LT's are not worth that much. Talk to any real shop or people that tune them. I had a small cam in mine and everything else stock just emission delete and my car was a screamer and got 29 mpg at 90 on the highway and 20 in the city.

On exhaust manifolds. The restricition is in the cats not the manifolds. Maybe a little more than ten hp at the wheels no more than 20 at the flywheel. They are a waste of money unless you are doing alot of other stuff too. Get a set of corvette mannys for cheap and call it good they will get you maybe like 8 to 9 more at the flywheel and be like 7 or 8 less than any lt's you can find.

 

LT's are worth 20 rwhp - sorry to burst your bubble. Go to the header section of the forum and ask the vendors of this site what LT's add to the wheels. Maybe it's you that hasn't ever understood what's going on with headers vs. stock manifolds.

And, 29 MPG @ 90 mph??

 

Long tubes are not worth that much and sorry for those of you who think they are because you really aren't that famaliar with the engine so before you ridicule and poke fun at my expense learn what you are talking about before sounding like an idiot.

Check this data out then talk to me about it:

Power Numbers
Avg. Avg. Peak Peak
Combo TQ HP TQ HP
LS1 Vette
Manifolds 369.7 301.2 391 @4,900 396 @ 6,100
LS1 Camaro
Manifolds 360.5 292.3 384 @4,400 384 @5,700
TTS 1 5/8
Headers 372.4 301.9 397 @ 4,400 396 @ 5,600
TTS 1 3/4
Headers 372.5 302.5 396 @5,000 396 @5,700
TTS 1 7/8
Headers 373.1 303.3 396 @4,400 402 @5,800


Best headers gain 18 at the flywheel compared to the stock manny's which at the rear is maybe 11 like i said not much more than ten. With the average being way less than that. I guess I have no idea though just check out the article for yourself. I just do this for a living.


http://www.carcraft.com/techarticles...o_numbers.html

Haha i guess i missed the memo where 18 at the flywheel turns into 20+ at the rear wheels. Maybe I am just an idiot you guys are right. I am sure you all design and work on cars for a living so I better not argue and just ask the guys who make money on selling the parts.

29mpg is pretty easy too when you assume the new vette gets 24+ at 100 with an ls3. I had an ls1 at 1800 with 3.23's and a 6 speed. My lt1 in stock trim was get 23 on the highway at 70. Thats just bs too.

Sucks when you bash on a guy and tell him he doesn't know anything then get proved wrong by scientific results. Especially when multiple people bash. Some people should consider not working on cars, building them, or buying parts because they think they know it all and clearly dont.

 

Okay - there's your results using TTS headers. Here are some results using Kooks headers:

http://www.speedengineeringanddyno.com/dynotuning.htm

Look at the '99 Vette that only added Kooks headers. The arguement can be made that a portion of the gain is from the tuning, and at the same time, the tuning alone wouldn't have gained that much hp without the headers.

18 hp at the flywheel is 14.4 if you use 20% driveline loss - at this point it's just semantics, but it's higher than your estimate of 11, which would be almost 40% driveline loss. But, since you do this for a living, I'm sure you already know that your number isn't right, so why argue?

As far as 29 mpg @ 90 mph goes - that is just and makes no sense. I'm really sure your numbers were developed "using scientific results". I'm really sure you drove your car 90 mph for the entire fuel tank to come up with that, but hell, since you do it for a living..... I like how you 'assume' fuel mileage results based off of what an LS3 does where the hell is your "scientific results" that prove out you can get 24+ mpg @ 100 mph in an LS3 Vette??

On a side note, I had an LT1 car too, and saw about the exact same 23 mpg mileage you saw at/around 70 mph.

 

LOL

No offense dude, but with that link YOUR the one that needs to put the tools down.

Just looking at those JUNK headers makes me wanna gag. Look at the collector for christ sakes, its like 2" long LOL. THATS the reason they didnt make any F'in power right there. Look at every other header brand out there and see that the collector is more than twice the length of those pieces of junk.

