Wild Balt

I figured the only way the turbo made power all the way around the tach was by having a twin turbo setup so one would pick up the PSI after the other one already topped out on its power. But then that adds more weight, a *real* intercooler, more research, etc.

I figured roots style superchargers were more practical for cars since the power is there in the bottom end, where the car will be spending most of its time.

And turbos being "free power" isn't going to work, b/c they are actually interrupting the exhaust flow, aren't they? So some power is being lost the in higher end of a turbo b/c its trying harder to push exhaust out.

Meh, I'll step out of this. I'm half braindead from working 14hrs a day for a week.

IonFeright

lag is just a turbos way of giving its opponent a chance

Wild Balt

Instead of just saying wrong, could you please just go ahead and say how a turbo spools up w/o obstructing the exhaust flow?

TVS_SS

you are correct, it dramatically obstructs the exhaust flow.. on most OEM vehicles the Exhaust backpressure is greater than the Boost pressure on the intake side.. This is the only way to get 'reduced lag'

Hahn RaceCraft

You better check again...

Cobalt SS
HHR SS
Solstice GXP
Sky Redline

...all Turbo

And as of this moment...zero supercharged cars from a company that produced them for almost two decades. Sure, a $100,000 supercharged Vette is coming, but as for the average Joe, GM has abandoned supercharging altogether in favor of turbocharging.

I still maintain that GM's produced more supercharged cars than any other manufacturer, but what's important is why they stopped doing it, and that they DEFINITELY have stopped.

TVS_SS

wow, lol thats because they are all the same engine!! tada!! it makes way more sense to put the same engine in all your vehicles.. if you have one already designed.. they just drop it in all of them.

you sir are pointless to argue with. they have not produced more supercharged cars.. MERCEDES has produced significantly more supercharged cars than GM ever has.. You just dont know about them because they are mostly sold in europe and other places in the world.

They definately 'have not' stopped.. Corvette, caddilac, and others to come.. so yeah they definately are not stopping.

And since were on the topic.. since the corvette was all about performance and thats what most here care about.. why did GM pick supercharging? they started designing with turbos.. hmm

WhiteSSBalt

Lets say I had a car that all 3 options were readily available in a kit, like a 350Z/G35.....you have turbo/twin-turbo (Greddy, VRT, JWT, Power Enterprises, APS).......centrifrugal supechargers (Vortech, Procharger) or a roots type supercharger (Stillen)......

i'd probally go with a Procharger/Vortech centifrugal. Makes better power than the roots type Stillen setup, and is cheaper/less maintnence than a turbo/twin-turbo setup. Plus they make good power across the board.

TVS_SS

i really wouldnt consider a centrifugal supercharger if i had the other two options..

no boost till high rpm.. the centrifugal design is meant to be on a turbo and then you fix the rpm directly to the engine.. no to mention no OEM would consider them due to durability.

you can make tons of HP with a centrifugal, no doubt, but you have an engine that does nothing till 5000rpms.. not what i would want. Even turbo's can do better than that. Its like the 'ultimate lag' turbo

I'd pick a positve displacement supercharger or turbo's before i bought a centrifugal. Their only benefit is cost.. but you know how the saying goes..

Hahn RaceCraft

Well, I wasnt really arguing, but I will agree on the pointlessness

I'll leave it with this...

Introduction of new turbocharged models in North America has continually outpaced supercharged models for some time now, and the trend is becoming more marked with each passing model year. This trend is not going to stop anytime soon, as the coupling of new Direct Injection technology with turbocharging has created an entirely unprecedented set of capabilities for the modern powertrain engineer.

Why do more and more automotive engineers prefer turbocharging?

• Easier packaging
• Less moving parts
• Multiple power levels
• Better fuel economy
• Automatic altitude compensation
• Less destructive to catalytic converters

Why do more and more performance enthusiasts prefer turbocharging?

• All of the above and..
• Greater upgradeability
• Many more options for turbo size and interchangeability
• Easy application to any vehicle
• And the best one...MORE POWER

While I cannot claim responsibility for these undeniable trends in both OEM and aftermarket, I will claim satisfaction. The world is loving turbos...and I am loving that!

You'd be incorrect, at least on a four cylinder...centrifugals make less power at low RPM than turbochargers.

Darkmanx

you guys are all idiots.

TVS_SS

ok bill

we'll talk in a while..

What if i told you we may get away from direct injection in the future?? I'm fairly certain I know the 'trends' in the industry and what options are availible 'to the powertrain engineer' lol

Hahn RaceCraft

Oh, I don't doubt that there's other emerging technology. Variety is the spice of life, thank god for it!

I'd like to say, for the record, I am NOT anti-supercharging. I am, however, very pro-turbocharging, having been involved in it for 30-plus years.

