ExhaustPost your questions and suggestions about stock or aftermarket exhaust setups. Third Gen exhaust sound files and videos!
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Yeah that does look good. I was checking out the topic and i have done a few true duals on 3rd and fouth gens. I've done long and shorties, 2.5" and 3" all over the axle with no ground clearance issues and dynoed before and after. I must say that true duals done right will make a huge difference on a cars hp and trq out when tuned for the exrta flow. To me thats the only way to go.
haha its coming along... if all goes well i HOPE to start it up and do some break in this weekend. Y pipe is mostly done and i just need to get hangers installed for the exhaust.
Yeah that does look good. I was checking out the topic and i have done a few true duals on 3rd and fouth gens. I've done long and shorties, 2.5" and 3" all over the axle with no ground clearance issues and dynoed before and after. I must say that true duals done right will make a huge difference on a cars hp and trq out when tuned for the exrta flow. To me thats the only way to go.
These things always take longer than expected. Thats why I'm saying this winter for the next mods on my car to be completed. I think you are better off taking a little longer and do it right the first time.
Yes I do, the systems we've done has been on stock cube heavy modded LS1s, 355-383 sbc heck we even got a sbc 355 with a tbi converted to lay down 380hp 390lbs. Basically you want the engine to see the collectors (tuned lngth of course) and that's it. No back pressure and not too loud (hard to get races) Then all you have to do is make sure your tune is right.
These things always take longer than expected. Thats why I'm saying this winter for the next mods on my car to be completed. I think you are better off taking a little longer and do it right the first time.
Couldn't agree more.
Even when you think you're done there will be something else needing your attention.
Last edited by skinny z; 06-07-2008 at 08:33 AM.
Reason: Automerged Doublepost
Yes I do, the systems we've done has been on stock cube heavy modded LS1s, 355-383 sbc heck we even got a sbc 355 with a tbi converted to lay down 380hp 390lbs. Basically you want the engine to see the collectors (tuned lngth of course) and that's it. No back pressure and not too loud (hard to get races) Then all you have to do is make sure your tune is right.
Our problem has been lack of available room to build a suitably sized enclosure.
Last edited by skinny z; 06-07-2008 at 08:37 AM.
Reason: Automerged Doublepost
[quote=skinny z;3782839]Our problem has been lack of available room to build a suitably sized enclosure.
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Not really, if you have access to a car lift or four 6 ton jack stands there's plenty of room when you make some simple mods. Fore the enclosure you can go with a 4" or 5" pipe, depends on the motor size and ci you need. Next on 10 bolt cars you will have to take a little metel off the pass side of the dif case (not much). Then slight mod on the upper part of the panhard brace and thats it. Enough room for your enclosure and two 3" pipes with your choice of mufflers.
i'm gonna need to see pics, cause i'm having a hard time visualizing what you're saying.
No problem, I'm work on a heavy modded 2000 Z28 right now. 1.75" pacesetter long tubes 3" trues, 4" res and two 3" bullets (TOOO LOUD) so I can get somes pics when I get to my shop.
would love to see it! i know you can squeeze 2 3" pipes over the axle, especially if you take off the upper panhard bar support.
i'm thinking 5" pipe would work but not sure how you would join two 3" pipes into that and then back out again. you'd have to do a box it would seem and somehow weld around it to seal the joints
would love to see it! i know you can squeeze 2 3" pipes over the axle, especially if you take off the upper panhard bar support.
i'm thinking 5" pipe would work but not sure how you would join two 3" pipes into that and then back out again. you'd have to do a box it would seem and somehow weld around it to seal the joints
5" will work although a 4" long enough is good for 427 cubes. Joinning the two pipes is not hard. Just cut off a section of 4"/5" flare the ends hammer the two pipes to fit then weld it all up. After that just weld the y to the rest of the system. I don't know why GM didn't do this in the first place.
Hmmmm. This is getting interesting. What kind of horsepower gain are you seeing? Pictures would be a big help. For most of us the collector ranges are 18" for best, 36" next and then 72".
where can you buy 5 inch pipe, most places i've seen only carry 4. And where to get 4/5" flare? I know diesel trucks use 5inch pipe but i cant find it for sale other than in catbacks
Hmmmm. This is getting interesting. What kind of horsepower gain are you seeing? Pictures would be a big help. For most of us the collector ranges are 18" for best, 36" next and then 72".
Well here are some pics that we took over the weekend. We are now installing the sbfc. It's a convertable so I have to make some mods to get them on. This system has 100% of the ground clearance that the flow master cat back had. The car will be getting dynoed tmro so I'll have some more data for you guys. The car should put down 460 to 470 to the wheels.
As far as the hp gain it depends on the motor output and what you started out with. Most 350ci+ that's making 275+hp to the wheels with headers and a 3" cat-back see about 25 to 35hp gain after tuned duals and af/spark tunning. A GOOD tune is the key.
O by the way this car is going to race a 3rd gen that we also did a lot of work on (from paint to drivetrain) in the 1/8th mile.
I'd love to see some pictures.
We've been pursuing a true tuned dual exhaust for a while now.
