Shagwell

I've been asked countless times now, and I've needed to post it...

My Exhaust

Headman LT's
Headman universal 2-1/2" x-pipe
Hooker Maxflow mufflers

I've said it before and I'll say it again. It's not worth it. There's no power gains to be had over the LT's, a good y-pipe, and a good single system. There's only the sound and the wow factor. My system tucks completely up under the car, out of site, and off the pavement. It takes a lot of frame modification. I was doing the LT's and homemade sfc's at the same time and things kinda got outta hand with the smoke wrench.
- Now the pics. Some of these were taken as I built the system, some have been taken now, with everything partially dissassembled(re-doing the car) I can't seem to find any shots with the mufflers in place, so the x hangs a ways toward the back, as the trans x-member is the only thing holding it up.

Shagwell

more....

Shagwell

frame mods/sfc's...

Shagwell

more....(sorry mods, hope I'm not going overboard, just been asked many times)

Shagwell

final two...

Shagwell

I know the pics aren't the greatest, but I have a single car garage and a floor jack. - I have no lift, and the car is down(getting completely gutted floors, firewall, and all unibody crap included) All welding on this car was done with a stick welder(Lincoln Ranger 8 gas-powered)

The factory front sub-frame was cut out from the firewall back. I used 2x2 box tubing welded to/through the floor full length. The box actually slides into the rear frame, then back into the front(to the outer edge) and was plug welded. They are also tied to the factory vert rocker box braces and tied to my roll cage. I then took two pieces of 1/4 thick 2" angle and welded them from the inside edge of the front subframe to the box tubing. This allows the header pipe to come directly off the headers, no drop down/twist around. I have no rear-seats, so I cut the humps out of the floor and put flat panels back in place, which allows for placement of the mufflers. I could have run tail pipes but never did, I simply had two short pieces of pipe coming out the back of the mufflers, stopping just forward of the axle tubes.
The two pieces of angle have a welded 3/8 nut on the top side of each(untouchable after install) for my trans crossmember bolts.
Also the pipe you see at the top of the last two pics is my tq arm/ds loop crossmember. It sits just tailhousing of the trans.

CamarosRUS

I wish I could do my own dual setup. Nice job!

rwdtech

thanks for the information

stage20

iTrader: (3)

you cut the unibody subframe?
what type of metal did you use to replace it?
looks unsafe to be honest.

Schultzy89GTA

May I ask what data you have to conclude that there are no power gains to be had and that it is not worth it?

Curious to know what power level you are at and how you made this determination.

Thanks,

-Schultzy

gray89vert

iTrader: (3)

very nice work...major props

stage20

iTrader: (3)

Rottluver

I dunno about anyone else, but when I went from just a catback and bolt ons to long tubes and true duals (3" mandrel bent all the way over the axle with x-pipe, dual 3" cats and 18" magnaflow 3" diameter bullet mufflers) I actually did not gain one single hp or ft/lb of torque. Granted I was not using the same dyno as before but the numbers were identical!!!!! It was kinda weird. I picked up a little at the track but unless you have a stroker motor (more cubes) or are using forced induction, or some pretty healthy heads & a wild cam, true dual exhaust won't provide a HUGE increase in power generally speaking. Obviously every car/person is different but you have to have the other parts be able to move large volumes of air before you will really sdee too much diff with true duals. They sound nice and look cool and it is cool to say I have em, but they didn't do a lot for me performance-wise. 2-3 tenths at the track tops. :shrug:

Granted this is on a 4th Gen LS1 but the concept is the same on any motor......if you don't have the equipment to move the air at a much higher rate, having that bitchin hi flowing exhaust won't be as big a help as a person might think.

Just my $.02

stage20

iTrader: (3)

dude, that is a HUGE gain.

