[areasix]

Hi Rob & Co

I have already 'recreated' (read as professionally engineered) a turbo using my P trim 0.84 twin entry T4 big shaft assembly, and grafted a GT42 56 trim comp wheel (replacing the T72 comp I had) with the intention of eliminating surge at 4500rpm/2.0bar, however, as I've yet to run this in anger, I wish to ask the following:

1) Will the current turbine/housing allow 800HP+ ??
2) If answer is No to 1) what is recommended to flow 800+ and still allow swift/similar spool? ( s trim in a 0.7??)

Thanks in advance for your imparted knowledge and experience

Ian

[Robert]

Originally Posted by areasix

Hi Rob & Co

I have already 'recreated' (read as professionally engineered) a turbo using my P trim 0.84 twin entry T4 big shaft assembly, and grafted a GT42 56 trim comp wheel (replacing the T72 comp I had) with the intention of eliminating surge at 4500rpm/2.0bar, however, as I've yet to run this in anger, I wish to ask the following:

1) Will the current turbine/housing allow 800HP+ ??
2) If answer is No to 1) what is recommended to flow 800+ and still allow swift/similar spool? ( s trim in a 0.7??)

Thanks in advance for your imparted knowledge and experience

Ian

It might be a stretch but I think that turbine will at least get you close. I have seen a T3 Stage V .77 A/R make 650 WHP on a 350Z before. the T4 P trim is larger and you are running a larger A/R. You may not flow 800+ but you should get to 800 or very close to it. It's tough to say to be honest. The S Trim would DEFINITELY get you there.

[areasix]

Thanks Rob, that's kinds what I expected you to say.

OK - Now I'm thinking 'S' trim - what housing is appropriate, and how would this spool please.

Obvious second question - does the S trim interchange with the parts I already have, or is it a whole new core?

Thanks

[Robert]

Originally Posted by areasix

Thanks Rob, that's kinds what I expected you to say.

OK - Now I'm thinking 'S' trim - what housing is appropriate, and how would this spool please.

Obvious second question - does the S trim interchange with the parts I already have, or is it a whole new core?

Thanks

I don't believe an S Trim will bolt on to what you have but let me double check that.

[steve]

rob would be correct.

p =/= s

neither of them are in production (both the turbine wheel and its housing) - replaced by F1-65 and F1-68, respectively.

[Robert]

Thanks for posting Steve!!!

[areasix]

So to clarify, P does not equal S and therefore doesn't fit.

With regard to my question about spooling an S trim - I really would appreciate some advice over A/R to top 800 and still give a sharp spool.

I am running a short duration with high lift exh camshaft profile (226@0.040 x 0.465)

I will test the current turbo unit and monitor backpressure and report back once all data available.

I'm trying my best not to buy a Garrett GT42r!!

[Robert]

Originally Posted by areasix

So to clarify, P does not equal S and therefore doesn't fit.

With regard to my question about spooling an S trim - I really would appreciate some advice over A/R to top 800 and still give a sharp spool.

I am running a short duration with high lift exh camshaft profile (226@0.040 x 0.465)

I will test the current turbo unit and monitor backpressure and report back once all data available.

I'm trying my best not to buy a Garrett GT42r!!

You'll want a smaller S trim turbine housing. I know of a drag race DSM that uses the GT-K 1000 with a GT-K 850 turbine housing with good success. Both the GT-K 850 and 1000 use the S trim turbine wheel. The GT-K 850 turbo uses a .81 A/R housing

[areasix]

Update following testing

I ran the motor (on an engine dyno) and found it was comfortable at 740HP (flywheel) with 33psi. We managed to push it to 760, but it was clear that the turbine had peaked - back pressure was just starting to exceed boost, but the engines VE was dying. We fitted a longer inlet cam to check that we had enough inflow, and that offered no benefit, so will try a slightly larger exh cam, but don't think it's the cure.

I am going to try a GT42r on it (as I can get one today), but will still be looking for a turbine to fill the gap - can we confirm - is the s trim still available, or is it now called the 68? I still want to use my current comp wheel but just want a better turbine to drive it!

[Robert]

Originally Posted by areasix

Update following testing

I ran the motor (on an engine dyno) and found it was comfortable at 740HP (flywheel) with 33psi. We managed to push it to 760, but it was clear that the turbine had peaked - back pressure was just starting to exceed boost, but the engines VE was dying. We fitted a longer inlet cam to check that we had enough inflow, and that offered no benefit, so will try a slightly larger exh cam, but don't think it's the cure.

I am going to try a GT42r on it (as I can get one today), but will still be looking for a turbine to fill the gap - can we confirm - is the s trim still available, or is it now called the 68? I still want to use my current comp wheel but just want a better turbine to drive it!

The S trim is still available. They just call it something different now. Its the F1-68 now but its the exact same wheel. Let us know how it goes.