Longtubes VS Midlengths
Registered User
Joined: Jun 2003
Posts: 2,626
From: Baylor University - TX
Originally posted by Montezuma
If this is true, 23 more hp at 6k seems worth it over a little loss at the low end and much more headach to install. Not trying to be biased but it seems that way to me. Does anybody have any dyno numbers?
If this is true, 23 more hp at 6k seems worth it over a little loss at the low end and much more headach to install. Not trying to be biased but it seems that way to me. Does anybody have any dyno numbers?
Registered User
Joined: Mar 2002
Posts: 3,634
From: Newark, Delaware
This is the test Car Craft did with a small block Chevy:
1 5/8" 34" long-tube headers.......1 5/8" mid length headers
RPM... TQ HP............................TQ HP
2,600 430 213......................... 422 209
2,800 434 231......................... 420 224
3,000 439 251......................... 427 244
3,200 438 267......................... 431 262
3,400 434 281......................... 433 280
3,600 431 295......................... 432 296
3,800 424 307......................... 432 312
4,000 415 316......................... 422 321
4,200 402 321......................... 411 328
4,400 389 326......................... 398 333
4,600 374 327......................... 386 338
4,800 355 324......................... 369 337
5,000 334 318......................... 351 334
5,200 314 311......................... 337 333
5,400 294 302......................... 316 325
As you can see, the mid length made more torque AND HP from 3,600 RPM - up.
The only place the LT was really any better was below 3,200 RPM.
With a longtube you're getting 14 more FT/LBs at 2,800 RPM, but you're giving up 23 HP at 5,200 RPM.
What's the flash point of all of our high stall converters? Aren't most ABOVE 3000 RPMs? I'm coming out of the hole making around the same power as a longtube, but I'm making more power upstairs.
Also, I wanted to ask all the longtube guys. How much did you pay for your headers? Did you pay extra for AIR fittings? How much for the y-pipe? And where did you mount your catyletic converters?
My $330 set of MACs came with a y-pipe that bolts to my catyletic converter, and already had all the fittings...And, I hate to mention it again, but it goes 12.0's
.
Frank
1 5/8" 34" long-tube headers.......1 5/8" mid length headers
RPM... TQ HP............................TQ HP
2,600 430 213......................... 422 209
2,800 434 231......................... 420 224
3,000 439 251......................... 427 244
3,200 438 267......................... 431 262
3,400 434 281......................... 433 280
3,600 431 295......................... 432 296
3,800 424 307......................... 432 312
4,000 415 316......................... 422 321
4,200 402 321......................... 411 328
4,400 389 326......................... 398 333
4,600 374 327......................... 386 338
4,800 355 324......................... 369 337
5,000 334 318......................... 351 334
5,200 314 311......................... 337 333
5,400 294 302......................... 316 325
As you can see, the mid length made more torque AND HP from 3,600 RPM - up.
The only place the LT was really any better was below 3,200 RPM.
With a longtube you're getting 14 more FT/LBs at 2,800 RPM, but you're giving up 23 HP at 5,200 RPM.
What's the flash point of all of our high stall converters? Aren't most ABOVE 3000 RPMs? I'm coming out of the hole making around the same power as a longtube, but I'm making more power upstairs.
Also, I wanted to ask all the longtube guys. How much did you pay for your headers? Did you pay extra for AIR fittings? How much for the y-pipe? And where did you mount your catyletic converters?
My $330 set of MACs came with a y-pipe that bolts to my catyletic converter, and already had all the fittings...And, I hate to mention it again, but it goes 12.0's
.Frank
Last edited by 12SCNDZ; Dec 24, 2003 at 03:05 PM.
Registered User
Joined: Sep 2002
Posts: 464
From: Orlando, FL
Originally posted by 12SCNDZ
This is the test Car Craft did with a small block Chevy:
1 5/8" 34" long-tube headers...............1 5/8" mid length headers
RPM... TQ HP................. TQ HP
2,600 430 213........................... 422 209
2,800 434 231......................... 420 224
3,000 439 251......................... 427 244
3,200 438 267......................... 431 262
3,400 434 281......................... 433 280
3,600 431 295......................... 432 296
3,800 424 307......................... 432 312
4,000 415 316......................... 422 321
4,200 402 321......................... 411 328
4,400 389 326......................... 398 333
4,600 374 327......................... 386 338
4,800 355 324......................... 369 337
5,000 334 318......................... 351 334
5,200 314 311......................... 337 333
5,400 294 302......................... 316 325
As you can see, the mid length made more torque AND HP from 3,600 RPM - up.
The only place the LT was really any better was below 3,200 RPM.
With a longtube you're getting 14 more FT/LBs at 2,800 RPM, but you're giving up 23 HP at 5,200 RPM.
