I have a .63 hotside and was wondering how much is to be gained by going to a .82 or larger. If you have done it please chime in and give us your experience. What did it do to your spool time? Also did you do a before and after dyno to see what the difference is?

 

I know someone has done this please chime in to give us some answers...

 

It will move the powerband to the right of the graph as well trading some midrange torque for a little extra power up top

 

So it doesn’t sound like something worth doing if a guy streets his car. I am not sure I would want to move the power band any further up or loose torque in the middle. It seems to me like going up on cam size. I often thought of going to 280's over the 272's but for the same reason have not done so...

 

probably 50awhp going to a 82. and some extra lag about 300-400

 

I went the other way but I may be able to shed some light. I went from from a .82 back down to the .63 IMO I would never consider a .82 on a street car again. It gets horribly raspy and there is a huge differnce in spool, My car picked up 800 rpm sooner and also made 60 more wtq with .63

It wasn't an apples to apples comparison tho, I changed cams,hotside,turbo manifold and added a Br stage 3 head.

For reference tho with a built 2.0 stock head and cossie 272's with the .82 I made 480whp and I forget tq but its in my sig i think.
Then after the changes listed above and going back down to a .63 I made 514whp and 400wtq, peak tq also shifted from 5800 to 4900.
Both times it was on CBRD's mustang dyno

 

Thanks for the insight I think your disappointing results with the .82 is because of your power level. Its obvious going to a .82 or larger housing would be more effective as the power rises. I am wondering even at my power level will I benefit much going to a .82?

 

It depends which turbine housing you are going to pick, If you are using the T31 style turbine housings, then the results will be as others have indicated. However try the GT turbine housings. In my particular case, I switched from 0.63 T31 spec turbine housing to a GT 0.82 , The volute design is leaps and bounds better than that 1960s technology that the T31 employs. I don't have hard and fast number differences between the two, but I will report that the spool difference was minimal, but the power difference was very noticeable.

 

Which turbine housing do you have to start with?

Is it a GT series turbine housing or something like a T31, PTE, etc?

 

I have a T3 .63 housing on my AMS 37r kit. Do you think I would benefit going to a T3 .82 hotside at my power level?

 

AMS is never really clear on what their kits include but I assume it is a PTE T3 .63 5 bolt hotside but not 100% sure.

 

well you are going to hear all kinds of opinions when it comes to 5 bolt / 4 bolt turbine housings.

In my case I was using a 4 BOLT T31 ( 2.5 inch discharge) turbine housing 0.63 ar, by switching to the 0.82 ar 4 bolt 3 inch discharge GT garrett housing , there was minimal spool differences but the power up top was noticeable.

dave buschur did a little description on this particular housing last year sometime and he saw a big difference in his RS.

 

if someone cut a GT T3 housing for the Ptrim wheel (what you have) you would notice a good difference in spool and power...spool for the better

 

Could you explain what you mean by "cut a GT T3 housing for the Ptrim wheel".

 

what about this with a 0.82?
http://www.atpturbo.com/mm5/merchant...egory_Code=GTH