thanks guys...one more question if i am cruising at negative boost at like 120mph - 130mph as long as i am not boosting it i should be fine correct? By the way this is my first forced induction car so i have minimal knowledge on sc's but that will change when I start modding. Also i am assuming, correct me if i am wrong.....i should do intake full exhaust, then cooling then a stage 2 kit and tune??? Also i just talked to my buddy and he said when i start doing the cooling mods i should a FMIC along with what i already planned, meth kit, dual pass and colder sparks

 

A FMIC won't help you at all and only pull money from your pocket. your stock air to water heat exchanger is better than 90% of fmic anyway now go check out my video!
https://www.cobaltss.net/forums//showthread.php?t=64449

 

Replying to the "knock" you mentioned. Mine stock off the lot has made the knocking noise a few times. It hasn't done it lately but I still should get it looked at. Now, the cause for the knock would be just a bad tune or is there a different cause for it. Also, I have a bouncy idle as do other people I know. Is this a common problem with the balts that does no harm? I'd like to know before I start doing anything to my car. Last thing I need is to start modding with a small problem that can easily be fixed rather than ignore it and boom. Also, I know that superchargers can be intercooled. They are on Lotus's. Is there any intercoolers in the making for the SS or are there no plans for it because of the heat exchanger or something else, and would it help out in cooling?

 

the knock i speak of is inside the engine. detonation, pre-ignition. not the audible knock from the blower, or a bad throw out bearing so to speak.

intercoolers and aftercoolers work on the same principle.

intercoolers = cools the intake charge before the throttle body.
aftercoolers = cools, or attempts to cool the charge after the throttle body/super charger.

air to water is what our cars use.

turbo cars generally run air to air intercoolers. no liquid heat exchange.

 

That's what I figured as far as the cooling. The knock though, it sounds like it's from the engine, not the supercharger. And generally will knock on a cold start. After running a few minutes it stops. As to the cause I had/have no idea and figured someone else might such as yourself. Don't need a dealership screwing me out of money for checking/replacing crap they don't need to.

And I was somewhat that way as well. Thought smaller pulley was better but this has been quite helpful to me. I was planning on possibly even a 2.7 pulley but now that I see all the problems with 2.7 or less forget it. From what I gather, a 2.9 could probably put out the same performance as a 2.7 or at least close to it. Correct? And most people I know always want to run high PSI. Most SRT-4's I have come across are 22+ but when I have toyed with them, there wasn't too much of a difference that I noticed.(unless it shines in higher speeds)

 

As far as the "knocking" sound at cold startup goes, it's probably either the timing chain tensioner or a lash adjuster etc. that finally gets it's prime when the oil is nice and hot and at it's proper consistency. This usually isn't too big of a deal although I believe I have read where a few people have gotten GM to fulfill a TSB on the timing chain noise.

 

The question was why do they blow up, not why do they have to run so rich. You proved my point. They can't run as rich as needed because that crappy returnless fuel system can't provide enough fuel, hence them blowing up and always blowing the last cylinder on the rail which is the one that gets starved for fuel. Return system isn't better it's nessesary if you want the furtherest injectors to get fuel. All the Walbro pumps and 9000# injectors in the world can't compensate for the fact that fuel needs to flow through the rail and not just into it. But instead of addressing the known problem that all returnless systems have, we'll just ignore it and blame the blower. Sounds like a plan. I wish your motor luck.

 

Okay, whatever you say. Haha, "We'll just ignore it and blame the blower."

Edit: You do know that during WOT the fpr doesn't flow any fuel on a return system right? It only circulates when the extra fuel is not needed and this is vacuum controlled (return style does lead to better filtered and cooler fuel in certain cases). Trust me, I fully understand the advantages of a return system, but it's not the ONLY way to go.

So are you fully convinced that the fuel system is the reason why the engines are blowing? You don't think it has to do with heat in any way?

There is one thing about returnless that affects FI cars more than anything and that is the lack of a variable fpr. In our system the fuel pressure is kept at a constant level as opposed to varying (Varying, but a specific amount above manifold pressure) in accordance to manifold pressure/vacuum. Since #4 is going to be the hottest cylinder due to coolant flow, and it is favored to recieve boost, it can be a bad thing that there isn't a variable FPR to adjust fuel pressure on the fly at high boost which helps to always keep fuel pressure above the pressure it will be facing.

 

its dumb ass people running small ass pulleys that. Not only over boost the car but your over spinning the blower. And I think the stage tune is not that bad its set up rich for this very reason so stupid people dont blow there cars up. People are half fasting this **** lets get 60's at 2.6 and a tune and call it a day ...

 

Overspinning the blower just decreases supercharger life. GM was retarded for giving us such a high static compression ratio. 16+ Psi on a 9.5:1 motor is retarded and i would never even consider it.

