So a guy I go to school with has a bolt on 2v mustang I've dragged on multiple occasions, and he claims he could beat me naturally aspirated, which I know he couldn't, (ls1 with 317s, tick stage 2 turbo cam, ls6 intake, etc.) So my question is, if I remove a few pieces from my cold side, set up the MAF in a stock location where it wouldn't have boost going through it, would it run fine NA with the current tune? It would also be cool to see how big of a difference 11psi makes. Thanks, Logan

 

I'm guessing that you have a turbo motor, and are a little slow on thinking things through. You will probably lose the race AND burn your turbo bearings at the same time if you follow this present course of action. Then again, I'm just some random guy on the internet, so go for it.

 

No it's fairy dust induction and if I was an engineering genius I wouldn't be asking questions that I already know the answer to but thanks for the smart *** answers I find them funny

 

why would the bearings burn up
he never said he was going to remove the oil to it



if you pulled the coldside pipe and tuned it for na it wouldn't hurt a thing

 

I could understand how it may spin the turbo too many rpm as it wouldn't build any boost and the wastegate wouldn't open, an I wrong? I was also unsure if the tune would be totally out of whack

 

Just point out to him that your car isn't a NA car. You have a turbo car, and he only wishes he had a turbo car, so you wouldn't spank him so hard. What your car would do NA is unimportant, since it is a turbo car. Also point out that if he had a vagina he'd be a chick. Don't mess with your car just to prove him an idiot, you know he is, move on.

 

Tell him your car is now running in NA trim, line up for race, let him tree you, then gap him, video his reaction, please post...

 

That is a common misconception. Flowing a turbo into free air does not make it spin faster. If anything it would spin slower as there would be a huge load on it from trying to move more air. It takes a bit of thinking to understand and wrap your head around so I'll try to explain with some examples.

If you have a leaf blower (or you could actually even use your girls hair dryer), run the thing at wide open throttle and listen to the motor. Now plug up the outlet of the leaf blower (or hair dryer) and listen to it at full throttle. The first thing that you should notice is that the engine rpm increases significantly with all of the flow blocked. It does this because it is no longer having to flow or pump any air and therefore removes the load on the motor.

Another example was shown by testing on prochargers by Steve Morris (the procharger guru). Procharger will not release any sort of efficiency mapping for their blowers, so he set up a test to measure required input horsepower to achieve specific impeller speed and measured air flow starting with an open flow (nothing hooked to the outlet) and then started adding restriction plates to the outlet. The results where astonishing and 100% proved the concept I mentioned above. While free flowing the blowers, it took a tremendous amount of power to achieve impeller rpm as it was attempting to flow tons of air. Once the restrictions started coming into the picture, required drive power started coming down and measured boost went up. Once he fully closed off the outlet of the blowers, required drive power fell to nearly zero as there was no longer a restriction on the impeller (because it wasn't moving any air).

I hope I have explained this in a way that yall understand. Like I said, this is a very common misconception and I'll be the first to admit that before studying this physics concept, I thought the same way you did.

 

There had/has been some recent ideals that you could pulley a procharger to max impeller speed and then use a waste gate of sorts on the cold side. The use of an electronic boost controller would be to open the the outlet flow of the blower to limit max boost. The theory is that you get a ton more power down low in the rpm band due to the pulley ratio allowing greater impeller speed at lower rpms. Then once your desired max boost was attained you could open the waste gate to keep the boost level where you wanted it.

It has been done and it works, but the downside is that when the waste gate opens up you start free flowing the blower and required drive horsepower skyrockets. This increase in load on the blowers transmission has proven fatal for the blower in some cases as the load on the blower skyrockets when you take the airflow restriction away and the transmission just can't take it.

 

That's great information. So let me take this to a actual testing situation. Take the same blower, D1, F1a, whatever, spin it at the same rpm, and in theory, it should move the same amount of air. So let me ask this, what is better, for that amount of air to feed more or less cubes? Let's say at max boost with the same pulley combo, a stock ls3 at 36x cubes, would see 20psi of boost, but on a 416ls3 stroker, it would see less boost, say 15psi of boost at the same max rpm setup. So which combo would be more efficient?

