anyone got one?
by the way i got a greddy sp for sale. make me an offer
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anyone got one?
by the way i got a greddy sp for sale. make me an offer
A 3" exhaust won't do you much good unless you have a turbo. Sure the 3" will make more noise but don't be fooled...it'll be making LESS power. I'd stick with your GReddy or better yet go back to the stock exhaust.
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Fred G.
'97 Civic EX supercharged http://www.geocities.com/motorcity/track/4059
Beech 1900D driver...2,558 shp, 10,000+ ft./lbs. tq., top speed 331 mph :)
I'm in the same exhaust decision dilemna for the JRSC. It seems no one has any reliable, real world results isolating data on exhaust options http://www.hostboard.com/ubb/mad.gif . I have a stock exhaust now and the torque falls off quickly at the top end. I think freeing up flow will help, but what size piping and/or which exhaust seems anyone's guess.
3" would even be good for 6psi, maybe not mandatory...but beneficial...basically anytime you force more air though your engine, you have to move more air out...sorry to be so simplistic, but people need to move out of this 50's style thinking when it comes to exhaust back pressure. In any application you want the biggest exhaust you can get without decreasing exhaust gas velocity. I'm too old to flame so I hope no one takes it that way...I don't have the energy for it. However, as the dynamics of the modern small displacement engines have changed, the masses of "street class" hotrodding minds have moved forward very slowly...hell, 10 years ago a 60mm exhaust(Greddy SP for example) was thought to be to huge for a NA small displacement engine...now the fastest small displacement engines are being run with quote-unquote huge primaried open headers...go figure. It depends on what you want to "tune" for...yes it can be argued that some torque can be lost down low, however, I really don't think that to be an issue as the average SC'd Honda owner hasn't learned to control their "new found torque" off the line (or light) anyway... I'd be willing to bet that most people would be disappointed in their boost gauge after "opening up the exhaust" header back. All things being the same, you would "lose" a pound, maybe two of "boost pressure"(excessive back pressure is more like it) on the gauge, but the dyno and more importantly, the speed at witch your engine accelerates through its power band would sing a different tune. Now if you look at my sig. below, you would think me a hypocrite. Remember that my wife?s SC?d GSR was built fast enough to land her with adjudicated probation...I quit building on it when she couldn't control her right foot...If she can be good for a while, I?ll pick back up with the fuel issues and a full exhaust including a 3? section from the rear of the header back...
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1998' 4dr GSR, 8psi JRSC w/hand ported plenum, Walbro HP fuel pump, valves set to .005i/.006e, MSD BTM, B&M CommandFlo regulator(working it out), stock intake w/resinator cut off at fenderwell for "cool air", Greddy sp exhaust, Tokico Illumina 5-ways, Neuspeed springs(sux!), Skunkworks 22mm rear swaybar, ES motor mounts and front swaybar bushings, Yokohama AVS 205/50/15's, Metal Master brake pads(KVR Carbon Fibre pads sitting on work bench) ,B&M fuel pressure gauge, Autometer sport comp A/F gauge in dimmer location...
YLW 00' ITR #00-1011 with AEM CAI and 143db triple air horns
Honest officer, I had no idea how fast I was going...the speedometer only gos to 150...
IMO, a 3" exhaust is overkill on a supercharged engine. An aftermarket exhaust has proven to be benficial over the stock exhaust. It all depends on how restricitive the factory parts are will determine how much of a gain aftermarket products will show. I think a 2.5 inch is more than ample for a blown motor. I run a 60mm Greddy exhaust on my car.
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Marc
1997 Civic EX, Supercharged
Don't forget that there's no point in running a 3" exhaust if you still have the stock cat.
I have RSR 4-2-1 headers, stock cat and a Greddy PE (60/70mm) and I STILL see over 8psi on the boost gauge with my 6psi setup.
I've seen people with my same setup but a Random Tech cat and they only see 6.5psi.
Soon I will be getting one. I'd get a straight pipe, but the thought of exhaust work every year to pass inspection and the risk of breaking O2 sensors in the process makes that idea not worth the ponies.
