DO LONG TUBE HEADERS ADD HP? 1 3/4 vs 1 7/8 HEADER TEST. WHAT MAKES MORE POWER ON AN LS? BONUS TEST

HOW MUCH POWER ARE LONG TUBE HEADERS WORTH? WHAT MAKES MORE POWER, 1 3/4 HEADER OR 1 7/8 HEADERS? WHICH HEADER SIZE MAKES THE MOST TORQUE? DO LONG TUBE HEADER IMPROVE LOW SPEED TORQUE? HOW CAN I ADD MORE TORQUE? HOW CAN I ADD MORE POWER TO MY LS? DO LS EXHAUST MODS WORK? CHECK OUT THIS VIDEO WHERE I COMPARED 1 3/4-INCH LONG-TUBE HEADERS VS 1 7/8-INCH LONG TUBE HEADERS WITH TWO DIFFERENT CAMS (BTR TRUCK NORRIS AND SLOPPY BEST CAM). I ALSO TESTED THE EFFECT OF COLLECTOR LENGTH ON POWER BUT COMPARING A SHORT COLLECTOR EXTENSION VERSUS A LONG COLLECTOR WITH MUFFLERS. LOTS OF GOOD LS HEADER INFO HERE!

[@minig4126]

Would have liked to see the 1 7/8” headers with a “ full exhaust” also keep the dyno runs the same color it’s confusing lol

[@Pitman556]

I learned more in 2 weeks watching your old videos than i did watching power block tv. Great work again man

[@jaguarman1983]

So much great data! Thanks Richard for the awesome videos.

[@dwightvoeks9970]

Love your comparisons. They get right to the point.

[@mattmorrison6958]

Really cool test and probability highlights how camshafts and headers work in conjunction, with headers often reducing the negative effects of extra duration down low, showing more improvement since there is more to "clean up"

[@calivette805]

Head bang with the intro is an absolute must

[@nurburgringdreaming2221]

Well this is good knowledge because some of us with LS7s have a clearance issue with 2” as opposed to 1-7/8” . I’ve always read guys will lean towards 2” headers but rarely speak of the collector length on the LS7s.

[@z0lan0solano14]

Just in time. I've been surfing the web for info on which one of these headers would benefit my lc9 on my truck. I'm running beehive springs, a CompCams camshaft (dur. 214/228 lift .559/.571 lsa 114 ), and 799 ported heads. Thank you so much Richard. With this info i will go with 1 3/4 and magnaflow muffler with a beside cut through exhaust!! Especially knowing that this test was done on a bored out 5.3, which is my plan for the future. I really thought i would miss out if i didn't go with 1 7/8, but for a offroad truck, i'd much rather have low end torque than high end RPM. Thanks again Richard!

[@johnpublic168]

that's what it's all about, great work. you worked hard for that info, thank you

[@themrjones]

That into is just so awesome. 😎

[@robertwood3970]

This 100% correct that a full exhaust system will work better than open headers. I did this same experiment at the race track by putting a capable cutouts on my headers. When I took the caps off the headers the car slowed down 2/10 of a second in the 1/8. Put the caps back on and the car picked up and ran where it had previously. Glad to see the myth of 1 7/8 headers busted, I had long wondered about that. Thanks Richard.

[@brettrichards787]

Hi Richard, I love the videos and keep them coming! I think it's great that with this round of testing, we see that if you have a full exhaust plus headers, that this will positively improve power and torque production at a lower rpm. I wonder if this is because the camshaft manufacturers do their cam grind testing with full exhausts?

[@timmyneeley478]

Thanks Richard.

[@laiky71]

I'm absolutely thrilled to see you running low rpm tests with exhaust! This is real world driving data. I would love to see all your tests run this way.

[@robertwest3093]

Richard's Mustang 5.0 dyno tests book is literally the bible of the fox body Mustang enthusiast. Absolutely awesome!

[@richardholdener1727]

thnx

[@jamesmooney5348]

Cool. Thx Richard

[@Kincentc]

Fascinating. Wish I got paid to do header R&D. Pretty sure with enough fabricating, you could erase most of those mid rpm dips. Little bigger here, little smaller there.... Header setups would be exclusive to the engine setup though lol

[@hambone7777777]

Thx, I just figured primary size for a 660cid @ 5700rpm power, to be 2.125. A 572cid 6800rpm piece. That's what I want in a heavy SUV, making crazy power.

