Vortech Questions

[justinschmidt1]

I like how hes showing a 5.0s n/a torque curve compared to a 4.6 :hammer:

 

[Shocker98GT]

I like how hes showing a 5.0s n/a torque curve compared to a 4.6 :hammer:

It's a stroked 4.6, aka a 5.0L modular engine-VT heads, custom comp cam grinds, full bolt ons. Read before you type. Stroking a modular doesn't help it a ton until you have boost or nitrous to take advantage of it.

Your argument is absurd in this situation anyway-that article from the toilet paper rag in your previous post is from a "T" trim Vortech that is designed to make HP in the high RPM range for race engines,not the more street designed "S" trim. That comparison is also on a car with an intake designed for a roots blower-the Vortech kit simply uses an adapter plate-no wonder it's low on torque-the runners on that intake are all of about 4" long.

A T trim is no less streetable than an S trim, nor is it functionally different. Hell it really isn't that good of a race blower, a Novi 2000 outflows both of them and makes more overall power in street applications. The T trim, Novi 2000 and the like are more efficient because there is less restriction in the blower itself, thus less heat discharge. The principle and function of a centrifugal supercharger remains the same regardless of how much airflow it is capable of, you have to spin it to high RPM in order to create boost. It's just the physics of the design, it is just like any other centrifugal pump. There is no such thing as a centrifugal supercharger that provides a flat boost curve, or one "optimized" for a wide torque curve. An intercooler can help flatten it out a little bit just due to it being more efficient with less airflow (increasing restriction as boost gets higher), but the curves will all be the same.

The intake is different, but it's a fair comparison saying they're comparing the nature of the blowers to one another. The boost curves are the main thing to look at in that article. It doesn't matter what engine you're using or what intake design you're using, it won't change how the supercharger itself operates. Put a longer runner intake on that same car and the only thing you'll do is kill off the high RPM power and try and trade it for more power at lower RPMs, and at that point a centrifugal unit doesn't have enough boost at that point to overcome a roots or twin screw unit. In that specific application it's pretty much the only way a centri blower is going to outmuscle the other offerings in any area, they made the right decision.

I OWN a N/A car that makes approx 300rwhp,and I've driven many other stone stock NPI modulars that have had a simply box-stock S-trim intake,and they ALL made 320-340rwhp with a correct tune installed, They also make lots more torque all over the place vs my heavily modified N/A engine.
This whole argument is stupid. Your point,while a decent one,is twisted by these "articles" you've read or seen that are lopsided in one way or another. You don't see the big picture.
JL

Your car is also much different than a PI N/A mustang. For one you have a T-bird, the extra weight is a hindrance, and also the extra chassis strength is going to make it feel slower opposed to a "flexi-flyer" mustang.

Yours is also different in the form of ported NPI heads, which have different characteristics dependant upon what method the head porter uses. Once you've ported the heads, you've altered turbulence, if you remove or grind down the emissions mask (swirl dam) you've completely altered the characteristics of the cylinder head. You have more concentric airflow into the chamber, removing the swirl dam also gets rid of a big piece of metal that retains heat very well. The more concentric airflow also cuts back on the vortices that hinder airflow around the exhaust valve, which means you can take advantage of overlap more because the engine now scavenges better. The swirl dam creates a faster burn duration, thus faster combustion, and works well for a stock engine, you also advance the timing closer to TDC because of this. Removing that and the decreased turbulence created by the porting means you're going to have to alter the timing curve in order to more your peak cylinder pressure where you want it. Basically now that your heads are not "fast-burn" heads anymore, you're going to have to alter the timing so that the burn will progress through the chamber and reack peak cylinder pressure at 14 degrees ATDC.

But to really take advantage of the characteristics of whatever ported heads you have, the camshafts have to be pretty exacting. You're going to want something that will take advantage of the added flow, that will also take advantage of the increased scavenging you've achieved from modifying/removing the swirl dam from the combustion chamber. The stock cams open so close to TDC that the low lift flow isn't as much a factor because the cylinder pressure is so much higher than the pressure in the intake, but by the time you've spread out the duration you're able to take advantage of what flow either head offers. And IMO most of the off the shelf grinds don't do it, though some come closer than others, but most of them are made to be a jack of all trades kind of application instead of a focused deal, concerns about the idle or about the flexibility to supercharge or turbocharge or modify elsewhere means some conservative grinds. The ones making the most power with these engines are the VT and Hitech N/A cams, IMO Hitech had the right idea for a n/a cam when they biased the duration to the intake side, which works well with PI heads considering they get the exhaust flow closer to where it should be relative to the intake. The tight LSA creates really strong midrange torque as well. NPI heads the exhaust bias isn't as bad, and ported NPIs you'd probably do better with a straighter cam profile, which none I've seen offer. But essentially by the time you've done the 2V n/a (aka the "unpopular" route lol) you're doing better to get custom grinds tailored to the application. Really that's the case with any engine but even moreso with this rather unsupported side of the modular performance world. I'd go with Comp custom grinds personally.

