Modifying for " Dummies"

[Dr Jkel]

What is the purpose of forced induction systems, At C5F a naturally aspirated 67 Camaro with a stroked motor was eating peoples lunch running low 11's, didn't see the benefit of all that other stuff.

[Dr Jkel]

Bump for discussion

[Dr Jkel]

What is the difference in shorty headers vs. long tube header?

[DSteck]

Originally Posted by Dr Jekel

What is the difference in shorty headers vs. long tube header?

The length of the primaries.

Why the hell am I the only one participating here?



Shorty headers will typically provide more low end torque at part throttle conditions compared to long tubes. However, long primaries typically result in more peak torque and peak horsepower... typically just more powre in general. There's a partial downside to long tubes, though... They space your collector and catalytic converter much farther back. This means your O2 sensors are slower to respond at idle and low load, low rpm conditions (partly because of the distance, partly because of the reduced heat). This also means your catalytic converter falls out of the preferred operating temperature range, and if it's too cool, it won't work properly. The O2 sensor thing won't mean much, although some brands of headers will throw codes for insufficient switching (result of the runner design). I don't run cats, so I couldn't care less about the other trade-off.

[Dr Jkel]

Originally Posted by DSteck

The length of the primaries.

Why the hell am I the only one participating here?



Shorty headers will typically provide more low end torque at part throttle conditions compared to long tubes. However, long primaries typically result in more peak torque and peak horsepower... typically just more powre in general. There's a partial downside to long tubes, though... They space your collector and catalytic converter much farther back. This means your O2 sensors are slower to respond at idle and low load, low rpm conditions (partly because of the distance, partly because of the reduced heat). This also means your catalytic converter falls out of the preferred operating temperature range, and if it's too cool, it won't work properly. The O2 sensor thing won't mean much, although some brands of headers will throw codes for insufficient switching (result of the runner design). I don't run cats, so I couldn't care less about the other trade-off.

Well I am glad you are responding, alot of knowledge for people on this thread.



I would like to do a CAI, Headers, Cam, and will have to have a tune. I have had one quote for CAI, Inc. CAI, ARH LT Headers, Custom Comp Cam Stage II, Dyno Tune, plug wires and a 160 themo stat.

I have heard this package on a car like mine and liked the sound, 6300.00 is alot for sound though, it does increase HP by about 100. Headers were 1895.00 not installed. So just trying to figure out the best way to go about this and your help is greatly appreciated.

[DSteck]

Get headers, and put a 150-shot of nitrous on. Call it a day.

[Dr Jkel]

Originally Posted by DSteck

Get headers, and put a 150-shot of nitrous on. Call it a day.

OK, I do not intend to race my car on the strip or otherwise, basically want the ole muscle car sound. I have only heard about ARH and DT. So what would you recommend Shorty's or LT's, ARH or DT. Not real sure about the Nitrous yet.

When adding headers do I need a CAI? Do I need a tune? Thanks John

[1fastdog]

The best advice I can anyone looking to get more out of their car, Camaro or otherwise, is to consider the characteristics and drivability that are your absolute must haves and consider that you need to truly avoid thing you can't live with which might be a natural characteristic that goes with the changes you make..

Almost anything you change will have some tradeoff associated with it. The big deal is that you need to understand and judge how comfy you will be with the total result. IOW, what is the good and what is the "bad"? Can I live with the "bad".

The good is very important, it's the only reason to consider shelling out your hard earned money. Vendors and internet pimps will usually only talk up the "good". It's the nature of getting folks excited enough to part with their cash. Mentioning the possible downside does not induce "mod fever" the way dyno results can..

Not to belabor the point, but I plead that anyone looking to making their car "better" truly be honest with themselves, and any they seek advice from, regarding what you won't tolerate being included as a characteristic introduced in the course of your quest.

I'll share an example that might better illustrate my point.

I advise some roadracing teams that run Corvette. Road racing is my thing. Handling is a big key to success in that sport.

I like a car to handle in a very specific manner. Part of acheiving that sort of handling carries some trade-offs. Particularly when it comes to NVH < Noise, Vibration, Harshness >

Stiffer mounts, less compliant bushings, higher spring rates or stiffer sway bars, heim jointed end links, all can improve holding alignment, weight transfer control, etc.

They can also introduce more NVH. Usually a whole lot of NVH.

I have driven roadracing prepped vehicles. I know why things feel and sound as they do.

My wife, on the other hand, perceives the same characteristics as horrible and barely tolerable. IOW, it's perception that best explains the differeng conclusions.

As for shorty headers? There are less intrusive and far more cost effective ways to change the exhaust note of a vehicle. Shorties do not deliver enough power, for me, to justify the expense. More pain than gain, IMO.

