I'm just curious about why there is such a propensity to favor LT over ST headers on this forum. I never see any data, just opinions from other forum members who may or may not have run both types. The only actual data I have seen is a negligible increase long vs short (2 to 3 hp) over the range. Hib Halverson has a piece on this on another forum that you might want to read. My real life experience with long tubes is a loss on low end torque vs stock manifolds. I had LG Motorsports LT's on a C5/LS1 that was tuned post header install. Sure it sounded a lot better than stock, but I lost low end torque. Once I got over about 5k rpm it seemed to catch up to the pipe/length volume. The problem with that is that I don't need to be going 150+ mph on too regular of a basis around here. IMO without a built motor, you don't benefit, you lose with LT headers. LT's, LT's, LT's that's all I ever hear! I am going with JBA shorties on my LT4. What say you?

 

The shorties made by Doug's will fit a lot better, pacesetter too.

LTs will make more torque, thats what the ads dont tell you. Its always hp this hp that. Thing is shorties arent a whole lot better than the stockers so what they are saying is if youre going to spend money and really want to know you got a worthwhile gain they recommend LTs.

If its stock, just a cruiser it doesnt matter I suppose.

 

Sounds like your mind is made up -- you sure you really want any opinions?

 

What say me?

I say any header/exhaust system is tuned for an optimal rpm range. It doesn't matter whether you pick short/long tubes, if you don't size it according to your needs, you'll probably be disappointed.

When you installed long-tubes, you probably oversized it and/or didn't have it electronically tuned for the result. But, this goes for intakes, heads or any other part of the system.

I'd leave it the way it is, if you don't get that (and follow-up accordingly).

 

 

I looked around and was really surprised. There is not a whole lot of difference between the two. Nowhere near as much as I thought. Although the Stainless works headers (long tubes) did make more power then the Gibson's (short tubes) is it really worth the extra cost and effort considering the RPM that most noticeable gains occured.

Engine was a 5.3 chevy:
Line-by-Line Dyno Result
Stock Gibson Stainless Works
RPM HP TQ HP TQ HP TQ
3,126 170 283 186 312 191 320
3,226 192 312 195 318 198 321
3,326 202 319 204 321 207 327
3,426 212 323 212 324 215 330
3,526 219 327 221 329 225 334
3,626 232 335 229 332 233 337
3,726 240 338 241 339 243 343
3,826 249 341 248 341 252 346
3,926 255 341 257 344 260 348
4,026 263 342 264 344 268 350
4,126 270 344 271 344 276 351
4,226 277 343 278 344 283 351
4,326 284 344 284 345 291 353
4,426 288 341 288 342 298 353
4,526 294 340 293 340 305 353
4,626 298 338 299 339 311 353
4,726 301 335 303 337 315 350
4,826 305 332 308 334 319 347
4,926 307 327 310 329 322 343
5,026 309 322 314 327 325 339
5,126 309 316 316 324 327 334
5,226 311 313 317 318 330 332
5,326 311 307 319 314 332 327
5,426 All Done! 317 307 331 321


Peak Numbers
Horsepower Torque (lb. ft.)
Stock 311 @ 5,176 rpm 345 @ 4,076 rpm
Gibson 319 @ 5,176 rpm 346 @ 4,276 rpm
Stainless Works 333 @ 5,376 rpm 355 @ 4,476 rpm

 

Interesting data. My car will be stock other than the exhaust and I don't plan on building the motor so I wont realize any gains from the LT's. Besides when you look at the RPM range where the real spread starts to occur I'm just not in that area real often.

 

I look at it like this, Shorties are for looks, and LongTubes are for engines with mods. I wouldn't put longtubes on my car till I did any head modifications & cam, forced induction or a stroker motor. Otherwise I'd just leave the stock manifolds. Shorties are just a waste of money for our cars unless you just like the look and want to add more heat to the engine bay.

 

If you don't have emissions testing you could gut the cats and keep the stock manifolds & mufflers . But I would not bother with shorties if you looking for performance gains .

 

If its stock just leave it unless you like the look.

 

And you'll also get a 'throatier' sound from LTs.

 

If your looking for a bump in sound just get mufflers. Headers are a go fast part, which is when it boils down to it are a part that helps you win races. The long tubes still increased power through the whole powerband which would possibly mean the difference between a win and a loss or picking up 2 tenths or picking up as much as 5 tenths which means the long tubes are doing their job. I like the chart SS posted as it really shows it. At the beginning of the rpm range long tubes picked up 5hp and 8lb ft compared to shorties(understandable for you to want more to justify buying longtubes) but at 5300 it made 13hp more and 14lb ft more then shorties(enough proof for most to buy them). Yeah that may not be where your at alot but thats the purpose of shorties or long tubes. Unfortunatly to increase low end grunt tons means shifting the torque curve lower which also means decreasing peak hp and rpm which most would consider a bad. Also as someone else said lt1 headers come in 1 5/8 and 1 3/4 sizes which also affect it. I only wanna get around 350 hp which means the 1 5/8 is what i'd choose. Kinda like the motto the right tool for the right job. Not to mention the ceramic shorties are only like $150 less then long tubes which almost all of them are ceramic coated. Sorry for the long post, hope it helps.

