Changing turbine housing?

[cliff-1972]

Haven't posted in years,but still around.I have been running a S475 (75/96/1.32) in my compound set up (63/68/.70 secondary).I have Weston 5 x .016 injectors, Ponci benched 180 hp pump (468cc with 181 dv's has 7 mm dv's now),5k and 22 degrees timing.It has a Maxspool 2.5 cam and ported bowls and exhaust ports head.I have a chance to buy a Garrett GT4202 (74.7/83/1.15) but was wondering if a 1.10/96 turbine housing for the BW would be better.The truck is a F250 4x4 reg cab with a built 4R100,4.10 gears and 315/75/16 tires.What is your opinion on what to do if anything?Thanks

[Backhoe man]

It looks to me like for the power level you are at the smaller turbine and ar will work much better. A 96/1.32 is way overkill in the 600 range, the truck will be a lot more fun to drive with the smaller setup. I have a very similar set in my 12 valve 5x14 with 351 over k31 (basically a 4202 made by BW) it drives really nice with very little smoke. My egt's are well controlled and there seems to be a little more left in it.

[cliff-1972]

Thanks for the input.My secondary is basically a 351CW made to a 63/68/.70 by River City Turbo.I was thinking going to a 78 mm compressor wheel,but thought a smaller turbine may give me what I want.

[turbo2387]

I run a 75/96/1.15. The difference from the 1.32 to the 1.15 was maybe 100rpms faster primary spool about 3psi more primary boost and zero change in egts. Was it worth newrly $300.....? Probably but wasnt a huge seat of the pants change.

I run at 425cc’s with 5x16’s and am smokeless. My secondary is a smudge bigger.

[cliff-1972]

That's the kind of info I'm looking for thanks.