A bullitt intake, an automatic, many other factors contribute to why your car would be different from a supercharged NPI car, or a N/A PI mustang really. You have a strong N/A car, but yours is also different than the ones that most will build due to the methods required to get there, as well as the differences in vehicles which no doubt affects the final outcome just as much.

 

[Johnny Langton]

I like how hes showing a 5.0s n/a torque curve compared to a 4.6 :hammer:

It's a stroked 4.6, aka a 5.0L modular engine-VT heads, custom comp cam grinds, full bolt ons. Read before you type. Stroking a modular doesn't help it a ton until you have boost or nitrous to take advantage of it.

You're a fucking idiot. I give up.
Stroked engine=more torque and a lower peak power.
Any grade school child knows this-it's a fact you cannot hide from,and comparing it to ANY stock displacement modular is like comparing a 460 to a Honda 1.6L-it's useless and ignorant.
You don't know dick about my cylinder heads,how they're ported,how my combination is setup-NOTHING.
I have nothing more to say in this thread,and honestly-I'm about fed up with the stupidity over here on this forum.
JL

 

[justinschmidt1]

exactly....why dont we compare a 5.4s torque curve to a boosted 4.6 why were at it.

 

[Brian95SVT]

exactly....why dont we compare a 5.4s torque curve to a boosted 4.6 why were at it.

hahah ok!! :rollinglaugh:

 

[97stanger]

Yeah man seriously, you're comparing apples and oranges. :tickedoff:

 

[justinschmidt1]

I guess shocker was trying to compare a n/a option vs a boosted option...but the whole arguement was based on the fact that a boosted 4.6 with 300 rwhp will be faster than a 300 whp n/a 4.6...

and the blown 4.6 will make more torque everywhere

 

[Shocker98GT]

More specific applications then:

Vortech S trim, straight onto a NPI 4.6 with BBK throttle body with C&L plenum, Shorties, Bassani X and Flowmasters. In other words a very typical NPI GT, no PI bits yet, no power pipe yet, just S/C on a fairly stock NPI setup. And yes, the car is a stick. 267RWHP/310RWTQ. Why so low? The NPI stuff really does breath that bad, it's due to the rapid dropoff in torque due to the NPI intake and cams.
http://www.modularpowerhouse.com/forums/showthread.php?t=41349
Anybody that is a member on that site can log in, go to his profile and see the dyno chart in his pics. Or it takes no time to join the site, I'm posting both cars because both cars were tuned by Tim on his dyno.

Comparing that with N/A cars that put out in the same region, in this case a PI 4.6 car with 267RWHP/303RWTQ, a pretty basic bolton car with accufab TB/Plenum, JLT intake, longtubes and exhaust and UDPs. it isn't hard to see the difference in the torque curve
http://www.modularpowerhouse.com/forums/showthread.php?t=48067

Are there N/A guys and boosted NPI cars with more? Sure. You could crank up the boost or use a more aggressive tune on the NPI stuff and get in the 300s, later add more to it. Many NPI cars put out 320s or so once you add a power pipe and other odd and end boltons. There are N/A guys putting out the same. But sticking to my original point that a n/a engine will be stronger overall than a centrifugally supercharged engine with the same peak power output, it's pretty easy to see that with the power curves. If anything the fact that it's a centrifugally supercharged NPI engine biases this comparison MORE toward the boosted NPI engine when comparing torque curves because of the fact that the engine makes peak power at the point that the torque has fallen off, means that for the same given power level it is even stronger in it's peak torque region than the power numbers would indicate (with these engines it's around 4000rpm), or would otherwise be had the torque curve been shifted more toward peak power output. Yet it STILL has a narrower torque curve than a head/cammed n/a engine with the same power output. I really don't see why this is so hard to grasp, the characteristics of centrifugal superchargers have been well known for a very long time, and every major automobile magazine has posted up enough data on boost curves, power curves, torque curves, timing curves of engines that run said superchargers, essentially every possible number you'd want to slap onto a piece of paper and verify.

If you want to make further power with a boosted NPI car, you're going to do a PI intake, if you go the RTV "cost effective" route it's $200, or add $500 if you want a kit with adaptor plates etc., after that you're going to want to go with new cams, which if you do blower cams it's gonna be $600 plus another $200+ for springs, or go with stock PI cams, spend whatever you can get a used set for, then you're going to be either spending time to install those, or paying money to have them installed and perhaps degreed should you choose to do so. So basically, you're buying a blower, then on top of that you're doing the exact same modifications that you would have made had you gone N/A and decided to grow later, and you're doing it just because you're trying to extract similar output to what a blown STOCK PI engine will put out.

