DOES IT STACK UP? SPEED IR LSX 

I love that 650HP NA is a disappointment. As a kid in the 90’s I remember every other issue of Car Craft had “How to build a 350hp 350” on the cover.

For an air cleaner on an IR setup i think the best way is to have a sealed filter box in a cowl hood scoop. Individual filters absolutely kill power.

It's funny to think 600 hp isn't enough

Btw, thanks for all the great information and videos! I've been shopping ITB systems and your comparisons are part with what I was expecting in performance. Monday I'll be calling Borla....

Woot!!! ITB's About to have my GTiR pulsar tuned (can't wait.) comes factory turbocharged with 45mm ITB's :) as it was Nissan's Group-A rally car from back in the day. similar to the GTR-Skyline with it's 6-ITB's. As Richard say's tuning can be a challenge as you get a very erratic vacuum signal as there is no plenum and any imbalance between the throttle blades can be problematic. Also the MAP signal is very unstable when at low loads, any small action results in a total loss of manifold vacuum. This is why it's best to tune ITB + boost using 4D tuning using both the TPS x MAP load settings. The Holley EFI cannot do this (to the best of my knowledge, as it's a pretty basic ecu.) Need to use Motec/Adaptronic/Link/Haltech... to get best results. To balance the throttle's you need to use a specialised sync tool (if you've ever tuned DCOE or IDA weber's you'll know all about these. As for air cleaners on NA systems. if you're using a DCOE or IDA style throttle bodies, there are off the shelf solutions that work very very well. Just as any Ford Escort owner. But with alot of custom designed systems from the US you're kind of on your own. keep up the good video's Richard. Will we ever see a rotary?

On my ITB setup I used a carbon Airbox made identical power with and with out. Mapping wise never had a problem, either map it alpha N (tips vs rpm) or hybrid Alpha N with a switch over. But I think this style of setup is alot more common over here so tuners are more experienced in ITB setups

All these parts and motors must be getting in the way. I'm happy to take them off your hands free of charge.

I've found, through personal experience, heavy internals slow the car down, engine revs slower. The first engine I ever built, a Mopar 440, reved like a 340, all the way to 7,000 rpm, (though it was done making power by 6,000). Blew that up with a sticking Slap Stick shifter button , (got first at about 80 mph instead of second). I built another 440, same heavy ass TRW pistons, but used six pack rods instead of the standard LY 440 rods, a lot thicker beam and bottom, a lot heavier rod. Same cam, heads, intake. Engine reved like a locomotive diesel. Very disappointed. Should have made the same power, but felt noticeably slower. Years later, built a 355 ci LT1 Chevy with light internals, reved like lightning!!!!! With the stuff you do with boost, I would use the heavier stuff, with small boost or small N2O, the lighter internals would work really well. Very good test, keep em coming!!!!

Crazy how the destroked ls (4.8) made about the same power just less torque. Destroked ls for the win

Thank you for replying to my question about the Speedmaster the other week after seeing it in action I'm ready to finish my ls 65 valiant with it!!

Would have been nice to see how the Holley Hi-Ram compares to the stacks.

The jenvy itb set up from 🇬🇧 can be specced with a proper filter set up, and is high build quality. It’s a cross ram set up so long runners too.

I'd love to see boost on the speed IR down draft!

!I knew it, the 8 stack is the better throttle body!. My second custom throttle body will be the 8 stack under a normal hood, believe me. Thanks for the test.

very interesting comparison video here. In comprehending the pro's and con's of ITB setup I do see the Megasquirt MS3 pro being a solution for tuning with it's alpha N tables for ITB's as I am considering this for when I build my aluminum gen 3 hemi block. I have been eyeing the Speedmaster and Borla ITB manifold's; even though expensive they match the theme for my build.

This, like any motor is simply a harmonious assembly of mechanical and electrical components ( though apparently not in this case). There obviously is an answer to the question of ‘Why less than expected’, and it shouldn’t be too difficult to discover ( easy for me to say...). It must be driving Richard crazy trying to get to figure it out.

Build an air box for the IR manifold and feed it with a pair of turbos.

I know this test was run four years ago, but I'm guessing there was something with the grind on the BTR cam that didn't sync with the package.

IR with boost would be an awesome setup for sure.

I hear ya about itb's. I built a straight 6 cylinder Hemi back in the stone age. I fitted a set of triple webbers that were not the factory type but salvaged of a early Nissan 6 they were 42 doce. I spent hours with vacuum gauges and eventually went to a manometer as it had a finer scale {nothing fancy just a few plastic tubes filled with rubbing alcohol and food coloring} I could never get them to balance properly. I gave up eventually and went to 2 1/2" triple SU instead. LOL

Pantera EFI Stack Injection looks great with filters.