Rottluver

:sorry:

I expected a lot more going from factory manifolds, y-pipe and catback to long tube (QTP) headers with full 3" dual exhaust............that 2-3 1/10's was also at a track with a MUCH lower DA then then one I normally used.........not saying I dislike the gain, just that I guess I thought it would be more significant.

stage20

iTrader: (3)

depends on the HP level. your manifolds might have been doing a pretty good job, even a hundreth is a huge gain. always fun to go faster.

Schultzy89GTA

Exactly. So what were your dyno runs and what were your 1/4 times. Just trying to qualify this with some objective data. Thanks.

-Schultzy

slowfast

I was thinking about making street legal true duals just for the wow factor

Rottluver

Well that would be the first time I ever heard of LS1 F-Body manifolds (and the adjoining 30+ lb each - <no joke> catalytic converters) doing a good job compared to top of the line long tube headers, but I suppose anything is possible.

With factory manifolds, the normal LS1 bolt ons and an SLP Loud Mouth catback I got 357 rwhp and 367 rwtq. On the same brand (different location) dyno a couple months later I got 357 rwhp and 367 rwtq after installing QTP long tubes and the full on 3" mandrel bent true duals........including "high-flow" cats, 18" bullet mufflers, etc. (it was kinda spooky that they were IDENTICAL #'s) Temp, humidity, etc were pretty much the same both dyno days. For the (almost) 2 grand I spent in headers, exhaust, etc I was hoping for more then 2/10's & ZERO hp or tq. Not the end of the world, just little bit of a downer. Yes, going faster is fun but I had slightly higher expectations. Cest la vie.

My 1/4 times (and yes, I am a sucky driver) went from 13.6 @106 (before) to 13.4 @ 108. And again, those first time #'s (which were pretty consistent the 5-6 times I ran at that track) were at LACR in Cali, high elevation, even higher DA. The "faster" times (ran 3 times and they were all pretty much the same) were at Pacific Raceways near Seattle.....MUCH lower elevation and DA!! And yes, yes, yes, I know my times suck. It is a 6-spd with a weak-*** 10 bolt and I am a sucky driver. Oh well, life isn't over, just bummed me out. I am sure with a better driver and an automatic, my car would be significantly faster.

Rottluver

That is exactly why I did it, along with the delusion that I would get some good power out of it.

If you can get it done where they don't scrape or hang so low that shadows get stuck under them, I say go for it if you want to. Only reason I am bitching is cuz the place that did mine did a crap job running the pipes and so now, 2 years later, I am paying the price......I am actually going back to a catted Y-pipe and catback at the first of the month. Found em both brand new for a total cost of a good catback and that was about 1/3 the price that the best shop up here (not the same place that did my duals) quoted me for "fixing" my TD's to make them suck less.

TJs57TPi

so who makes a y pipe for long tubes for the third gens? besides the 4 inch mufflex one that is ridiculously priced

Stang Stomper

New here and don't want to make anybody mad but I have true duals on my car with out any frame mods. The mufflers are a little low in the back but no real drining problems. I dont now about the power gains but it sounds good.

383firebird84

i got true duals on my car the sound is just so much better then my old 3 inch single and i picked up 4 tenths on my 1/4 times with using the same haeders as i had on there just added some s extensions an x pipe and spintech pro shootouts and dumped it

Randy82WS7

true duals are simple

long tube headers

and summit s-curve collectors

straight pipes on them, and a coupel cheap turbo mufflers at local auto parts store, about 22 bucks each


not full length, but its cheap and simple and easy

good luck

Shagwell

- It's been a while since I checked back, I don't "cruise" the exhaust board, mostly suspension and the drivetrain board. -

I gained nothing in the 1/4 when I switched from headman Lt's with a 3" cat-back to the 2-1/2 duals. Same 60ft's, same 330, 1/8th, etc. The car sounded very different, but my numbers remained the same, conditions within a few degrees and the same humidity at the track. I did gain some switching from shorty headers/y-pipe to the Lt's though.