[@heavyliberty9763]

Best channel on YT.

[@tomdriscoll8667]

Congratulations... I belive you found the origin of the back pressure myth!!

[@stephanouellet3673]

thank you again i very appreciate your video compared parts

[@HighGearAutomotive]

Big if you need them. Just like intake, peak power increases from exhaust will only go as far as the engine requires.

[@thecitiots]

Richard I spend way too much time watching these videos 😃 keep em coming. Also have you done a comparison for LS/LT engines on equal length headers vs non-equal length? I know there is a sound change but is there a performance benefit on one vs the other?

[@danawilkes6174]

I wish he would try more Tri-Y setups. These are designed for mid-range 2,500 - 5,500 where all of this testing is being done. Another I have not seen here anywhere is Megaphone type collector setups.

[@lancecnichols]

I’ve been waiting for 1 7/8 to get back in stock based on some tests on Engine Masters (not LS) but good to know I can go 1 3/4 with an LS swap and put the $100+ in savings elsewhere in the build. Thank you for the valuable data!

[@Low760]

There is a good build in Australia on a Holden Commodore ss with an l77, similar results but backed up on the drag strip as a gain with smaller

[@joepetreng471]

I read all the comments and learned that I know far less than the NOT MUCH amount I thought I knew about exhaust performance.

[@keything8487]

NO YOU CANT !!!!!.........love this no nonsense in your face type comparisons. keep up the great videos, i like when you do these types without making any internal mods, takes all of the "YEAH BUTS" outta the comments !!!

[@paulthompson1654]

Hi , Seems its all about cams and cubic inches. A good strong street cam on BB 427 can use either 1 7/8 or upto 2 inch and still make power . Need to try on a N/A stroked LS or Sbc at 400 cu. inches . Thats an interesting test. Do the header calcs and 400cu.in is the minimum u would use 1 7/8 . With a strong street cam the requirement is somewhere between 1 3/4 and 1 7/8 tubes .

[@bodyshotjake7475]

Is the gain subject to displacement. Will a 4.8 ls or ford 4.6 have similar gains? Or even say an Audi 4.0 V8. I’m sure it’s a factor of many different variables and displacement is one of them. Another great video

[@jefffogle915]

Nice vid.. I'm sure there's going to be way to many bad replys My chevy 2 with a 385 ci small block with hooker fenderwell headers only changed a 1/10 of secoond in my 60 times. And that only from weight of exhaust. Still pull front wheel off the ground. Vs open headers

[@gloriamaletta8667]

If your running a 3000-5000 stall converter the reason for it is so your engine when at full throttle doesn't spend much time from idle to where the stall converter starts to catch so more torque below that say idle to 3000 would benefit street cruising but not so much full throttle now a heavy truck or SUV with a stock stall converter would benefit greatly with more torque from idle to 3000rpm

[@mark_osborne]

So interesting ! I'll bet going to 1 5/8 or even dropping down to 1 1/2 headers would get you even more low end torque

[@dennisrobinson8008]

On that size engine if you were 2000-4500 RPM most of the time a 1 5/8" would probably be better than a 1 3/4".

[@grahamerosewarne6656]

Awesome content Richard. It doesn't make that much difference. Depends where you want your power . 🆒👏🤟💯🔥

[@boharris8179]

Would it be accurate to say that scavenging was being affected because of the resonance pulse changing with size and length of the exhaust? BTW I'm looking forward to the 2.2 turbo colab with DV

[@melvinmoten9427]

What are your thoughts about the 2-in headers for a 5.3 l ? I saw that these were offered by speed engineering for the 5.3 l. In your opinion, are these worth buying?

[@johnplump4340]

It would be very interesting to see how the stock cam responded to the exhaust changes. Apples to apples.

[@richardholdener1727]

agreed

[@darcybritton1609]

You should do a test with ls swap s10 hedman long tubes with 1 1/2 primaries compared to the 1 3/4 long tubes

[@tysonyukich6927]

Hi Richard I was wondering if you’ll be able to do more back to back testing on 8 into 1 headers, 180 degree headers, and long tube tri y headers similar to what nascar would use. Comparing them to what most people use 4 into 1 headers. Love all the videos you do cheers

[@richardholdener1727]

would be cool-but not very practical since most of those can't be used in a vehicle

[@QuicKurtZX14R]

Looks like I chose the right size for a street 6.0 in a heavy car with a not yet installed 217/225 cam, 1 3/4 tri-y's should do good Thank You Richard Holdener !!!