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Greg Holden
96 GSR, JSRC, I/H/E, yada yada yada...
My JRSC Install Site
I have an RS-R exhaust, stock header and cat, I see 8-9 psi max and I run an 8psi pulley.
I do think the right header can help, and that a 3 inch exhuast would help also.
Think about it this way, cars making 220 at the wheels have larger, or sometimes dual exhausts. If you take the entire cross section of exhaust, you'll find that it is equal or larger than 3 inches.
Usually guys that have a 6 PSI kit and see higher boost pressures is a result of a choked up exhaust. It's basically back pressure the blower is creating with a restrictive exhaust.
Upgrading your exhaust: Cat. muffler,pipe ID should reduce back pressure and ultimately lower your boost readings. You will in essence get a more accurate reading on your gauge.
A 2.5" ID should be fine. The cat. is probably the most restrictive part in the System. IMO.
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'96 JR6 GSR Sedan (black currant pearl)
'93 Honda CBR 900RR
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<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Holden:
Don't forget that there's no point in running a 3" exhaust if you still have the stock cat.
<HR></BLOCKQUOTE>
Sorry Holden, that was supposed to be an unstated "given"...
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1998' 4dr GSR, 8psi JRSC w/hand ported plenum, Walbro HP fuel pump, valves set to .005i/.006e, MSD BTM, B&M CommandFlo regulator(working it out), stock intake w/resinator cut off at fenderwell for "cool air", Greddy sp exhaust, Tokico Illumina 5-ways, Neuspeed springs(sux!), Skunkworks 22mm rear swaybar, ES motor mounts and front swaybar bushings, Yokohama AVS 205/50/15's, Metal Master brake pads(KVR Carbon Fibre pads sitting on work bench) ,B&M fuel pressure gauge, Autometer sport comp A/F gauge in dimmer location...
YLW 00' ITR #00-1011 with AEM CAI and 143db triple air horns
Honest officer, I had no idea how fast I was going...the speedometer only gos to 150...
the other thing to consider is- how big is your dump on your header, i doubt it is 3 inch. prolly 2.5. no point in going bigger than that, if you could find a quiet muffler you could go 3 inch on the openings to aid on flow. cuz i hear the straight thru on a sc is really loud.
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http://Albums.photopoint.com/j/ViewP...581&p=19261809
If you are going to do the exhaust right, it has to begin with the header.
Since you have fat pockets, this is what I would do.
1) Buy the Hi-Tech SC Header with a 3" collector
2) Full custom exhaust from a 3" cat to a 3" mandrel bent exhaust with a resonator and a Dynomax UltraFlow muffler.
I believe there is at least 20 H.P. and 15 Torque with this setup.
If you add a header to your system (DC RSR, etc) it still goes into a 1.75 inlet on the cat and a 1.75 outlet. Then from there adding a exhaust does really nothing. If you are cheap, just replace the factory muffler. That is the only restrictive part of the Integra Exhaust system because they want to control the noise. If you want the stealth look, get the Type R exhaust. 2.25 with a high flow factory muffler.
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00 Naples Gold 3.2TL
crom is a idiot, always and forever.
SSBP is right about it being nice to have the biggest collector u can, but on a turbo car people still see gains using 3in pipping when there down pipe doesn't equal that length. i think the 3in exhaust would work well on a SC'ed car, im sure real gains would be seen when running higher boost, but every little bit counts. a bigger exhaust always helps when ur engine is compressing more air, whether turbo, SC, nos, or a built all motor car. good luck
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www.importpo.com
right now i'm running the rsr header i want to go with a straight pipe but i dont kno how to ground my second o2 sensor(obd2). i know its gonna be loud but i dont care as long as i'll gain power. anyone kno a 3in muffler? i wanted the 5zigen fireball but they only make 2.5
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99 white gsr
18x7.5 te37
oem front lip
tein type na
greddy exhaust,rsr 421,iceman, JG tb, aem pulleys,
JRSC
no stickers, no body kits, no bull sh*t
Given a pipe with two ends, each have a cross section of areas A1 and A2.