Gotta love how those bumps leveled out with the ITBs. If I had to guess... I'd say the reason you were disappointed with the NA performance, was too much port volume in the heads. By the looks of it, those heads could flow a significantly bigger cam. Really makes me wonder how it would respond to a narrower LSA.

Boost is Robitussin for sick engines!

Another thought, I totally have that same issue with ITBs on the weber carbs on my VW. I had some foam motorcycle air cleaners on there for a while, but ultimately they just killed power. I gave up and pulled em off for just running it open throttles. It was tricky to tune too, but once I got it dialed it hasn't been much of an issue.

It's funny, ya know...it use to MEAN SOMETHING to have 300, 330, or 350hp. Now, with head flow, and boost/fuel technology, it's just amazing... It's like the famous quote from Charles Manson: "It usta mean something to be crazy....now, everybody is."

I definitely can see the benefits of a big displacement engine like that the potential is definitely there but yes Richard I got to tell you I have a problem with these aftermarket components not so much the quality of them which some of them are questionable but definitely the price these folks are out of control with that pricing especially the performance you get versus what you pay for it for instance 22 horsepower gain for that Atomic intake manifold that thing is over $1,000 I think there's something wrong with that scale big time that in itself is bad enough but the worst part is people buy them and these suppliers keep jacking up the prices even more and the benefits are so small versus what you're spending, I say screw these so-called go-fast Parts get yourself a 5.3 iron block invest your money in places like Pistons Rod studs good head gaskets and lots of boost!

I'm liking the bread box on top for boost idea....hmmm

Maybe the less than stellar power on this engine, is due to stronger ( maybe heaver) rotating components being used, as it was always going to be a boost engine. Just a thought

making over 100 hp/L NA is pretty tough (especially with push rods) to do when you peak below 7000 rpm. If you want that number then you need more Rs. More head, cam and intake and push the curve right and get the peak closer to 8000 and its easy.

It kinda seems it wanted more head and why I say that is it picked up all the way across the board in power by basically placing a venturi over the intake port.

It would be cool to see a test on the same turbo with different exhaust housings/turbine wheel sizes. See how the exhaust housing/turbine size affects hp/torque curves at the same boost, spool/boost curves, etc

This is why you go to Texas Speed...head/cam/tune stock bottom. Over 600 all day long on a N/A motor.

the LS7 manifold has runners that are MUCH smaller than the ports in the heads...and it still supports 640+bhp. I've seen a ported stock manifold support 750+bhp.

Its the cam holding it back....

More 427 stuff please!

curious what the compression ratio was my bet was it was way too low considering that is the norm for LS7s also to be fair that cam is a bit on the small side for such a big NA engine

I need more specs, compression, cylinder head runner volume, chamber cc, piston specs ect. And if you're going to build a max effort na 427ls why would you not run a holley hi ram or a big single plane from CID

Love this test!

Does this actually work at speed when the stacks are exposed to that speed of moving air? That's what I would be curious to see, and would easily require a 100mph-capable fan to evaluate IMO.

I really like your videos but a lot of the time you seem to say things twice in a row. Just something I noticed. Long time watcher and love the content. 👍

Why dont we see more stack injection videos? Looks like there is a lot of potential there for power gains and NOTHING looks cooler on an NA engine than ITBs

Build a boost box for the ITB's! Please!

What was the cost of the extra boost hp? supercharger and all the necessary support gear to take advantage of the boost. IMO the total cost of the boosted package can be bested by a N/A Big block with money to spare . No replacement for displacement!

As has been proven with the big chevy heads in big oval vs square port a big high lift flow number don't always translate to more power. We had a guy at our drag strip pull off a set of ported 781 heads and went to a set of big edelbrock heads. He sold the 781 heads while doing the swap. He lost a lot of power almost a 1/2 secound slower and he tried every tuning trick. Even after having a local machine shop redo the valve job that had some leakage it was still slower. After market heads need checked for a concentric seat before they go on a motor. I don't care who the supplier is. They need checked.

If you had to build a 427 again, what would you have done different to make that 700hp NA.

Sounds like a not enough lift in the Cam issue. Those super trick big bores like more duration and 700 lift. Anything else is for 5.3s and. 6.0s lol.

That motor can take way more boost! I want to see it at 25psi+ boost possibly 30 😀😀😀👍👍💯💯

There is another set of videos where they test all the different LS intakes on a 6.0 and 6.2. And they found that the truck intake... was the best across the board. But that was with aft heads and a mild cam. So ur average build i guess. Im assuming the msd, or fast intake is better with a more built engine tho. Any chance u could test that out starting with a stock engine, a mild one, and advanced build? Would like to see those results replicated. I know these engines love longer runners until u get into larger cams tho.

