garrett gt4082 users

[williamb82]

ok, so whats the diff of goin with a large exhaust wheel with smaller ar vs a smaller exhaust wheel with larger ar? theoreticlly you could size the ar for a gt4082 and the one for the gt35 where they are equal in overall flow and equal spooling characteristics. its only a 77mm wheel on the 4082 iirc. not that big.

 

[IJ.]

William: Done just that now with the T04z on my motor, my "guess" would be Spool remains around the same with less backpressure/choke at high engine speeds.

gt3540r 1.06 ar

T04z .84 ar

We'll see soon

 

[williamb82]

thats kinda what i figured. i was thinking once i got all out with the next 7mgte after this one id opt for the gt4094r with a 0.81a/r turbine. then again depends how much i like this turbo once its all up and goin. with all the other stuff including the 6 speed the car should be about perfect for a street car. quick spool but still good top end pull and nice cruising rpm's. 1900rpm at 80mph. hehehe. if all goes to plan ill be starting the construction of my ffi saturday.

 

[IJ.]

Might consider a lower diff ratio William.

 

[logan]

Wouldn't the A/R vs exhaust wheel effect power delivery too , maybe make it more linear ??? Looking at IJ's videos , I think it takes me longer to say "spool " than it does for him to actually spool . Notice they're entitled " traction problems " , lol .

 

[IJ.]

Logan: Yes it all has to work as a system.

The last vid was with a LOT of changes to make the power delivery Softer and to kill off as much low to mid range Tq as I could. (very short runners on the FFIM and large plenum volume)

The new motor is built to get ALL of this back and more and I'll let the DBW system handle traction control.

Lag is way over emphasised and in a lot of cases I think there are other factors at play.

 

[williamb82]

Might consider a lower diff ratio William.

nah, i like the ratios with my current 3.727. its an lt1 t56, 6th is a 0.5:1 ratio. 1st will be a lil long but thats fine. i think itll actually help at the strip to be honest as itll load the engine better and with the r154 1st is usuless anyway.