KZEFI 810 Turbo E85 Build

Some really cool stuff going on with this, I love it. Why did you decide on a front mounted turbo with the added complexity of oil scavenge ?

I'm assuming you mean instead of under the seat? 

-Reduced spool time (turbo closer to the exhaust ports)

-Better intercooler pipe routing (shortest, least restrictive route is key for fast spool and efficient power). I'm not stoked on that sharp cobra hose from the turbo to the intercooler, but oh well, it's better than two 90s.

-More efficient packaging (turbo not taking up space under the seat where the intake and efi system can go) 

-Far easier to make an efficient intake manifold design without the turbo an inch away. Plus, it would bake the fuel system.


Also the scavenge setup is really easy. Literally an aluminum box with a crankcase pressure equalization line, then a drain from that box to an electric facet pulse pump. I did design an adapter plate for mounting a stock oil pump externally to the secondary shaft cover... Might switch over to this, but also might not as the electric is working fine 

Saablord wrote:

I'm assuming you mean instead of under the seat? 

-Reduced spool time (turbo closer to the exhaust ports)

-Better intercooler pipe routing (shortest, least restrictive route is key for fast spool and efficient power). I'm not stoked on that sharp cobra hose from the turbo to the intercooler, but oh well, it's better than two 90s.

-More efficient packaging (turbo not taking up space under the seat where the intake and efi system can go) 

-Far easier to make an efficient intake manifold design without the turbo an inch away. Plus, it would bake the fuel system.


Also the scavenge setup is really easy. Literally an aluminum box with a crankcase pressure equalization line, then a drain from that box to an electric facet pulse pump. I did design an adapter plate for mounting a stock oil pump externally to the secondary shaft cover... Might switch over to this, but also might not as the electric is working fine 

All makes complete sense (lag has always been an issue with turbo's, especially on a bike where a sudden delivery of power mid corner is less than ideal) I wonder why variable geometry turbo's never appeared on petrol engines ??? Lag is almost non-existent on modern diesels 

There are a few, but it's far less common. Google says a Porsche and the VW golf have it.

Petrol exhaust temps are higher, which means they inately spool better, but it also makes variable vane technology harder to implement. 

Most factory petrol turbos already have decent responsiveness because they're small and don't have to make large power gains. There's also divided inlet turbine housings to help with spool. For example, my 2.5T Volvo c30 has full boost by 2k rpm... Variable vane just isn't needed.


I remember this turbo bike spooling quite well. I think it was around 3k rpm for the 8psi of base boost which is far more usable boosted rev range than most turbo'd cars.

I am worried that the additional intake tract volume will affect this...we'll see just how much.


Part of the reason I went to the single TB is barely off throttle lurchyness. this isn't turbo related but more so all of the throttle area, and using map based engine management rather than TPS + boost compensation (which was not available on my ECU at the time). I think I could do tps control now, but I decided to try something new and simplify the intake system a bit. Also, a single TB is not a restriction with a turbo system... You're already limited by boost piping size.