ok so the uk spec evo 8 and 9 have 2 hard metal lines coming off the exhaust manifold im guessing there going to the egr? if i need to i can post a pic for those who dont know what im talking about. the us spec doesnt have it and i was wondering what they were and whatr they do?

 

They are a mild form of anti-lag, NOT found in the US models.

 

Not sure if it's the same, but there are companies that coat and port the exhuast manifold. It does help with lag.

 

It can, and will a little bit, but it mostly helps with the heat and keeping it inside the exhaust mani. The anti lag is amazing and really makes a diff, if tuned correctly!

 

Coating the mani and wrapping the turbo & down pipe(not the whole down pipe) helps the hot air move through it more quickly.

 

thank you for your post nemore people find out tech info on it that would be great thank you

 

I'd like to know the answer to this. If anyone knows, please post up the tech info...

 

I am also quite curious as well. I PMed a member here that has a JDM evo and this is the response I got:

"hi there it goes from the manifold to some sort of valve with hoses going to the intake manifold."

Wasn't really that helpful.

I somewhat have an idea, but haven't posted it up yet. Remember people this is just an idea. What if you connect the BOV to those ports on an aftermarket manifold? It would require a speed density setup so you don't run ruch. There would have to be some kind of valve so exaust gases/fire doesn't go up the lines towards the BOV. Also, who says that the air coming out of the BOV has more pressure than the pressure of the exhaust in the manifold. Think about it though, it should help keep the turbo spooled without the harmful effects of explosive antilag. Anyone want to comment on my idea?

 

I posted some information in this thread:
https://www.evolutionm.net/forums/sh...d.php?t=234231

And heres a pic from the evo4-6 workshop manual:


This only works under the conditions stated above and when you lift the throttle, so this will not work at idle/standstill.

 

most guys over here (uk) remove it and fit proper anti-lag!!

Chris.

 

No one has commented on my suggestion. By the looks of this diagram it should work. As long as the pressure in the exhaust manifold is low enough that you don't get compressor surge.

 

Well like you said, the danger of exhaust gases melting the BOV is one problem, but that can be overcome.

But the only time I think that the ex. manifold pressure would be lower than the pressure in the piping would be when you lift of the throttle, which is what the factory system works under.

I can't see anyway for this system to work like a proper anti-lag system.

 

It won't work like true combustive antilag.

Hot air never hits the BOV by the way I read that diagram:

-ECU reads conditions as yes/yes
-ECU activates secondary air solenoid
-solenoid opens secondary air valve
-cool compressed air (measured by the MAF) is piped in after being intercooled and is then routed through the now open secondary air valve into the exh. manifold, thus creating pressure to keep the hotside impeller spinning in absence of exhaust gases leaving the manifold.

Hot air could reach the exit side of the secondary air valve, but I doubt it would affect anything beyond that point.

It does seem that BOV calibration in this system would be extremely critical. The BOV would need to recirc. the measured air correctly (just like any stock ECU/MAF Evo) , but not vent at levels that would reduce pressure to the secondary air control system, thereby reducing the antilag effect. ECU program would have to be different to account for intake air normally recirculated to intake now being sent to the exh. manifold.

Do you smell what I'm steppin' in, or am I way off base?

 

Yes on the factory system the exhaust would never reach the BOV, but Markley02 was asking what if you used a BOV instead.

But what you said sounds right.

 

MarkleyO2's idea sounds like it could work in theory:

-route recirc from bov into exh. manifold. It would be like an "always on" secondary air system
-use of a pcv type valve at the manifold connection could limit backflow of hot air back to the bov

It does seem that you'd want to be able to use ANY pressure available from the intake side, not just what is available if and when the BOV is venting. Also, it seems that use of air directly from the intake charge would provide immediate flow vs. air vented from the BOV as a reaction to decel.

Whatever valve to be used must eliminate backflow of hot air into the intake charge as well as ensure flow of cold air into the ex. manifold at a specified threshold of pressure within the ex. manifold. I'm envisioning a two-way pv valve, or a y-connection in which flow is mutually exclusive (one way flow at any given point in time)


It seems as if Mitsu opted to use an electronically controlled system closer to the cold side of the system vs. a mechanical arrangement on the manifold as it would preclude heat induced failure of a valve or actuator located on/near the ex. manifold.