help me pick cams/turbo

[khubner1]

Yes the entire setup has been dyno tuned and run hi only and low only to pick engage point

 

[Ian O'Connor]

I'd look into why that turbo is dropping off

 

[Jayz-1]

Unfortunately the big mivec cams are better suited to a big exhaust housing and therefore some lag. (They do however make the turbos spool a little better then non mivec)
I feel the GT28 is not suited to the cam combo however if 200kw is all you are after then it would be a good choice if you get the big mivec cams ground down from the 300/285 deg to something around the 264 deg and leave the small profile as is.

In theory the above is a good choice however no one stops at 200kw. You will want more I can garentee it. (I remember when I only wanted 200kw)


I've ran a GT3076r (with a 4G93 mivec) with both the 0.82 and 0.63 exhaust housing. The 0.63 made 28psi by about 4100rpm and I think topped out at around 280kw. The 0.82 made 28psi at about 4600rpm and topped out a little over 300kw. Although the boost came on a little later there wasn't any difference below 4600rpm in torque due to the increased VE due to the bigger A/R being better suited to the cams.
So sometimes looking at dynos and boost logs doesn't tell the whole story. And a bigger exhaust housing doesn't always mean less power low down.

So in short sub 220kw GT28 and regrind cams to 264. 220 to 300kw GT3076r and still probably better to grind cams to a 272. Over 300kw GT35 and leave cams.

Regards

Jason