eviltwins

Who gives a crap about linear power when my turbo has a broad, flat powerband? Saying you like a linear powerband is saying you like less power and torque, that doesn't even make sense.

buschman

I agree with everything you said but right here. Turbos are far LESS reliable than blowers, both on the street and for DIY installers. reliability is why the Supercharger(with all it's many flaws ) is still around. Other wise we'd all have STS turbos. Turbos looks great on paper and the big boys can do amazing things with them. but for on the street action the gap is far closer than you'd like people to believe. Especially when downtime is factored in.

JMHO,
Mike

F8L Z71

I resemble that comment!

I have not kept up with many of the racing bodies since back in 98' when i was a big Mustang fan but even then Turbo cars were ruling the day evern with their weight and cubic inch penalties. Even with his penalties and cubic inch deficiencies our buddy Crhis chow is doing very well racing against my buddy Rocky Robinson witha much bigger motor and a huge roots blower.

Check out the PSCA Heavy Street results:

Vegas Results

Vegas Results

Fontana Results

Notice how the fast cars in the top 3 generally are either BBC/nitrous, BBC/blown, or SBC/Turbo?? Notice how well the small block with the turbo is comparing to the Big Blocks with a power adder?

Chris's best time so far is 8.0@175mph and Rock's best is 7.98@178mph.

Now if we can just get Rocky to get to more races I can give Chris more crap (Rock's a friend and Chris is in our car club). LOL

DamanSS

How much more challenging is the STS turbo to install compared to the procharger?

F8L Z71

It is actually quite easy but all the associated parts like fabbing in an intercooler or meth injection will make it more difficult in the end. I think it will put you on more even footing with a centrifugal and shouldn't be compared to a proper front mount system. To make the same kind of HP that a front mount would you will have to use a large turbo but that in turn will cause much more lag than a front mount wouyld see with the same size turbo. Not to turn this into a STS vs front mount debate but since you are talking about the most powerful type of FI I thought I would explain that the STS would be closer to the centrifugal, if slightly ahead, than it would a front mount. I'll probably get flamed for that though. LOL

DamanSS

Sorry, i guess i dont know where the STS mounts, i was under the impression it was in the same place as a cent supercharger.

F8L Z71

Nope, it goes in the rear behind the rear axle or in my case, right in front of the axle.

DamanSS

wouldnt that affect the lag with the turbo located so far back?

smokinHawk

iTrader: (48)

yes it does

sb427f-car

What you fail to remember is that the NHRA OUTLAWED them YEARS ago from competition. Why, because cars with them simply spank cars without them. This will be the first year we will see a return of Turbos to big dog NHRA racing with the rule changes to the AMS Pro Mod Challenge. Turbos WILL be allowed, so I'm sure we'll see Moran run some events this year. The IHRA tech director doesn't want to deal with handicaping the Pro Mod fields as they have had a good parody for quite a few years, though the Alky cars are pretty much king. Also, I don't think you need to be concerned about durrability issues as long as you keep your oil changed, let the car idle down, and do the common sense maintenance. The thing about turbos is that they are softer on engines than nitrous. And I'd have to agree after thinking about it but I'm sure blowers will put some extra stress on the No. 1 main bearing. Whatever you're choice, have fun doing it though

Got Me SOM

iTrader: (2)

WITH TURBO'S YOU GET 100-200 HP INCREASE WITHIN A COUPLE HUNDRED RPM, I DON'T THINK THAT'S VERY LINEAR. LINEAR POWER IS MORE CONTROLLABLE POWER WHICH WON'T ANNIHILATE THE TIRES WHEN YOU LET OFF AND ON. MAKES PERFECT SENSE TO ME..

AN LINEAR POWER DOESN'T MEAN I HAVE LESS POWER AND TORQUE...

Zombie

iTrader: (2)

Nope, it's not, it just means you bought a turbo thats way to small and you need to go BIGGER!!!! Full boost should be right around 3.7k-4k (in 3rd - 4th) in my book to create a really nice power band without too much wheelspin.

Yes it does Who wants linear when you can have exponential!

My biggest complaint with centrifugal supercharges is how laggy they are. They are the ultimate in lag. You don't get full boost until right before you shift... WTF! Does not compute!

Turbo cars usually have more area under the curve, more area = faster when compared to a car of the same power level and weight.

Got Me SOM

iTrader: (2)

Superchargers Aren't Laggy.... You Are High.

Zombie

iTrader: (2)

centrifugals are very laggy. You don't get full boost until right before you shift. With a turbo you get full boost way before you shift. I'd call that lag, what would you call it?

mongse

iTrader: (2)

It's not lag. My old ATI started making boost around 3100-3200 rpm and increased at a LINEAR rate all the way up till I shifted. You people are crazy.

A supercharger only makes full boost @ high RPM b/c the amount of air it moves is directly related to how fast the crankshaft spins. A turbo does not have this, thus they build boost at an exponential rate.

As for the supercharger/turbocharger debate in racing, two things dictate how well the turbo cars do: class rules and track conditions. I follow a lot of ORSCA racing (1/8 mile, heads-up) and at the World Finals last year, the turbo cars were running out the door in Outlaw...when they'd hook. That's why a nitrous BBC Camaro from TX took home the top prize over the turbo Mustangs.

Zombie

iTrader: (2)

I know how they work, i'm just tired of people always saying a turbo is lag when people have no clue what lag is. There are two ways to define lag:

1. the amount of time it takes until positive manifold pressure is realized.
2. the amount of time it takes until full boost is made.

I'm just going by #2 since thats all I care about, therefore a centrifugal supercharger is the ultimate in lag

buschman

They have zero lag. It is true that on a full WOT run a turbo will hit full boost usually before a Blower. But try downshifting in a turbo and blower car and tell me that a blower has more lag than a turbo. At 5000 RPM a blower car will always have the same level of boost. That's what he means by linear power curve. It's predictable. Predictable is good. No need to spool up, the power is there on demand and is always at the same level in a given RPM band.

Mike

mongse

iTrader: (2)

But by your own definition, (#1) an oversized turbo (think a large-frame on a Supra) is also the ultimate in lag. I have ALWAYS known lag to be the amount of time to build positive pressure.

Zombie

iTrader: (2)

Technically speaking, lag is the time it takes to build positive pressure, but #2 is what everyone wants to complain about when talking about lag.

Large frame on a supra is most certainly what most people would consider laggy. I had the T76 in my sig on my supra but changed it out since it was better suited to a 5.7L motor and I wanted something with a little faster spool so I went with the 67 for it.

When it was on the supra it was definately what people would consider laggy even though by definition it was not since it would make 1psi around 2200 rpms. It would not reach full boost(18psi) until 4700 though.

Most people equate lag to power, not to manifold pressure and it's more in perception than anything. The reason people complain about lag in turbo cars is due to perception. It takes a small amount of time to fully spool a turbo due to load being needed to create the neccessary exhaust volume. Once the turbo fully spools though the power is so much greater than what was available before. It's the time between flooring it and full power that almost everyone considers lag. In most cases the turbo will make 1psi before you foot even reaches the floor (if sized right), but you still need it to finish building boost to get to your final level. If that level is 5 psi, then it's really responsive and "not laggy", if that level is 20 psi it takes more time and since the transition is a lot harder people call it laggy even though it's the exact same power at 5 psi as it was before.

With a supercharger the results are a bit more immediate and the transition is not as great as with a turbo, therefore people consider them "less laggy" since the difference in power is not as noticeable.

It's all about perception... there is no spoon.

sb427f-car

oh no you did not!!