[@richardholdener1727]

Tri Ys?

[@QuicKurtZX14R]

@@richardholdener1727 Yes

[@QuicKurtZX14R]

@@richardholdener1727 What do you think of them ?

[@mitchellerwin7449]

Richard, my man. Can you do a test on the BTR torque cam? In either a 5.3 or 6L that would be cool to see. I want a better low speed cam in my 2500hd without the chop or need for a looser stall. Maybe even some other cams that can be classified as “stealthy daily driver cams” not everyone wants the “chop chop”

[@richardholdener1727]

THE BTR TORQUE CAM WAS TESTED IN THE TRUCK NORRIS VS SLOPPY BEST CAM VIDEO

[@PCMenten]

The curves converge at 3000 rpm. If you could raise the values at 3000, you’ve found more power. Great stuff.

[@hisproperty1438]

G'day Richard. Thanks for another great video, but your results are not a great surprise to me. I learned a long time ago that dips in an engine's torque curve are a result of a bad exhaust for the RPM range of the dip. This issue is more common with 2-stroke motorcycles than 4-stroke cars & bikes, and much more common on with aftermarket products than with factory products. Whilst the original exhaust system on a motorcycle prevents the engine from making its peak power, compared to an aftermarket system, the original system gives a smoother torque curve. Obviously the manufacturer has the opportunity & ability to test & refine an exhaust system, & they use that to create a well rounded system - from airbox to exhaust tip. However, I do have a few questions for you. Have you considered trying a step design, say from 1 1/2"-1 3/4"-1 7/8"? Also, have you ever tried a cross-over design, where the outer 2 cylinders of 1 bank are collected with the inner 2 cylinders from the opposite bank? Finally, are the 1 7/8" extractors built with more anti-reversion than the 1 3/4" extractors? Once again, thanks for a great video - I enjoy watching shows that encourage thought. Andrew

[@rustysausage69]

Motorcycles quite simply cannot be compared to cars in regards to exhaust, because a factory exhaust on a motorcycle IS a header. There aren't the packaging constraints like there are under a car, and motorcycles aren't treated as much of appliances to the manufacturers as passenger cars are to their respectful manufacturers so performance is first and foremost on the agenda.

[@nickl3872]

Thank you

[@bobgyetvai9444]

Id bet a 2 3/4 collector extension would really bump up that lower speed torque getting its acceloration up better . Especially if this was a 4.8 tested . Torque is king getting that jump and it takes Alot more hp to run that down !!! Towing youll definately feel it !!!

[@RHYNOMAN12]

Could you do a 8 to 1 header to prove if they add torque? Then add a supercharger. Curious of actual torque gains.

[@ng6424]

Good stuff

[@bill2178]

13/4 is big already sbc is 1.5- 1-5/8

[@aidzybruh6884]

Thanks richard for your video's, do you have any dyno comparisons on dual 2.5 vs dual 3 inch exhausts on a ls?

[@richardholdener1727]

yes-that exhaust test video is up

[@jeffwooton7138]

Ahhh, the perfect example of exhaust pulse frequency dynamics. There is a bunch to learn on this subject. Quite the bit of information on SpeedTalk about this. I find it interesting that everyone wants to get air in, but then just leave it to chance to get air out. A well designed exhaust system lets you have both torque and horsepower. It is of my opinion that torque is the more valuable of the two.

[@foghornleghorn8536]

"It is of my opinion that torque is the more valuable of the two." Since torque and horsepower are directly related thru a mathematical calculation how is one more 'valuable'? H = T x rpm/5252

[@harperjmichael]

Perhaps Richard could fab up some NASCAR style headers and boom tubes to see if there's still an advantage to be made.

[@jeffwooton7138]

@@foghornleghorn8536, in my case, a tow vehicle, it is everything. I need grunt down low. My cattle get scared if I'm using all the HP to haul ass. But, they are well fed, so I need torque to move them.

[@foghornleghorn8536]

@@jeffwooton7138 "It is of my opinion that low rpm torque is the more valuable of the two." Edited your earlier comment for accuracy.

[@hydrocarbon8272]

@@harperjmichael Not sure how that would be remotely relevant, NASCAR stuff is designed to rarely go below 7000rpm - above what 98% of his tests peak at.

