turbo vs. supercharger

[Spikely15]

I've noticed a couple of complete turbo kits being released for our favorite car and I was wondering if you all had an argument for one method over the other. I realize turbos are more efficient from an energy standpoint, but does one place more strain on engine components than the other? Disregarding turbo lag, is one a better performer than the other?

For example, one turbo kit runs at a much heavier psi rating (8-11) than nearly all of the big name superchargers (6-7 psi) and advertise much higher potential hp ratings. Thoughts/suggestions/opinions?

Thanks guys,

-Dustin

 

[stangdude2000]

Anytime you run more boost, you will get more power. I dont believe there is any reason that one method would put more stress on anything than the other method IF the boost were the same.

Not sure about this one since I've never driven both types of power adders on the same type of car, but I'd imagine the turbo wouldn't feel as fast as the supercharger, especially under normal driving conditions. Since the boost is there from the get go with the supercharger, you'll have more power off the line.

 

[Gearbanger 101]

Turbo's with all things being equal will always make more horsepower and torque. That being said, I've never liked the powerband for a street car. When you're running a heavy car like the S197, you want that torque coming on fairly early on in the power band. The only way you're going to see this is with one of the positive displacement blown kits on the market.

I know turbo lovers will argue about how turbo's will make more peek torque than a PD blower, which is true but there's still the issue of "lag" to take into consideration. I realize the newer turbo systems are far removed from the ones of the 80's and lag has been reduced considerably....but it's still not gone altogether. I've been in a dozen or so small and large displacement turbo cars and not one of them didn't have that lazy, off idle characteristic that they all suffer from. I don’t care who’s built the kit, or how much turbo lag has been reduced, nobody has eliminated it completely. As a result, Turbo’s need to be loaded up in order to perform flawlessly and that's just a luxury you just don't always have on the street. Otherwise, they’re lazy down low, then hit like a sledge hammer when they do come on....which as interesting as that sounds, isn’t the nicest recipe for a daily driver.

I’d look into one of the PD kits if it were me….Saleen, Whipple, FRPP, Magnuson, Kenne Bell, Roush, etc.

 

[Spikely15]

Thanks Brian, that makes a lot of sense, with the whole sledge hammer analogy. Another question in that regard if ya have a minute - do centrifugal superchargers such as the Vortec have a lag in them thats comparable to turbo lag?

 

[Gearbanger 101]

Thanks Brian, that makes a lot of sense, with the whole sledge hammer analogy. Another question in that regard if ya have a minute - do centrifugal superchargers such as the Vortec have a lag in them thats comparable to turbo lag?

Not the same, no. Putting it in layman's terms, Turbo cars actually feel lazier down low in comparison since exhaust pressure is needed in order to drive the unit and produce the needed volume of air to feed the engine. The turbo actually acts as a bit of a restriction under hard throttle until the point where exhaust pressure builds up enough to pressurize the manifold. This makes the hit when the turbo does come on feel that much more violent.

Centrifugal blown cars still move all the air and make all the power they would without the blower up till the point where they start making boost, since the head unit moves the air in relation to engine RPM, not exhaust pressure and is continuously moving the same amount of air through the engine as it would at stock levels. When blower speeds have reached appropriate levels and the manifold pressurizes, boost pressure builds and the power comes on relative to engine RPM from there. They'll feel a lot less violent and their power curve broader by comparison.

PD blowers start making power right off idle, and manifold pressurization takes place early and boost pressure remains almost continuous from start to finish. The pressure is controlled almost exclusively via the bypass valve under normal driving.....so the power surge is only as violent as your right foot allows it to be.

 

[steedman07]

I can only speak my vortech w/ 4:10's, Steeda Motion delete plates, and an automatic tranny..Boost starts somewhere around 3,500 rom's or so on up to 10.5 lbs @ about 6,300 rpm's..With the 4:10's, it gets to building boost really fast, as stated above that engine rpm's will determine how much boost and how fast the boost climbs..As far as a street car, it is perfect for me..Its a tame car down low, but I feel very little lag because the car gets to 3,500 rpm's so fast with 4:10's..I may eventually go with a whipple or Kenny Bell, once I am bored of the centrify and switch to a 3:55 gear or a 3:73...All that being sad, I have never driven a high horsepower turbo car, so my opinion is limited to a Vortech..Good luck with whatever direction you go..

 

[anthony05gt]

My Whipple produces about 5 psi at 1500 rpm's. Over 400 ft lbs torque at 2500 rpm's. A PD blower will put more stress on the crank than centrifugal and a turbo actually puts the least amount of stress on the crank when comparing equal hp levels. Turbos will also make more hp and tq at equal boost levels than any blower because the blower uses a belt drive which takes power away. For the street I like the PD blower the most.

 

[SpartaPerformance]

I disagree a little guys. A super charger is going to put more stress on the engine but not with boost...the super charger is belt driven so it puts strain on the pulleys and their mounting units for example it puts stress on the crankshaft if it's driven off the crank pulley. I also believe that these motors will work better with a turbo, the VVT gives you full power....full air intake in the upper RPM band so I believe a turbo will work better being the generally make power up top. If you run 1/4 mile doesn't matter if you come out the whole harder down low if your motor can make up for it up top, down low power is for short distance like light to light racing which we all agree street racing is bad idea. My $0.02

 

[walter]

A well made turbo system with proper tuning will be always superior to superchargers because unlike superchargers turbos don't require power to make power (I read somwhere that at redline the Ford GT required 100HP to make its power so in theory the car would have had 100 more HP if it were turbo). That said the power delivery is different and is something that some might have a difficult time getting their driving habits adjusted to (not so much these days because turbo technology is exponentially more efficient then twenty or even ten years ago.