Long tubes with the best possible merge collector and length will deliver a sound change and power capability. The trade off is pretty severe as far as emission controls, and sensors that will require being shut off and loss of cats or effectiveness or efficiency of cats will become an issue. It's a situation that clearly can improve power output. It's also a matter that you will be illegal by the letter of the law. No two ways about it if the streets are where you intend to drive.

I'd think a well chosen pre-throttlebody intake and catback system is the best route for exhaust note. Resonance of the catback will be the biggest consideration.

BTW, I think this is a great subject that gets very little attention.

Also, avoid nitrous. If you really don't undertand it, it will eat your wallet. IMO, nitrous fed motors need to be built as nitrous motors. Lots of planning and failsafes required for any peace of mind.

[Matster]

Originally Posted by Dr Jekel

OK, I do not intend to race my car on the strip or otherwise, basically want the ole muscle car sound. I have only heard about ARH and DT. So what would you recommend Shorty's or LT's, ARH or DT. Not real sure about the Nitrous yet.

When adding headers do I need a CAI? Do I need a tune? Thanks John

Hey John,

I am assuming you have the SS with an LS3 engine. Do you have a HP/TQ number in mind that you would like to achieve? Dyno testing has shown that the stock LS3 with 426hp at the flywheel is putting down between 365 and 375 at the rear wheels. I did my CAI first, to see what effect it had, found that it was a lot more responsive at the bottom end of the throttle. I then added a complete stainless steel exhaust system, 2" long tube headers, 3" high flow cat exhaust. I now have an engine light which I fully expected, 02 sensors. I have a tune on the way which will address this and will have it Dyno'd once I install the tune to get the most out of it. I have seen similar packages advertised quoting 485hp and I am almost certain that is at the flywheel, not the rear wheels. The right cam will probably give you another 50hp +/-.

[Dr Jkel]

Originally Posted by Matster

Hey John,

I am assuming you have the SS with an LS3 engine. Do you have a HP/TQ number in mind that you would like to achieve? Dyno testing has shown that the stock LS3 with 426hp at the flywheel is putting down between 365 and 375 at the rear wheels. I did my CAI first, to see what effect it had, found that it was a lot more responsive at the bottom end of the throttle. I then added a complete stainless steel exhaust system, 2" long tube headers, 3" high flow cat exhaust. I now have an engine light which I fully expected, 02 sensors. I have a tune on the way which will address this and will have it Dyno'd once I install the tune to get the most out of it. I have seen similar packages advertised quoting 485hp and I am almost certain that is at the flywheel, not the rear wheels. The right cam will probably give you another 50hp +/-.

Yes I have a manual LS3. Call me crazy but I am not really into power on this car. I have a truck for that, another story pushing over 550 hp. The Camaro is fast enough for me and the fastest I have had it was on the cruise during C5F, 105 mph. The car is not my daily, I will not race it on a strip, or the street. My main goal is to have the " Muscle Car Lope" of years past.

While I am reasonably sure that I will add some power that is not my main goal. My main goal is drivability, dependability, and sound.


I read the post above yours about be illegal, which is a concern. Even though my state does not have any inspections, they may in the future. I was "TOLD" by a company that the dependabilty and drivability would be great especially because of my driving habits and with the headers, high flow cats, 160 degree thermostat and cam that it would be almost like stock in it but just increased hp of about 100 and not alot of cabin noise so I could cruise down the interstate with no problem. Of course they did not mention any bad.

[1fastdog]

Originally Posted by Dr Jekel

Yes I have a manual LS3. Call me crazy but I am not really into power on this car. I have a truck for that, another story pushing over 550 hp. The Camaro is fast enough for me and the fastest I have had it was on the cruise during C5F, 105 mph. The car is not my daily, I will not race it on a strip, or the street. My main goal is to have the " Muscle Car Lope" of years past.

While I am reasonably sure that I will add some power that is not my main goal. My main goal is drivability, dependability, and sound.


I read the post above yours about be illegal, which is a concern. Even though my state does not have any inspections, they may in the future. I was "TOLD" by a company that the dependabilty and drivability would be great especially because of my driving habits and with the headers, high flow cats, 160 degree thermostat and cam that it would be almost like stock in it but just increased hp of about 100 and not alot of cabin noise so I could cruise down the interstate with no problem. Of course they did not mention any bad.

If power increase is not really what you want, I believe you can get what you want with a catback.

I will offer that headers will also change the exhaust, but other things you mention lead me to believe that you really shouldn't add that to your thinking process.

