I think he is referring to this one.

 

I'm still not certain what the question is but peak power is going to rise in the rpm band with larger pulleys, more timing, ported head, cams, open exhaust, etc. Any one of those or combos of those will increase power in the upper rpm ranges.

 

I think the point Bryan is trying to make is, TQ > Peak HP.

 

question...
Ive never experienced a track, nor with a small pulley..

Now lets say you got too small of a pulley, and in fact too small your doing more harm than good..

will "boost" start to drop off towards the end?

i think the reason people are saying you over spin the blower is because the air gets so hot that the CFM drops dramatically which in turn doesnt allow for a full burn so on the next stroke its almost like the engine was double fed which creates a larger burn = blown engine... no?

 

Matt, the one thing that doesn't make much sense though is that you guys are claiming you are looking out for us and helping the community make smart decisions but then your company advertises a twincharged kit that not only pushes several key bottom end components far past their design limit, they are the same parts that you guys are saying will fail on a small pulley m62 setup.

To be honest, to push 440whp out of a stock bottom end LSJ is wreckless. Because one engine takes it and hasn't popped doesn't speak for any type of majority, especially when the OEM advertises the design limit for bottom end components. Many here have proven that the OEM doesn't overengineer very far from what they state.

I'm not saying don't produce powerful upgrade paths for Cobalts, I'm simply stating that its flawed logic to claim inefficiency and safety in one instance, but completely disregard it in another.

Closer to being on topic, the drag list 2 years ago ended this arguement back then. While its not a very accurate list now because most serious drag racers have left this site for greener pastures, back when all things remained the same other than the tune and pulley size, the 2.5 pullied guys dominated the list.

EGTs start climbing dramatically which results in excessive heat near the piston crown and first ring land. The height and thickness of the first ring land is a contributing factor to which pressure level and heat range the piston begins to fail.

 

hey witt how has ur car been running lately. last time i heard anything was when i saw you at the track early last season

 

Like many people on this site I followed ALL threads started by ZZP or any member regarding the ZZP twincharge kit.

No where in any one of those threads does anyone from ZZP state that EVERYONE should be running their Twincharge kit on a stock engine to 440 (or whatever) wheel hp. To say that they advertise it is safe to run that my HP on a stock engine is false. That was simply a demostration to show the potential of the TwinCharge kit.

BUT

I think ZZP might be a little behind the times on how most LSJs are being modded these days. Although there are a very small handful of people running 2.6" or 2.7" pulleys on CSS the mass majority are running a 2.8" or larger. And by now the mass majority know that we can only run pulleys smaller then 3" with many supporting mods.

I joined the forum about two years ago and even back then people would recommend 2.5" and 2.6" pullies. And many people did run that setup on stock engines...until they popped.

I hope ZZP does not think that most of us are still running those tiny pulleys.

On a stock engine with ZERO cooling mods a 3" pulley is definatly safe and could possible make the most hp. But once you add in cooling mods like an additional heat exhanger, Dual/Single Pass IMs, option B kits and so on there is more hp and tq to be made with smaller pulleys.

 

Completely agree with ya bud

 

Great, I replaced rings with ones of higher tension this fall as the previous ones I had installed were not holding up well to the current power level.
Zooomer already made the post on this forum that he can make 400whp safely on a customer's car, and he did exactly that. Is it going to be reliable? Time will tell but GM's design limit is saying it will not be.

 

Wiit what rings did you go with? I'm planning on replacing pistons/rings coming up in the next 2 months and have been wondering this. Also planning on a 18-21 ring gap. Any thoughts?

 

So if you run a 2.6 pulley setup and run the boost too say 18.5 psi or so will you still get the heat??? But I am sure the torque down low will be major increase vs 2.8,2.7 etc...

 

There are multiple parts to my answer.
First, at no time did we ever state or imply that running 440whp was safe. We have never recommended it. We push our own cars much further than we would ever recommend for customers. When discussing our twincharge kit with the customer, we stated that 350whp was safe and that we would not recommend pushing it much further on the street. We were asked to turn it up for the dyno pulls to hit 400 which we did.
Second, customers that purchase twincharge kits are serious modders who go in knowing that things can easily go wrong. They didn't have the slightest worry when we told them that the clutch would not last more than a few days.
Third, turbo cars can not be compared to M62 cars. A twincharged setup with a large FMIC has far better intercooling performance than an M62 with factory intercooler.

 

wow

liberal views VS conservative views

with major modding = major knowledge
know your car know your limits and have the self restraint to not abuse it

we are talking about a GM !!!! not a lotus or maclaren

vendors do not want people to go hardcore bcs their clientele says

do it for me I don't want to know .... therefore they need to push safety not to get sued

tuners say here's what's going don't be an idiot with your car and enjoy


responsibility risk VS awareness

I am a tuner I am biased but I understand both sides

a vendor should never sell below a 2.8 because it takes a higher level of knowledge
to have a 2.7 and below on your cobalt

it's the difference between a ride poney and a thouroughbred

my .2 ( yes 20 cents)

p.s. love the 2.6 for the torque = fun

p.s. the vendor can sell below a 2.8 but is smart enough to say
not going to be responsible for you ignorance..... which is fair

be informed or be a *******

 

If you can tune the engine (the s/c is questionable) will live for years on a 2.5/2.6 I have a redline that I tuned that is running great for over 2 years along with a few others that are 2.5 no cooling mods and have been that way for atleast a year or 2 with no issues.

The blower bearings is what i cautioned them about though as soon as I saw mine fail I warned them all...some stepped up in size others didn't. Was their personal choice.

BTW on a intake, 2.5, 60, cat deleted car (still stock header, downpipe, and catback) you can run 20 deg of timing at 19psi...and not knock on a full 1/4 pass...on 93.

 

not on the pump gas here you can't!

 

How bout on Ultra Sunoco 94 or 104??

 

I fill up with 93 in North East WI. hmm

 

ramping timing will get this number. doing it the way i do will not.

power over an entire curve > peak

 

Any reason you don't ramp timing? If the engine is spinning faster, wouldn't it make sense that the mix needs to be ignited sooner? I feel this is especially true based on the fact that there is less cylinder pressure on each compression stroke after you have surpassed your peak torque RPM.

 

torque. it's that simple.

 

But, why would anyone want torque? I don't know about you, but peak horsepower is lot more important.

 

i don't know bout that cause i have a stock ss/tc and raced an 03 with an intake and beat him.... only by half a car but still(heavy ftl)

 

I'm not saying to run less timing in the lower RPMs. I'm saying run more up top. For example, if you can run 18 degrees at 5000 RPM, then you can run 20 degrees at 6500+ in most cases. In this case, you would have the same torque that you speak of, and more peak HP.

Do you realize that your sarcastic comment will be read by many as a serious statement?

 

It ramps from stage 2 values to 21deg at 4300rpm to redline in mine

Tho i want to play around with cramming as much timing as i possibly can into it one day

 

https://www.cobaltss.net/forums/show...4&postcount=67

QUOTE=Zooomer "I am going to say a few things.
1. The power levels here of 266 were no enough to blow a stock engine. They can go to over 400WHP when done properly with no meth."

I never compared the two types of setups other than the reliability. One of your coworkers foaming in an above post made the comment about blowing cars up. My point was that if that is the concern here, 270whp from a 2.5 pulley isn't any more reckless than 400whp from a twincharged setup on a stock engine.