I've built my current system to allow for easy adaptation to resonator/terminator box if space and ground clearence permit.
The lowest point is at the crossmember (which is modofied) however the box would be beyond that with an average collector length of about 36". Still there's not a lot of room for a 700 cubic inch enclosure.
Here is another picture of one way to enter a pipe into a termination box. You want it to extend into the "open air" an inch or two.
If my application, the header collectors end up a different lengths if they were to be stopped or cut off at the existing merge pipe. Extending them into the box (as per the spec) will allow me to stagger the ends to provide equal lengths of around 36".
Question remains. Where does it all fit?
Thanks TheBadazz for the pictures. It looks like on this particular car going by the 2nd picture in post #275 you have two different collector lengths. Maybe one about 18" long and the other maybe 36" long.
So with a car making maybe 450hp at the flywheel or 370rwhp would you expect maybe the same 25-30 horsepower gain with a terminator box? I fully understand a new tune would be required for maximum gain.
Last edited by 1989GTATransAm; 06-09-2008 at 04:23 PM.
Your welcome, on this particular car we didn't mod the collector much. (owner liked the way it looked). The only mods to it was at the y. That's why the lengths are dif. The hp increase should be high 30hp+ and we are expecting that 450hp+ at the rearwheels. This car has ported heads,cam,tb,maf,intake,higher cr,lid,cai,roller rckrs,injectors,pullies and more. It is really a sleeper (expt for the exhaust) in Chicago we like it that way.
If my application, the header collectors end up a different lengths if they were to be stopped or cut off at the existing merge pipe. Extending them into the box (as per the spec) will allow me to stagger the ends to provide equal lengths of around 36".
Question remains. Where does it all fit?
Hard to see in the pic but I think I understand what you are saying. I have a third gen in the shop, let me check under it and do some looking to see how we can hook you up. You say you want 36" collectors and what size res you need.
Hard to see in the pic but I think I understand what you are saying. I have a third gen in the shop, let me check under it and do some looking to see how we can hook you up. You say you want 36" collectors and what size res you need.
I've built a stainless y-pipe ahead of the magnaflow merge pipe you see in the pics.
Those collectors are about 36" to where they enter the merge pipe. I would think the terminator box (single) would start where the merge pipe is currently located and based on the info I have regarding terminator boxes ( David Vizards Exhaust Science article ) I would require no less 16 times the volume of one cylinder for a single resonator box setup (or 2 by 8 times one cylinder for duals). In my 350 cubic inch application that works out to a box volume of 700 c.i. In general terms that's a 4" pipe, 55" long or a 5" pipe, 36" long. Provisions also have to be made for the proper entry into the box, (in my case that's 2 x 2.5") and the exit (where a single 3" still meets my minimum cfm requirement.)
we'll keep that in mind when the guys here who have done all this r&d are consistantly 1-2 tenths quicker/faster than you or anyone else with a similiar combo, lol!
j/k...but for real, there's alot of cool truth in all this mess!
"...but for real, there's alot of cool truth in all this mess!"
Yes there is.
I was over at Dyno Don's shop today and did some measuring on a car on the rack. When I do my 4L60E swap I'm going to make up my own rear transmission mount. It will have clearance on the right side for the exhaust to run through, it will relocate the torque arm to the transmission mount and have a drive shaft loop.
I might be able to do the termination boxes without a tubular K member. Then again if I can knock off 100 lbs of weight that is .1 et. If the termination boxes give me another 20 horsepower we might be talking an 11.5 second TPI car. Hehehehe, lots of fun talking about this stuff and what might be.
Maybe Orr or skinny z will have some results by the time I get around to doing it next year.
well i was planning on either dynoing my car or running my car at the track with and without the exhaust. With my full length 4inch and then with 18 inch long collector extensions. I'll probly race track it since it would be easier for me to do that
I wonder how much the tune would be affected by the difference in the exhaust with the open and closed headers? You might have to bring your tuning equipment along with you.
"...
Maybe Orr or skinny z will have some results by the time I get around to doing it next year.
I was enjoying my new headers immensly, as well as excellent new ignition tune however my OEM flat hydraulic lifters weren't. Half of them are wasted and the whole thing has to come apart. Not going to have data to collect for a while.
On the upside, I found a cherry donor Camaro in Virginia and it looks like I'll be bringing it home in a couple of weeks.
Win some lose some.
Good luck.
Wow! Sorry to hear about the flat tappets. There seems to be a lot of horror stories regarding flat tappets recently. Hopefully it won't take that long to get back on the road.
With the new headers and exhaust, upgraded stall to about 3500rpm and LCA relocating brackets I was quite confident I would have my 12 second time slip. After this debacle, I'm upgrading to a hydraulic roller (Comp XR270HR).
12's are in the bag. ( Comments on the XR270HR?)
With the new headers and exhaust, upgraded stall to about 3500rpm and LCA relocating brackets I was quite confident I would have my 12 second time slip. After this debacle, I'm upgrading to a hydraulic roller (Comp XR270HR).
12's are in the bag. ( Comments on the XR270HR?)
