You summed it up right there. I 100% agree with you and not only do I agree with you, it's a realistic point of view. Too many people have a point of view from the buyer or customer or tuner side where they want want want but don't realize why they aren't getting what they want.

Money rules the world...especially in the car industry.

I hope you honestly don't believe that...

No matter how much aftermarket support people have, no car is "Easier" than another if you don't know what you're doing ESPECIALLY when it comes to forced induction & forced induction on a factory naturally aspirated vehicle.

It's called having the funds and smarts behind it. Rare combination to find now and days. If you look at people in the magazines, lots of times they have alot of backing either by shops or companies and if they are independant, they had that rare combination.

No matter if you have a SS/SC or a EVO, you can still **** up a car.

The main reason people aren't accomplishing much is because they are sticking with their stock M62 supercharger and pushing it WAY pass it's efficiency point. At one point, they are just fighting heat and wearing down the life of the supercharger.

The M62 was not put on the car for someone to create 300 WHP, it's sufficient enough for a sub 200 HP like GM set it up to and a slightly smaller pulley like with their stage 2 kit.

Comparing a SS/SC and a SRT-4 or an EVO or an STI is comparing apples to oranges as far as the type of forced induction they have from factory, the funds of the typical person who owns them and their aftermarket support. It's easier for the guys with SRT-4s to make gobs of power because they have Turbochargers from the factory which are more efficient, much cheaper to replace, much easier to replace and turbocharge parts are for the most part NOT application specific (unless you're talking about a actual manifold or certain items that are a direct replacement or manufacturer fit for a vehicle).
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Bigger?

Their engine is fine. Their main source of power is the issue.

Make it look different? I don't even know what that means...

 

I think the problem is then a matter of how the pressure is maintained not where the pressure is regulated at.


I guess the point I'm trying to make is that regardless of where you input the pressure source from, as long as that pressure is properly maintained, then the entire system will see the same amount of pressure.

Think about it like this... You have an air compressor that creates 40psi. It pressurized an 8 gallon tank to that 40psi... now you hook a 3/8ID hose to that compressor and put 2 t-fittings into that hose, and a hose on each T-fitting, off of each hose you place a pressure guage. The pressure measured at each guage will be the same regardless of the distance from the tank because the ENTIRE system pressure is being maintained at 40psi, not just the pressure within the tank.

Now understanding that all the injectors do not open at the same time, as each injector opens a small amount of pressure is bled off, the pump "should" restore the bled pressure before the next injector opens. If that is not happening then it would be a detriment to all the injectors after the first injector flows, not just the one farthest from the pressure source.

 

What you are not taking into account is the effects of increased flow. Using your example would mean a returnless system would have no limit, which simply isnt true.

You have to realize that the injector size most people upgrade to flow nearly twice the amount the stock fuel system was originally designed for. Also add the fact that the manifold pessure that the injectors have to spray against is increased a significant amount over stock level as well.

Also if only one injector is flowing at a time that means your injectors never exceed 25 percent duty cycle. That obviously doesnt happen as you can run up to 80 percent safely.

 

Let me clarify, I was not suggesting that only one injector is open at a time, I was merely pointing out that all the injectors do not go from closed to open simutaneously even though they may ultimately all be open and flowing at the same time.
I see your point but the upgraded components don't necessarily point to a flaw in the design of the system, just the method of the upgrade. When we upgrade one component of a system it is reasonable that another component of the same system will then need to be upgraded. What I'm hearing from this post is that the problem does not exist in the stock system and only when injectors and pulleys(increasing manifold pressure) are upgraded. This would reason that the fuel pump may also need to be upgraded in order to compensate for the increased flow. The increased flow is escentially and increased bleed of the pressure for each injector. The pump would need to be upgraded to better compensate for the increased demand for the same amount of pressure.

Using my same example replacing the guages with nozzles and adding 12. In a system with z amount of constant pressure, 3 nozzles will bleed x amount of pressure and the pump will need to reintroduce that same x amount of pressure to the system... however... 12 nozzles will bleed y amount of pressure, the pumps ability to reintroduce x amount of pressure is not significant enough to maintain flow. Now that pump can reintroduce y amount of pressure when the usage is lessened however upgrading the pump to a unit that can maintain the z amount of pressure at the y bleed rate would correct the flow degredation issue.

I guess what I'm saying is that regardless of where or how the pressure is regulated the ability to maintain the pressure is the issue, not the design of the system. The drop in flow caused by a, theoretical at this point, drop in rail pressure as it hits #4 injector would be overcome by a stronger more capable fuel pump.

