anybody see this yet

[idahoBLKss]

I would put money on if you have a stock ish truck and put these on you would loose power.

[skolman91]

I would put money on if you have a stock ish truck and put these on you would loose power.

Really?? So why didnt you put a 76mm turbo on your stock ish longblock truck? Im guessing because you plan on moving some serious air out of your setup, so how can you say moving more air out of an engine will lose power?

Edited September 4, 2013 by skolman91 (see edit history)

[Cramer]

I am going to run with no headers since that moves the most amount of air on my stock short block.

Bigger is not always better. On these motors non forced induced the motor can only let out what is entered. The velocity of the exhaust is the same out of the port but hits a wall with less velocity. I talked to some cobra jet guys at the track last week and only one of them ran a primary over 1.75". They all said they lost power.

 

Sent from my Motorola RAZR MAXX using Tapatalk 2

 

 

[idahoBLKss]

Really?? So why didnt you put a 76mm turbo on your stock ish longblock truck? Im guessing because you plan on moving some serious air out of your setup, so how can you say moving more air out of an engine will lose power?

Because on a stock ish truck you need back pressure to make power. Unless your highly modified and making some serious power you will not benefit for that big of a primary and in most cases will loose power down low dramatically , if you do a simple web search this is a know fact and is nothing new.

[skolman91]

I never said bigger was better, he just said put these on and you will lose power, which i disagree with is all. Yes velocity might be reduced somewhat, but will you make more power than the 1 3/4"? You might move the efficency range around a little, but yes they will make more power, as much as pacesetter is claiming, i doubt it.. Do 1 3/4" and 3" collectors work fine with what most people do to their trucks, sure do.

And you said it yourself "On these motors non forced induced the motor can only let out what is entered", an engine is just a big air pump, air in, air out...

And we dont have cobra jets, LS engines are pretty efficent, but which side needs help majority of the time on ls stuff, the intake or exhaust..?

Edited September 5, 2013 by skolman91 (see edit history)

[skolman91]

Because on a stock ish truck you need back pressure to make power. Unless your highly modified and making some serious power you will not benefit for that big of a primary and in most cases will loose power down low dramatically , if you do a simple web search this is a know fact and is nothing new.

yes i know all about back pressure and what you can read on the internet, i just believe its a myth to a certain degree.. Would you lose power down low with 7/8th's, maybe a little, but they will make more power. Just like with the bigger turbo you picked, you have lag, why? because you just moved the efficency range up higher, but you will make more power with a bigger wheel..

 

 

either way, everybody has their opinions, i can already tell im just gonna get overrunned by people saying this is whats said on the internet, so thats the way its gotta be.. Just trying to get people to not be so close minded..

I'll leave this thread alone now..lol

Edited September 5, 2013 by skolman91 (see edit history)

[GI.SS]

In a 5k lb truck you need all The low end power you can get. Moving the efficiency level up that much will Hurt you as 95% of the time you aren't in that efficiency range. It's like putting a cam in that peaks at 8000 rpm but your rpm range is only to 6500. Sacrificing the power down low to compensate for un-usable power = one step forward and 3 backward

[skolman91]

In a 5k lb truck you need all The low end power you can get. Moving the efficiency level up that much will Hurt you as 95% of the time you aren't in that efficiency range. It's like putting a cam in that peaks at 8000 rpm but your rpm range is only to 6500. Sacrificing the power down low to compensate for un-usable power = one step forward and 3 backward

you know what i completely agree with you 100%, imo i see people too often put huge converters and cams in heavy trucks, when they need to focus more on what moves these things, TQ not peak HP numbers. Basically what i think me and people disagree with is just how much these headers would hurt down low is what it comes to, i dont think they would that much compared to the gains, other people seem to think the low end would disapear over very minimal size increase..

Edited September 5, 2013 by skolman91 (see edit history)

[Cramer]

Can they make more power..... the answer is yes. Is it usable power with a good torque curve for a big truck like ours with simple bolt on's that only increased the incoming air by a fraction of what would be exiting the exhaust? A stepped header from 1.75" up to a 1.875 or 2" would be a very good header. It allows the exiting gasses to create enough velocity through the primary till it meets up with other cylinders exhaust waves thus keeping back pressure controlled in most ranges of the rpms and expelling efficiently in terms of keeping the velocity up through the whole exhaust system.

 

In Jons case he is using stock manifolds that flow very well to begin with and they will allow the turbo to spool quick with smaller primaries and his exhaust housing. Force more air in a smaller area and the velocity goes up. Hot exhaust gasses expand.

