T3 or T4 hotside?

 

t4. It's twin scroll.

 

Awesome build! good to see something different. looking forward to your final numbers

 

Here's the boost plots for those who are interested.

 

Very nice. very fast spool for that setup. will be a joy when tweaked out.

 

I think there is way too much boost taper on the E85 graph, and the car would have an even better looking power/torque curve if I could take care of that. I originally planed on Ecu boost control, but my tuner talked me out of it in favor of dual MBC's, and I'm not sure it was the right choice. 3psi of taper in the higher rpm's would probably make the graph quite a bit flatter.

 

How much spring pressure do you have in your gate(s)?

 

1 bar. The MBC's aren't even close to fully turned in, so I don't think that is an issue. I am running a metal OEM diverter valve though, I wonder if that could be leaking.

 

That boost profile is pretty good; 2.2l and twinscroll make for a responsive setup. I'm not seeing 20psi until ~4500 rpm and 30psi until ~5000rpm on a 2L single scroll. Might be time to upgrade the valve to avoid the boost taper up top. Good luck , look forward to seeing more results

 

Will an 86 hold the top end better than the 82?

 

By valve do you mean the diverter valve? If so, I will crush it first and do before and after logs to see if that is the issue.

Yes it will, but it gives up spool. Unless you're running 40psi, I don't think the gains warrant the loss of spool. If the 82 keeps gaining 25 hp/psi that means another 6 psi will put me around 700whp. Thats a lot of power for a street car.

 

Yeah I run a little over 1.5 bar spring pressure in a single gate and that allows me to run about 3 bar without issue. You run two gates though correct? So you have a 1 bar spring in each gate?

 

Correct, 1 bar in each gate.

 

Sounds like plenty then. Thanks for clarification and good luck finding the cause of the bleeding boost.

 

why not get an aftermarket valve?