[@bcbloc02]

I would estimate that if you run a header with a diameter close to that of your exhaust valve you will b very close to optimized.

[@lethlbu]

Great video as usual. I feel this particular video would be more relevant in the 2002 era where guys were putting bolt ons on their F bodys and vetts, but considering headers. So I can see the little change in power vs these 2 header sizes at this lever/rpm range This is 2022 and most guys using LS engines for power are wanting to make some big numbers. Im talking NA, N2O, Boosted. I would love to see you do a comparison of say a N/A (6.2 based) Rec head, 416ci , 11.5:1, 650hp, 7000rpm power peak with these 2 header sizes. Let me know. Thanks for your time and effort in all your videos!

[@richardholdener1727]

You are mistaken about the market-you (and others) might want to make big power, the vast majority are not building high-hp race motors

[@ziptiejedi5658]

I wish I would have watched this video before buying my headers. I bought 17/8" headers and probably should of got the 13/4"s since my car will see alot more street miles then passes at the track. The 1/34" headers probably fit a little better also.

[@C6Z_Bob]

Very interesting, I didn't think the 1-3/4 would gain anywhere in the powerband. I'm curious what would happen with a larger displacement and a more aggressive cam revving to 7000 or higher.

[@Ws6Ms]

2 inch ftw

[@Torquemonster440]

Pretty sure you'd need more than 1-3/4.

[@someinternetguy955]

So where is the limits on either side? What does 2” or 1 5/8” or even 1 1/2” do? Interesting findings, but time to min/max the crap out of this topic!

[@adeptpeasant6161]

Be cool to see what stock truck manifolds with these set-ups

[@richardholdener1727]

same differences

[@LightningFast240]

I think the size difference is very situational and dependant on heads flow and the operating range. i.e. stock engine vs blueprinted. My head porter runs 2in+ headers on his 416+ strokers running out to 7600-8000rpm high compression builds. That is what he recommends

[@richardholdener1727]

ask him if he ran a back to back test ever on 1 7/8 headers

[@wowzzing5571]

​@@richardholdener1727 Hoping to hear back. Do you have an explanation for the up tick in below 2200rpm for the 1 7/8 headers? Below 2200rpm is was higher then all the 1 3/4 runs. Wondering what the results would be for 1000-2200rpms Range as i have a c5 corvette and the gearing really utilizes sub 2k rpms alot on the highways

[@dubandy01]

Crazy how 1/8” difference make such a change in scavenging

[@torqueandbeanssauce]

So fat what I'm getting is 1 3/4 header with a electric cutout so you can go from open free flowing for higher rpm loudness to daily driving and good down low response with it closed. I can def tell a diff just driving around in my t56 4th gen fbody with cut out closed down low.

[@1HeavyHitr]

What would the same comparison look like on a 6.2 L versus the 5.7 or 5.3?

[@JAGMotorworks]

I have a 5.3 with 1 7/8 speed engineering headers. The collectors are 3". I am going to be running a 2.5" exhaust. Should I go right to 2.5 at the collector or run it a few feet before reducing it. Thanks for opinions!

[@Vgorruso]

I have a 5.3 Silverado with true dual exhaust 2.5 piping. Should I go with the 1 3/4?

[@tturi2]

maybe the next evolution in power is testing full exhaust systems

[@derrelcarter9401]

How much compression did the 5.7 ci engine have with the aftermarket heads?

[@magnusdanielsson2749]

I spent a few days reading the views of Calvin Elston on how he does headers and exhaust. Very interesting stuff and a bit unusual to what most might think. Would be an interesting test to see one of his system. But kinda impossible since theyd be custom made for the heads and engine..

[@motorosso3349]

Collector outlet sizing is important.

[@magnusdanielsson2749]

@@motorosso3349 Yes that and the head-to-header flange transition. He (Calvin) says the first part of the header is as important as the last part of the intake runner and that the trnsition from the port to the header is very critical. Correctly designed stepped headers seem like a godd idea also. The thing that might surprise most is that he use smaller size on everything than what is otherwise used. He suggest people use the Burns Stainless calculations for the overall dimensions. Its all up on Speed-Talk forum.

[@motorosso3349]

@@magnusdanielsson2749 Yes, using the smallest diameter without hurting HP is the way to go as it keeps the gas speed up. I agree on the Burns Stainless calculation for header dimensions.