 

Sent from my Motorola RAZR MAXX using Tapatalk 2

 

 

[idahoBLKss]

Lol the reason I put the size turbo I did on my truck is because i want to put down 1k to the wheels not move my power band up lol. And I'll take you for a ride and you can tell me if I have "lag" lol this thing moves out as soon as I stomp it and is hitting full boost in a matter of seconds , way faster then my procharger did anyway. Look you can look at dyno graphs of people doing this swap you speak of and see the power loss it not a matter of being closed minded its facts. Like I said i would put money on it so let me know when you decide to do it.

[tburkdoll]

you know what i completely agree with you 100%, imo i see people too often put huge converters and cams in heavy trucks, when they need to focus more on what moves these things, TQ not peak HP numbers.

Just for discussions sake not to argue... Torque down low is needed and is great but i have watched shadowsnipers truck launch a few years ago, he had heads, HUGE cam, and intake combined with a HUGE convertor. That truck had balls and launched with authority, fastest N/a, stock Cubic Inch SSS on the site, at least he was. The truck obviously made more HP and TQ than stock but the point im making is that what you are changing is the TQ curve and where the power is made. With his cam the power was made in the High RPMs, and required the large 4k-ish rpm stall to get up into where the power was made. People just choose to stay N/a and if its not stroked than this is what you gotta do to start making big power out of our engines, the fact that they choose to do this too often is just there choice of how they wanted to try to go fast, not that its the best.

 

Again, not arguing just stating it for discussion

 

 

 

Edited September 5, 2013 by SweetSS24 (see edit history)

[skolman91]

Lol the reason I put the size turbo I did on my truck is because i want to put down 1k to the wheels not move my power band up lol. And I'll take you for a ride and you can tell me if I have "lag" lol this thing moves out as soon as I stomp it and is hitting full boost in a matter of seconds , way faster then my procharger did anyway. Look you can look at dyno graphs of people doing this swap you speak of and see the power loss it not a matter of being closed minded its facts. Like I said i would put money on it so let me know when you decide to do it.

id love to take a ride in your truck, dont think i wouldnt...lol and my lag comment comes from the way you describe the way it drives from your mexico racing and boost comes in in "seconds"... But its the internet and each person is different in their descriptions so we will just leave it at that, were getting off topic anyway..lol

If i had a awd dyno somewhere close and some cash and confidence these headers fit awd good i would really consider taking you up on that offer, because i hate my hump headers i have now. But since i cant i looked around and found this..

http://ls1tech.com/forums/generation-iii-external-engine/981229-stock-motor-1-3-4-vs-1-7-8-engine-dyno-results.html

to sum it up, 2008 TSP dyno test

-stock ls1 on engine dyno, 3k-6k test 1-3/4 vs 1-7/8 headers

-lost nothing down low same until +4800, then 1-7/8 gained above that

Ive also read elsewhere that ARH has never seen any loss in TQ with 7/8s over 3/4 in their testing, only more HP up top, and minimal change in header size can affect the peak tq curve by as little as 500rpms if that..

Im not dogging 3/4" headers, they do the job fine, but if i was going to buy new headers(and knew i was gonna do more mods in the future) i would go with the 1-7/8" knowing i wont lose any TQ and get a free 10+HP above 5K over 1-3/4s..

So how can you say "put these on a stockish truck and bet it would lose HP"?? Are you saying completely stock manifold truck, or lose over a 1-3/4" truck?

Just for discussions sake not to argue... Torque down low is needed and is great but i have watched shadowsnipers truck launch a few years ago, he had heads, HUGE cam, and intake combined with a HUGE convertor. That truck had balls and launched with authority, fastest N/a, stock Cubic Inch SSS on the site, at least he was. The truck obviously made more HP and TQ than stock but the point im making is that what you are changing is the TQ curve and where the power is made. With his cam the power was made in the High RPMs, and required the large 4k-ish rpm stall to get up into where the power was made. People just choose to stay N/a and if its not stroked than this is what you gotta do to start making big power out of our engines, the fact that they choose to do this too often is just there choice of how they wanted to try to go fast, not that its the best.

 

Again, not arguing just stating it for discussion

 

 

 

Your right, nothing wrong with going with big cam heads converter and let it rip, but he was trying to go as fast as he possibly could race truck style it sounds like..lol But i dont care what anybody says you start going that big with stuff it makes it a horrible DD.. Guys put 4k converters with 23x cams and wonder why it doesnt drive good or its not as fast unless you give it alot of go pedal, quick under the curve power is what makes for a fun DD.