 

[fobra559]

Compound Boost

 

[Gearbanger 101]

For you guys that state that the blower is "harder on the crank shaft", when was the last time you ever heard of a crank breaking on a modular engine.....ever? What.....1 in 25,000? The weak link on the mod motors is the rods and pistons and to a certain extent the oil pump gears. All of which can be broken pretty easily with a poor tune, continuously agressive driving habits or batch of bad gas. It doesn't matter what kind of forced induction you're running.

You wanna built a fast track car, go with the turbo system. You can load them up on the starting line and not have to worry about lag time at part throttle or stop and go traffic because there is none when you're running WOT from a dead stop down the track.

You want a fun street car that isn't a pain to negotiate as a daily driver, go with a blower. The power band is a lot broader and more usable under normal driving conditions and their easier to negotiate as a daily driver. And still provide plenty of motivation for the weekend warrior who wants to hit the track once and a while.

 

[Mr_Q]

A pile of replies already. My simple take since I've had both.

Turbos...lots of power, great for light weight cars since the power comes later (lag).
Turbos...crap loads of heat to deal with. You've got to have your heat management mastered to ensure longevity and problem free pump gas operation.
Turbos...none CARB legal in SOCAL as far as I know.

Superchargers...Pure, even powerband, legal, joy.

To this date, as far as S197s are concerned, only S/Cs make the car drive like stock except that is goes faster than stink. They can be completely transparent in how they affect drivability. In the end that is very nice.

 

[anthony05gt]

For you guys that state that the blower is "harder on the crank shaft", when was the last time you ever heard of a crank breaking on a modular engine.....ever? What.....1 in 25,000? The weak link on the mod motors is the rods and pistons and to a certain extent the oil pump gears. All of which can be broken pretty easily with a poor tune, continuously agressive driving habits or batch of bad gas. It doesn't matter what kind of forced induction you're running.

Harder on the crankshaft....meaning the rotating assy. It's a fact that a twin screw is especially hard on the crank/rotating assy. And yes, I've seen 2 cranks break in half not even running a twin screw. One was N/A and one was a centrifugal, both modulars.
Like others have stated turbos will always have some sort of lag but I'll be the first to admit they make the most power pound for pound. They also hog up a huge amount of space, make way too much heat and can (depending on the system) cause some serious problems when you are in the rain or go through a puddle.

 

[1ba96gt]

Its funny I just got off the phone with my dad about a car they are working on. The owner bought the kit from a very respected turbo company. He waited 17 weeks for the kit. They told him his Mass Air Meter would be fine as well as the fuel pump. The kit was supposed to make 7lbs of boost and be a safer 450rwhp. In reality the pump and meter were maxed. The car made 11lbs at 4000rpms and had the tuner not been watching the screen would have blown the engine had he not gotten out of it. Owner said its been nothing but headaches.

Cliff Notes: Turbos can be awesome, with huge power. But complicated, expensive, and can be headaches. Put a Vortech on with a 3/36 warranty and save yourself the stress.

 

[belzebub2u]

speaking from a turbo owners point of view, i love mine. This is in no means saying that i dont love S/C cars, i just got a great deal on mine. as for power, im putting about 440hp or so at the ground on 8lbs of boost. and yes it does hit like a sledgehammer. I have the turbonetics single kit and it is crammed in my engine bay. My turbo starts spooling about 2500 rpms and hits at 3k, and the lag is not really that bad at all. if i am trying to go fast, (not that i would EVER street race!) i just launch out of boost or i just spin the tires anyway. i took the cats off my car and it started spooling at 2k and hit at 2600rpm, that was just too much, so i went back to the cats. as for drivability, IMHO turbos are the s**t. my car is as quiet as a v6 (which i love) and if you dont get into the boost (which only will kick on at 0 vacuum) and drive conservatively it drives just like stock and i still get 23mpg on the highway (no lie) and 15 in town (about 8-10 in boost tho ). they are much harder to install, and take up alot more room. all that said, get a custom tune for it from someone who is very good if you go turbo. I dont think you will be disappointed no matter which way you go, because Boost is KING!

 

[forensicsteve]

My car had a Prochager P1SC until very recently excellent unit...zero issues. Decided I wanted a lot more and since the P series was not upgradeable to the F series, I decided to go with a turbo. Started with the base 67mm from Powerhouse. Had a stock motor at that time. MAF gave out during dyno, so stopped prematurely, but the rear wheel torque was easily heading in the 500+ range.

Since then car has undergone major rebuild including upgrading turbo to 76mm, reinforcing FB Performance race tranny, a stroker MMR 950 block, adding 2 single KB boost a pumps to the GT500 dual pumps, 95 lb injectors/drivers, and much larger lines and rails. We think the fuel system will still be the weak link but target rear wheel hp and torque is 800 on C16.

The street tune is going to be tame on the minimum 11 lb spring (550 rwhp???), since car has limited street use and I don't street race. Present track plan is to use the digital boost controller to incrementally increase boost per gear. Not been redynoed yet.

 

[Spikely15]

awesome, thanks for all your input guys. Looks like I'll be saving my nickels and dimes for a supercharger of some sort now!