 

Wrong again. If you'd like me to pull my return line off during a dyno pull to prove you wrong I'd be more than happy to, you'll just have to pay for a new car after mine burns to the ground. Fuel is ALWAYS flowing THROUGH the rail on a return system. Did you forget that fuel pumps run at 100% ALL the time. That means that if you ever DON'T have excess fuel that needs to be bypassed, then you've maxed out your pump. The only time it wouldn't be is if your pump, lines, or rail suck and can't keep up with demand, causing the FPR not to bypass any fuel because... well because there isn't any extra to bypass.

You fail to realize that with a non-return system, the pressure in the rail is lower at every successive injector. During high duty cycles, this difference increases to the point that the last injector gets very little fuel.

No, as a matter of fact it has very little to do with heat. Heat can be dealt with with extra fuel, but you can't supply extra fuel if your #4 injector can't get any.

I'm not even sure why this is being questioned or debated. Go check out srtforums and ask those guys why everyone trying to make any kind of power automatically switches to a return system. Honestly, what does your background consist of? Do you have any experience with something other than an LSJ? I'm still baffled as to why you're even disagreeing or why someone hasn't said something about this years ago.

lolzlzllzlzzlzl

 

You're very wrong on the bolded statement. People will chime in to correct you on that one. I'm not saying that fuel isn't an issue, just that heat is FOR SURE an issue in our engine. Okay, fine some fuel will still bypass the FPR during WOT at zero vacuum or above atmospheric pressure (Depending on FPR), but my point was that when you have spring tension only on the FPR fuel pressure will rise because LESS fuel will be allowed to pass; if the need is high enough with an adjustable FPR, there may be some occasions under heavy load where you do MAX out your pump, so I don't know what in the hell your point was with that; that's why there's an fpr in the first place is to regulate pressure without altering fuel pump output and still maintain the proper pressure in the rail for the situation the engine is experiencing. .

I'm a technician for Mercedes, that's my background. To me it sounds like you copy and paste from other threads. There's no point in arguing with you because you're misunderstanding my posts. At least read my posts before you respond next time.

The reason why nobody else has started to defend you is because it has already been agreed that it is NOT ONLY the returnless system, but ALSO the heat at cylinder #4 that is causing the problem as well. I am not talking out of my ass, but talking based on the general concensus.

You can argue until you're blue in the face, but I've been here on the forums for a while and have already witnessed alot of intelligent conversations about the problem; we don't need your input, there are already other people on this site who know ALOT about the LSJ.

And, please quit putting words in my mouth. I already told you that I realize there are advantages to having a return style system.

Edit: Even NJHK, the person who made the thread about the returnless system will agree; there are many things which contribute to this problem.

#1. Read some info about this issue at the SRT forum; you will find that it applies to higher power cars (300hp+) so obviously we have other issues stopping us from reaching up to that point (Heat from the M62 maybe? just a thought haha).

#2. At the SRT Forum, if you continue to read on the subject, you will discover that the main advantage to converting to a return system is because you can then run a rising rate or 1:1 fpr etc. and you will have a return line it will make tuning much easier (Always the proper fuel pressure available for any load). The reason why tuning will be easier is because you will have more control over the potential flow of the larger injectors through a varying fuel pressure. With the returnless system, the pressure is constant; without tuning it would be very rich (Of course). If you have a varying fuel pressure, always ready to match the opposing pressure, you can tune accordingly, so that at ANY given amount of load at ANY rpm there will be a proper amount of fuel delivered. There are ways to compensate for this with a returnless system, but it is much easier to convert to a return style.

 

Okay... just a quick question semi-related to the discussion at hand...

Has anyone blown up on a cylinder that IS NOT #4? (As in 1, 2, or 3? )

If not, what do you guys think is the next most critical cylinder for heat or being leaned out?

 

This is quite simple. Note the bold areas, they're addressed in order.


If the pump is maxed, you have the wrong pump. Get one that flows more. Under any situation in which your pump is maxed, you are in danger of running lean and thus blowing up from lean detonation. You're still failing to understand how a return system works. And if you think a 1:1 regulator would help you out at all, you're a certified retard. Because if that was the case then people would be blowing something other than just the last cylinder on the rail.



The question of the topic is why do these cars blow up, not, why do they not make any power. The blower and it's heat are power related issues and hold the cars back in that area. While they may contribute to unreliability they are not the cause of it. You fail to realize that heat is bad, but alone it breaks nothing. Heat leads to detontation. That heat related detonation can be stopped with enough fuel. Clearly these people aren't getting enough fuel.

