LetsGetThisDone

iTrader: (1)

If that's the case, make one of these small enough tot fit in the MAP or ETS down pipe. Put a threaded turn buckle on it and it would be fully adjustable.


http://www.absurdflow.com/exhaustflapper.html

RJones

iTrader: (5)

Interesting... Never seen that before

BluEvo210

So, I couldn't remember where I got the idea...

There are a few mufflers that come with a flapper like that. At the very end of the exhaust I wouldn't be too worried about it leaking around the pivot pin. In the downpipe I'd be more worried about it leaking, and I'd be more worried about the leaking exhaust being hot enough to damage something.

(Then again, I'm one of the more conservative Evo owners. I don't believe in this "Everybody needs a long block some day" business.)

If you install such a thing in your downpipe, you could keep the spring, but experiment with different springs.

LetsGetThisDone

iTrader: (1)

It won't leak if the shaft is fitted properly to the "bushings". That's all the shaft for the wastegate flapper on the turbo uses. There isn't a rubber seal or anything. I could definitely see that thing needing to be made of much more robust material to able to act as a secondary waste gate though.

Construct

iTrader: (4)

I love how deep we are in to the grey area of the rules just to get a few more pounds of boost.

Ssshhhh! Don't call it a secondary wastegate, because then it sounds like it's part of the boost control system.

This is just a part of the exhaust, right?

LetsGetThisDone

iTrader: (1)

It's an "exhaust turbulence controller" LOL


For you guys, 2-3, maybe even 4psi of boost if you design it right, could be 50wtq/50whp. A big gain...

BluEvo210

I was wondering what the tune would do for my gas mileage, and it certainly didn't hurt it.
Yesterday I drove from Durham, NC to Chesapeake, VA on about half a tank of gas.

203.4mi/7.666gal = 26.53mpg

The last time my Evo got that kind of gas mileage was the trip from FL to NM where I unbolted the wing and put it in the back seat.

Construct

iTrader: (4)

Your tuner may not have even touched the parts of your maps involved in light-load cruising like you'd see on a road trip. Your car should be in closed loop at steady-state cruise anyway, so fueling maps wouldn't even come in to play there. There could be a little bit of efficiency to be had by tweaking timing, but it's not much and your tuner would have had to pay attention to light-load steady-state to dial that in anyway.

There are a couple threads around here about dialing in light-load timing for better cruise efficiency if you're interested. Some people take it a step farther and use a wideband O2 gauge to output a simulated narrowband signal around a leaner mixture point, but there are some issues with that method as well.

Your TBE probably helps with mileage a bit though. FWIW, I average around 25-26mpg for freeway driving with my IX and I haven't touched any of the relevant cells in the tune. The trick is to cruise at a consistent speed and have a light touch on the gas pedal on the freeway.

LetsGetThisDone

iTrader: (1)

A tune should get your fuel trims dialed in much closer than stock, especially if you have replaced the intake. This usually results in better mpg. Also, most tuners have their own complete timing table. I know in my car they are very different from stock, even in the low/cruise load areas of table.

BluEvo210

After 8 years and 80,000 miles it has a leak in the flex section. I think I got my money's worth out of it.
I might just replace it with another pipe of the same kind.

Butt Dyno

iTrader: (10)

In other news, we can fiddle with boost in the tune now. Not that it makes a difference.

MrAWD

It doesn't??

Butt Dyno

iTrader: (10)

Not on the 8/9 without changing the pill.

MrAWD

I guess, time for upgrade!!

Barn_13

iTrader: (1)

Is this legal for STU?