alsil Posted August 24, 2000 Share Posted August 24, 2000 What's up! I'm building a V8z, and I'm debating about how to do the exhaust. I have seen the ways people do it, from using 3" single to dual 2.5" exhaust. My car will be fast (how many V8 z's aren't?) but not super fast. I don't want the car to be loud, but I don't want to restrict the engine. It will be pretty stock, except an Edelbrock 1406 carb and Intake. I'm taking a long trip (across country and back) and don't want to have an obtrusive exhaust. Here's what I was thinking: a dual 2" exhaust, 2 flowmasters, 2.25" chrome tips. Not sure whether that would be good or is a single 2.5" better? I know that duals flow better (I've had Mustangs, Camaros, Chevy Trucks, no problem there, but there's more room for the exhaust and for insulation) but I also don't want anything too loud. Let me know what you think. ------------------ http:/refuse.netdojo.com/Zcar Quote Link to comment Share on other sites More sharing options...
Guest Fast Frog Posted August 24, 2000 Share Posted August 24, 2000 alsil: Check back thru some recent past posts-5-6wks ago-we kicked this subject around pretty good. Dual 2 1/2" are better than a single 3" which is better than dual 2 1/4". I think that's the way it went. Use the Search feature to help you find what posts you need. Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 24, 2000 Share Posted August 24, 2000 Here's the way I did it for a mildish 327: Pete's Exhaust 1-3/4" Hooker block huggers, Dual 2.5", X-pipe, two Dynomax Super Turbo Hemi mufflers (20 inch case) on the left side of the car. It took some fabrication to get it tucked up in the tunnel and 1/3 or the spare tire hole is filled in now. Just one way to do it, but I built it with much the same goals in mind. No data yet on how quiet it is, but very soon, I'll know! ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com - Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted August 25, 2000 Share Posted August 25, 2000 I manage an exhaust and mechanic shop and a mandrel 3 inch is fine but duals are the best when possible. I have dual 2 1/2 but am in the progress of 3 inch with poss. sidepipes. 2 2 1/4 pipes add up to a total volume of 4 1/2 inches so 2 1/4 dual has a larger volume than 3 inch single. What kind of power are we talkin here? 325 and less will be okay but any larger horsepower figures will have bad breathing problems. Dual is best but time and money are two factors you may need to consider. A fuel cell centred in the rear solves your need to have more space for duals. ------------------ Drewz Quote Link to comment Share on other sites More sharing options...
Mikelly Posted August 25, 2000 Share Posted August 25, 2000 I also wouldn't run dual Flowmasters... I have them, three chambers on dual 2.5 inch exhaust and it is anything but quiet. I think you would be better off with dual Dynomax Super Turbo units.. They have good exhaust note, flow well, and are quieter until you get on it... The flowmasters are loud when cruising on the highway at 65mph. Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
Drax240z Posted August 25, 2000 Share Posted August 25, 2000 Just thought I'd add to the discussion a little, there seems to be a bit of confusion about what pipes are bigger than what. # of pipes.....Diameter.....X-sectional area 1..............2 1/2".......4.91in^2 2..............2"...........6.28in^2 1..............3"...........7.07in^2 2..............2 1/4".......7.95in^2 1..............3 1/2".......9.62in^2 2..............2 1/2".......9.81in^2 1..............4"...........12.6in^2 1..............4 1/2".......15.9in^2 Note that the relationship is an exponential one, doubling the diameter of the pipe quadruples the cross sectional area. This is not exactly indicative of how the flow will be, because of things like wall friction, but its a pretty good guideline. ------------------ Drax240z 1973 240z - L28TURBO transplant on the way! http://members.xoom.com/r_lewis/datsun.html [This message has been edited by Drax240z (edited August 25, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted August 26, 2000 Share Posted August 26, 2000 If anyone has any questions about muffler #'s pls call on me so I can empty my brain of some useless info. such as price, flow characteristics vs horsepower, and how max. power and flow cannot come without a noise sacrifice. Flowmasters and rhinos are not meant to be quiet because of their aim at max flow with excessive tone and drone. Dynomax has good flow with some restriction. You sometimes have to sacrifice volume for power. What is your ultimate goal? ------------------ Drewz Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted August 27, 2000 Share Posted August 27, 2000 I'm not sure I agree that it has to be loud to make max power. I've seen a couple of tests where mufflers have shown some gains over open pipes and certainly some torque gains as well. Supposedly some of the racers while bitching about sound requirements are secretly using it to their advantage and gaining HP.. Personally, I am willing to sacrifice some power for a reduction in sound and the DynoMax upper end stainless mufflers may find their way onto this car unless I can find a reasonably priced "import" type muffler that's not too loud . I've had 3 chamber Flows on a Mustang and the resonance nearly drove me out of the car! Supposedly the factory mufflers are of two slightly different sizes to prevent this but I've never been able to tell by lookng (shrug). Droning or resonance is the LAST thing I want from even a quiet muffler! It's liek a wave of souond that travels forwards and backwards right through your skull - it really hurts. I put turboes on that car and it quieted right down - when the crappy Flowmasters rusted I replaced them with Dynomax and it's fine now even without the turbos. Pete - which Hooker headers did you find that were 1 3/4? The ones I've seen are 1 5/8ths and I've been considering Sanderson headers to get the larger size. Any regrets on the purchase? Were they coated and if so were they done well? DrewZ - don't suppose you've seen any import styled mufflers on a V8 by any chance? If so.. Loud or not? Did it choke the motor? Seen any reasonably priced? I looked at the Borlas but they're maxxed out at 2 1/4 it seems (sigh). Need at least a 2.5 inlet - I'll be running duals. Stainless is nice but I don't want to pay alot for this muffler (lol). seriously, $150 each wouldn't be too bad but much past that and I'd be hurting I think... Quote Link to comment Share on other sites More sharing options...
