TheShodan

iTrader: (14)

Please make sure that you have proper boost control. (I don't mean features like "Boost-by-gear" and all that), but that your boost reference is on the Intake manifold and not the turbocharger itself, with a proper boost controller that can keep boost creep and boost spikes at bay.

I say this because you're using a relatively low amount of boost pressure for such a large turbocharger for 400whp or so, on a very small 38mm wastegate. The wastegate isn't going to vent enough excess turbine exhaust pulses running lower boost with such a large turbocharger )in addition using such larger 1.75 exhaust primaries from your exhaust manifold) without the ability to vent more.. This causes boost spikes during tuning and boost "creep" in the higher rpm range. Since you're using such low-knock resistant fuel like 91 octane, I can easily see this engine detonating due to a boost spike if this issue isn't resolved first. But, hell what do I know?

1) Larger wastegate like 44mm+ for such lower boost pressure levels on that 61lbs/min turbo
2) Electronic boost control via standalone or laptop-based is optimal
3) Ensure a clear vacuum source (like the intake manifold) when plumbing vacuum lines to the wastegate.

Dark_Teg

This is a nice build. do not try and make big power on 91 octane. One bad tank of gas or some boost creep and your motor will be toast. Ask me how I know.

LD9Stunner

Thanks guys and Shodan for the advice. I will be running 93 octane and possibly a mix of 93/110 on higher boost levels just to be safe.

the_unknown

I second the need for a bigger wastegate and proper boost control. As much as I understand the desire to save money, doesnt everyone know at this point that you're better off using the largest wastegate possible? I mean especially with the way most turbo manifolds are designed (i.e. NOT wastegate priority) if you just think how the system works, the larger the opening created by the wastegate, the less work the wastegate has to do to get the boost in check. And doubly so in this instance where you are using a fraction of what the turbo is capable of, so you need to vent more exhaust gas then someone trying to max out their turbo. Chances are if Shodan is saying it, there's a dam good reason. Dont be like all the other newbs that "want to do it their way" or "Im gonna prove people wrong yo" or "my homie did it and ran 700WHP for 5 years on an ebay T25 and still going strong", listen to those who have come before you and save yourself the headache and expense down the line..

TheShodan

iTrader: (14)

That still doesn't address the issues of the lower boost pressure levels. Getting the proper sized wastegate will make a more enjoyable experience at all boost pressure levels.

Jdm90hondacrx

Maybe a little bit off topic but have you had a chance to drive the car with the CSS block and has it caused any overheating with prolonged use? I have a D16 Z6 block that I'm wanting to use in my girlfriend's EG Coupe Turbo we want to be able to drive it around on weekends but make some pretty decent power and also have the reliability. It is a CSS block and I've heard some people say that a CSS block will cause the car to overheat due to the water jackets being so restricted if it is driven for a long amount of time without cooling off