[@gabeesquivelLethalZR1]

Im waiting for the AR 2 1/8 Race headers test.

[@blueovaldude]

I am more interested to see this test with a 600-650+ hp engine , to see the difference between 1 3/4" and 1 7/8" headers . 450-500 HP just isn't moving enough air for 1 7/8" headers. Thank you sir.

[@fullnoyz7670]

I’m with you!

[@ALEX.THE.RUSSIAN]

100%

[@makingcash4life]

Now let’s see 1-3/4” vs 1-7/8” vs 2” on a bigger cube motor say a 6.2 ls. I was not expecting these results but then again that’s why I watch your videos to see real world testing. So many people get wrapped up in peak power but under the curve is what matters.

[@oliverscorsim]

I'd really love to see a taper tube header from 1.75in to 1in at the collector. I know on rotaries it makes a huge difference. Rule of thumb I was always told was 1inch = 100hp of flow. Don't see many 800hp na v8s lol

[@someinternetguy955]

Throw on 1 5/8” too, may as well test the limits.

[@gloriamaletta8667]

Remember a 1 7/8 header with a 3 inch exhaust and X pipe into simular mufflers may give you the same or even better results than the 1 3/4 did in this test I'm pretty sure it would help with low speed torque

[@richardholdener1727]

I know you want the bigger header-it's not needed

[@christophermix6845]

I'm regretting getting 1-7/8 for my 6.5 stroker now. Guess I'll have to try and sell them and hope whoever buys them hasn't seen this video....

[@MrScottt28]

Really interesting... but on a smaller engine with a mild cam, im not terribly surprised that smaller headers did well. The fact that the full exhaust helped it was cool. Sure, it was down 3 hp or whatever on top, but that wouldn't change 1/4 performance. The added weight of a full exhaust system with mufflers out the back might. Switching to tubular headers and full Magnaflow exhaust on my 2012 Boss Mustang, weight dropped almost 50 pounds. On a street driven truck (as we would expect given a smaller engine with a smaller cam and a truck intake), a full exhaust system is required. Still fun to discuss

[@itseithergonnaworkoritaint7852]

With both header diameters bigger than what is needed from both configurations, maybe a set of 1 5/8" diameters would of made things more obvious how to choose header size?

[@donaldgminski8621]

That was fun

[@r0bkills]

I'll be that guy and ask why no results with a crossover pipe or balance pipe? V8s benefit a lot in that scavenging rev range . And do boosted engines benefit?wether power or economy/fuel efficiency. Love the testing Richard. Playing with a 454 and a 250 blower pulled out for a freshen up

[@christophermix6845]

From what I've heard the Gains are very minimal, but I've also heard that you lose low end torque with headers lol. so we need Richard to test it haha.

[@Cowboy.underwater]

Belt driven power adders and nitrous benefit from headers and crossovers and stuff because they have normal exhaust pulses that still scavenge normally. Turbos, not so much. Having a free flowing system that helps organize exhaust pulses going into the turbo is somewhat beneficial, but too much volume/pipe length pre turbo hurts performance, and anything after the turbo is just an obstruction.

[@r0bkills]

@@Cowboy.underwater thanks not going to mess with the beautiful stainless steel exhaust under the 57 yep fabricated hi flow x pipe in there too looks mad . So just a freshen up for the bb head's bit of bowl work, new total seal ring's

[@timothythomas1737]

Cats probably change things up is say.

[@r0bkills]

@@timothythomas1737 HAHAHA don't run cats just dogs hot dogs!!sorry couldn't resist lol but yep they do

[@blindguygarage]

Not with the stock camshaft do Under the same circumstances with the exhaust was it tested with the same headers with the same collector extension? I know the test was done to see the difference between these two camshaft but what they saying modifications help the stock camshaft possibly even more and it would outperform the aftermarket camshafts in the RPM ranges that it does. So down around that 2000rpm Mark would it gain torque at the same places as the Chuck Norris cam in the sloppy cam

[@richardholdener1727]

I wish I would have tested that but removed the stock cam then decided to do the header test

[@ericstick1299]

Can you do a 4.0 jeep h.o., renix, amc, stroker. Ive had a few and have always wanted to build one but there are no real informational on what and no test so dont know which way would be the best to go.