What's the flash point of all of our high stall converters? Aren't most ABOVE 3000 RPMs? I'm coming out of the hole making around the same power as a longtube, but I'm making more power upstairs.
Also, I wanted to ask all the longtube guys. How much did you pay for your headers? Did you pay extra for AIR fittings? How much for the y-pipe? And where did you mount your catyletic converters?
My $330 set of MACs came with a y-pipe that bolts to my catyletic converter, and already had all the fittings...And, I hate to mention it again, but it goes 12.0's .
Frank
This is the test Car Craft did with a small block Chevy:
1 5/8" 34" long-tube headers...............1 5/8" mid length headers
RPM... TQ HP................. TQ HP
2,600 430 213........................... 422 209
2,800 434 231......................... 420 224
3,000 439 251......................... 427 244
3,200 438 267......................... 431 262
3,400 434 281......................... 433 280
3,600 431 295......................... 432 296
3,800 424 307......................... 432 312
4,000 415 316......................... 422 321
4,200 402 321......................... 411 328
4,400 389 326......................... 398 333
4,600 374 327......................... 386 338
4,800 355 324......................... 369 337
5,000 334 318......................... 351 334
5,200 314 311......................... 337 333
5,400 294 302......................... 316 325
As you can see, the mid length made more torque AND HP from 3,600 RPM - up.
The only place the LT was really any better was below 3,200 RPM.
With a longtube you're getting 14 more FT/LBs at 2,800 RPM, but you're giving up 23 HP at 5,200 RPM.
What's the flash point of all of our high stall converters? Aren't most ABOVE 3000 RPMs? I'm coming out of the hole making around the same power as a longtube, but I'm making more power upstairs.
Also, I wanted to ask all the longtube guys. How much did you pay for your headers? Did you pay extra for AIR fittings? How much for the y-pipe? And where did you mount your catyletic converters?
My $330 set of MACs came with a y-pipe that bolts to my catyletic converter, and already had all the fittings...And, I hate to mention it again, but it goes 12.0's
.Frank
This engine may be in design a Small Block Chevy, but not many plain jane small block chevys flow or perform like an LT1 in near stock or mildly modified form. Look at the L98! The LT1 has more flow capability stock for stock than a regular small block like in that test, so it needs more CFM up top.You are comparing a set of FULL LENGTH 1 5/8" headers to a set of 1 5/8" midlengths. In this test, the primary diameter is held constant, and so of course, with reduction in primary length comes increase in top end. This is called a "control."
Now, name me ONE 1 5/8" longtube for an LT1.... can you? Now, keep in mind that all the longtubes for the LT1 are at least 1 3/4". That right there will provide more top end than ANY 1 5/8" header, period. There is no control variable between 1 5/8" mids and 1 3/4" longtubes because both variables are changing. But the fact of the matter is that by going UP in primary tube diameter, you are increasing your top end torque far beyond that which even the shortest 1 5/8" shorty could provide. Still with us? Good.
You seem to butt your head into every one of these mid vs. longtube debates and brag about your times, and blah blah blah. You seem to think that you are unrefutable scientific proof that since you have these headers, you should get a cookie since you run 12.0. Lets break it down:
Purple pearl '93 Z, Stock 95,000 mile bottom end, CC305 COMP cam, COMP lifters, COMP "Pro Magnum" non self-aligning 1.6 roller rockers, GMPP guide plates, AFR "Hydra-Rev", JPR race ported LT1 heads with 2.0"-1.56" Manley valves (271 CFM @ .550" lift), 58 MM Holley throttle body, Accel 30 # injectors, MAC headers, Flowmaster exhaust, Jegs cut-out, PCMFORLESS chip, MSD 7AL-2, MSD "Blaster" coil, MSD 8.5 MM wires, CSI water pump, 9.5" non lock-up, ProTorque converter, "Bulletproof" 700 transmission, 4.10 GM gears (In the stock 10 bolt) M/T 26"X 11.5" x 15" ET Streets, Weld 15" x 3 1/2" and 15" x 8" Draglites. COMPLETELY STOCK suspension! 3448 # with me in it (the only weight reduction are the wheels and front sway bar). 12.05 @ 112.35 MPH 1.67 60 ft.
Maybe those heads that flow 271 @ .550" just aren't breathing through the obviously superior MAC 1 5/8" diameter headers? 12.0 @ 112? That just doesn't fit. Lets look at the rest of it... hmm, stall converter, "bulletproof" tranny, 4.10 gears... that may be something to do with it. Is it possible you are just really good at launching? My friend traps 110.9 with a HOTcam and stock heads. Your race ported heads are only worth one MPH on him? Is he making ALMOST as much HP as you?
Some points to ponder.
I would like to add that I gained 7 tenths and 5 mph with my longtubes. I'm sure glad I wasted my money.