LS motors will never sound exactly like the smallblocks of old. The firing order has alot to do with that. LS motors will have a more exotic exhaust note at high RPM.

The sound at idle is what upsets some tradionalists a bunch. You can certainly get more of a authoratative voice from your Camaro. Part of being happy will involve going to a number of Camaro enthusiast events. I will be willing to bet that owners will brag or bitch about different catbacks out there. Shoot for being happiest above idle.

The best part is that anyone really happy with their exhaust mods will also be happy to demonstrate.

[Matster]

Well said 1fastdog, my finally exhaust set up was more trial and error. I went with Stainless Works "Aggressive" exhaust system front to back and that was a year ago so there wasn't a whole lot available to compare with. The first set of "Mufflers" (in name only) were just a little loud for my liking, pretty much the same as running straight pipes. Sounded amazing at WOT but drown on the highway and back pop on down shift drove me nuts. Go to the 2:10 mark of this video for the first start up with this exhaust system on it.

Switched the mufflers out a month ago to something a little tamer and am now VERY happy with the sound of my exhaust.

John you may want to check out some of the other video's on YouTube if you haven't already. I think there is a video on there with ever possible configuration you can think of. This may help you narrow down some of the notes you like best. I would then, like fastdog mentioned, try to find a Camaro in person to have a listen because in my opinion a video never does it justice.

[Dr Jkel]

Originally Posted by Matster

Well said 1fastdog, my finally exhaust set up was more trial and error. I went with Stainless Works "Aggressive" exhaust system front to back and that was a year ago so there wasn't a whole lot available to compare with. The first set of "Mufflers" (in name only) were just a little loud for my liking, pretty much the same as running straight pipes. Sounded amazing at WOT but drown on the highway and back pop on down shift drove me nuts. Go to the 2:10 mark of this video for the first start up with this exhaust system on it.

Switched the mufflers out a month ago to something a little tamer and am now VERY happy with the sound of my exhaust.

John you may want to check out some of the other video's on YouTube if you haven't already. I think there is a video on there with ever possible configuration you can think of. This may help you narrow down some of the notes you like best. I would then, like fastdog mentioned, try to find a Camaro in person to have a listen because in my opinion a video never does it justice.

Fastdog and Matster,

I really appreciate the and both are good advice. I did see one car at C5F that I did like the sound, it had the mods that I describe above, but 6300.00 seemed like alot.

I have talked with Ted at Jannetty Racing and we have had several conversations on this topic. I currently have the GMPP street version exhaust on my car and it sounds ok to me, but the lope is not there. I have ordered a Cold Air Inductions cold air intake, it seemed to be the best all around from the Jannetty Test that was performed and posted plus I like the way it looks.

Matster you said that you changed you exhaust to be tamer, was the cabin noise too much with the long tube headers, or do think it was just the exhaust.?

I think I will try a set of headers. Jannetty recommended some headers
Full Dynatech SuperMAXX Stainless Steel Exhaust w/ Cats and he says they do really well especially for what I am wanting, so with the headers, cai, and axle back exhaust I think it may sound pretty decent. At the suggestion of Ted I will do this first before I install a cam, I may like it this way without the cam and save a few buck. The only downside I see is that I will have to tune it and Ted is providing a custom tune for my application. Plus if I upgrade and put a cam in it he will also provide a tune for that. So I guess time will tell.

[1fastdog]

Originally Posted by Dr Jekel

I think I will try a set of headers. Jannetty recommended some headers
Full Dynatech SuperMAXX Stainless Steel Exhaust w/ Cats and he says they do really well especially for what I am wanting, so with the headers, cai, and axle back exhaust I think it may sound pretty decent. At the suggestion of Ted I will do this first before I install a cam, I may like it this way without the cam and save a few buck. The only downside I see is that I will have to tune it and Ted is providing a custom tune for my application. Plus if I upgrade and put a cam in it he will also provide a tune for that. So I guess time will tell.

"Lope" will have a lot more to do with cam specs.

The more radical the cam grind, the more "tennis shoes in a drier" the idle will sound. Lots of overlap will contribute to a nasty idle sound. I'm not up on it, but I think some outfits like Comp Cams have a Thumpr series that's aimed a car show fans who want a pumpity idle as opposed to out and out power. You might consult with them on what it iis you want and what you can get or give up to get it.

That said, perhaps the shop that is advising you can let you listen to another customer Camaro they have done just a header or catback mod to and save some dough IF that, or that and a catback will do the trick.

Lopey idle is more of a cam thing in my book. Headers will just change the volume and tone of the sound and not the smooth or rough characteristics.

I'm not a cam engineer, but I know some folks who are.