My NA LS 427 made 707hp and 600lbft so they can get up there

You need to try spring car IR injection air cleaner set up and see if your impressed as they don't lose any, not going to fit under your hood

What is odd to me is "why point the individual stacks in any direction other than directly in line with the intake port/runner?" Why would they not design the manifold to have a straight shot so the airflow didn't turn until it hit the short-turn radius?

Kind of interesting with the throttle blade adjustment on the IR setup. I have never tuned one of those, but I have a V12 with six carbs that have 12 individual blades, linkages, jets, mixture screws etc. Obviously one needs to sync those blades and carb, but I can't help but wondering if it is that much different. I hook up 12 anemometers that I use to sync idle from. Then go step by step and make sure that each is synced between idle and 3500 rpm. If they are synced in that range, they continue to be synced all the way up. Does an IR intake like that behave differently? Really curious on this. Thank you.

Thx for the ls7 test haha. Just asked about one and you provided..how does the lsxr fast intake manifold do ? Over these manifolds? And are those the best heads to to run on the motors ?

What cam did you use and what’s the specs? Also love to see some LSX 454 crate motor builds. Thanks Richard for all the great videos

id love to know how to make a small block IR set up work well.

Dang, you just so much as muse about an ITB intake and bam, there it is! Oh, and just a note, if you've got a camera with an external mic in the dyno cell (which, I suspect not, likely that's a phone or something), some microphones have a "pad" switch, that will improve sound quality a lot. What you hear in the ITB video clip is the microphone clipping because the camera's internal gain control can't pull it back enough, it's just too loud. So if you see a "pad" switch on a mic in a dyno cell, flip that switch!

This man knows something we don't. That's why he's not impressed, I mean I thought this was like a 302 but nah when he said 427 I kinda get it, once you get to that kinda displacement some can be pushing 900-1000 n/a

So you’ve been doing this for a while right? What would you say is the best LS cathedral port intake for maximum low end torque? I know you mentioned cross rams, is there anything better than a cross ram? If not witch have you had the best luck with? I don’t care much about top end, matter a fact i’d be perfectly fine with loosing say 50 hp up top to gain 50+ lb. ft. Down low. Ps I really appreciate these videos by the way, Im always learning something new!

I'd expect close to 100hp/ litre, for that money, it should been 700 HP Na, and 1200+ with boost, it seems to be 50-75+ HP shy, what could it Be? Cam? It would be alot cheaper to go with a 6.0 with rods and forged pistons, and ported heads, and boost, it may not have the TQ the 7.0 has, but a proper turbo will help with that! And a ton cheaper!

Do you have afr distribution data for the two motors? Curious if the IR intake solved the usual AFR discrepancies you see.

I wonder how the Speedmaster set up would have done on your LM7\383 stroker that made 600fhp?

Well Richard....why didn't it make closer to 700hp? Valve timing, compression, rotating assembly? By "rotating assembly" I mean ring seal, weight, clearances.... I too was scratching my head about the power numbers. Your thoughts? I'm not pointing a finger. I'm very curious. The cost is really up there.

So what was your compression ratio? Thinking either that or the cam is where your power was you expected but never realized.

"BOOST CURES EVERYTHING".... NICE! Question, what gap do you usually gap the rings when you know you will boost a LS motor, and does it matter if its turbo or supercharged? Thanks, great vids!

Your expectations and results beg for tests comparing identical parts, cams, heads, intakes etc. How much variation is there between, what should be identical parts and for that matter, complete engine builds?

I wanna see u show us what a 5.2 or 5.9 magnum engines can do

Great video

You have the most expensive engine videos on RU-vid

Could you do a video on the Holley hilborn and the borla 8 stack efi I’d like to know the cfm for these units but haven’t even found any ball park figures so it’s frustrating because part of that is what I need to identify a cam

stock LS7 is rated at 505hp. you added 150 with a head and cam swap. i don't see a problem here.

If the IR setup made more power everywhere, doesn't that point to a serious deficiency in airflow for both of the competing intakes? In theory the longer runner intake should make more torque than the IR, if it's not, sounds like maybe the cam was mismatched. How often do your pushrod NA motors make 100HP per liter? The vaunted 100HP/l benchmark has mostly been the domain of 4v heads, that's my observation. I would guess you need closer to 500cfm intake flow to see 100HP/l on a 7l engine.

I'd love to see the IR setup on nitrous vs the ls7 intake on the same size shot. Curious to see if the IR set up makes more nitrous hp

Richard,,I've heard that the itb throttle bodies on this ls7 intake are manufactured in Colorado...Is this true? If not,,where are they manufactured.?