You don't run a full service garage with complete plumbing for air tools off a $100 Pep boys compressor. Why run your expensive aftermarket increased flow injectors of a pump designed for less demanding load?


Again I could be way off on this but I think this discussion is getting us all closer to understanding our cars. Atleast I am.

 

Hmm....me either......lol.....

I guess i mean restructure the entire engine in certain areas to produce hp increased.

 

Hmm....me either......lol.....

I guess i mean restructure the entire engine in certain areas to produce hp increased.

 

Comparing a SS/SC and a SRT-4 or an EVO or an STI is comparing apples to oranges as far as the type of forced induction they have from factory, the funds of the typical person who owns them and their aftermarket support. It's easier for the guys with SRT-4s to make gobs of power because they have Turbochargers from the factory which are more efficient, much cheaper to replace, much easier to replace and turbocharge parts are for the most part NOT application specific (unless you're talking about a actual manifold or certain items that are a direct replacement or manufacturer fit for a vehicle).
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kinda sorta....but the srt-4's rotating assembly is also much stronger than the stock lsj rotating assembly.

same goes for the evo/sti. Everything else remains to be seen, but the stock hyperpathetic pistons are NOT strong in the lsj.

 

also sorta... except for the pistons themselves the LSJ has forged internals.

 

I gotcha

 

yea, but once again you have to pop the **** open to safely make big league power. There are ******* 500whp srt-4's on stock internals, same goes for the sti's and evo's.

 

Well that too. You know what I mean

 

yea i know just throwing that out there.

 

Agreed. I think people want/expect too much out of the car. Can the SRT4 make "big league horsepower" without internal upgrades? Yes. Would I rather have an SRT4 than my SS/SC. Hell no and I am a Mopar fanatic. A. IMO they are ugly B. Beside the drivetrain they are poorly designed C. they don't have the options/amenities we have

Face it, if you wanna track monster and have the money to spend outside of financing you should buy an old CRX or Golf and build the crap outta that. Cheaper, lighter, and you can build it however you want to and for what you want it to be without having to deal with factory flaws for less than you can buy an SRT4 or SS/SC.

I didn't buy my SS/SC to make 300whp. I know that makes me the minority here but I hate drag racing, always have. I think it has to do with my love of Sportbike racing. Tight, High speed, high G turns FTW!

 

The returnless system uses PWM to turn the pump on and off rapidly to maintain exactly 60psi via a regulator in the tank. So the fuel pump also has a duty cycle.

ALL HYPOTHETICALLY:
At 12 volts the pump might need 100% duty cycle at wide open throttle to maintain lets say 50 PSI with 60# injectors because the injectors let out more fuel than the pump can keep up with.

With a boost a pump the fuel pump is getting 18 volts so it's pumping more fuel than a pump at 12 volts. So it might only need to be on 80% of the time to maintain 60 PSI instead of 100% on an over stretched stock system.

This concept does work or else Kenne Belle and MSD and other companies wouldn't be selling them. BTW most of what I am reading is from the Kenne Belle articles on how and why this works.

The point of a return style is to keep the fuel flowing to cool a pump thats on 100% of the time because it's not capable of PWM and it keeps fuel temps down. So when you are not using any fuel because lets face it most of the time you aren't WOT on a street car. Also another bug benifit is an adjustable FPR or rising rate ect. But there are other ways to get around having a static fuel pressure and the LSJ pcm does that part fine.

I am not saying that the boost a pump is unlimited because at a point if you boositng the voltage too much you will burn out the pump or wiring.. and you can only move SO much fuel through the fuel lines at 60PSI. But if your problem is your fuel system can't maintain that 60PSI well then the boost a pump systems can help that.

 

You're confusing the two systems and how they work. Your theory above can only be applied to a return style system unless the pump in the tank is not able to match the regulator's pressure.

On our cars, you can have a 60psi regulator on the pump, but with high flow injectors the actual pressure at the end of the rail can be lower. Upgrading the pump doesn't do a thing, if the regulator on the pump only allows a pressure of 60psi.

This is the point I'm trying to make that you're not understanding about having the regulator located so far away from the rail. Think of a pump with a 60psi regulator attached, then a fuel filter attached to the line with check valves then to the fuel rail. You will lose pressure when high flow injectors are installed to the rail, even though the pump is still working at a relatively low duty cycle, still providing 60psi of fuel, although high flow, to the regulator. The larger the pressure drop in the rail, the larger the delta pressure difference between injectors. This is the reason you also couldn't install injectors with adjusted flow, as the delta pressure value between injectors is not a constant. If one injector flows 5% more than another, when pressure increases at low duty cycles, the delta value may drop to 1%, however your fuel injector is flowing 5% and simply moving the problem to another injector/cylinder.

