DSMTalk Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum banner
1 - 6 of 6 Posts

·
Founder/Former Owner
Joined
·
5,120 Posts
Discussion Starter · #1 ·
Freeflowing intake and exhaust is good.

So, I removed my intake, right at the turbo, while at the track. Performance suffered dramatically... an obvious loss of power which resulted in almost a second slower e/t.

Another time, my downpipe got loose right at the O2 housing. I mean hanging off. Thinking I'd have the ultimate free flowing exhaust I took it out for some runs. The car was obviously slower.

I've seen turbo cars (DSMs and not) run quite successfully with no intake and no exhaust. One thing, I think they all had big turbos. Is that the difference? Is it turbulence? Is it speed, meaning the pipes speed up the air/exhaust? How come the big guys get away with it?

BTW, my turbo is a small unclipped 16G, exhaust is 3" turbo back, and intake is 3" hard pipe with K&N and no MAS.

------------------
Ted - 95 GSX
[email protected] MPH
 

·
Registered
Joined
·
836 Posts
WhoaTed, unless you don't have the VPC I don’t see why would your dsm run worse? I don't have VPC so I can't even think about removing the intake duct, but i did run my car with only a downpipe and let me tell you.. :) :) :) I wish I could do that everyday :) I don't really know why your performance would suffer if your downpipe came loose, unless it's a 2G and the second 02 sensor detected a lean situation and flooded your engine with gas? ...maybe... I would like to find out myself... :)

Hey I've just noticed -- it is a 2G so maybe I'm right? -it does have two o2 sensors or is it on the later models?

Mike


[This message has been edited by TurboMitsu (edited September 08, 2000).]

[This message has been edited by TurboMitsu (edited September 08, 2000).]
 

·
Founder/Former Owner
Joined
·
5,120 Posts
Discussion Starter · #3 ·
Maybe you are right about the 2nd O2, it does have one, everybody has always told me it did nothing. So maybe you are on to something there.

Still wonder about the intake though.


------------------
** Ted - 95 GSX **
 

·
Registered
Joined
·
62 Posts
I can relate to this. My friends exhaust clamp fell off during a run and thus was running just a downpipe and the performance thereafter suffered. It is with a 1G, the similarities are both 3"turboback and 16G. My current thought is that it may be something related to the turbulence of the exhaust gasses like you said and this seems very plausible.
 

·
Registered
Joined
·
112 Posts
The 2nd O2 sensor has nothing to do w/ adjustment of the air and fuel. That is up to the 1st sensor. 2nd O2 is for obd2 where it needs to monitor if your cat is working and if emissions are ok. As far as running no intake pipe (w/vpc right?), I would only be able to guess that the turbo was sucking in hot air since it is by the exhaust manifold....Maybe this didn't give you as much timing either. I could also be wrong. As far as the exhaust side, maybe you can try running open downpipe (instead of by the O2 housing) and see how that goes. I doubt that your exhaust system is choking off major power (if any)....and you can post your results.

Jeff
 

·
Registered
Joined
·
232 Posts
well as far as the exhaust goes.. i know that the sound waves and heat waves play a big role in moving exhaust gas out of the engine.. with a big turbo im sure the back pressure outweighs this phenomenon. but with a smaller turbo it probably is better to have a little amount of exhaust.. here is a quote: "They [turbochargered exhausts] duct the hot, high-pressure, high-velocity gases from the engine to the turbocharger. This temperature, pressure and velocity should be maintained as much as possible."
here is another related quote:
"Exhaust gases exiting the turbocharger will be spiraling like a helix. The direction of this spiraling can be either the same or opposite turbine-wheel rotation. Which direction depends on exhaust-gas speed." yadda yadda "In either case, the path for exhaust gases is considerably longer than if they came out axially".. oops hate to leave but the rents are here to go to dinner.. finish up later..

------------------
J. Hunter Allred

'95 GS-T free mods, K&N, 3" HKS Superdragger, ACT2600, lightened flywheel, and otherthings that escape me at the moment. T-25 handicapped though. As you can see its a work in progress. Figure if i buy it i should buy it once :)
 
1 - 6 of 6 Posts
Top