Thank you. Always interesting to learn something. Wondering about AFR distribution with the IR setup. Should not all cylinders be equal with a setup like that? I have noticed that max power rpm needs to be north of 7000 to get 100 hp/L. I guess you need more cam for that displacement.

Great video very informative, could you do staggered stack injection for one of your big block Chevies ???

How about staggered stacks

Would love to see some boost through the 8 stack i have been hoping someone would do it 🙏

I'm looking to install a NA 427 (Dart Block) ci LS in my jet boat. Top RPM will be 4500RPM. Which head/cam combo would result in the best low mid range power. I was thiking of swapping my LS3 intake, injectors, throttle body as well. Comments would be appreciated.

How much comp ratio? And did you chek the quench? Just for my Booker. IT'L be appreciated. You know that real optimised n/a engine wont take à blower without compromise. So, did you tricked it n/a for the blower? If no. Your 700hp 7liter would have done it. Thanks for all your testing.

@Richard , why is it that as engine size increases, and that's everything valves ports n all, do the engines make less power for the size? For example, 600cc bike motors, vs any size car motor.

I just wonder if the intake runners aren't size right with the heads? But just thinking out loud.

I hope you put a 4.8 crankshaft in that thing with a mechanical camshaft so we can see what all to do

What was the comp ratio and cam specs Richard? Definitely disappointing power with the list of components you have in it... a real problem if it was to stay a natural aspirated deal. But there is always the boost band-aid.... makes it all better in the end!

Has there been a test on a similar motor, of say 1 3/4", 1 7/8", and 2" headers ? ( and even the stock manifolds )

I've seen a lot of disappointing numbers with trick flow heads. Try as they may. The aren't AFR

I was hoping you had a box to run boost through the ir.

Ir sound neat:) why do you think that thing was down on power na? Whats left bigger cam?

Amazing videos

Question on how to tune an Itb intake with hptuners, i have a speed master ls1 intake, do u know of any links for info on how to go about it? It will start, high rev for 3-4 seconds and die.

Woah déjà vu. What did you just say? Nothing, just had a little déjà vu. What did you just see? What happened? A brown dog just went past us, and then another that looked just like it. How much like it? Was it the same dog? Might have been, I'm not sure...

How would a Holley Hi-Ram perform? Somewhere in between the Atomic and ITBs?

You think you could have gotten similar results with a 2.9 Supercharge Whipple ?

Do you mind if I have that engine? Thanks friend

That is pretty disappointing. We did a 2018 camaro with a LT1 Ported heads.(heavily ported) big cam Atomic intake headers. Full exhaust and it made 713hp to the wheels with a manual. The new LT engine are just far superior to the LS. But we did a couple lsx 427’s and 454’s and they made 600+ to the wheels all day

Oh so it is such a bother to synch the stacks. Bull . Sport bikes have been doing it for decades. It makes more power because it works better. From idle all the way to peak rpm the mix is better and flow from one stack to another is not effected no matter the firing order or cam specs. 8 pod air filters are easy to fit.You want more power use a cam with more overlap. Limiting overlap for the map sensor is what limits power. Mechanical Fuel injection or individual carb throats is what is needed here. This isn't no streetrod engine.

I would like to see a Holley high ramp intake on a junkyard LS to see if it's worth the 1000 bucks. Also a Frankenstein intake (the one cleetus has Leroy) that's water cooled on a junkyard LS engine there like 3000 bucks lol both N/A and with boost

Do a rotary engine??? Talk about porting and what size turbo. Also there is a big mystery about the intake...

Speedmaster = procomp Enough said

Hi Richard. BlindBat say's..read what he say's. I agree compltly. However Since Honda built the S2000 with a 2L making 200hp NA and every other road car on the planet making nearly 100hp/ Liter. This EXPENSIVE! LS427 "race" engine NOT? reaching that level?.That's not disappointing, that's unacceptable. Even old Toyota Carollas with 1.6l engines are making 150-160 hp, race engines these were not. That is until someone adds a little boost. There are little 4cyl out there with "a little boost" making 600hp, more, much more! A 7liter LSX is 3.5 times bigger than a 2 liter Toyota or Honda, I can't believe you let that slide, "sometimes that's how it goes". NO NOTTA AIN"T good enough. That LSX cost $20,000 I'll bet. Tell us Rich, how much did that doggy cost? I'm not intending to call you out or discredit you, I'm wondering if maybe these LS's are as good as we've been led to believe? Do me another solid favor, put different heads on that bottom end, try that test all over again. Maybe its the compression ratio, SOM THINS FISHY!

Richard Holdner ..I would be very curious your thoughts on actually building a stock 706 heads to max hp while still on the cheap I would think a self port and polished Budget roller rockers Upgrade springs Possibly shave What kind of power can be gained doing this to 706 heads? Thoughts?