Dyno Death March! Testing Jeep Engine Combos for Power

today on the horsepower monster we are doing the straight six dino death march of intake manifolds and throttle bodies because we geek out over this stuff and i'm betting you will too [Music] okay let's get right to it and don't let anybody ever say that the horsepower monster wasting your time we've done jeep builds and some dyno tests with jeep engine specialist newcomer racing before and they've been both insightful and if you'll forgive a little humble brag here pretty popular so when keith newcomber called and invited us along for a dyno session testing several different intakes and throttle bodies for the jeep straight six engine needless to say we were on board and although we'll be testing jeep straight sixes specifically the design aspects we'll be looking at can be useful for practically any straight-6 engine the engine build is from what newcomer racing calls their torque monster series it's their most popular engine package and designed to give huge torque gains down low but also significantly improving both the upper and the mid-range the big key here is the ported tuffy cylinder head and the stroker crankshaft and connecting rods out of a 4.2 engine which bumps the displacement up to 4.6 liters there's a bunch of other goodies on here like newcomers ati balancer adapter and billet water neck which are definitely nice but not critical for the power production we're looking at today the camshaft is newcomer's own ground it's a hydraulic flat tappet with approximately 212 and 216 degrees of duration at 50 000 tappet lift for the intake and the exhaust respect it also has approximately 500 000 valves left we did however make one change from the typical torque monster setup newcomer wanted to be able to stress both the intakes and the throttle bodies we'll be testing so we swapped out his usual valve springs for a set that's slightly stiffer to help push the red line even higher these beehive springs have about 115 to 120 pounds of pressure on the seat and approximately 300 open so that's that first up we wanted to test how throttle body size affects performance obviously bigger is usually better but can you get too big for the jeep engine to find out we tested four different throttle bodies by the way for the test the guys actually stripped two of the throttle bodies off of the jeep cherokees they used for testing and drove to the dyno facility that morning i guess you can't get more real than that anyhow i'll let keith newcomber explain the differences in the throttle bodies so basically all the throttle bodies we've got here this will start as a stock throttle body anything from 91 to o6 and stuck when you open it up this this is 60 millimeter if you measure on the front side of it but on the back side it actually rolls in and that's 54 millimeters so if you look through you can see where it's you know it kind of necks in you can actually feel that on the dyno when you swap these out you go to the next one which is a 60 and all it is is just bored all the way through 60 millimeters just taking that out you can feel the difference in the throttle you can hear it it's it's audibly different what jeeps did these run in versus the bigger one so this is all stock these right here are all stock castings 91 to 06 it's essentially the same this would be this has a map sensor on the side of it so this would be i don't know so what do we think i don't know mine's at 96 so yeah 70s yeah so basically 96 to 06 would have this style map sensor hanging off the side 91 95 would not throttle body themselves are the same it's just a little few little differences here and there um this one would be modified even more it's all rolled in this is 62 millimeters all the way through this is the one you modified right yeah the blade's been you know cut down arrow wings whatever this one it's had more modifications it's got you know like a meth injection port in the side of it also this one here is an aftermarket unit that's 68 millimeters you have to cut your intake all these intakes have been cut already so if you look over here [Music] it's uh it's quite a bit bigger we just simply went in and opened them up every intake has a 68 to say 70 millimeter opening so the tests are you know pretty fair even on a stock intake but it doesn't affect you know everything below this is totally stock so it's really not a difference you're still limited by the orifice size and in the top so yeah we're gonna find out what they do i think it's it's obviously just gonna run better in different places i'm hoping the whole graph goes up and not just a peak number so we'll see but the real kicker is everybody wants to know what's the difference between a curved intake and a straight runner and i've kind of argued the point that the curved one is better on the bottom in my experience but i don't think we can pull this dyno down low enough to really see the bottom end gains but we'll see if it'll keep up with the straight runner mid-range and up top personally don't think it will maybe i'll be surprised so just so we're clear the first three throttle bodies are all stock units the second and third however have been modified by opening them up on a mill newcomer racing can do this for you or if you have the skills you can do it yourself for the throttle body test we'll be using a stock unmodified curved runner intake these came on 99 through 2006 