Think of it this way, take a garden hose, cut a bunch of holes in it and turn the water on. If the holes are small, the pressure from each hole is even. However increase the size of the holes and you lose significant pressure in the hose. However the pressure behind the valve is still the same as it was, its just flowing more. Adding more water, but keeping the same pressure behind the valve doesn't help a thing, since the restriction is the hose and valve itself.

The only two solutions that I can see working to help this problem is Zinner's idea of a boost a pump and a return style system. I imagine a boost a pump is mounted close to the rail and reclaims whatever pressure value is set by the regulator. This would guarantee a stock pressure feed to the rail under all flow conditions. Converting to a return style system would also keep constant pressure at the rail and also allow for pump upgrades should the need arise.

Ok, I wasn't sure what a boost a pump was, but I have seen voltage boosters for fuel pumps, just never heard them called that.

The point I was trying to make earlier is why simply increasing pump flow or changing individual injector static flow rates won't work if the pump is meeting the regulator's pressure setting.

Someone mentioned to me (Dan maybe?) they found a way to scan for pump duty cycles and it came out to 90% max. I don't think I'm dreaming, but if I find out where the value is for it, I'll let ya know.

 

If we can log the pump duty cycle then we can actually have some data to back up the boost a pump's effectiveness.

I think you are right, if the fuel pump can't keep up the injector at the end of the rail is going to suffer first.


http://www.kennebell.net/accessories...boostapump.htm

It's got some very good info and it's a heck of a lot easier than a return style system.

I might be wrong about the PWM on the ecotec.

I read something that indicates there is a FPR in the tank that operates just like on on the end of the fuel rail would.

 

so what is up with the hahn turbo kit? read 4 pages and didnt see any thing. any word?

 

Read again starting from page One.....

 

So I looked up the fuel pump schematics in the shop manual and it's just a relay and from there out it's running 100% No PWM controls.

 

read it again, well not exactly word for word but i still dont see any thing about it? i understand there is a lot of problems but is there in one in development with hahn? sorry if there is something in there that i missed but i ddiddnt see any thing man

 

Ok I think I understand. The difference in the theory I was working off of and the way the system apparently works is that you are saying the pressure in the system is not maintained at 60% but the input pressure from the pump is 60%. That makes sense. Could we not then install a FPR on the end of the rail and eliminate the one on the pump and accomplish the same effect?

 

You got it. Although if you add a regulator to the end of the rail, you would need somewhere for the excess fuel to go once regulator pressure is met. That would be the fuel return line.

I think the best way to get an answer on what to do is to monitor fuel rail pressure from the schrader valve and see if it does drop. Somehow you would have to find out if its the pump not keeping up with the regulator or if the fuel system not allowing enough flow to maintain stock pressure to the rail. That would tell us the route that we would need to take to upgrade our fuel systems.

There are some really good online mechanic's tech articles I remember reading a while back about this and they mentioned that some vehicles do have return style conversion kits. I never looked into seeing if any are available for us.

 

I agree with u on this because I want "big league horsepower." I know that will never be done on stock internals but after that internal forged upgrade of everythign is complete where are you going to get the power from. Sure a small pully, cooling mods, and nos can get u there but it wouldn't give you constant steady power. I feel that the twincharge kit if it worked and gave substaintial power coupled with a sucessful supercharger swap (still a work in progress) would make a sucessful amount of power. Of course these are all assumtions and my dream expensive build if everything else pulls through sucessfully. But despite price the power would be amazing. I might be a dreamer but ive been saving up and once these compnies finish up i can't wait to try and make everything work.

 

I just read every single posts int his thread and my brain hurts from the knowledge intake.

Quick question, back tracks a little.

I thought the twinscrew SC's were a lot mor efficient and also created a lot less heat for the LSJ's, or any motor for that fact. I heard mention of the cat's creating parasitic loss as well, would a TS SC with a high flow cat fix a bti of the parasitic loss, or would a turbo w/ high flow/no cat be the best option for us?

 

well no matter what any kind of supercharger is going to have parasitic loss, including turbochargers (which are technically a type of supercharger). The great difference is that turbo's have an almost nill parasitic loss, just about as much as a stock catalytic converter does. Now a twin-screw is more thermally efficient than a roots, there you are correct, and it is slightly less parasitic, but the most important thing to notice here is speed. The twin screw that is coming out for your car is a much more efficicent blower than the m62 overall, which means it has to spin less (slower) to compress the same cfm. The faster you spin a blower the more parasitic loss, so you will have quite a bit less parasitic loss with the twin screw, but the turbo will always be able to make the most power at the same cfm/stress on the engine.