Registered User
Joined: Sep 2003
Posts: 1,917
From: Las Vegas
LOL OWNED
You also have to take into consideration the gain differences. LTs are going to perform differently based on the engine setup. Remember that these are a % based gain. I feel from everything Ive read, the LTs give a larger % in almost all applications. Plus as stated above, the larger diameter LT is what is out there. This added size WILL OUT PERFORM the mid length of smaller diameter.
You also have to take into consideration the gain differences. LTs are going to perform differently based on the engine setup. Remember that these are a % based gain. I feel from everything Ive read, the LTs give a larger % in almost all applications. Plus as stated above, the larger diameter LT is what is out there. This added size WILL OUT PERFORM the mid length of smaller diameter.
Registered User
Joined: May 2003
Posts: 1,132
From: Atlanta Ga
Originally posted by simple
i dont buy the myth of LT's producing more lowend tq. heres why..
a friend of mine with a '94 M6 cai, catback, without headers made maximum tq at 2600rpm
now on my car with Hooker LT's cai and catback made maximum tq at 4200rpm
both cars are stock cam and stock valvetrain, both cars were done on the same dyno
i dont buy the myth of LT's producing more lowend tq. heres why..
a friend of mine with a '94 M6 cai, catback, without headers made maximum tq at 2600rpm
now on my car with Hooker LT's cai and catback made maximum tq at 4200rpm
both cars are stock cam and stock valvetrain, both cars were done on the same dyno
Registered User
Joined: Mar 2002
Posts: 3,634
From: Newark, Delaware
Originally posted by TheHeadFL
You just don't get it do you? This engine may be in design a Small Block Chevy, but not many plain jane small block chevys flow or perform like an LT1 in near stock or mildly modified form. Look at the L98! The LT1 has more flow capability stock for stock than a regular small block like in that test, so it needs more CFM up top.
You are comparing a set of FULL LENGTH 1 5/8" headers to a set of 1 5/8" midlengths. In this test, the primary diameter is held constant, and so of course, with reduction in primary length comes increase in top end. This is called a "control."
Now, name me ONE 1 5/8" longtube for an LT1.... can you? Now, keep in mind that all the longtubes for the LT1 are at least 1 3/4". That right there will provide more top end than ANY 1 5/8" header, period. There is no control variable between 1 5/8" mids and 1 3/4" longtubes because both variables are changing. But the fact of the matter is that by going UP in primary tube diameter, you are increasing your top end torque far beyond that which even the shortest 1 5/8" shorty could provide. Still with us? Good.
You seem to butt your head into every one of these mid vs. longtube debates and brag about your times, and blah blah blah. You seem to think that you are unrefutable scientific proof that since you have these headers, you should get a cookie since you run 12.0. Lets break it down:
Ok, so let me lay it out for you. You've got a CC305 cam and RACE PORTED heads. Awesome, I bet those heads put out a lot of top end. But wait, 112.35 mph? That isn't as high as you'd expect to see from this top end machine, especially one that weighs not even 3500# with driver. People outtrap that with stock heads in some cases. Most people with race ported heads would hope for a little better than that I think. Maybe your top end isn't as magically powerful as you thought? Maybe those heads that flow 271 @ .550" just aren't breathing through the obviously superior MAC 1 5/8" diameter headers?
12.0 @ 112? That just doesn't fit. Lets look at the rest of it... hmm, stall converter, "bulletproof" tranny, 4.10 gears... that may be something to do with it. Is it possible you are just really good at launching? My friend traps 110.9 with a HOTcam and stock heads. Your race ported heads are only worth one MPH on him? Is he making ALMOST as much HP as you?
Some points to ponder.
I would like to add that I gained 7 tenths and 5 mph with my longtubes. I'm sure glad I wasted my money.
You just don't get it do you?
This engine may be in design a Small Block Chevy, but not many plain jane small block chevys flow or perform like an LT1 in near stock or mildly modified form. Look at the L98! The LT1 has more flow capability stock for stock than a regular small block like in that test, so it needs more CFM up top.You are comparing a set of FULL LENGTH 1 5/8" headers to a set of 1 5/8" midlengths. In this test, the primary diameter is held constant, and so of course, with reduction in primary length comes increase in top end. This is called a "control."
Now, name me ONE 1 5/8" longtube for an LT1.... can you? Now, keep in mind that all the longtubes for the LT1 are at least 1 3/4". That right there will provide more top end than ANY 1 5/8" header, period. There is no control variable between 1 5/8" mids and 1 3/4" longtubes because both variables are changing. But the fact of the matter is that by going UP in primary tube diameter, you are increasing your top end torque far beyond that which even the shortest 1 5/8" shorty could provide. Still with us? Good.