Let's analyze why the motors blow. Detonation on the #4. What caused the detonation? Well since they're all blowing the same cylinder, it isn't ignition timing, compression, boost, etc. It must be a lean condition. What is the definition of lean? Not enough fuel. Does heat cause a lack of fuel? No. Does a lack of fuel cause heat to break stuff? Yes. Looks like you have a fuel problem. Better fix it instead of blaming "heat" for your lean condition.

So there you go, in the simpliest baby-like terms I could muster, the train of logic that leads to a fueling issue being the problem.

 

barfing the rings lands is 90% heat related on these cars.

 

There is even a vid of a SS racing a 300 hp SRT-4 and had this very problem we are mentioning. And I believe it was #4 as well. SRVidz is where I think it is at. If I find it I'll post the link. (But the SS did win =D)

And here is the video...sorry, it's on streetfire.net...

http://videos.streetfire.net/video/6...f300790eea.htm

 

Note bolded: Do you even know what a 1:1 fpr is? It maintains a specific ratio of rail pressure over manifold pressure at all times. That means more boost equals more fuel; it's similar to a rising rate but exactly 1:1.

I'm not talking about maxing out the pump as far as it's maximum flow CAPABLE, I'm talking about the maximum flow that the FPR allows when at WOT if talking about a rising rate.

Heat does not break anything? Hahahaha. Okay, whatever you say. Just based off of that one comment I choose not to continue this conversation with you.

 

Yeah Cameron won by about 2 bus lengths in both races in the video. SRT-4 couldn't hang. I think that SRT-4 also runs 13.5 ish. Cameron and I were cursed at the 14.00 mark, yet you can see how fast ours cars actually are.

 

Again you're missing the point. You're ALWAYS bypassing fuel. Even on a WOT pull at 30psi with a 1:1 jacking fuel pressure up to 75+psi, you're STILL bypassing fuel. If you weren't bypassing fuel, that means that the FPR is totally closed and you're left with a returnless system which would defeat the purpose of the return and run into all the same problems already mentioned. This is so simple and universally know that I can't believe you're even aruging it. Let me make it even simplier.

Pump in my car, Walbro 255HP. Rated at 255lph @ 85psi. That's enough fuel for around 600hp. It flows that 600hp worth of fuel ALL THE TIME. Just like any normal fuel pump with non-variable voltage. That's what you're missing, pumps flow their max rating ALL THE TIME. Obviously the flow drops off as the pressure rises, but that doesn't change the fact that the pump is always running full blast and if when you're flowing 600hp worth of fuel and only using 300hp worth the rest is being bypassed, it doesn't just disappear magically. That's the whole point of a return system, to keep a steady and constant supply of fuel running past the injectors that they can tap into as needed. Instead of shooting fuel into a rail and hoping to maintain pressure all the way to the end with the injectors under high duty cycles. You're missing the fact that it's a matter of fuel distribution and not just a matter just fuel supply, which is why a 1:1 isn't going to do a damn thing if the only cylinders benefiting from it are #1-3. There are about 99999999999999999 Hondas running around on stock regulators making tons more power than the most powerful ss/sc on here and they do so without any fuel pressure problems. If the ratio of boost/manifold pressure was the issue, you'd just be running lean period, not just lean in one cylinder. I'm in total awe at how people try to skirt the issue and blame the problem on everything but the obvious. Seriously, it's like walking into a wall and blaming everyone from the painter that didn't paint it neon orange so you could see it, to the arcitect that put it there, to the engineer that said it was nessesary, but never stopping to think that maybe the problem was you not looking where you were going.

I hope that made sense, it's really not that hard of a concept to grasp.

 

Yes, CGSS blew 1 and 4

 

returnless systems do not flow max fuel pump pressure all the time.
you can not compare this set up to a dsm.

a 255 can support 600?
odd.

 

No kidding. That's why these cars NEED return systems to make power safely and maintain proper fuel distribution with larger injectors. Please understand what I'm aruging before making ignorant replies.

Yes, a 255 at 14 volts flows enough fuel for 600hp on pump gas.

 

if you would actually look, all of this has been "argued" before.

you're just beating a dead horse. we ALL know this.

so if a return style is so bad ass.

why is it.
the ls1/2/4/6/7's can support over 600 to the tire on the stock style system?

 

Because they have x2 the injectors to make the power with. Them making 600hp on 8 injectors is just like us making 300hp on 4 injectors. That means the injectors can be smaller and put less demand on the fuel system. Think of it as two 300hp 4 cylinders.

Sorry if I'm "beating a dead horse" but I'm simply replying to the topic. I didn't see it covered in this topic so maybe you should tell the OP about asking redundant quetions.

 

oh so that explains why the returnless system on a turbo setup, on a cobalt, can handle well into the 300's

you are also forgetting, peak effciency for the m62 is 7 psi before the cooler.
the eaton is not the best way to make power on these cars.

i however, don't give a ****, im not going for highest/faster blah blah blah.