 

Exhaust headers effectiveness is a portion of the overall system. The heads matter, the cam matters, the compression matters. The induction system matters, gearing matters.

Change any one of these things and the headers effectiveness will be affected.

So if your street driving, then what matters is Price, looks, and fit.

There are programs floating around where you can input header dimension and the other parameters and it will tell you what to expect.
So you can pick a set that won't produce the dismal 3Hp results some folks have had?

I don't have one, but I'll bet somebody reading this knows how to find it?

TJM

 

Thanks for all of the feedback. I got the JBA shorties in today from Corvette Guy's (man they ship fast!) I paid about 20 more dollars for them from CG than I found elsewhere but went for the reliable vendor. I will update you all on how everything turns out. I should get them on this weekend along with a Hurst short throw, Bosch III injectors, plugs, wires and a new fuel filter. She will be about as good as she's gonna get for me after that.

PS. I still say this LT4 would outrun my LS1. It's a freakin' rocket!

 

You are correct... it looks decision was made up prior to posting this thread
Good luck with your freakin' rocket.

 

Take some pics of the process if you have time!!! That would be sweeet! Good Luck!

 

I can only speak from my experience. Though I have to say, you can't hit 5,000 RPM in your car unless you are going 150+mph?

Here is my dyno of before and after the installation of 2" primary long tube headers with bullet cats. The exhaust downstream is modified, and the intake is ported. I wouldn't call it a "built" engine.

http://img42.imageshack.us/img42/3365/headerdyno.jpg

You can see that by 3,000 RPM the torque is equal or greater with the long-tubes. I am not certain if they make less torque lower down or not, the dyno reading isn't very stable there. That's a fair bit lower than 5,000 RPM, and it's absolutely in an area of the tach I see a lot of. Though so is 5 grand...

 

and there are some guys here with the dyno that shows at which rpms the long tubes had like 40 more hp, and lots more torque. It is not a total gain every where, but at certain rpms it is way more power than stock. This was on a basicly stock motor IIRC. There is thread floating out there with this on it.

 

Then there is the arguement that if you go with 1-5/8" primaries like I did you pick up low end torque and the expense of high rpm torque. As others have said it all depends on your intended use and what you want to accomplish.

My long tube headers with rt cats and stock exhaust sounds low and throaty in my 95 and I really love it. Very glad I invested the $$ in the LTs rather than a stainless exhaust / muffler system.

To each his own that's what makes this so great

 

Think of your shorty headers as a water spigot on the side of your house. Turn the sigot on with no hose attached to it. The flow coming out is pretty good. Now hook a short piece of hose to the spigot and turn it on. The pressure is better, correct? Headers work the same way. The longer the tube the faster the gases will get out of the engine. This is called scavenging. The back up of gases is actually helping pull the gases out of the cylinder. There is a short piece of hose for each cylinder with long tubes. None with shorties. So the longer the header tube the better the flow will be.......to a point of coarse. Now, say that piece of hose was 1 5/8 in dia. and you turned the spigot half way open. Still a pretty good flow, yes. Now put a short piece of 1 3/4 hose on there and turn the spigot half way open. The flow decreased, yes? Now turn the spigot wide open with the 1 3/4 piece of hose. The flow increased better than it was with the 1 5/8 hose, yes. Engines use the same principal. The 1 5/8 hose is good to a point but when the hp is increased the tubes need to be larger. The closer these tubes are to the same length the better. That makes the scavenging equal on each cyl. It is said that point is 400 rwhp with 1 5/8 headers. Over that you should use 1 3/4 headers. Then 1 7/8 and then open tubes just like the big boys use. This principal is why some actually lose rwhp when running open exhaust. The spigot doesn't have enough pressure against it to help get the water out of the house. Hope this helps!

You can also check just about any cam company's specs on what size headers were used when they tested a cam for the stock or slightly modded LT1. It will just about always list 1 5/8 headers that were used in the test.

I have 1 5/8 headers on my '96. I only picked up 3 rwhp with a Corsa exhaust system and simple bolt ons. I picked up 17 ft lbs of rwt though. That's because my pump isn't big enough. I'm working on enlarging it though.

Some more info for you
http://forums.corvetteforum.com/c4-t...longtubes.html