Ever been to a drag strip before? Walk through the staging lanes and I bet that every race car you see has headers...even if their car doesnt have 700HP.

My car right now is H/C/I and has stock manifolds. If you care to send me the money, Ill have the car dyno'd with the manifolds and in a week or so after I put my headers on ill get it re-dyno'd for proof.

Let me know.

EDIT: Sorry original poster for whoring up your thread.

 

+1 :d

 

those headers in that link looked TERRIBLE, there is no way you can use an article like that to go against common knowledge that headers gain substantial power.

but to the OP, yes get an LS6 intake. THey are fairly cheap and very well designed. one other awesome thing is that they hold there value very well, so if you decide to upgrade to a FAST later on, its failry easy to sell it for what you bought it for originally.

I would look around in the regional section to see if you can find someone in your state that has LT headers, and see where they are getting there car checked. Some shops are more "friendly" than others and might cut you a break.

 

"John's A4 GTO gained 25.4 RWHP & 30.8 RWTQ from our custom Speed Engineering dyno tune. After he added Kooks 1&3/4 long tube headers his car was in desperate need of a tune. His only other mods were Flowmaster catback, ASP Pulley, and a K&N Cold Air Intake. Even though the peak numbers are awesome for the combination along with an automatic transmission the area under the curve is extensively impressive."

Thats with a few other add on's not the header alone. Tune will not have an affect on headers but you can gain hp on any motor with a tune. LS1's run maf tunes so it will not affect mass flow fueling.

Your results still verify my comment about a lightly modded engine doesn't gain much from headers. All race cars should have headers.


Also if you read the results about the headers it said it was tested with a full exhaust. Now if you know fluid flow dynamics you would know that collector really has no affect after an exhaust is added. Its used as a flow straightening device where the primaries discharge into a larger orifice. Its basically tuning flow so the losses exiting just after the collector will be minimized due to it acting as a flow recovery device.

And as for getting 23 mpg on the highway in your lt1 haha did you stay there at 70 from fill up to fill up or what. Its really not that hard to do a fuel economy test u fill the tank up till you can't anymore. Drive it a little record mileage go back fill the tank up. Divide the mileage by the amount you filled up and wahlah magic mpg appears.

OK so 18 will probably be 12-16 at rear wheels. Depending on transmission.


Common knowledge is common. And makes a fool out of even the smartest people when it is used to generalize a specific thing.



Also i won't send you any money but what I will do is run the engine on the best modeling software to see the difference between the "restrictive" manifold compared to no restrictions which is ideally better than a header.

 

I tried to get you to look at the '99 Vette results since that was the only modification, and that's what the discussion was about. So, objectively, why don't you check it out again, just for fun.



As a matter of fact, yes, I did - I obsevered that mileage on a 470 mile trip, each way.

Here's an interesting thread going on right now about this debate about headers:

https://ls1tech.com/forums/new-ls1-o...y-worth-3.html

More than one person in the thread above went from ~13.3's down to ~12.9's with adding headers.

 

[QUOTE=Radcannon;11952591
Also i won't send you any money but what I will do is run the engine on the best modeling software to see the difference between the "restrictive" manifold compared to no restrictions which is ideally better than a header.[/QUOTE]

So you basically wanna run my setup on a "Desktop Dyno" to "compare" manifolds to headers is what your saying?

LOL, what a joke.

 

Wow there is alot of people in this thread who should not give advice. 98's had the strongest bottem ends heh? This thread needs to be locked before someone turns retarded.

 

Its actually called GT ISE. Which has a few different software levels with it but u wouldnt understand. I do performance and production engine analysis though a 1d flow simulation on 2d models.

I also am responsible for dyno tuning some production motors. I think we actuallly use desktop dyno at work to do all of our analytical engine design.

I am done arguing this is superficial. I know my background and I know my knowledge and there is probably a reason I have my job where I do and I get paid like i do.

98's are the most popular in high hp drag cars so I would say yes strongest bottom end.

