3400 turbo.

[Guest]

The Borg Warner Diesel works great on my 2.8L Nissan I6. Maybe a tad on the large side, since the boost threshold is a little later in the RPM range than I would like, around 3200 RPM to get full boost (I've seen 20 PSIG, but keep it around 15 to 16, until I get some time to tune the 20 PSIG level.) Using it on a 3400, or maybe even a 3100 would pretty decent, due to the better flowing heads of the 3100 and 3400 and the slight displacement increase.

I've already recommended that the OP go with a supercharger based his his desire to have boost come in late, and that boost and therefore power increase would be more linearly tied to RPM, possibly keeping any traction that he already had in tact.

What should really be done is forgetting about adding any more power and concentrate on the suspension and chassis, since he is already complaining about traction issues, which is why he mistakenly believes that a late boost threshold and low boost will help with traction.

[NateD4]

Maybe I'm wrong but can't a waste gate controller get him a similar feel? I hesitate recommending supercharging unless with the newest Eaton super chargers as used on the CTS-V or ZR-1. These new units have CFD optimized air paths that have efficiencies on par or surpassing turbos. They heat the air less, require less power to run and have bypass valves that help with fuel economy.

For the amount of power he wants why not go NA? 327 HP is obtainable with all motor. Get a good pair of heads and port everything...

[Guest]

Maybe I'm wrong but can't a waste gate controller get him a similar feel? I hesitate recommending supercharging unless with the newest Eaton super chargers as used on the CTS-V or ZR-1. These new units have CFD optimized air paths that have efficiencies on par or surpassing turbos. They heat the air less, require less power to run and have bypass valves that help with fuel economy.

Boost controllers are not designed that way, at least not most. There are some that will allow a bit of a slope to the onset of boost, but there has to be pressure to control. In order to open the wastegate, there has to be positive intake pressure, to provide pressure to the wastegate actuator (be it internal or external wastegate they all work the same way). To delay the onset of boost pressure, a huge turbine A/R, large turbine wheel, large compressor housing, or a combination all are required. This will make it hard to achieve solid boost pressures once the RPM is achieved. This could also cause the turbo to be run outside of it's efficiency, actually this is almost a definite, especially at such a low desired boost and power level.

To open a wastegate without boost pressure requires some technology that is never seen on street cars, and requires the use of stepper motors or actuators, to directly control the wastegate. I have not seen a consumer product like this so it would need to be custom made, not really worth it, when there are better options available. A variable nozzle turbo in theory could be made to work like this, but again, I haven't seen any aftermarket controllers for these, again, there are better options.

Why does the the supercharger need to be the latest technology? A simple centrifugal charger will work fine, and give that linear onset of power, when sized well.

For the amount of power he wants why not go NA? 327 HP is obtainable with all motor. Get a good pair of heads and port everything...

I kinda agree. I do like to use forced induction, simple because the engine can be built a little more "mild" to promote good driving manners, and then when power is needed, get into the boost.