454 vortech power and torque numbers and AFR

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John Cunningham

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Completely disagree but I understand the desire to keep the manifolds for maintenence and reliabilty.

After I put tri-y headers on the Express it made ALOT more grunt even down in the 1,500-2,500 rpm range. Same torque converter would stall 200 rpm higher. I was suddenly able to climb hills in overdrive that had previously caused the trans to drop to 3rd. My vacuum at cruising speed on the highway also increased 2-3 in/hg at 70 mph.

I am sure header selection plays a HUGE role in the results. If a person was to throw some header with a massive primary and collector diameter on a stock engine I could see it not helping or even hurting through the 4,500 rpm range. A good quality tri-y like Doug Thorley makes will wake up the bottem end and midrange ALOT!
Maybe a tri y...but no shorty will ever work...you need some 36 long small primarys and a small collector extra long....I have paid thousands for headers over the years from the best guys there are that make them......Davis Step Headers. Jere Stahl.......Headers By Ed
Lemons Headers....I was a serious drag racer and have spent hundreds of hours on engine dynos spanning 35 years....cruising at 2500 rpm part throttle will give you nothing and maybe under full power and exceeding 4000 rpm you might see a little. Most of my engines were tuned for over 10,000 rpm. We shifted at around 9700 and they fell back to at the most 7700 rpm...headers are crucial then. I have dynoed some street engines with kids bring me 1 3/4 headers for 350 street engines.........no power gain below 4000 rpm and had Headers By Ed build me some 1.5 inch 38 long equal length headers and we picked up...The problem is ..........hard to purchase and out of the box header that fits and performs...there all made like crap...I dont want to chase header bolts either. No thanks...1000 rpm to 3500 would not be worth it...
 

John Cunningham

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That's what throws me off, some people don't see a change with headers, some people say it woke their truck up. I'm willing to take a gamble though; I'd be interested in getting my truck on a dyno for some comparisons to before and after with the 0411 and full exhaust.


He got back to me within a couple days; I got the pinout and I've been meaning to mail him payment for a swap kit but bills keep getting in the way. $190 for a tuned PCM and all the connectors is a pretty good deal to me.
he sent it without you paying him? Man if you received something from him you certainly should have paid him? Send it to me and Ill pay you on a paypal account that way you can pay him and get it later when you have the money?
 

John Cunningham

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Good deal!

Of you are going through all the trouble of the 0411 swap anyway as well as the engine build it gets almost shameful not to update to the 24x system. Its only about 12 wires that get added to the engine harness and you can pull the coil wiring to the PCM of any junkyard 99-06 LS truck for practically nothing. Just have to find someone that can setup the correct PCM file to get it going.

EFI connection even went so far as to convert a 454 to a Ramjet intake and drive by wire system.

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Thanks for the info..........I wondered about the ram jet deal...wondering how that manifold works down low?
 

L31MaxExpress

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With the stock manifolds, my 350 wheezed horribly even at lower rpms. When I put the thorleys on with the same exhaust setup it transformed the engine. It was 2 seconds quicker 0-80 mph with thorleys shifting at 4,700 than it was with the manifolds shifting at 5,300. Shifting with the thorleys at 5,300 it was about 3.5s quicker 0-80 mph than the stock 2.25" outlet manifolds. Same stock 3" dual pipes and cats with a dual 3" in/single 4" out muffler.

I have had numerous sets of headers installed that I have not touched for years at a time. No loosened bolts, blown gaskets or flange leaks.

I know I am not changing your mind but I personally will not run an engine without some form of header.

My 2011 Infiniti M56S has shorty tri-ys from the factory with cats welded directly to the outlets. It has the flatest torque curve you will ever see. 338 cid made 378 rwhp and 390 rwtq factory stock. With K&N drop in filters and the ignition timing advanced 2* it made 390 rwhp and 410 tq. Which was enough to take a 4,500 lbs car down the track at 12.6 @ 108. With the timing advanced it made over 90% of its torque peak from 1,500 rpm. 12:1 DOHC engine loaded with variable valve duration, lift and variable valve timing as well as direct injection.
 
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L31MaxExpress

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Thanks for the info..........I wondered about the ram jet deal...wondering how that manifold works down low?
I think it would work about like a Holley Stealth Ram on a 350.

I wonder if you could get your hands on one of the big block TPI setups Arizona Speed and Marine once made. I hear they make great low-midrange torque.
 

L31MaxExpress

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I think this intake would be worth tracking down for your build. Look at those long runners and that massive monoblade throttle body. The intake almost looks like a Ramjet until you notice the runners feed opposite sides of the engine and are close to 2x the length of the Ramjet runners.

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88monteSS

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he sent it without you paying him? Man if you received something from him you certainly should have paid him? Send it to me and Ill pay you on a paypal account that way you can pay him and get it later when you have the money?

Unless he's changed things he always provided the spreadsheet for free, he just asked that people not redistribute it so he has the chance to offer the swap kit. You might try him on the other forum, I know in the past he mentioned he'd sometimes not get notifications about PMs from some forums.
 

John Cunningham

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With the stock manifolds, my 350 wheezed horribly even at lower rpms. When I put the thorleys on with the same exhaust setup it transformed the engine. It was 2 seconds quicker 0-80 mph with thorleys shifting at 4,700 than it was with the manifolds shifting at 5,300. Shifting with the thorleys at 5,300 it was about 3.5s quicker 0-80 mph than the stock 2.25" outlet manifolds. Same stock 3" dual pipes and cats with a dual 3" in/single 4" out muffler.

I have had numerous sets of headers installed that I have not touched for years at a time. No loosened bolts, blown gaskets or flange leaks.

I know I am not changing your mind but I personally will not run an engine without some form of header.

My 2011 Infiniti M56S has shorty tri-ys from the factory with cats welded directly to the outlets. It has the flatest torque curve you will ever see. 338 cid made 378 rwhp and 390 rwtq factory stock. With K&N drop in filters and the ignition timing advanced 2* it made 390 rwhp and 410 tq. Which was enough to take a 4,500 lbs car down the track at 12.6 @ 108. With the timing advanced it made over 90% of its torque peak from 1,500 rpm. 12:1 DOHC engine loaded with variable valve duration, lift and variable valve timing as well as direct injection.
its a 4 wheel drive anyway and there is not much room....anybody that has had as many headers as I have had would know...I am not looking for power over 3500 to 4000..the gains would be minimal and the chance leaks there.
However lets not forget the tinny noise you are always going to get out of headers. I could not stand that on a trip. Cast iron is quiet and even if you gave me 25hp and thats a doubt I would not want to put up with the tin sound of headers...but it would be fun to engine dyno with some real numbers and no pulls over 4000 rpm
 

John Cunningham

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Unless he's changed things he always provided the spreadsheet for free, he just asked that people not redistribute it so he has the chance to offer the swap kit. You might try him on the other forum, I know in the past he mentioned he'd sometimes not get notifications about PMs from some forums.
I dont want anything for free...he has time and effort in this and should make some money because he has something that guys need and want= Money
 
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