rxspeed7

iTrader: (5)

so i was looking at some new options for a turbo, right now i have a stock port 13b-re motor with a microtech, hks log manifold and enough fuel to set florida on fire. the turbo i have been using for the past year and a half is a precision 6776e with a .60 a/r comp housing 66.7 inducer 84 exducer and a p trim turbine with a 84 inducer and a 76 exducer in a ..68 turbine housing. now ive gone threw 2 motors on this setup with a mazsport tune(also bought the turbo from scott at mazsport). now i dont like to get into turbo sizing stuff because it makes my head hurt but, everyone else i see has a huge turbine housing compared to mine and still has full boost at around 4 grand. so my question is would a .81 housing better suit my motor and have less back pressure but still spool fast?

the last dyno numbers i had were 330 at 14psi, and the car is primarily used for autocross and spirited driving. so a big laggy turbo is not an option. and help is greatly appreciated. zack

Aaron Cake

iTrader: (1)

Wow, that's a small turbine. And probably why you've fried two engines.

Try .96 if it's available as a minimum.

Your turbo is not exactly a well suited autocross turbo either...

rxspeed7

iTrader: (5)

why would you say thats my motor prob. too much backpressure pushing hot air back into the cylinder? how much more laggy would a .96 exhaust housing make it? before i was getting full boost(14psi) at around 3200rpm and id like to stay in that area

dean23

ive always thought it was the combination of the compressor and turbine thats creates lag, nt the size of the turbine alone.

Eclipsed4ever

Surely a lot of the back pressure is dictated by the flow of the exhaust?

Turbo II Rotor

iTrader: (2)

That exhaust housing cannot flow enough air and it's creating high pressures and heat in your engine, turbo manifold and turbine housing.

Aaron Cake

iTrader: (1)

What he said. High backpressure, high EGTs.

That sounds like a large compressor. A bigger hotside will help it spool. However a compressor that size isn't exactly an autocross turbo.

rxspeed7

iTrader: (5)

sweet thank you guys a lot. i guess im in the market for a new turbine housing.`

Rx7TyreBurna

iTrader: (1)

I am confused. Your rotary engine has cylinders? How?

rxspeed7

iTrader: (5)

sorry meant to say pushing hot air back into the housing?

Turblown

iTrader: (12)

You should have a completely different turbo, not just a bigger turbine housing. The compressor is too large for what you are doing. Move way down to at least a 61mm...