Today, there's just so much compelling evidence, well over and above GM's recent decisions to remove superchargers in favor of turbochargers. Here's just another one (and they stole my screen name too!):

Ford to equip half-a-million vehicles with turbocharging by 2013

bridfi

mark my words... by 2020, almost every new car will have some kind of turbocharger.

widebody_balt_ss

this thred is good! very good... It looks like I am the only one that is going twin charged. I dont care tho. I voted turbo. to me its prety obvious.
but I like the fact that it is looking like I will be the only twin charged Cobalt.

jimbos'ss

iTrader: (2)

wow ford isn't completely copying gm at all are they..........................let me see a 4 cyl direct injection turbocharged engine called ecoboost...................hmmmmmmmmm

TVS_SS

lets just say i know a little about that..

P.S. im not anti turbo either.. in fact.. VW did a great job of combining the two.. http://www.autobloggreen.com/2006/05...ngine-of-2006/ Why have one.. when two is better? I like to look at ALL of the comprimises for each technology before choosing.. and your point about better fuel economy is incorrect. The playing field is more level than you may think with some newer technology..

Hahn RaceCraft

Our customers report increases in fuel economy when they've added our turbosystems. We've studied this, and attribute it to reductions in pumping losses at cruising speeds. Under these conditions, some of the otherwise wasted exhaust energy is converted into reduced intake system drag via the turbocharger's assistance in airflow. This negates a portion of the engine's pumping losses, which otherwise require fuel burn to overcome.

Reports are typically a 5-10% improvement.

Turbo06Sedan

...Saying you get better mpg with a turbo'd vehicle (especially yours(HAHN)) is a double answer.

It gets more gas mileage when your not on it cruising @ 75-80mph (I see an average of 45mpg). And when I floor it at the track for example, I see 4mpg.

But lets be honest here....hahn kits are too much fun to just "cruise" with. its hard NOT to be a lead foot.

chevytech007

I love turbocharging! In fact im going to go with gt35r hear next month after jimboss car is all done! But I would love to race someone with the S20g stage 5 vs the procharged cobalt just to see the outcome. I think it would make you think about it a little longer! LOL

Does anyone have one in the socal area?

TVS_SS

i was saying between supercharger and turbocharger you'll see the same benefits on a properly designed system..

Boosting is here to stay, its just a matter of design targets

Most benefits can be seen due to calibration and final drive ratio.. keep the manfold pressure up, spark timing as advanced as possible (a little water injection helps), and keep the engine rpms low!! This is the overwhelming factor.. If you just add a turbo with no other changes.. your fuel economy will go down at cruise.. the backpressure of the turbine does add more pumping loss. I understand where you are coming from, but your area of focus is a small portion of the puzzle..

Hahn RaceCraft

I cannot agree. The backpressure a turbo adds at cruise speeds, which consume approximately 1/10th of the engine's overall airflow potential, is inconsequential at best. Bear in mind how little airflow the car is actually using during cruise. It's nowhere near enough for the turbocharger to induce a significant pumping loss or restriction.

We've not seen the same reports of increased fuel economy with superchargers, and we attribute this to the fact that the turbocharger is using otherwise un-utilized exhaust gas heat energy to help overcome pumping losses at cruise, as opposed to a parasitic loss off the crankshaft via a belt drive like a supercharger. The supercharger always requires additional fuel consumption to operate. With the turbo, it's essentially a bonus of converting some of that otherwise wasted energy into cruising efficiency gains.

Additionally, the linear air delivery of superchargers versus RPM means that, unlike turbos, thay are not load-sensitive, and rely on additional devices such as supercharger bypass valves to discourage boost pressure during light throttle acceleration. This does nothing except pump the same air through the super more than once, which wastes energy and adds heat. Turbo cars are not subject to such inefficient 'recycling' of air during cruise. Additionally, their ability to infinitely respond to varying load conditions makes them much more effective, providing minimal airflow (as compared to a super) that results in improved fuel economy during light throttle commuting and cruising conditions.

chevytech007

Im going to agree! The turbocharger exhuast resticition in nothing compared to supercharger belt load even with the bypass valve fully opened. I have seen cobalt`s hitting the 32 mpg mark on the highway with the stock supercharger! Hahn what kind of mileage are you seeing on the S20G kits?

The procharger is the worst thing for gas mileage! I lost about 4 mpg easy because I have to compress the air all the time! There is a bypass but the blower itself is not stopping. (which is great for quick response on hills but sucks on the gas)

But I would still love to see a race batween the three:
TVS vs Procharger vs Hahns S20G But truthfully I think the tvs would win in this case only because of the power range here. If we were shooting for all out gt35r vs tvs vs P1sc then the game would be way different!

Raven SS

price wise thats not a fair race seeings how both procharged and turbo'd kits will double the price of the tvs..and the tvs will still "hang" in that race

ColeJJones

turbo = good gas mpg
super,pro = bad on gas

Raven SS

depending on how u tune and drive..no ones getting good gas mileage with a lead foot...