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View Full Version : headers are on,,,im not impressed


Dave B.
08-20-2005, 01:37 AM
For the longest time iv had a magnaflow catback and Xpipe,,,the cars always had a really exotic sound and lots of bottom end torque, a few days ago, i asked those of you who had long tube headers if bottom end was lost,,

Well I think its gone,,,not only that the mid pipe they put on was an off road, and I think it sounds like a truck without a muffler, loud as hell, is this what most of you are running on your street daily drivers??

Does anyone know if we put the cats back in line the exhaust will it get rid of that loud raspy ?? the engine spools up real fast and its hard to tell if its just going right thru that power band where all the torque was before,,,,you guys who put LT's on,,,what did you find out about your power band later?? what did you realize later as far as power and torque goes? did you ever regret putting them on afterwards?

Any feed back would be great,,im a little bumbed about it at this moment though,,,,

blk04cobra1
08-20-2005, 05:25 PM
the cats would definitely quiet it down just a little bit...personally I think it's in your head about that torque, I just cant see -20ft/lbs being that much of a seat of the pants difference...only way to tell for sure is to put her back on the dyno...sorry your initial reaction hasnt been positive, but just wait til you run in to a car you previously beat by one car and now beat him by three+ :bounce:

BOOMER23
08-20-2005, 06:57 PM
Do whatever you have to do even if you revert back to your old setup, i am that type of guy that i like the way my car feels with the bottom end from hell in it and mine is still very, very close to stock. Just remember if you dont enjoy it as much even if it is a bit quicker on the top end go back to where you were happy with it. Personally I like my exhaust tones loooooowwww, Ive got a steeda catback and I wanna go with an MRT H pipe, I like em not even close to loud and really low. If picked up 40 horse over a setup i was happy with previously it still wouldnt be worth it to me. I like to look around at people on the street and think yeah this car makes the sound I want it to, it personifies me, if you hate it loud and raspy (which i cant blame you, itd be hard not to) chuck that setup. I know you have spent good money on it but do whatcha gotta, give it some time and see if it grows on you, I really hope it does. Exhaust is an easy thing to screw up. Best of luck to ya though, but like i said if the exhuast sound isnt that bad for ya then throw on some cats and quiet it down a tad and get rid of some of the rasp and then dyno her to see if you are exagerating the torque loss.

Ashton

InfamousSVT
08-21-2005, 10:57 PM
Agree with the above.....if you want to get rid of the raspy sound put the cats back on it. That will also provide you will a little more backpressure too!

Linn@Amazon
08-21-2005, 11:49 PM
what Jason said...cats should help with increased back pressure and raspiness..Im sorry that you didnt see my post earlier. we have only ever sold one set of headers in the 3 years we have been working exclusively on these cars.

sssvtcobra
08-22-2005, 12:09 AM
Sorry-I don't mean to be a thread stealer.

But, what I am getting from some of these posts in this thread is that these '03's-'04's are better off with some back pressure? Possibly from having cat's, than no cat's at all? And would I gain hp & tq if I was to put my cat's on? Right now I have a Bassani o/r x-pipe and SLP loudmouth 2 catback.

Just curious

Dave B.
08-22-2005, 12:31 AM
I have been reaching out to a lot of perople in the business, mainly tuners, and others around the country who have done a lot of things to there cars,

so what I think its all going to come down to is the 03-04 Cobras have a cam set up that causes enough valve over lap that a portion of boost is getting pushed out thru the slightly open exhaust valves what normaly would be kepted in check by back pressure in the OEM manifold

I would not be surprised if this ends up being the situation, thats why a bigger supercharger works well with LT's because then, not only does the exhaust gases get pushed out faster, but theres more than enough increased air flow to still pressurise the chamber.

I would bet a lot this will be the final answer to this question.

bluebyu
08-22-2005, 01:05 AM
You can try running 2 chamber Flowmasters with a BBK off road H-pipe. A lot of local Die Hard Mustang fellows around here agree, The x-pipe teamed with the Long tubes make the exhaust sound like a dump truck. I am running BBK long Tubes with the off road H- pipe and 2 chamber flows on my 98 Cobra and it is extremely throaty.And so is a buddy of mine on his 03. And they sound alike, very deep and evil sounding. I guess its your taste though. Some people swear by the Magnaflows and some by Flowmaster and some swear by the Xs and some the Hs. As for mine I noticed better reaction coming off the line and just playing around too. As for my buddy he actually did beat a car he beat before and pulled it by 3 more cars. Try this set up sometime, Hope it helps.:thumbsup:

Linn@Amazon
08-23-2005, 06:51 PM
Sorry-I don't mean to be a thread stealer.

