BlueSteel

i was digging around a junkyard the other day and came across a supercharged millenia and was wondering if it would be possible to adapt it for the FC. it would probably be way more trouble that its worth, but i wonder if anyone else has also considered this?

RotaryEvolution

iTrader: (30)

is it a standalone or does it bolt to the LIM?

if it bolted to the manifold with direct ports to the lower intake it would probably be more work than it's worth requiring alot of fabbing and measurements for port volume and lengths to determine its flow rates for bottom and top end performance, you would be better off just swapping out a T2 setup.

BLUE TII

iTrader: (9)

Yeah, I bought one thinking I would adapt it to my FC if turbo lag was a problem- but it never was and I got addicted to the turbo.

88IntegraLS has it now and is planning to adapt it to his FC.

It is a Lysholm supercharger like a Wipple- much more efficient than roots or improved roots. I thought the size would be right on for the 13B as it was off a 2.6 liter V6 Otto cycle engine.

It is internal compression supercharger so it would work much better for the standard 13B long runner intake manifold and turbo style intercooler than a roots that will lag badly with any volume between it and the engine.

It is pretty long, so you have to creative with the packaging and you don't want to put the e-shaft pulley out to far as e-shaft flex is a known problem with supercharged applications.

Also don't want to put it on the exhaust/intake side of the engine as the people with the aftermarket Wipple kits (Miata and BMW mainly) have had problems with them seizing from heat off the exhaust manifold. Imagine how bad it would be with the rotary exaust heat.

pengarufoo

Otto?

Isnt the supercharged millenia a miller cycle engine, which depends on the supercharger to operate?

NZConvertible

Correct, it uses the Miller cycle, a revision of the Otto cycle that needs forced induction to work. The intake valves stay open for a goos part of the compression stroke so the supercharger does much of the compression work instead of the piston, and the nett result is a mechanical efficiency gain.

Icemark

Hmm thought those were 2.3 V6 miller cycle engines...

BLUE TII

iTrader: (9)

Doh! Yep Miller cycle as opposed to Otto.

Doh Doh! 2.3 liter V6 as opposed to base Millenia 2.5 liter.

I just read the Millenia S Miller cycle is 10:1 compression ratio! That is up from the 9something:1 in the base engine. Pretty unusual for a supercharged engine to up the compression, but I guess Miller cycle is pretty unusual. I wonder what boost the Millenia S runs? Is it just enought boost to stop reversion w/ the late closing valves?

Or is it the dual intercoolers and good efficiency of the Lysholm compressing the air fuel mix in the cylinder for the duration of the compression stroke that the intake valve is still open is MORE effiecient than the piston compressing the mix w/ the valve closed as in an Otto cycle so they can up the compression with the same reliability?

Hmm, I wonder what supercharger Mazda used on the supercharged top mount intercooled RX-8 that was spotted in Irvine and rumored to be the Mazdaspeed RX-8. Wonder if it is another Lysholm on a 10:1 compression engine?

Snrub

iTrader: (1)

Mazda even did some R&D on direct injection Miller Cycle Rotaries. It would be VERY cool if that's what they had in mind for the Mazdaspeed RX-8. I'm kind of surprised that more Miller cycle engines have not been made...

NZConvertible

From an AutoSpeed article on the Eunos 800M, aka Mazda Millenia:

"The Miller cycle engine is unique in that it closes the intake valves much later than in a conventional Otto engine. In fact, for the first 20 per cent of the compression stroke, the inlet valves (two per cylinder) are left open. The valve timing of the intakes is from 2 degrees before TDC until a mammoth 70 degrees after BDC, with the exhaust duration from 47 degrees BBDC to 5 degrees ATDC. Thus the intake valves remain open for another 30 degrees of crankshaft rotation beyond "normal". So, why do Mazda do that?

Firstly, pumping losses are reduced. Power is required to squeeze the mixture on the compression stroke, power that is robbed from the crankshaft output. Reducing the amount of compression that occurs therefore frees-up power. But won't the intake mixture be pushed out of the open inlet valves on the compression stroke? Well it would - but there's a twin-intercooled Lysholm screw-type supercharger using no less than 14 psi boost (we measured it!) to push that mixture back in. The supercharger absorbs less power than is released by reducing the pumping losses, giving an overall benefit. The late closing of the intake valves also reduces the effective compression, dropping it from the nominal ratio of 10:1 to just under 8:1. This drop in CR reduces frictional loadings, also releasing power, with the blower then boosting the dynamic comp ratio.

The result is 149kW at 5500 rpm (87hp per litre) and a peak torque of 282Nm at 4000 rpm, accompanied by a claimed 10 - 15 per cent less fuel consumption than an equivalent 3 litre engine. The quoted torque curve is also high and flat - more than 275Nm is available from 2000 - 5500 rpm."

For the metrically challenged, that's 200hp @ 5500rpm, 208ft-lb @ 4000rpm and 203ft-lb from 2000-5500rpm.

patman

iTrader: (3)

should work with a little fabbing.

BLUE TII

iTrader: (9)

Thanks NZConvertible! I hadn't found an article that mentioned the boost pressure.

So lets get this straight. That SC provides 14psi of boost from idle to redline? I mean if it wasn't providing the boost at idle the 30 deg later intake timing would ruin the idle and low speed driving, right?

yearrgh

I thought I read somewhere that it produced something ridiculous, like 25-30 lbs of boost.