Turbo A/R advice

[adam g]

After much deliberation and saving moneys (combined with the fact that my old turbo snapped its shaft) Ive decided to purchase a GT3071R. Ive yet to confirm the spec required though so would like advice on whether a .63 or .82 hot side would be preferable to my requirements.

My target bhp is 400 and I believe the rest of the engine is up to delivering this, but a turbo that could provide enough flow to hit 450 would be nice in case I want to mod the engine more in the future.

Assuming the .63 AR was the limiting factor, what bhp can you exepct to achieve. If anyone has tried both your feedback would be appreciated.

Additionaly I would like it to come alive before 4000 rpm.

Cheers.

[my2000apb]

if you wnat it alive before 4k, the 0.63 for sure

[JP]

.63 400-410hp max. .82 430-440hp max

Depending on boost figures you may get surge on the .63 housing but defo give you more of a kick in the back and more fun to drive.

[Jamo]

3071 .63 will do 430 to 450
.82 will hit maybe 470

[JP]

3071 .63 will do 430 to 450
.82 will hit maybe 470

You sir must visit some enthusiastic dyno's max I've ever seen on any engine on a real world dyno is 456hp on a .82 housing I'd love to stand corrected but looking at compressor maps and ve's I doubt without overspool you'll ever see more than 460 on normal 99 octane.

[Jamo]

You sir must visit some enthusiastic dyno's max I've ever seen on any engine on a real world dyno is 456hp on a .82 housing I'd love to stand corrected but looking at compressor maps and ve's I doubt without overspool you'll ever see more than 460 on normal 99 octane.

ask Prj he has even posted one did 380 whp so depending on correction anywhere between 455-475 bhp

I've seen a 2871 do that more than the figure you've quoted, Repo tuned, dyno plot on the forum

http://www.s2forum.com/forum/showthread.php?t=5297&page=6

I don't place stock on compressor maps, when the 3076r came out people were reading them and saying they would do 400 bhp on a I5 a few years later people are doing onver 500 easily on them.

So many variables, the turbo can do it whether the engine setup can is another matter.

[adam g]

Thank you all for the feedback. As a result Im leaning toward the .63 as it i do want a good kick in the back and have something fun to drive. My previous blower didnt get going until circa 4500 which was too late for me. I would rather limit the bhp to circa 400 and go for the earlier spool up I think. Cheers.

[caterpillar]

earlier spool up; change the exospiping to something big ones....3",no cat and one box...or even bigger 3,5" (89)mm...then you have the really change...!!