Is it possible to put a single turbocharger and individuel throttle bodies on a s2000 at the same time?

 

Yes. You will have to have a sealed plenum over all of the ITB airhorns. R34 GT-R Skylines have ITB's.

Moving to FI as well.

 

Most anything is possible but would it buy you anything. Also without a traditional MAP sensor does it make tuning significantly more difficult?

 

I'd venture to say yes, but not impossible. I wouldn't let just anyone take a crack at it.

 

Actually, all generation GT-Rs have them as did the little Pulsar GTi-R hatchback.

 

The Nissans use mass airflow sensors which overcome many of the MAP sensing problems associated with ITB's


Alternatively, To use ITB's and a plenum the best thing is to use a ECU that allows you to run the motor using TPS as the load input for MAP less than 100kpa, then use MAP for load input for greater than 100kpa.

The MAP sensor needs to be connected via a vacuum passage that bridges all the ITB's together on the engine side of the butterflies with some inbuild pulse damping.

It can be made to work correctly, but takes a lot more effort than a shared plenum with a single TB.

A single TB allows for good cylinder filling from the plenum on mid throttle settings whereas the ITB's have the butterfly in the runner.

Chris.

 

so what real advantage would ITBs have for FI over say a large single TB....midrange?....top end??

 

ITB's are meant to provide a better throttle feel than one large ITB. The problem with a large single throttle is it has very little off idle progression at small throttle openings. I normally install a scroll shaped cable pulley on the side of it so the first part of the cable movement operates on a larger radius than the later part. Some cars like Maseratti use two throttle plates in a progressive two stage setup.

In terms of ultimate power, you could probably make up for any differences in the setups with slight changes in boost pressure anyway.

One of the most significant things I've found with FI is the plenum volume. It needs to hold at least 2-3 times the engine volume. It works as a staging area for air, If its too small its much harder to get peak power out of a motor. Surprisingly the volume doesnt make much difference to throttle response with the same sized throttle bodies on different sized plenums.

 

IMO its just like

single fogger setup (regular turbo setup) VS direct port setup (ITB turbo setup)

with single fogger your spraying into the intake and what ever chamber it falls into will results into your power increase (rpm range "low, mid, or high")

with direct port the nitrous is falling into every chamber equally giving you power at all rpm range. "pure drama"

Im not a turbo man but i can go on with nitrous =) The concept looks very similar.