jeeps up first will be the stock unmodified throttle body that added smallest diameter is 58 millimeters oh and one more note we're running the stock ecu but newcomer has tuned it he says the stock tune from the factory really can't take advantage of much extra airflow so if you try this without upgrading the tune you won't see much in terms of gains enough talk here we go [Music] with the stock intake we made the pull from 3000 rpm to 5100 keith stopped there because power had already rolled over at 49. our peak numbers were 331.3 foot-pounds of torque and 293.7 horsepower at 4900 not bad considering that the best the stock 4-liter jeep was ever able to produce was a mere 190 horsepower and 235 pounds of torque but even with that improvement we can do better swapping out the throttle bodies is quick and easy so we were able to blast through our four test subjects pretty quickly for all these tests both for the throttle bodies and later the intake manifolds we never change the tune on the ecu except for the very end but i'll make sure you're aware when that happens and explain why anyhow after the stock throttle body we swapped on the unit that had been modified so that the 58 millimeter choke point has been milled out and now it's a consistent 60 millimeters all the way through the throat here are those horsepower and torque numbers overlaid on the graph our lightly modified throttle body always lagged a little bit behind the stock unit for some reason the only place where it really showed up was in its ability to move air at a higher rpm levels in fact it didn't hit peak power until 5400 rpm the 296.3 peak horsepower was only 2.6 better and the 328.9 foot-pounds of peak torque was actually less than our previous pull so that's not exactly a winner we have on our hands here disappointing but let's move on our next throttle body is a more highly modified unit that's been opened up to 62 millimeters along with a few other touches newcomer has done in-house this time around the changes show up quick we're better from the get-go and stay that way all the way through the pull peak numbers are 332.1 foot-pounds of torque at 4 200 rpm and we actually break the 300 horsepower barrier with 301.8 and 5500 so the lesson to be learned here is if you're going to modify your stock throttle body don't bother with just milling out that 58 millimeter ring at the base of the unit after all the engineers that came up with that design almost certainly put it there for a reason instead if you want to see results you need to go for the full money last on our list of throttle bodies is the 68 millimeter aftermarket unit this is the perfect high velocity throttle body that's from of all people painless performance that's right the wiring company if you're interested it's part number 65301 and best of all it's made right here in the u.s of a so let's make our final pull of the throttle body test so [Music] the aftermarket throttle body is six millimeters larger in diameter than our next biggest unit but the increased size didn't really seem to hurt the torque down low the power lines early in the pull practically overlay each other but by 3 800 rpm it surpasses the stock throttle body and our previous best version the fully ported throttle body is beaten just 100 rpm after that and from there the 68 millimeter throttle body never looks back we hit peaks of 333 foot-pounds of torque at 4 100 rpm and 306 horsepower at 5500 for a stroker motor build the extra air capacity provided by this bigger throttle body definitely looks like the way to go next up we're ready to swap some intake manifolds mostly we're testing the newer curved runner intake manifold which you just saw in the throttle body test against the older straight runner intake but we're also throwing in a curveball by testing them purely stock like they came from the factory versus a few that newcomer has ported himself i asked keith to explain what all we've got here okay so the straight runner intake would be anything from not even one even rent excess straight runners we don't use the radix you're very limited on the power they have like a 50 millimeter throttle body so basically an h040 starting at 91 to 98 would run this style intake 99 it goes to a curved intake all the way to o6 and the stock curve one is on the motor now this one has been poor matched and the difference between these two since we can compare [Music] we just blend it around the injector boss is really kind of restricted so we open all that up you're still limited by the port size down in the port and then we just open all these up like i said before this style you can even open it up a little bit more and you can cut one of these bosses like in here you can cut those out of the way and then you can open up this divider wall get down inside there it's kind of rough but it does the job for this test this one is blended just like the straight runner so it'll be an even comparison then i think this is the best one because i take this one cut the whole side off go in and fully port it just pour it all the way through add some plenum volume and the runners themselves you know are much bigger too so i think this one hopefully won't lose hardly any bottom end and really carry out up top so we've already gotten the numbers from the fully stocked curved runner intake because we used it in the throttle body test while philippe sardina and devon rowell handle the swap