pistons are intercompatible between generations. They've been out for a long time.

 

Thanks for the link...

I don't want to derail this too far from the topic...but for a NA build, there is no reason to go for 11.5:1 over 12.5:1. 12.5:1 is totally street able with a decent tune. A rough estimate is 10 whp for every 10 point gain in compression....this alone would yield roughly 20 hp for the L15a7. Porting the intake and exhaust valves along with a WR header, AEM tune, and high comp pistons might yield 40 whp altogether. (The WR header has shown 10 bhp gains by itself)

I think this is a worthwhile discussion in this thread because these mods would also increase the gains from a SC (although head porting might be unnecessary with forced induction).

Personally, I'd prefer a Rotrex SC because I imagine this would be gentler on the transmission than a traditional SC.

 

So, just wanted to post an update. I got a hold of Rick at Boostec along with Sprintex (Australia) and the reply was the same. The overseas GE8 does not have an EGR valve and the USDM GE8 does. Exact quote, "we will not be looking at the US market in the near future." This is sad, I was looking forward to this. I guess we will just have to wait a few more years. Someone is bound to come out with something eventually or should I say hopefully.

 

Egr block off is really really easy. I even did it when I was na for shiggles, and of course I didn't waste time trying to make the egr work now. What an odd thing for them to worry about.

 

Why dont we think outside the box here a little and get to know thine enemy....


1. What exactly does the EGR valve do?

2. Why not swap the USDM EGR valve for the one on the JDM Jazz (or whatever apparently occupies the same space on the JDM block)????

Thoughts?

 

The egr consists of a pipe that diverts from under the cat. It hooks to the back of the head with a copper pipe. It goes through the head and into the intake manifold where it is measured for flow and it's flow into the intake stream is controlled by the egr valve. The exhaust gas is reintroduced to the intake manifold, increasing combustion temps, but saving like a mpg. If you simply remove the pipe and block off the port on the back of the head and in the cat, you are done. The engine will detect no egr flow and will not be affected, except an annoying cel.

Iphone typing sucks.

 

Block off the stupid EGR and do something useful with it:




All it does in practice is induce knock and serve as a potential boost/exhaust leak. I use the one on my Laser for my MAP sensor, and to log my turbine drive pressure.

I have no idea why Sprintex would sh*tcan the USDM because of something that trivial.

 

^haha, I knew the calvary would roll in...

If someone more informed (ahem...DSM or LyonKR) could contact Sprintex about how trivial this is, maybe they would actually consider pushing the SC kit into the US market?

 

Has it been determined (or discussed), as to what Sprintex is using for fuel management on their SC system? I had read something about an extra injector ...

 

THIS

I think Sprintex just doesn't want to develop a SC for the USDM Fit. Maybe they're learning from Kraftswerks? I heard they didn't really sell that much SC for the GD and actually lost money. Not sure if this is true though..

 

^ that and the fact that sprintex wants to make the car daily drivable. Since an egr will throw a CEL and screw with the emissions, they don't want to do it. They will however, sell you a "parts only" kit with out the ecu and tune for $195 dollars less if you tell them that's its off road use only.

 

Actually, reintroducing exhaust gaz in the combustion chambers decreases temperatures as you fill the cylinders with inert gases... It also increase MPG and decrease power!! I wont block it because i don't want a CEL on my 2 years old car but i may try to check out if i can control it via the analog A or B maps of my AEM FIC!! I will start by checking if EGR is off when at WOT!! If not, it will be a motivation to block off that shit and gain some more pony's!!

Marko!!

 

I don't want to sound like a dick cuz I like you and a lot of what you say Marko, but that bit I put in bold is absolutely not true.

 

In a way I could see how it could appear to be true (or rather why the literature says egr lowers combustion temps), For x airflow (at the valves) w/ egr vs x airflow w/o egr, I could see lower combustion temps due to filling some of the volume of the cylinder with inert gas would result in a cooler burn since less oxygen would be available b/c less flow would be allowed from the atmosphere due to egr taking up some volume, in effect we are reducing the volume of fresh air that can be pulled into the cylinder w/egr. Because less fresh air is being pulled in we would see a lower amount of fuel injected as well. So since the actual combustion will have a smaller quantity of reactants, fuel and air, but still be at the same afr, since the remaing volume is taken up by inert gas, the actual combustion temp will be lower, since the volume of recirculated combustion gasses is going to exit at a lower temp than the same volume of ignited fresh air and fuel would.

But, for y power vs y power or z outside airflow (fresh, measured at the throttle body not at the valves, so not including any volume of exhaust gas) vs z outside airflow - the egr loses and proves worthless. Because with the egr I have to force the same quantity of fresh air into the cylinder as I would without it to make the same power. Thus all the egr does is heat up my intake charge, increase the amount of boost I need to make the same power, and offers nothing of value.

tl;dr

The egr sucks.

 

I'm struggling to articulate this.

Given an engine of fixed displacement:

10 units of air/fuel + 1 unit of egr, makes roughly the same power, at a higher combustion temp, than 10 units of air/fuel + 0 units of egr.

10 units of air/fuel + 1 unit of egr makes less power, at a lower temp, than 11 units of air/fuel + 0 units of egr.

 

Could you put a resistor at the egr plug to get rid of the CEL?

 

It is actually true, and is the very reason for the design in the first place.

The point of EGR is to reduce your NOx emissions by reducing the combustion temperatures, as the temperature envelope for NOx catalysis is very specific.

By reintroducing O2-poor exhaust air, you reduce the amount of available O2 for a given air/fuel ratio. Less combustion = lower temperature = lower exhaust temperature = more conversion of NOx. Since the ECU adjusts fuel trim for the O2 level, your power for a given cycle is reduced.

Conservative throttle usage simply reduces your average RPM. Combustion temperatures remain the same.

 

Actually it will make you more knock prone in a boosted situation, and as I mentioned earlier it is simply another potential boost/exhaust leak.

I am not talking about it's merits on an NA vehicle, this is a thread about a supercharger.

It also takes up volume that would be better filled by oxygen. Lose-Lose.

 

IF CARPART = "EMISSION CONTROL DEVICE"
THEN
DISP "IT SUCKS"
ELSE
DISP "IT MIGHT NOT SUCK"
END



tl;dr

the egr sucks.

 

And considering other markets don't have the EGR, that just says it is not needed and is not really doing any benefit for the car. If it increases FE, by how much actually versus same car without? I have a heavy foot and deal with Tokyo Metropolis traffic daily, but my avg FE is like 29.5 since owning the car. I'm quite happy with this figure.