alsil Posted August 27, 2000 Author Share Posted August 27, 2000 Ok, there's the problem I wanted to avoid. I had a '66 Mustang about 2 years ago, with 2 1/4" duals, into 2 Flowmasters, and out to the rear. That car would drone like crazy, so I put about 1.5" of insulation under the back seat, and that killed a lot of it, to where it was tolerable. I loved the way the motor sounded, I just couldn't take the resonation. That's why I'm thinking now about maybe a Turbo muffler, or Dynomax. Not sure, thinking still, the car won't be ready for that until December (closer than it seems for this project). I'm not worried about killing power in my car since I will only run about 200-225 hp anyway (keeping it close to stock) and really don't want to go any farther than that (14's in the quarter are fast enought for me, although it should be goos for close to 13's; as long as I can take out those pesky Camaros, Mustangs, and Vette's; not trying to beat Vipers). I'm planning on going on Power Tour 2001 all the way, and want to be able to handle it (especially for my wife, since she's going for me) and I want to be able to listen to the stereo without straining. anybody have an opinion about the muffler resonance? Thanks. ------------------ http://refuse.netdojo.com/Zcar Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted August 27, 2000 Share Posted August 27, 2000 I will try to be a little clearer. I get a ton of people that want it quiet with no restriction. This is not possible. All dyno results with the engine in the car prove that there is always a trade off point. Everyone has there own dyno results so you need to beware because they try to make theirs look best. Dynomax is what I sugg. to people that want the least amount restriction with good sound. What you are talkin about is a drone. This is sometimes associated to situations such as 3" duals on a 200 horse motor, lack of pressure and velocity. Also too small a pipe creates volume from excessive pressure. You need to match your engines need to the proper muff. and pipe size. Huge exhaust does not create a lot of power, it frees up a lot of power sometimes. ------------------ Drewz Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 28, 2000 Share Posted August 28, 2000 BLKMGK, I was wrong about that. They are the Hooker 1 5/8 block huggers. I had them stainless/ceramic coated, along with the rest of the exhaust (except mufflers). They haven't seen the engine start yet (soon, I swear), so I don't know about how it will work. It looks terrific. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted August 28, 2000 Share Posted August 28, 2000 Thanks Pete - I'd hoped you'd found something I'd missed On a 450 horse motor is there likely to be a big difference between say 1 5/8ths, 1 3/4s, or 1 7/8ths inch headers? Enough to care about? I mean they're going to be block huggers so they may choke the motor anyway right? Would a larger pipe diameter help much? I swear I'm tempted to get cheap headers, wrap them, and then upgrade them later on when the car is running and the wrap causes them to become brittle etc. Sanderson headers look mighty nice though - all the way up to 1 7/8ths inches! Maybe just 1 3/4 would be okay - I want to be able to get to the silly plugs and not fry wires... Quote Link to comment Share on other sites More sharing options...
Cyind Posted August 29, 2000 Share Posted August 29, 2000 I have Hooker Comp headers (no flange) the pipes are for the street only so who cares. If you want to make power two bolts and one tug and the are uncapped... case closed or should I say open ------------------ Z U V8ter http://cyind.com Rspencer@satx.rr.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 17, 2000 Share Posted September 17, 2000 For a stock motor (200-225 horse)2.5 inch collectors using a flowmaster (or whatever) Y pipe into a single 3" exhausts dumping into a large turbo muffler will DEFINATELY flow enough exhausts. Consider they did the same on 396 big blocks in some chevy trucks from the factory (cept for the turbo muffler, they used something a bit more substantial). The droning is a real problem on flowmasters IMHO. They make a strange exhaust note to my ear (known as the 'Flowmaster sound'), but its a personal preference. But what do I know, I thought smitty's and cherry bombs and thrush can style mufflers sounded cool when I was a kid... (and yes, these were not on flatty's, I'm not that old!) Lone Quote Link to comment Share on other sites More sharing options...
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