM	#1
Kevin Panzino Senior Member Join Date: Oct 2002 Location: Pittsburgh Posts: 521 Likes: 246 Liked 550 Times in 106 Posts	Dissapointing results switching to 7" converter Recently bought a new 7" converter from a reputable converter company. Had run an old tried and true Munsinger 8" for eternity. That converter flashed to ~6,200 RPM with my combo (255/294 HP 350 SBC, powerglide, 2.08 1st gear) Was looking to try an additional ~500 RPM stall. Converter company stated they would recommend a 7" converter for this application. Put it in the car. No other changes. They got the converter quite close, as it flashes right around 6,600 RPM. So far so good, right... WRONG... Car lost a FULL TENTH in 60' and is down .2 to .25 in 1/4. Car is confirmed to be hooking up with no spin. Big end speed is only 1/2 MPH off when the ET is .25 down, so Engine HP is still there and slip is same as old 8" Munsinger at big end so this tells me the converter is pretty efficient once it gets to overunning the sprag on the big end. It seems the 7" converter just physically has much less torque multiplication than the 8" at a given stall speed.... Anyone else have similar experience that can chime in?? Feel free to PM me, if you'd rather not discuss in public... Kevin Panzino Last edited by Kevin Panzino; 07-28-2015 at 08:33 PM.