I know that besides cooling issues, the fd was balanced as far as engine/turbo performance. Even though I read responses like "if you're just adding a [part], you'll be fine", there always seems to be one guy that had a bad experience. There seems to be general info on when to upgrade ecu, fuel, bov.



Are there any numbers on stock back pressure? Do we know of anybody that's tried to measure that or is it only an issue at the threshold when you've done enough mods that you notice a lean tendency? I know I am paranoid but I guess I would want to know the degree to which I have upset the stock balance after each part I upgrade (catback...then downpipe...then hi-flow or mp...etc.)



https://www.nopistons.com/forums/index.php?...hl=backpressure



Any words to calm my fears and paranoia (WHO's THERE?!?) will be greatly appreciated. https://www.nopistons.com/forums/pub...IR#>/blush.png



fritz

That's way above my intelligence... Course, basic math is too... Very good question, and I'm sure one of the brains here can help...

Idiot. https://www.nopistons.com/forums/pub...IR#>/bigok.gif https://www.nopistons.com/forums/pub...DIR#>/ohmy.png

gordon monsen and jim labreck have both had a lot to say on that matter, but you might have to travel to the *club* and do a search. every part, that has to do with the flow of the stream of air or exhaust that is bolted onto a car, affects the backpressure to a certain degree. whether or not you maintain a specific level of back pressure is whether the parts are added in compensation to one another. turbos related to which manifold, the downpipe, and so on.....there were even debates on whether to add a type of flapper, if you will, into the exhaust stream to keep a *desired* (x) level of back pressure in the stream and then when under acceleration, it would open, and you get the rest.....

Aren't you more concerned with the RESULT of less back pressure, rather than the amount of backpressure actually present? The result of less backpressure is increased boost, which is very easy to measure and monitor. (standard boost gauge)



To measure the stock exhaust backpressure you would have to drill into the exhaust manifold and install a pressure sensor that can take the heat. If you are doing this to avoid the expense of an aftermarket ECU, whoops, you just spent MORE on removing the stock manifold, drilling and tapping, re-installing and buying high temp pressure sensor equipment.

why ..

concur with tyson.. its the resulting affect of a mod ..

and what to do to compensate for possible issues that mod may provide..

if your lookin to maintain the factory backpressure...or as you say balance ..

in that regard...youve just negated the upgrade..

in reference to the flapper .. as a means to provide a dynamic switch mechanically..

there are other means to achieve the same effect...as in.. turnin down boost.. with relative fuel maps

good points...I suppose by balance what's on my mind are specifically how the effect of an upgrade trickles through the system. But I'm sure that every possible problem concerning modding an fd has been experienced by someone on this forum, so that's reassuring...and that's the reason for joining such a forum besides comradeship, right? https://www.nopistons.com/forums/pub...#>/biggrin.png



opening exhaust:

more boost, lower temps,less turbine stress(?), (any spoolup benefits?)

compensate fuel, control boost



thanks for all comments https://www.nopistons.com/forums/pub...IR#>/blush.png