[@ericstick1299]

At the moment i have a 4.0 with a . 030 over bore with a . 060 crack and a . 030 cam ported and decked h.o.head and intake, but stock h.o. ex.manifold. thing is a deffently drives different then a stock 4.0.

[@rustysausage69]

Interesting that the bigger header made hardly any difference on the curve on the LS1 after peak torque. I reckon a similar outcome would be reached when comparing 2" to 1-7/8 headers on stroker combos.

[@wantu2much]

Yea it just goes to show that when your at the limit of flow from the cylinder, once you go above the size that is a restriction, it doesn't make much difference.

[@orionsmith7669]

Curious to know if a centrifugal would change this at all??? Make it say 800hp blown engine and swap the headers.

[@sergebasque8460]

Would you have any content between the 1/34 and 1/78 longtube headers on a 2017 Gen 2 Ford Mustang Cayote engine, with just a 114mm cold air kit . Thanks for the awesome test always.😎💪🇨🇦

[@richardholdener1727]

NO SIR

[@sergebasque8460]

@@richardholdener1727 Hopefully if you are willing to bring the content for the Cayote engine it will be much appreciated.👍

[@richardholdener1727]

I have some Coyote testing vids up-but all Gen 1

[@sergebasque8460]

@@richardholdener1727 Much appreciated!

[@MWR-lg9qp]

Great work sir. This has been proven over and over and hot rod guys can't stand it. If you're not twisting a motor over 7K, huge headers don't help.

[@Torquemonster440]

Unless the Engine itself is huge.. 500ci +.. even at 5,000 rpm, a 500ci engine would be choked by 1 3/4 " headers.

[@TheSol115]

hola richard tenes pruebas con escapes mas largos aun ? pierden en alta rpm y ganan potencia a 1000 rpm ?

[@dailydrivenmuscle.]

Need to test 2inch headers

[@Dunwelll]

Can you test with and without high flow catalytic converter?

[@natesaforverk166]

It would be really interesting to quantify the effect of a cat, especially if we could see it on a couple of engines, like NA making 450ish and an FI making 600-700ish.

[@Dunwelll]

@@natesaforverk166 I'm curious for my blown LS2

[@jeffdobbinsZ06]

This is GREAT testing! The question I have now is where does the 1 7/8" headers start to become beneficial? I'm currently building an engine for my C5Z that will be estimated 750-800hp NA at the crank. What im trying to figure out now is how beneficial would it be for me to buy a 1 7/8" header to use over the 1 3/4" header I already have? Or do I just use what I have if im not going to see a 20ish or more hp gain?

[@Jason-ey9ln]

Maybe this video from popularhotrodding where the test four different size headers on a 427CUI engine producing close to 600hp will help you. Horsepower and engine size makes a difference. kzbin.info/www/bejne/hWLFiYOErpaMpJY

[@MurdahBassRecords]

@richard So how much of a collector extension did you use and do we even need one if were running full exhaust?

[@richardholdener1727]

your full exhaust is already an extension

[@justinwoosley3188]

Which injectors are you running on the stock truck intake?

[@Brother2Jis_27s4]

Have you done any testing with the gm inline 5cyl? The 4200s cousins brother, I'm curious to know how it would hold up(boost/nitrous) and knowing since it's a shorter package than the 4200 what percentage gains/loses does the 1 extra cylinder bring to the table

[@richardholdener1727]

not yet

[@Brother2Jis_27s4]

@@richardholdener1727 just curious, I have a h3 laying abandoned at our shop. Still runs, frame rotted out and customer doesn't want it... Maybe I'll pull the engine and build it and see what it will do, just wish I had access to an engine dyno...

[@DrewLSsix]

@@Brother2Jis_27s4 I've wondered about the 2.9 I4 version of the Atlas. It's kinda anemic in its application but it's a pretty big inch I4 with a nice head, I think it could be a solid performer in certain cases.

[@Brother2Jis_27s4]

@@DrewLSsix itd be cool to line the whole family of them up and do a side by side by side... See if going from 4cyl to 6 gives a proportionate increases in power as you add cylinders

[@austinwilbanks5919]

Great information but it would be really helpful if the file names correlated to the setup a little bit better.

[@richardholdener1727]

not really an issue

[@austinwilbanks5919]

@@richardholdener1727 I’m slow so when we add new data and the colors change I’m looking around to take it in while trying to listen to you is all 😄 like if one setup was red on one layout and you add another data file, the color changes from red to something else.