Edited September 5, 2013 by skolman91 (see edit history)

[poopnewton]

I'd go 1 7/8 over 1 3/4 if I got headers but then again I'd go to l92 heads and intake too if I could.

[shadowsniper3006]

 

 

I don't know if I add any useful info or not, but I love giving my opinion so...

Jon I don't know if what you said is true, but then again what sinner hit on may be more true. Back pressure equals torque not hp, the way I understand things, the less back pressure you have the more hp will be created but it will raise where your peak hp is made. If we needed back pressure to make power we would all still have the manifolds on. However, the argument of running straight out the heads producing more power hits on the scavaging effect of the headers. If you did run straight out the heads and had zero back pressure you may just be down on power because there is no scavaging or increase in volocity from the headers, plus burnt valves. If that's true, and I'm not saying it is, there has to be a line in primary diameter that allows scavaging but has the least amount of back pressure. And I guess this assumes you want to find the most hp in your truck, not target a peak rpm or purpose built torque motor or target a lower stall converter. Which I think is what Jon and I do with our trucks.

 

That being said, where is that line? And this where I agree that what's said on the Internet is kinda a myth. Look around, every body that knows something says 1.75 is the best all around header or the best for a stockish motor. Where is the info that they "know" coming from? Did they dyno everything from manifolds, 1.625 primaries to 2" primaries? I'm betting it came for years of tests with small block Chevys and small block fords being repeated time and time again. I know the ls motor is pretty old now, but you still have a lot of guys that know the sbc Inside and out, pretending they know the ls and what's good for it. I have a buddy at work building a 600 hp 427 ford motor for 7000 rpm use, and he is using 225 afr heads and 1.75 primary headers. The fricken stock heads on a ls motor are what 210 and we run 1.75 headers on stock motors...not 600 horse ones. And go figure you can buy a 205 head for ls motors.....because for a small block....that's a big head. So if you ignor all the opinions that guys "know" to be true, is it hard to believe that a motor that comes with a 210 head from the factory might want a 1.875 header? Yeah you'll move your hp peak up a touch and yeah you'll loose some bottom end, but if it makes more average hp and torque from 3000 up.....did you loose anything, especially when most guys run a 3000 converter. Hell zippy wants a 2" header on my stock cubed truck. We constantly fight what guys "know"', like the stock fuel pump needs to be changed if you do a cam swap, or you need a high pressure oil pump if you do cam swap.

 

As for building a truck for torque or for higher hp, I did both. One got me to 12.8 and one got me to 12.4. One with a 3800 converter and one with a 4500. Was the 3800 converter and enough torque for a 1.633 60 foot time better on the street, yeah. But right now I promise you if you rode in my truck, you would never see any street ability issues with a 235 cam and 4500 stall. You tune it right, and the biggest thing is learning how to drive the truck, if it doesn't like 30 mph in 4th gear unlocked....you drive in 3rd. Don't force it to do something it did stock if it doesn't want to. Or if it doesn't have the bottom end torque, add gears and it may just work great. You can believe me or not, my truck is not a race truck. It is not hard to drive. And it could be a dd. I drove it to Kansas City and back to prove to guys it's not that bad. If I remember right Jon was there, he sure didn't notice me limping it around nor did Brian who saw the truck on the street a lot. Does it have down falls, yeah, mpg sucks in the city(still gets 13.0 on the highway), valve guide life isn't good neither is spring life. But, if you want to go faster na....eventually you have to give up this bottom end torque everybody loves so much. With the limit of stock cubes, how do you get a truck with a 224 cam and stock intake and 1.750 headers to go faster? Bigger cam, less torque down low. Short runner intake, less torque everywhere. Larger headers, less low end torque. Eventually you say f it, and the 4000 stall goes in, and the truck still drives good at every mph on the street, because YOU learn how to drive it. Or you hold onto your torque...and you beat me to the 60 foot line by .055 seconds and then I pass you like your standing still, much like Jon and his turbo lag, lol....except he would pass me like I'm standing still.

 

So that doesn't answer the question, but maybe it gets you thinking about what we all "know" and maybe opens a few minds to some new ideas

[JC03SS]

All good points there Brad. I like it when you drop knowledge on us that aren't that familiar. I appreciate all the help and the research you put in and the detailed answers you give. It's nice to have members on the site that are always willing to help out.