I cut part of the factory subframe out because with 2x2 box welded full length through the floor(above the rear foot well, as they run straight through the car), slid into the subframes at each end, the tapered in part of the front subframe meant nothing in terms of strength. Even before I put the cage in I had very limited twist in the car with my "frame rails" installed.

I went for perfection, not cheap. I wanted zero clearance or any other issues commonly associated with routing duals under our cars. I hate being able to see someone's exhaust hanging down under the car, IMO, it just looks tacky and kills the lines of a car.

DeathStarr89

iTrader: (1)

if you had to cut the subframe you did it wrong...



Headman 1 5/8" longtubes from a 2nd gen Camaro, 2.25" pipe, H and flowdisasters. Engine made 300 HP and 400 TQ on bone stock 882 truck heads, 9:1 compression, .495/.502 cam, single plane intake and a 750 carb.



I did notch my subframe about 1/2" to get rid of some rattle... but it got welded back together with 1/8" plate. i've put about 1,000 miles on it and only scraped once. I also put normal sized front wheels on it so ground clearance got better...

Shagwell

Yes, it can be done differently than I did it. Your's is fine, looks good. As I stated, the reason I did mine this way was because I wanted ZERO loss of ground clearance, and I wanted it fully tucked up under the car so it couldn't be seen. Your collectors hang about 2-3" lower than mine do. The headmans' dump just below the floorpan, right at the subframe. I wanted straight back, no s-bends/etc to offset down. If it hung down any, daily driven with sportline springs would bounce it off of speed bumps, pot-holes, etc, which is why I didn't do it that way. Plus, it's completely out of site, as the factory vert rocker boxes are lower than the exhaust.

cronsformula350

.3 tenths is still about 30 hp though, I'm going to have my true duals done soon, I never had headers on this car at all or exhaust, so no loss.

It will be ceramic coated 2210's, with 2.5" duals, into a h-pipe, I'll do a x-pipe, when I'm going to 3" duals when it's over 550 hp, then bullet mufflers, and dumps before the rear wheels. I'll post some pics of it, when it's done.

Rottluver

Sounds like a good setup. Looking forward to the pics.

Comp788

Shagwell,

I know that your was done to be able to build true dual exhaust and I am not trying to thread jack you. I had not seen anyone else remove the factory sub-frame like I did. I now see that you have also done it. Nice job.

I am going to post a link to my cars exhaust. I built a single 4" system not true dual but the frame concept is the same. I just figured that some of the people here might care to see another way to gain room for exhaust.

https://www.thirdgen.org/forums/exha...t-picture.html

I spent a bit more time removing my sub-frame and fabricating new frame rails. I do not have pictures of the SFC installed in this thread but the concepts were exactly the same.

Nice job.

Ford2transam

Sumthing i worry about running pipes so close to the transmisson is heat the cooler the trans run the better we all are sure to know, so a heat sheild and after market large trans cooler should be kept in mind...
unless you have a few trans laying around. :0)
I do have a question tho what's the benifit of have the X so close to the headers as to crossing them lets say, for shoots and giggles, near the drive shaft? I did that on a truck i had and still had gain in low ends and real mellow sounds.

cronsformula350

Well, I'm not doing the x-pipe setup for a while, I'm just doing a h-pipe first. Scott Parkhurst, told me from Popular Hot Rodding, that X or H pipes are the most affective within a foot after the collectors. Y's are affective a little further from the collector. I am sure if that he will put enough room in between the y-pipe and the trans. Plus, the heat coming off the y going into the trans is not that hot, that it would damage the transmission, it's the cooler that does it's job, if he feels the heat after it's warmed up, he'll do what's needed.

Say he puts a piece of sheet metal on top of the y, that will prevent most of the heat from going right up onto the transmissions pan. And at least when your driving, most of the heat will go back.

stage20

iTrader: (3)

no matter what exhaust you run, its going to get close to the tranny. i dont see any issue at all.