[@MrChipDouglas1]

Are those 1 3/4 QuickTime performance headers? I remember back in he day they were known for having higher torque at low rpms compared to others headers. They were due to the merge collector. That's why I ran those on my ls1.

[@richardholdener1727]

QTP

[@MrChipDouglas1]

@@richardholdener1727 I figured they were QTP by the tag being welded to the header. I had done some research and showed up to 35 ft pounds of torque around the 2500 rpm range vs other headers. Thanks Richard awesome work.

[@edwardcold7431]

I hope inch 3 quarter is enough for my 408 windsor 220 afr super Victor 850carb 680 healthy cam

[@Brother2Jis_27s4]

Can you run a test with whatever engine you can where you test different pipe lengths after the collectors? Put like a 5ft length of whatever diameter seems to suite and keep cutting a few inches off after each pull to see at what point the corresponding pipe length helps and then starts to hurt scavenging. I'm wondering how accurate my text books were at tech school

[@andrewmontgomery1763]

He's actually tested this already. Hopefully he'll comment with the specific video, but I remembering him doing it.

[@Brother2Jis_27s4]

@@andrewmontgomery1763 id like to see the results, I know based on sheer volume from displacement, rpm, and other factors it will vary drastically. I know there's a ton of things at play. It would be cool to different displacements from 1 liter up to 10+liters

[@motorosso3349]

Richard, you didn't mention what sort of tuning changes were made with the exhaust changes, if any.

[@richardholdener1727]

each was run with an optimized tune to get every last ounce of power out of it

[@motorosso3349]

@@richardholdener1727 Yes, I assume it was optimized, but were tuning changes needed in the lower rpm range where you saw power differences?

[@musclebone7875]

Do a big block chevy header test. I'm using 1 3/4 on my mild 496

[@michaelallen2501]

That's tiny for that many cubes. I'd want 1 7/8" minimum for a big block. 2" and up for stuff with a good head.

[@richardholdener1727]

pretty small for a BBC

[@brandonnaves4880]

Any idea of the max temperature difference between the 2 headers with mufflers? Trying to keep under hood temps down thinking 1-7/8 might help even though I would prefer the low end torque of the 1-3/4

[@richardholdener1727]

I doubt the header size changes exhaust temps much

[@Torquemonster440]

E-85 is what you want to reduce under hood temps.

[@Charlie-qb4sy]

Can you show the final results of the 2 cams, truck Norris vs sloppy stage 2 with 1-3/4 headers with exhaust?

[@Charlie-qb4sy]

I been looking at these 2 cams for my ls2 corvette.

[@richardholdener1727]

it doesn't change the results

[@Charlie-qb4sy]

I wanted to see the results together so I can see the power difference's between the 2 cams@@richardholdener1727

[@jaredfarney675]

That was really cool. But, Truck Norris needs a Shanghai Sushi Slicer and some E85. For Science. It's what the People need 🤘🏻🇺🇸

[@richardholdener1727]

If I had to guess-the curve would be the same shape-just higher power

[@jaredfarney675]

@@richardholdener1727 #turbocam😎

[@ecc5119]

Need 1-7/8 tri-Y header with a chambered muffler

[@someidiot1984]

What if you did a X pipe and more normal mufflers

[@v8tergt653]

What happened with the stock cam when adding the longer extension and muffler?

[@richardholdener1727]

good question

[@HioSSilver1999]

It would have been nice to see the mufflers on the 1 7/8 headers too....jusssayin😁

[@richardholdener1727]

WE DID DO THAT

[@HioSSilver1999]

@@richardholdener1727 ok...i thought you only had the mufflers on the 1 3/4 and just the header extensions on the 1 7/8

[@thomasroth4695]

Curious if header wrap would make any difference The gas staying hot ?

[@richardholdener1727]

did not show any power gains

[@hoost3056]

How about a 4 into 1, 4 into 2 into 1 and a 180 degree header shootout.......then add turbo

[@Onalky87]

What would your opinion be on a 1000+ hp turbo ls? 1 3/4 vs 1 7/8

[@richardholdener1727]

stock manifolds work

[@jonadkins9339]

So would you say on a cam only (226/230 550"/550" 112 LSA) LS6 that the 1.75" header is sufficient? Or would there be some power left on the table?

[@jhutch1470]

1 3/4 all the way.

[@wiskyd]

1 7/8 gain more on supercharged applications