Who's The Boss? Stock LS3 Intake vs Performance Designs XS on the dyno!

In this video we do a direct comparison between the Stock LS3 intake with billet 95mm Holley cable throttle body and the new Performance designs XS intake with 103mm Nick Williams DBW Throttle body. The Car is the Custom Works 71 Camaro. The engine is a LS3 based 416, with Scat 4" stroke rotating assembly, Trick Flow GenX 255 heads and Comp cam 54-471-11 (239/255 @ .050", .624" lift 114 LSA. No changes were made to the tune including timing, which as 26* at WOT, and fuel which was 12.6:1 @ WOT. A Holley Dominator with Holley V6 software was used. We found no appreciable gains in power, except at 6000-6500, but I may attribute that to windage issues that we resolved between tests, which might had affected peak power with the stock intake. Performance Designs intake lost a heafty 20 ft/lbs of torque from 3-5000 rpm and 15 hp in the same area. I'm currious to see if changing the throttle body to a smaller size brings that mid range power back. that will be in part 2. Thanks to Chassis Dyno Solutions of Chico Ca for letting us use their dyno. we also did a follow up video with this manifold testing a 92 vs 102 throttle bodies • 92 vs 102 what size th...

[@PerformanceDesignLLC]

Please check port alignment at the cylinder head. If you have a borescope that can reach down the runner with the upper shell off that would be the best way to do it. We had another customer with those TrickFlow LS3 heads and the port geometry was not the same as stock LS3 which caused a step in the transition between the intake and the cylinder head. That could be why you are not seeing the same performance gains that our other customers are seeing.

[@ks71z28]

That's funny you bring that up, because you already heard my response to that before I made this video in a message on Instagram. The port alignment is perfect on the short radius (lower side), and slight off on the upper corners of the port, meaning the head surface shown, but this is absolutely minimal. I checked with a borescope (doing this on a stock LS3 intake would be really difficult) Keep in mind these are the same heads as were used on the LS3 intake, so if the heads are poorly designed, they would affect the stock LS3 intake as well. We aren't looking at an absolute power number here, just a comparison between the two intakes on the same engine, with the same tune. We are going to do a video with two different sized throttle bodies to see if that may have contributed to the loss of power bellow 5200 RPM. We will keep you posted

[@hydrocarbon82]

A mis-alignment would hurt flow all over, increasing with RPM. This is just a function of runner length, you see it with ALL aftermarket manfolds and most easily with the FAST that has swapable trumpets. The fact is there's an endless amount of dyno comparisons showing aftermarket manifolds simply can't touch best best factory intakes below 6k. The hard truth is you're buying looks or 1000rpm of powerband before redline.

[@ks71z28]

@@hydrocarbon82 I agree, We spoke to performance designs and they mentioned checking for a mismatch before we made this video. The bottom of the port was perfect, the top in the corners were a little off, but it would likely be the same with both manifolds, unless the PD intake was the mismatch. I feel this is an absolute fair comparison under the same circumstances. I also do think windage hurt the stock manifold dyno run, which we remedied by lowering the oil level for the dyno run with the PD intake. We aren't setting out to hurt anyone, infact I now am the proud owner of a $1000 intake and $675 Throttle body I am not going to use, due to my findings.

[@GETLITUP69]

Correct that what I used. Interesting that experience builders don't take the time to use bore scope to make sure everything aligns. I posted on lstech my journey. I dyno next week so will see my gains. I ported and smoothed everything as well as port matched my intake. Shaved the top too. It's perfect. I also ported and smoothed everything no step when the air enters the intake. I think my builds is the nicest out there. I portmatched the XS inake to my heads see if it makes any gains. I have TSP heads and big cam. Stock 376, 12.0 compression.

[@ks71z28]

@@GETLITUP69 I didn't see your link in LS1tech. You assume I don't know how to tune? I would like to see your wizardry!

[@GrandPitoVic]

I am doing a Ls3/6L90 in a 03'Crown Vic Police Interceptor. I turned a L94 into a Ls3. Flat top pistons and such. 821 heads. I was looking at that intake but i think it prob wont benefit me right now. I am planning on a larger cube engine later on. This is a temp engine. They had to 20 over the block. They checked it and said ut was ok. Its a N/a build so it should be fine. Till I build a bigger engine. Cool deal. Great info.

[@ks71z28]

I'm not so convinced its best for a bigger cube motor. Mine is a 416 with big heads. The loss down in the meat is a big sacrifice for what I use it for

[@GrandPitoVic]

@ks71z28 The comment was before I finished the video lol. I will stay with the stock intake. And a 92mm throttle body. Should be good with a BTR Ls3 Stage 2 V2 cam. I'm really not trying for all out power. Burnouts and ice cream with the grandkids until I get the suspension and brake mods done. Then burnouts and ice cream and some track time. She is going to be spicy!!! Considering it cam with a 4.6L 2V with 239 hp at the crank new. Great info.