You seem to butt your head into every one of these mid vs. longtube debates and brag about your times, and blah blah blah. You seem to think that you are unrefutable scientific proof that since you have these headers, you should get a cookie since you run 12.0. Lets break it down:
Ok, so let me lay it out for you. You've got a CC305 cam and RACE PORTED heads. Awesome, I bet those heads put out a lot of top end. But wait, 112.35 mph? That isn't as high as you'd expect to see from this top end machine, especially one that weighs not even 3500# with driver. People outtrap that with stock heads in some cases. Most people with race ported heads would hope for a little better than that I think. Maybe your top end isn't as magically powerful as you thought?
Maybe those heads that flow 271 @ .550" just aren't breathing through the obviously superior MAC 1 5/8" diameter headers? 12.0 @ 112? That just doesn't fit. Lets look at the rest of it... hmm, stall converter, "bulletproof" tranny, 4.10 gears... that may be something to do with it. Is it possible you are just really good at launching? My friend traps 110.9 with a HOTcam and stock heads. Your race ported heads are only worth one MPH on him? Is he making ALMOST as much HP as you?
Some points to ponder.
I would like to add that I gained 7 tenths and 5 mph with my longtubes. I'm sure glad I wasted my money.
Have you really ever been NEAR a dragstrip? It doesn't take a genius to know that 4.10 gears aren't going to trap really high MPH. Maybe you're new at this, though. I've been racing for 15 years. You quoted me your "friends" time, but neglected to quote your own. 7/10's from what?...14's? I'll bet I ran as quick with manifolds as you do with longtubes.
Yea, I interject myself in all the LT vs. mid length header topics BECAUSE I get tired of seeing guys like you spread misleading information about the longtube being so much more superior than the mid lengths.
Frank
Registered User
Joined: Nov 2002
Posts: 496
From: windsor,on
it depends on what you want out of the car
the idea is the same, the mid length should give you more power up high, but the longtubes will give more down low.
if you want a 1-3/4 midlength get the as&m's, slp and i think rk sport (as&m copy)
i myself went with the as&m's cause i found a good deal on them used, but did like the gains in the upper rpm's while going down the strip, i noticed that it pulled better thru 3rd
no matter what you choose, everyone still has their own opinion, not saying that they are wrong or right
the idea is the same, the mid length should give you more power up high, but the longtubes will give more down low.
if you want a 1-3/4 midlength get the as&m's, slp and i think rk sport (as&m copy)
i myself went with the as&m's cause i found a good deal on them used, but did like the gains in the upper rpm's while going down the strip, i noticed that it pulled better thru 3rd
no matter what you choose, everyone still has their own opinion, not saying that they are wrong or right
Registered User
Joined: Dec 2003
Posts: 27
I have Edelbrock midlengths installed, and I hate them. It could just be the brand/model of the headers, though. I've heard terrible things about mine (they weren't installed by me)...
I'm looking at a Jet Hot coated Hooker LT swap sometime in the near future.
I'm looking at a Jet Hot coated Hooker LT swap sometime in the near future.
Last edited by Super Mario; Dec 25, 2003 at 04:37 AM.
Registered User
Joined: Apr 2001
Posts: 1,132
From: Florida
Some more interesting stuff...see link below.
http://web.camaross.com/forums/showt...hreadid=191577
Thx,
Claude
http://web.camaross.com/forums/showt...hreadid=191577
Thx,
Claude
Advanced Member
Joined: Nov 2003
Posts: 3,874
From: Under The Hood
Originally posted by Super Mario
I have Edelbrock midlengths installed, and I hate them. It could just be the brand/model of the headers, though. I've heard terrible things about mine (they weren't installed by me)...
I'm looking at a Jet Hot coated Hooker LT swap sometime in the near future.
I have Edelbrock midlengths installed, and I hate them. It could just be the brand/model of the headers, though. I've heard terrible things about mine (they weren't installed by me)...
I'm looking at a Jet Hot coated Hooker LT swap sometime in the near future.
Take that back!
I have Eddie Shorties they're awsome. They went in like nothing. Even though I brought mine as temps. They feel pretty good. When your on it. Only problem I saw with my headers was that the tubes ar welded from the inside and they kind of get in the way of the air flow. cause the welds are really bulky and make the d ports un even....I got the Dremmel out and smoothed mine and gave the inlet tubes more flow clearance...other than that pretty solid.
Registered User
Joined: Oct 2003
Posts: 260
From: Turnersville/Washington Twp. NJ
Super Mario-
I have Edelbrock midlengths installed, and I hate them. It could just be the brand/model of the headers, though. I've heard terrible things about mine (they weren't installed by me)...
I have Edelbrock midlengths installed, and I hate them. It could just be the brand/model of the headers, though. I've heard terrible things about mine (they weren't installed by me)...