Go the N/A route and you're already in the 300rwhp region, and with the head flow as well as the camshafts, getting big power out of that will be a cakewalk compared to trying to squeeze it out of an NPI engine. A nitrous kit is the el cheapo way or if you went with a blower later you'd get bigger power gains with less stress on the motor because you're running less boost with the same airflow, meaning less friction and less heat, thus less stress on our rather fragile pistons and rods. It isn't like somebody has to go to the extremes of ridiculous cams and head porting to get close to 300rwhp n/a, lots of guys are getting 280s and 290s out of setups that have blower cams and mild heads. There are people in the 290s with stock PI cylinder heads and a good set of cams, with a wider torque curve than the car gives you stock.

I wasn't in any way saying the N/A route was always the better option, but in this particular case, I definately feel that it is because you're spending roughly the same amount of money for around the same power output, while it'll be a little cheaper to get a few extra HP with the blower via PI intake, power pipe, etc., in the big picture an engine with ported heads and camshafts has a ridiculous amount more ultimate power potential than an NPI setup would have, then add the benefit of having a newer engine. If we were talking about tacking on a Kenne Bell instead of a Vortech it'd be a LOT different, a no brainer because a Kenne Bell adds boost right in the meat of the powerband where an NPI car can surely use it most. The boost curve of a centrifugal supercharger, opposed to positive displacement superchargers or turbos, is very narrow in ANY application, and the NPI setup just fights it that much worse.

 

[justinschmidt1]

Im confused at what your looking at?

Im looking at both the graphs and the torque curves are pretty much the same except the supercharged NPI looks stronger from 3-4k.

the problem with this comparison is that a boosted car can always make so much more power. 267 rwhp out of a blown npi is weak...why?

the thing is like stock pushin what? 6 psi? throw just a pi intake and bump the boost up and hes making 330-340 rwhp.

I would expect a PI car with u/d's and long tubes to have a nice torque curve...that cars torque curve looks very healthy...much healthier than other pi dynos I have seen.

the NPI still looks stronger to me :dunno:

 

[Shocker98GT]

Im confused at what your looking at?

Im looking at both the graphs and the torque curves are pretty much the same except the supercharged NPI looks stronger from 3-4k.

the problem with this comparison is that a boosted car can always make so much more power. 267 rwhp out of a blown npi is weak...why?

the thing is like stock pushin what? 6 psi? throw just a pi intake and bump the boost up and hes making 330-340 rwhp.

I would expect a PI car with u/d's and long tubes to have a nice torque curve...that cars torque curve looks very healthy...much healthier than other pi dynos I have seen.

the NPI still looks stronger to me :dunno:

The torque curves are pretty similar really, boosted car slightly stronger in the 3-4k region, but the PI car is slightly stronger above 4.5k and below 3k. Close enough to be a driver's race, but it just shows how bad the NPI setup does wheeze from the factory considering you're talking a centrifugal setup that maxes out at peak RPM, the torque curve nosediving even with boost climbing at that point is pretty bad. The PI GT is a bolt on car, no modifications internally just the basic pullies, UDPs, CAI, and he does have long tubes with full exhaust. Later he added VT stage 1 N/A cams and the car gained slightly above 5k, but lost below 3.5k or so, IMO lost too much to justify it but it shows just how important good cams are for these cars, or at least how critical good heads are to take advantage of said cams. Or you get just like you said, a PI car with a torque curve less healthy than that one . I tend to prefer getting custom grinds for that specific reason. N/A is no doubt more difficult to get great results from but there are more and more examples of it done right now that the learning curve for these engines isn't really that steep compared to how it used to be. A lot of the Hitech setups are putting out some REALLY impressive numbers.

No doubt you could add boost, power pipe, PI manifold, cams, etc. but the n/a setup wasn't maxed out either, I'm just one that feels it's better to build an engine to go fast before you do go fast, I'd rather boost later if it means I'm boosting a newer, substantially better breathing engine, if it costs me some power or time that's fine, many won't agree with that I know, just offering a different perspective I guess. I will fully admit boost is the way to go to make big power, and the small upgrades on boosted cars make much more of a difference. Which is why Terminators are understandably so popular. And I'll fully agree that n/a on these engines isn't the way to go for big power, but you have to have a solid foundation with good potential, I just feel that a car that's that strong n/a will be so much stronger under boost that in the long run, it justifies the time you've waited. Keep in mind that in all this I'm not one that feels that 350rwhp is enough anymore either, not that it isn't fun, that's simply not the case, just the automobile market has progressed so far compared to when these cars came out that 350 at the wheels really isn't that much anymore when you look at the stock cars rolling off a parking lot now, I'm one to at least prepare to go big in the long run. Ported PIs, good cams, solid shortblock and you can pretty easily pull 600s at the wheels once you add boost to the mix.

 

[ju015dd]

take your time and look good. I got my whole set up minus injectors for 2300 shipped. just had new bearing and seals put in and the unit had less than 4,000 miles on it total. best part was he had already got it all set up for me with the power pipe and all so all I had to do was throw it all in the car. I had to buy injectors, fuel pump and new mass air meter along with fillter. with tuning I think I spent a tad over 3 grand for everything, but I installed everything myself.