we'll run you through the plan we aren't going to run every intake with all four throttle bodies that would just be way too much work for way too little benefit but we did baseline every intake with the stock throttle body and then threw on the big 68 millimeter unit to see how the intakes would perform with maximum airflow i bet i know what you're thinking right about now which is probably something along the lines of well let's get on with it so to keep from boring you to death with 300 dyno pulls i'm just going to highlight the results with the big 68 millimeter throttle body even though we also did every intake with the stock throttle body there's not much point in showing you all that because the smaller throttle body basically mirrored the same thing the 68 millimeter did with just a little bit less power it gave a couple more pound-feet of torque and then was passed by the big throttle body and lagged behind the rest of the way so when you see the stock throttle body in some of these video clips now you know why so here's our pull with the port matched curved runner intake with the big 68 millimeter throttle body i've also got the lines from the dyno pull with the unported curved runner intake with the same throttle body those are the blue and the orange lines and as you might expect we did see improvement with all throttle body tests we saw differences of ones and twos now we're making big jumps peak torque improved by 8.3 foot pounds to 342.1 at 4 500 rpm meanwhile horsepower was up 13.4 to 319.4 at 5500. next up comes the unported straight runner intake the jeep used from 91 until 1998 but i also wanted to show you the ports on the cylinder head while the intake is off this is a tuppy head from 2001 with the thicker decks that makes them better for performance applications as you can see newcomer has thoroughly ported this head for maximum airflow now if you're interested we already did a pretty thorough cylinder head test a while back with some interesting findings i'll leave a link to that video in the description below so unported straight runner intake by the way this has the same 24 pound per hour injectors that we used in the previous test in fact the same physical injectors are being used throughout here's how we did [Music] [Music] pretty mixed results essentially it did perform better than the unported curved runner intake but as you'd probably expect it did fall behind the port matched curved runner we did see our highest peak torque number so far 342.7 at 4300 rpm that was 8.9 better than the imported curved runner intake and six tenths of one foot pound better than the ported unit horsepower is also about six better than the stock curved runner at 312 but that still left it seven and a half less than the ported curved runner like keith i'd love to see how the numbers compare from even lower rpms but that's just not safe to do to an engine on a dynamometer let's move on in place of the stock straight runner felipe and devin bolted up the port matched version and before the headers were even cool we were ready to make another pull this time the two unported intakes get left in the dust so we'll just be comparing the two port matched intakes from here on out the ported curved runner intake did do slightly better up until 3400 rpm but from there the poor match straight runner was able to move more air and beat out its competition peaks were 346.3 foot-pounds of torque at 4 400 rpm and 320.4 horsepower at 56. now the problem with straight 6 intake manifolds is when it comes to porting you can't really reach all the way into the back of the runners and into the transitions for the plenum with the two intakes we've tested so far keith says that the runners are only able to be hand ported about six to eight inches in that's why we only did port matching but keith has done some really cool work cutting off the back of the intake platinum in a meal fully porting everything that can be a benefit and then fabricating a new plenum wall out of sheet metal and welding it all back up keith says this really only works on big inch or high revving engines still let's see how it does so so as the rule of thumb works when it comes to intakes and engines the increased airflow potential hurt the torque down low but significantly helped improve peak horsepower it was up 7.3 from our previous best with 327.7 at 5700 maximum torque came on at 4 400 rpm with 340.4 that's 6 less than the port max straight runner though something worth noting however is that when an intake is capable of feeding more air to an engine then more fuel is also required to make the most of it at this point we had not touched the tune on the ecu at all but keith noticed that the air fuel ratios were starting to get a little bit lean so he did make a quick adjustment to the tune to richen up the mixture a bit and we made another pull with this intake the extra fuel didn't really affect peak torque but we did get two more horsepower for a peak of 329.6 of course we've always got to have a little surprise for you keith actually brought one of his fully fabricated intake manifolds to include in the test this bad boy is designed for newcomer racing's full competition engines and this dino mule may be too small to really test it but i let keith explain what he's got here and what it's all about all right last but not least we got fabricated intake that we make this is one version this is uh like flanges