If we watch the fliud at one end for a short time, say dT, a fluid particle will move a small distance V1dt and a volume of dV or fluid, given by:
<CENTER>dV = A1v1dt = A2v2dt</CENTER>
We can write, for any point along the tube of flow: R = Av = a constant,
in which R, whose SI unites are meters^3 per second, is the volume flow rate. If we multiply R by the (constant) density of the fluid (or air), we get a quantity Avp, the mass flow rate measured in kilograms per second, which also remains constant.
We call R = Av = a constant the equastion of continuity. It tells us that, in the narrower parts of a tube of flow, where the streamlines are closer together, the flow will be faster. It is an expression of the law of conservation, which eventually lead to Bernoulli's Equation. But it is also helpful in the study of fluid mechanics.
Now the fun part:
If we have a 3 inch exhaust section of pipe, with the same volume of air moving as a 2.5 inch section of pipe we have:
[Where the 3 inch pipe is (1) and the 2.5 inch is (2)]
dV1 = dV2, and dV1 = A1v1dt, and dV2 = A2v2dt, or A1v1dt = A2v2dt. Since dt is the same, then the only difference is the change in velocity, such that A1/A2*v1 = v2.
What this means is that a smaller section of exhaust will move exhaust gases faster through the pipe, than the larger section. If the volume of gas goes up, then in order to maintain the same velocity (which is important for exhaust excavation), we need to increase the diameter of the pipe. Period.
The only other factor is what happends if you have a smaller collector that is 2.5 inches on a 3 inch pipe. Well air will move quickly through those areas, but once it passes out, it will slow down again. We shouldn't forget that the exhaust gas will cool off as it moves back. As the density chnages, and the gas compresses, it won't require as much pipe diameter to maintain the same volicity.
Also, we don't know what the effect of having the gas speed up near the entrance to the cat, or the exit. Maybe this is good.
In short, larger is better where ever it is found, to a point, where the diameter of the pipe reduces the speed of the air moving through it. This includes headers, cat and exhaust, where for larger boost levels, or FI at all, the pipe should be larger, and it's more important up front, at the header.
Sorry to take you back to physics class again.
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http://www.netbsi-kc.com/integra/
http://www.netbsi-kc.com/aa/
http://www.groupbuycenter.com/
Lundgren,
I realize you are smart but can you post it in lay mans terms?
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00 Naples Gold 3.2TL
I figured I would add on this.
Why get a 3" exhaust when the largest collector on any header is going to be 2 1/4". The DC collector is even smaller I believe. I think 2 1/4 is fine for our applications, 3" is overkill. Remember, the smallest part of the whole exhaust system is the weakest link and determines the flow of the entire system. So if you have a 12" exhaust, and a 2 1/4 inch collector at the header, you are still only going to be flowing as much as that header can flow. Many dont agree, but I have a lot of musclecar tuners who do.
Basically, large pipe is good for FI motors to a point, even if it's only part of the way. More critical up front that in back.
Thank you Lund...I was a mathmatical washout, but I knew what I ment...
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1998' 4dr GSR, 8psi JRSC w/hand ported plenum, Walbro HP fuel pump, valves set to .005i/.006e, MSD BTM, B&M CommandFlo regulator(working it out), stock intake w/resinator cut off at fenderwell for "cool air", Greddy sp exhaust, Tokico Illumina 5-ways, Neuspeed springs(sux!), Skunkworks 22mm rear swaybar, ES motor mounts and front swaybar bushings, Yokohama AVS 205/50/15's, Metal Master brake pads(KVR Carbon Fibre pads sitting on work bench) ,B&M fuel pressure gauge, Autometer sport comp A/F gauge in dimmer location...
YLW 00' ITR #00-1011 with AEM CAI and 143db triple air horns
Honest officer, I had no idea how fast I was going...the speedometer only gos to 150...
[This message has been edited by Zeus (edited July 01, 2000).]
Thanks GSR98, I love you to!!