SwampWS6

iTrader: (7)

I have a turbo LT1 with a TH400 and I was looking at logs last night and noticed that on my 1-2 shift the rpms dropped about 750ish rpms upon the shift. I know different setups like different rpms drops.

The converter is a local custom race converter that seems to work fine for what it is. But using a converter calculator it seems to show a 20% slip. That is why I was asking the question.

I am trying to get a basic rule of thumb for the rpm drop. I know turbo cars needs to be loose enough but tight enough to build boost on the launch and a little tighter on the big end.

Can anyone enlighten me on the theory? I want to make sure I fully understand.....

Thanks

FTICONVERTERS

iTrader: (3)

In short, when designing a converter for turbo applications you need (as you mentioned) a looser converter in the lower RPM range to allow the turbo to spool and start making power, BUT once you start making power the converter now needs to tighter as to not blow through it, aka tighter in the higher RPM range. We have several converter options designed specifically for turbo applications. If you would like to talk about specifics or get our opinions on feel free to give us a call here at the shop and ask for Justin or Troy.

SwampWS6

iTrader: (7)

Thanks for the input. So is a 750rpm drop good?

FTICONVERTERS

iTrader: (3)

in a typical bracket combination we like to see 600-800 fall back on the shift but all combinations are different.

if you want to get into specifics and talk more about it, then give us a call and ask for one of our converter guys, Justin or Troy.

SwampWS6

iTrader: (7)

Thanks a lot for the response!