That's a good cam. Strong low end good idle and the hp doesn't fall off as fast as some other cams I've used.
We've all spent a lot more on 'bolt on' parts for a lot less return in horsepower.
What would YOU do for an extra 30 or 40 hp?
The potential is certainly there (provided your not halfway there already).
I've built a stainless y-pipe ahead of the magnaflow merge pipe you see in the pics.
Those collectors are about 36" to where they enter the merge pipe. I would think the terminator box (single) would start where the merge pipe is currently located and based on the info I have regarding terminator boxes ( David Vizards Exhaust Science article ) I would require no less 16 times the volume of one cylinder for a single resonator box setup (or 2 by 8 times one cylinder for duals). In my 350 cubic inch application that works out to a box volume of 700 c.i. In general terms that's a 4" pipe, 55" long or a 5" pipe, 36" long. Provisions also have to be made for the proper entry into the box, (in my case that's 2 x 2.5") and the exit (where a single 3" still meets my minimum cfm requirement.)
You can get the volume buy going over the axle with the 4 inch pipe or using the 5". JC Whitney sells 4" u-bends for $54. With that pakage you should be running 12s already.
As for that 2000 camaro with the dual 3" and bullets. With pump gas and a half a#$ tune it put down 400hp @ 6k rpm and 379lbs @5k rpm. Car has more in it but the guy who tuned it didn't push the car at all. So we are going to a different place to get this thing dialed in. When driving the car yesterday we killed a modded 2000TA with DRs REAL Bad and we were on cheap street tires so things look good.
You can get the volume buy going over the axle with the 4 inch pipe or using the 5". JC Whitney sells 4" u-bends for $54. With that pakage you should be running 12s already.
interesting, as i'm going with a dual 3inch into 4 inch ypipe and straight thru tube muffler into another reverse y pipe to dual 3inch outlets. So that length of 4 could act like a resonator? even with the bend?
Quote:
What would YOU do for an extra 30 or 40 hp?
I'd do alot but if i could have my motor sound like a LSx C5 Z06 with a corsa catback, i'd take 20whp less
i dont follow all this terminator box, tuned length resonance nonsense. you either run open headers or just run dual 3" to some bullets/cherry bombs and dump at the rear end, you aint gonna get 40 extra horsepower with some magic box someone prove me wrong i dont see you gaining 40 horsepower
well maybe not 40 but i have posted a link proving correct collector length is worth 10-15hp peak, and much more under the curve on a 700hp race motor. Finding 15 hp on a race motor is hard to do
[quote=Orr89RocZ;3788099]interesting, as i'm going with a dual 3inch into 4 inch ypipe and straight thru tube muffler into another reverse y pipe to dual 3inch outlets. So that length of 4 could act like a resonator? even with the bend?
Sure it can, the motor doen't care about a bend as long as the volume of air is there.
i dont follow all this terminator box, tuned length resonance nonsense. you either run open headers or just run dual 3" to some bullets/cherry bombs and dump at the rear end, you aint gonna get 40 extra horsepower with some magic box someone prove me wrong i dont see you gaining 40 horsepower
It's like tuning a subwoofer box res to match the natural res of the subwoofer. If the box is tuned right then the output of the woofer will be more efficient than without the right tune. If you have a car that is putting down 350hp+ to the wheels with a single 3" catback and you get the duals with res box and tune right yes you can gain that much HP.
Me and my racing buddies like sleepers so we try to get the most out of our cars without showing a lot. To get a money race with open headers or having a loud exhaust is very hard (and I like win). I've seen guys lose $500-$1000 buy a half car so for me if I can do something to give me an edge over the other guy then it's done. Why wouldn't you want the same or better output from your motor but with a more streetable and maintenace free system.
And for the proof I'll have that as soon as we get the 92 RS dynoed again.
i dont follow all this terminator box, tuned length resonance nonsense. you either run open headers or just run dual 3" to some bullets/cherry bombs and dump at the rear end, you aint gonna get 40 extra horsepower with some magic box someone prove me wrong i dont see you gaining 40 horsepower
just because you can't wrap your mind around the physics involved in all this stuff doesn't mean it doesn't work. they've already proved you wrong. i've proved you wrong. my n/a iron headed 305 runs 12FRICKIN'30's and i'm running it through a 3.5" single y-piped exhaust. i'm sorry, but i KNOW that the scavaging effects associated with that large y-collector helped a TON. when i get my new headers (i'm running hedman longtubes right now) for my new combo (gonna need a 1.75" primary) i'm planning to do the same thing, with a large diameter 3.5" exhaust and then go up and over the axle and out the rear.
sorry, that was my emotions lashing out. i think it's pretty ignorant/arrogant to come in here and say "blah blah blah, your idea doesn't work, prove me wrong" when there are so many people working on this idea to make it work and all the physics and math supports it.
hey The Batazz, is it important to go back into dual pipes after the terminator/resonator box? that's alot of work, lol! i'm wanting to do a single dump under the rear bumper with my 3.5" system.
Then all you have to do is make sure your tune is right. 