But, what I am getting from some of these posts in this thread is that these '03's-'04's are better off with some back pressure? Possibly from having cat's, than no cat's at all? And would I gain hp & tq if I was to put my cat's on? Right now I have a Bassani o/r x-pipe and SLP loudmouth 2 catback.

Just curious

that is what the data supports with these cars and the stock Eaton..I have seen over and over o/R pipes causing boost loss..not only is it a federal offense to have one on the car the cars just dont benefits that much from it..(dont even get caught with one on your car or you will end up like one of our customers did)

these cars need back pressure to build boost..make it too much less restrictive on the bottom end and you will see boost dropping off..

unless you are going to run an aftermarket blower with high boost LTs are not worth the effort and expense..but like I said many guys do them and say they are happy with the results..I just have not seen data to support that theory..I see the opposite ..but it is your vehicle and the decision is ultimately yours to make.. ;)

BlueOvalPower
08-24-2005, 10:11 PM
that is what the data supports with these cars and the stock Eaton..I have seen over and over o/R pipes causing boost loss..not only is it a federal offense to have one on the car the cars just dont benefits that much from it..(dont even get caught with one on your car or you will end up like one of our customers did)

these cars need back pressure to build boost..make it too much less restrictive on the bottom end and you will see boost dropping off..

unless you are going to run an aftermarket blower with high boost LTs are not worth the effort and expense..but like I said many guys do them and say they are happy with the results..I just have not seen data to support that theory..I see the opposite ..but it is your vehicle and the decision is ultimately yours to make.. ;)
Just Curious are you saying that the stock mid-pipe or a high-flow catted mid pipe is better for a slightly modified Cobra, I have the Borla Stinger cat-back and have a o/r x-pipe not installed so I would like the best option with say a 2.76 pulley, stock eaton, nothing too much more other than some cooling upgrades and some suspension upgrades in the future, and if I do ever go to a whipple or KB I can change out whatever if needed then, have a long way to go before then, thank you for your reply.

Robert

sssvtcobra
08-25-2005, 12:12 AM
Linn@Amazon,

Thanks for the reply. I think I might have to put the cat's on and see how she responds for a couple of weeks. Although I do like the scream that I have now from the exhaust, I would hate for it to get to quiet.

Dave B.
08-25-2005, 12:28 AM
Im going to go out on a limb here with this one,,,,
Why dont one of you engineering types with a machine shop build a device that is a mid pipe with a pair of cats, and a 2.5 inch by pass tube with some type of passage way valve, so at lower RPM's the valve plate would force the exhaust thru the cats for back pressure, then once the engine gets past a certain RPM (to be determined) the valve plate for both cats one on each side, moves to uncover the cat by pass tube thus allowing all the exhaust to by pass the cats thus relieving all the back pressure for high RPM power, i guess it could be spring loaded with the proper spring pressure that would take the exhaust for a higher power/exhaust output to open the restrictions.

I think the 2003 suzuki GSXR 1000 and maybe the Hyabusa had such a set up as they were in line four cylinders that did not have a lot of bottom end torque without the automatic restrictors

best of both worlds, as easy thing to make for anyone with a machine shop and some time on there hands,,,,,

Linn@Amazon
08-25-2005, 02:13 PM
Just Curious are you saying that the stock mid-pipe or a high-flow catted mid pipe is better for a slightly modified Cobra, I have the Borla Stinger cat-back and have a o/r x-pipe not installed so I would like the best option with say a 2.76 pulley, stock eaton, nothing too much more other than some cooling upgrades and some suspension upgrades in the future, and if I do ever go to a whipple or KB I can change out whatever if needed then, have a long way to go before then, thank you for your reply.

Robert
each car is different and we can see different results but generally the data supports keeping the stock pipe or catted aftermarket for moderately modded cars...we lost boost when we put an offroad pipe on our 03 Cobra..got the boost back when we installed race cats back on it.. any change to the mid pipe will add change to the exhaust note and make it louder..but benefit to performance is limited..and catted pipes are not cheap..so this is a mod that you can hold off on until later if you go to a more radical application
but.. and I want to stress this, it is your car and the decision it yours to make..