 

I don't know what ECU you have, but if tuned for boost, it would prob be off N/A, esp in the higher RPM's
If you have something like the Holley HP, you could maybe set it up on learn and make a sep tune, data log it and adjust-i'll leave the turbo unhooked part to others to chime in.
I guess my question is why bother-make him go boost if he wants to race, never go backwards, lol

 

The derp is strong in here

 

Yeah. I don't quite understand the whole adjusting your setup to make a race 'even'. What ever happen to run what you brung, and hope you brought enough.

Your friend is just jealous that it's so easy to make a crap ton of power with an LS setup.

 

Ah yes, the "I would've beat you if.........." Always loved the "I've only got single exhaust" or "I'm on street tires" etc. It's like are you braggin' or complainin'? Leave your car alone.

 

Don't take the bait. If he wants to run, he needs to come with a better game plan for his own vehicle or learn to keep quiet and stay in his own lane. Let him know when he's ready, he has "heads up"!

 

From an efficiency stand point, the bigger motor is the way to go within reason. I say within reason because I don't want some jack *** to come in here and say putting a d1sc on a 903 cubic inch Sonny Leonard motor is not going to be better than using the d1sc on a 370 inch motor. Disclaimers out of the way.....

The preferred method to go about what you are asking is to certainly use the bigger motor (like picking a 6.2 over a 5.3). Even if pulley'd the same, the 6.2 is very likely to make more power than the 5.3 and boost levels would be lower on the 6.2.

There is no replacement for displacement.....and that is the end of the story.

The problem is that the turbo guys are about to come in here and put me on blast saying that such and such turbo is gonna make best power on a 330"-370" motor vs. a 408"-427" motor.

Most of the big numbers you see the turbo guys putting down in "class racing" are doing so on smaller motors when larger ones would still be within class rules (this is solely because they are "class limited" to a specific turbo). So you automatically get the group of guys who come on the forums and every time a 370" vs. 427" with "this turbo" thread comes up, they will argue to the death that the 370" is the way to go and the old saying of "there is no replacement for displacement" is stupid and blah blah blah. Sure, they may be right if that particular thread is asking about a specific turbo........but for the average guy who isn't bound by class rules the bigger the motor the better (again within reason), you just need to understand that the turbo needs to be matched to the size of the engine.

Again, sometimes it is hard to put into text what I want to say with my mouth.......so if I've misstated something or typed in a way that doesn't make sense point it out. I don't want to spread bad info on the subject.

 

I know that turbos are 'sensitive' to cubic inches, but I'm only worried about a blower at this point. I made the choice to go with a stroker crank because I spend almost all of my driving in the 2000-4500 rpm, and figured the bigger cubes would suit my driving style better.

My part throttle, mid range power is amazing, and I think a large part of it is the combo I put together, but was just curious about the efficiency of running the blower at a lower psi (which we all agree is just a measurement of backpressure) vs a higher psi at the same blower rpm.

I was always under the impression that it was better to make more power with less boost, especially with a blower, since it would require less power to spin the blower, but that may in fact be an incorrect misconception of my part.

 

Nevermind.

 

The answer ? same with any compressor.....compressor map. Where is that particular blower most efficient for the airflow/pressure it is running at ?

And more power with less boost....again depends on the combo and if it can be achieved. With low boost there will always be a limit on how much power can be made for any engine size, so if you want more, you need either more "boost" ( airflow ) or more cubes....ie airflow.
Ultimately it's all about airflow

And you wont overspin a n/a turbo simply because the engine will make ***** power so have only ***** power worth of exhaust gas to drive the impeller in the first place.

 

When you beat him with the charge pipe off, then he will say "ok, now unplug 5 of your spark plug wires and let's see who's faster". It's never ending with those mustang guys. Then when you beat him while running with no turbo and only 3 cylinders firing.....he will just get pissed and take out the nearest crowd. I guess what I'm saying is, don't do it.