A&Q about 350Z
Q:
That EXUP thing is an amazing idea...but they only made it for bikes?
were there any made for car applications?
A:
Im a senior in mechanical engineering and i get most of what you are saying but im having trouble applying to what i should do for my ride.
Looking at my stock exhuast i was wondering why it goes from about 2" to 1.5" near the muffler, but now i see thats their to maintain the exhaust gas velocity.
but what im trying to figure out is what my best option for modifying my exhaust to get better performance. I bought some "DC style" headers and a high flow cat, and that seemed to decrease low end torque a lil and maybe help high end a lil.
now im trying to figure out what to do about a catback, cost is a big concern for me being in school and all, so i could get a 2.25" catback for under $300, but im wondering if this will even benefit my performance much? what should i do?
A:
For exhuast, don't go over a 2 1/4" piping for your cat-back system. As for the header, was it 4-1 or a tri-y header (4-2-1)? The 4-1 gives more to the top-end at the expenisve of the low-end, the 4-2-1 is better it you want to mantain your low end. If you put in a 4-1 header, thats a big part of your reason there.
A:
You can order a high-flow cat from JEG's for $100. I have one on my car and haven't had a check engine light or exhaust leak since. You will have to weld it into the piping yourself though, or have somebody do it, because it doesn't come with bolt holes or anything.
A:
the headers i got are 4-2-1, to be honest im not 100% sure about top end vs low end perfomance gains losses i have seen, they are minimal either way i guess
i got a high flow cat off ebay, with bolts, gaskets, correct dimensions for $40, it seems to help a lil but since i put that and headers on i get an annoing rattle/whistle at mid range rpms sometimes, i ran it for a day with no O2 i hope the rattle isnt cause i burned it out doing that or something like that
thanks for the advice and knowledge
A:
You are welcome, I'm always glad to help.
A:
It depends on your HP rating - go to Flowmastermufflers.com - they have a chart as to what pipe size to use and check out their Delta Flow technology! Read through info at the top of left hand menu bar - it covers a lot of what the top pf the forum states!
A tech there told me they are coming out with a new Delta Flow technology around Dec with a muffler called Super 40 that will out do their existing lines!
I always say new techo is better than old!
Peace man . . . or noise ha ha!
Ron
A:
Ls motor in crx..which mounts can anyone recomend me ?
A:
uh..
I think you posted in the wrong area dude.
A:
Yea talk about off topic lol
A:
I'll give change to the bum anyways.
Here man,
Go to the crx forum next time, er 88-91 Civic.
A:
Ok, so what can i do to increase my delta p?? you can always take the cat off to decrease back pressure, but is the only thing i can do to increase delta p is exaust piping and headers?
A:
Alright just want to run this by the resident geniuses, mechanical engineers and experts in fluid dynamics. For a turbo application could another plus to haveing a large downpipe be the pressure drop created when air moves from a small pipe o a larger one. I believe they use this on carburaters to speed up the velocity of the fuel air mixture by runnng it from a large opening through a smaller restriction then back to a large one. When the air exits the smaller restriction it expands to fill the larger diameter space lowering the pressure and pulling the air behind it in faster. Could this apply as well when the (relativly) small amount of air exits the turbo and expands into the large downpipe lowering the ambient pressure of the air and effectivly pulling more air through the turbo to try to equalize. Wow or maybe the fact that the turbo is shoving air out into the downpipe evens things out and this is way off bt if anyone has a though let me kow I am curious about this one.
Thanks,
DoubleTap
A:
Car won't run wo/ back pressure? well, unless he was driving in space. regardless of exhaust you will have a minimum of 14.7 psi at sea level
A:
Rybred:
Not being an a$$, but in your search engine type exhaust pipe diameter vs. h.p. or horsepower. Several websites have charts that agree with one another.
You can go to flow masters website and look at there pipe dia. vs hp and ci.
and click systems on the left side of the page.
I have not calculated to see if any of these numbers make since, but they look reasonable and the people posting seem to know what they are doing. Plus they are not making any money selling you bigger pipe.