[@ks71z28]

so we did a follow up video on this intake after we designed a bracket to allow a cable throttle body to be used, we tested a 92mm vs 102mm to see if there is a difference and if so, how? kzbin.info/www/bejne/q4HHfZWqfsp9mdU&lc=UgzojzEX1i6ShAwAlvN4AaABAg

[@davecolquhoun9315]

I wonder if the intake likes more cubes, I noticed that when Richard Holder tested it on a 427 he saw a little bump over the stock LS3 intake, and if you’re chasing all the hp , maybe worth it , if you’re rich , haa ha

[@ks71z28]

Thats what I was hoping for, mine is 6.8, way larger than the sock 6.2, and close to the 7.0 Richard tested. If you look at his video, he really focusses on peak power, where on my test it showed a slight increase and a longer peak hp curve, but its the loss below 5200 that is really the killer. Yes my test won't reflect the intake in every scenario, but my experience was a bit dissappointing and costly for me, thanks for watching Dave!

[@davecolquhoun9315]

@@ks71z28 It looks like the intake only does a little something way up there in the RPM range and most people do not rev that high , For the $1,000 you could change your rear gears to say a 4.56 if you wanted to snap your neck, HAA HA

[@johnw3724]

All the other videos on this manifold show about the same as you are experiencing - why did you expect anything different?

[@ks71z28]

We had been in contact with PD for a while prior to this, they told us we would see a gain of 20hp and possibly some gains down low. Our initial dyno results with the stock manifold yielded peak power at 6000 rpm, which seemed low for this combo (even though power numbers were exactly what we hoped for this combo). We thought we might pick up some power because we thought the stock manifold was just running out of flow. Which to some extent it did. We also discover windage was dropping power, which we resolved with lowering the oil level in the pan (because it was too high, and should affect the oiling at the level it is at now). The only dyno video I watched prior to this was Richard Holdener's. Also we do a lot of dyno stuff and I want to see this stuff for myself. We aren't paid by ANYONE to do this stuff, and seeing for your own eyes is good experience. We have a follow up video with this manifold comparing a 92mm vs a 102mm throttle bodies. you should check that out kzbin.info/www/bejne/q4HHfZWqfsp9mdU&lc=UgzojzEX1i6ShAwAlvN4AaABAg

[@davecolquhoun9315]

If it really bugs you to have it around, I will take it and I will pay the shipping, haa ha

[@ks71z28]

$800 shipped

[@HioSSilver1999]

Classic example of both intakes being wrong for that build. Neither of those intakes should be on a engine with a cam that big.

[@ks71z28]

What would you suggest? As noted this engine is in a car used for autocross and track day stuff. It needs a broad powerband. It also sees the street. If it was a drag race motor, a high ram or something would make likely 60-80 more go, but at a steep cost in the mid range. Both of these intakes are perfect for this motor. Raced the car today. Barely saw 6000 rpm on the autocross course.

[@HioSSilver1999]

@@ks71z28 then I would do a much smaller cam if I was worried about midrange so much. No use in have that big of a cam and only turn it 6000 on race day. But in the end a intake that matches that cam would never lose any midrange......because gear multiplies torque. You could run more gear. There's lots of ways to do things and a oe ls3 intake is pretty good.....for a oe ls3 or something mild. But once you go so far it's holding a big engine with a big cam like yours back.

[@ks71z28]

@@HioSSilver1999 Well, there are lots of options yes. On your mentioning of a smaller cam, well this isn't our first LS build. We dyno a lot, we tune lots of LS engines of various combinations. This Cam/intake combo for its intended use is a great match. A smaller cam would yield less torque down low. This cam when we have used it in various LS combinations makes peak power around 6200-6400 rpm. The reason my engine only went to 6k this weekend was because of gearing. I don't have six different gear set to swap into the car for different conditions. What I do have is over 500 wheel tq, so gearing and RPM really don't matter. I do not need to wind the motor up to make it go fast. On the other hand, on the track the motor will see 7000 rpm at 142 mph. On the dyno the engine made peak power at 6200 rpm, but really only fell off around 10-15 hp at 7000 rpm. Yes the intake is likely limiting that power, but in my case, so what. The engine is so powerful and responsive down low, all while not needing to wind it way up to the moon to make power. This engine responds like a big block. So in conclusion.... I am willing to give up 10-15 hp on the very top end where the engine rarely goes, for 20-30 from 2500-5000 rpm where it spends most of its time.

[@HioSSilver1999]

@@ks71z28 you're not giving up 10-15 up top.....more like 30 + as rpm continues if that's a oe intake and tb. Hell we picked up more than that with a h/c ls3 and didn't lose enough to matter at low rpm with a l.o.d. intake....because we don't race at 3k rpm.

[@ks71z28]

@@HioSSilver1999 Did I mention this all needs to fit under the flat hood of a 1971 Camaro! Lots of stuff to consider. The point of this video was to show people that this intake really isn't very good. If you look at our other videos, I have one with a LS3 with a BTR Low Ram intake and a stage 3 cam, and shorty headers with 2.5" exhaust. This was such a bad combo, I compared it to the same engine with a stock intake and better exhaust, power numbers were amazing to see the difference. I hear what your saying. For my "box" I need to run this engine, the Stock LS3 would be the best performance and cost. thanks for your input.