you can get from our website and you can see we have temples we have templates for the top and the bottom this is all fabricated obviously started out as a carbureted intake um to try to get fueling and everything right and then we morphed it into an efi intake so you can actually run it in multiple combinations now so if you take this flange off this is a 4150 carbureted flange you take that off this is another adapter to adapt it to an 80 mm throttle body just finish this one so we can run it on the dyno and this one doesn't have the provisions for the air bypass so we fabricated that into the intake so it'll pull out of the intake tract into the intake to control the idle that's the thought anyway so we'll find out if it actually works but this one is a big plant of really long runners so in the past this is run well everywhere but you need a big motor you need to move a lot of air bigger cam i don't know this motor is going to be exactly what you want but we're going to put it on and see how it does one change we do need to note that keeps this intake from being a pure apples to apples test is it actually won't fit with the headers we've used so far so along with the fully ported straight runner we also pulled the six into one header for a competition level three and the two into one set of pipes to remove the trash gases now what's cool is that even with all these intake and header changes we were able to actually use the same gasket all day long i'm not getting anything out of this i just appreciate good product design this copper intake and exhaust gasket is a design keith has made to his specs and sells on his newcomer racing website he's also got a thick laser-cut washer set that holds the intake and exhaust manifolds a ton better than the stock hardware now if you're a jeep performance person at all those are definitely two things i think you should check out or not no skin off my back so the fully fabbed intake is on let's make a point [Applause] [Music] we actually ended up making a few pulls the intake was moving so much air the engine was going lean once more but even though keith updated the tune again the injectors were just maxed out and couldn't flow all the fuel we needed here's what the horsepower and torque looked like both horsepower and torque are way down early in the run compared to the fully ported straight runner but just when the fat intake catches up and looks like it's about to take over it sort of just evens out that's the injectors running out of capacity so ditch that run we'll try something different it turns out we didn't have any bigger injectors readily available that fit so instead we popped off the throttle body and dropped on a holley 830 cfm double pumper also that's a two inch taper spacer underneath the carb it was a quick fix to help to get the fuel log to fit and yeah that sort of kills the comparison by ditching the fuel injection and the ecu and instead of dropping on a carburetor but at this point we're basically just having fun anyway so after a couple of test pulls to determine the best jetting we settled on a set of 72s by the way we were ready to make our final pull [Music] [Applause] [Music] honestly the results here are pretty weird things were looking great up until about 4 700 rpm when power started falling off pretty quickly causing a big dip in the horsepower curve probably a little time spent tuning the carburetor could have fixed that but we were already beyond our scheduled time on the dyno anyway still the fabricated intake with the carburetor did hit our best torque number with 357.5 foot-pounds peak horsepower was just 321.3 which was mildly disappointing but i suspect that was a tuning issue more than the intake running out of air so what did we learn with this sadistic level of dyno testing well a couple of things first you probably already know this but there is no single best intake design for every application as you saw some intakes make better torque down low while others shifted the power band higher in the rpm range to help produce more power generally speaking smaller runners are better for torque down low while bigger shorter runners move the rpm band higher keith has all these intake manifolds on hand because he uses them all depending on what he needs to make the customer's desire for each engine build so that's lesson one use the intake to help tune the power curve to your needs the second thing we learned is even better no matter if you want tons of torque right off of idle or maximum horsepower with the engine screaming up against the rpm limiter it's critical that the intake's runners properly match the shape and direction of the intake ports in the cylinder head a little bit of time spent poor matching your intake to your cylinder head will almost always pay dividends plus it's really not that difficult either so if you've made it this far hey thanks for watching and please make sure to check out our other great videos see you next time

Channel: The Horsepower Monster

Views: 145,479

Keywords: jeep engine build, jeep stroker engine, how to make horsepower jeep, jeep race engine, 4.2 jeep, newcomer racing, jeep dyno test, jeep intake manifold, jeep throttle body, engine building tricks, engine building secrets, jeff huneycutt, horsepower monster, keith newcomer, devon rowell, jeep, wrangler, jeep cherokee

Id: IUGcth4KHl0

Length: 28min 3sec (1683 seconds)

Published: Mon Jan 03 2022