 

1. Headers are a complete waste of money unless there is a ton of stuff done to your car.

2. You can get almost 30mpg on the hwy. with a cammed LS1 going 90mph

If you believe that man then its your deal. And for what its worth, no one was bashing you or saying you "don't know anything". Most of us have gone through countless numbers of threads and tech/magazine articles as well as speaking to many professionals in the feild to gain the knowledge we know today about headers. We are just trying to give you a slice of what we know, but I guess if we don't believe everything you say we are "bashing" you or saying "you don't know anything".

BTW, posting up one random article from car craft about what they found when they bolted up sub par headers on an ls1 doesn't portray undeniable "scientific proof" that headers only give a certain amount of hp.

I'm glad you work in the car field and its great you get to do something you love, but if you want answers straight from the horses mouth give one of our sponsers a call who develop and dyno tune their own headers such as "Texas Speed", or "American Racing Headers". I understand you have had the opportunity to dyno tune some production motors, but these guys develop racing equipment for LS1's day in and day out. End Rant...

 

Have you been to the track before OP?

if not i'd say you're gonna make 13.2-14

first time in track i only managed 14.4@104 with 2.7 60' so driver's skill means alot, it was with stock 3.42 tho so your 3.73 would help alot for your ET

oh and BTW headers are the most worth bolt on i've ever done

 

ha alright the blue knight thanks. I know what headers are worth and what they do.

I was telling him bang for the buck like he asked. The manny's are good for a decent amount a power.

Sorry if i upset some of you.

Gearing in the rear and double over drive is also what makes fuel economy capable. 90 mph was 1700 rpms at very little throttle basically resting my foot on her.

 

No 98's do not "have the strongest bottem end." The reason you you see them more is just hear say. Maybe they are cheaper I don't know. To say that you see them more so the must be stronger is just stupid. Most will agree the earlier LS1's had a weaker bottem end and the later have a stronger bottem end due to the change in rod bolts. I am not sure if I really belive that either as I have seen many early LS1's spun to 6400, 6900, and 7000 RPM. Just like the 02's. The point of my thread is not to rag on you for your thought's, but rather to let you know this is how bullshit internet rumors start. "1998 LS1's must be stronger becuase thay race more." is nothing more then an opinion and shouldn't be taken as fact.

 

Alright. There were some design changes after 98 that affected a few things. Sorry for taking a generalization and the fact that I have seen the blocks take more but you are correct and that doesn't reflect rod, piston, crank, bearing and fastner strength. They did change rod bolts but that was one of a couple changes.

This is worthless you guys can tell me everything i say is wrong but I am an engineer who has been working and doing testing in this field for a few years on the production and performance sides. I do testing on all sorts of products and straight flat out will tell you u guys have misconceptions on headers.

They wake up other bolts on but not a stock engine with an ls6 intake more than 12-14 at the rear wheels. I know this for a fact. The reason the manifolds are somewhat restrictive is due to locating the catalyst as far upstream to get brick temps up and sustained quickly, but they create alot of turbulence within the manifold because of sudden expansion, quick direction changes and not long enough straight portions to straighten flow.

Headers are used so at higher rpms and in race engines due to the fact that under full load the intake will be at atompospheric pressure and the scavenge affect from the headers will cause a vacuum on the exhaust side allowing for even better gas exchange through the cylinder because of the greater delta p due to the header vaccuum created. Now how this really affects a stock car that doesn't spin to high and doesn't have a large overlap you tell me because I would really like to know.

That being said on a budget headers would not be my first choice because they alone do not have the ability to make power. Its them in addition to other bolt on's and "upgrades". Thus they are more of a sound thing for me if putting them on a base engine.

 

sooo when it comes down to it your comments are pointless. We all know that headers outflow stock exhaust manifolds. The reason why people install them is because they are inexpensive!

 

Mid to low 13's...maybe faster

 

i got 13.8@103 with flowmaster rest was stock with 130k. i ran 8 times in a row never above 13's...