I've placed this thread already but to no avail. On all EVOLUTIONS, there is some type of aluminum plumbing that goes from the intake manifold to the exhaust manifold. It supposedly keeps the turbo spooled better between shifts. It runs right along the top of the exhaust manifold and heat shield then bolts into it. Now as I see pics of the U.S. version, this pipe no longer exists there. Why is this??!!

 

You might be refering to the BOV dump tube that has been used in the past on the DSMs (4g63).

What this "dump tube" does is recirculate air that is "blown off" from the BOV (blow off valve) back into the the "intake pipe" (pre turbo) ... its suppossed to help keep the turbo spooled up and it also quiets the noise made by vented BOVs to atmosphere.

In a picture from an EVO VI I have, I can see the dump tube, but in the pictures so far that I have checked of the US EVO, I haven't seen the dump tube.... so I figure it has been placed somewhere out of easy view?

 

antilaq? (sp?)

i'm pretty sure it dosent come on all the evolutions though, just ones used for rally/race.

Its a system that dumps excess fuel (i think?) into the exhaust manifold to keep the turbo spooled when you let off the gas. Theres a thread about in engine/drivetrain that will explain it better.

 

That aluminum pipe going to the manifold isn't conected to the blowoff valve. The blowoff is off to the right a little. That pipe on a factory car doesn't do anything really. Its all for homoligation reasons. That system is for Antilag. It dumps air in the manifold while the throttle is closed. Thats the poping and banging sound on really cars. The US cars do not have that system from the factory.

 

Can an RFL blow off valve be installed on the new Evo 8 without any idle problems??? If so is it something I could do myself. I have changed brakes, all fluids, sparkplugs, and have done an intake before. Im pretty amature but have dissassembled a whole engine before out of car. I have basic tools on hand. Any responses would be greatly appreciated.

 

That description sounds like the BOV/dump tube is a wacky verison of a standard bypass valve or diverter valve found on VW and Audi turbo engines. Not sure if that's correct...

 

If it's the aluminum tube you're referring to in this picture, it's not antilag (which is what rally cars use to keep the turbo spooled up between shifts) Antilag does not require any additional hardware. It's switch activated, and dumps extra raw fuel into the intake when the car is at lower RPM's. The reason rally cars "pop" all the time at lower RPM's is due to all the extra fuel being burned off. THe only hardware required for antilag is a throttle bump stop to keep the rpm's up while antilag is activated. If you dumped too much fuel in at say 700-1000 rpm, the car would stall. However, at 3000rpm, it's fine (so the cars would idle at 3k rpm) Also, the ECU needs to be able to support this. Factory Mitsu ECU's do not. All rally cars (well WRC anyway) don't have factory ECU's, they have replacement ECU's, like Haltech, Motec, etc. Even in SCCA rally a lot of cars have replacement standalone ECU's that support antilag.



As to what that tube does, I'm not sure, but it does look like a return line from the BOV into the exhaust manifold, altho I have no idea why you'd want that.

It may also *may* be the oil feel line for the turbo...on 1g dsm's it's taken from the top of the head, but runs below the exhaust manifold. (On 2g DSM's the oil feed for the turbo is taken from the oil filter hookup)

 

I give you this....

http://www.dsmtalk.com/forums/showth...threadid=30252

enjoy

 

Thats air injection - part of the emissions equipment. Puts air into the exhaust post cylinder head to help light off the cat. Especially for cold start.

Called Secondary air system in the service manuals.