super or turbo

[TFord]

glad my useless knowledge helped...lol

[Mr. Wyndham]

That's definitely NOT useless info.

speaking of knowlege, though.:p I have heard that superchargers rob the engine of torque - being belt driven and all...understandable. But if I were to install an underdrive pulley (not too hard, I imagine)...would that compensate some?

AND

:pwhat type of Supercharger type does GM use on factory vehicles...


Sorry to keep pumping you for info - but this is a topic on which I have virtually NO knowlege base

[The_Stache]

dragon, a good site here Whipple superchargers.

Its not the normal roots style but it is an after market alternative, and Whipple's are reliable as well as being competitively priced.

[TFord]

Originally Posted by Dragoneye

That's definitely NOT useless info.

speaking of knowlege, though.:p I have heard that superchargers rob the engine of torque - being belt driven and all...understandable. But if I were to install an underdrive pulley (not too hard, I imagine)...would that compensate some?

AND

:pwhat type of Supercharger type does GM use on factory vehicles...


Sorry to keep pumping you for info - but this is a topic on which I have virtually NO knowlege base

I havent been under every hood, but Ive seen roots style superchargers on GM cars. (especially the 3.8L) yeah there is some lost power because a blower is belt driven, its not a big amount, and with the amount of HP and Torque you gain it wont matter they have different belts and pullies to minimize the effect though. and yeah a underdrive pulley would free up some horses.

Originally Posted by diarmadhi

dragon, a good site here Whipple superchargers.

Its not the normal roots style but it is an after market alternative, and Whipple's are reliable as well as being competitively priced.

yeah I like whipple to...really the exact same thing, but whipple is a little more flexable for your cars needs most of the internals can be changed out, upgraded, and interchangeable. but the can get a lil pricey.

[Mr. Wyndham]

Twin screw, huh...impressive (and pricey) but worth it...if centifugals are a lot like turbos, and roots are poor performers...then twin screw is the way to go
Whipple doesn't seem to make superchargers for any GM cars, do they?

btw. I'm sold on the whole supercharger > turbocharger argument. I'm just trying to learn more about it. And you've all been a big help!

[TFord]

roots arent poor performers... they're just not as efficient as turbo's. which to me dosent matter. but the plus is you get great gains on the whole power curve. turbos are efficient because the compressed gasses from the exhaust spins the turbine, not a belt. the trade off is the boost threshold (lag) because untill you hit the higher rpms the pressure built up isnt enough to make a difference in performance. thats why turbo's have great high end gains, but not much for low-mid rpm range. so its just up to your driving style what you perfer.

[Mungo]

Has anyone checked out ststurbo.com to see what they've been doing for us GM guys. They have a twin turbo kit that doesn't go under the hood. It replaces the mufflers, and the boost is variable between 5 - 7psi. Just a sweet setup.

[TFord]

Originally Posted by Mungo

Has anyone checked out ststurbo.com to see what they've been doing for us GM guys. They have a twin turbo kit that doesn't go under the hood. It replaces the mufflers, and the boost is variable between 5 - 7psi. Just a sweet setup.

WOW...have not heard of that one. Ill have to look it up!

[The_Stache]

Had seen that mungo but only for a corvette zo6 (625rwhp) didn't know that they did other gm cars.

Dragon yea Whipple has kits for the ls series engines but they are not emissions legal, look here

With the camaro coming out I am almost positive they will jump on the band wagon like they did with the mustang. The biggest thing I like about the Whipple's is they have the valve that opens under normal driving conditions so that your not running boost ALL the time and in turn takes stress off engine components and then it closes the valve when you get aggressive with the right foot. Well that and the fact that any shadetree mechanic can install one..


Edit - Oh and I have looked around and 5-8k is very competitive when you realize that that includes EVERYTHING you need for install and out the door. If you can find a cheaper kit that does not require internal engine work or custome pcm tunes please post a link.

[MerF]

Originally Posted by Mungo

Has anyone checked out ststurbo.com to see what they've been doing for us GM guys. They have a twin turbo kit that doesn't go under the hood. It replaces the mufflers, and the boost is variable between 5 - 7psi. Just a sweet setup.

I've not seen a TT kit, but I made a video for a single-turbo Formula a year or so ago.

And this video also gets me started on the turbo-lag point made:
http://www.merfproductions.com/vids/whistler2.wmv

First and foremost, your average street turbo will not have any noticeable lag. You don't start having lag problems until you get into a turbo that is rediculously oversized for the application...namely huge drag-racing applications that would be laughable on the street anyway.

Secondly, there's a slight advantage to NOT having all the power instantly available...namely traction. Even if you have an ideal suspension and tire set-up, it's pretty unlikely you have the freedom to release all the power right off the line, you have to have some level of feathering. So using that as an argument against turbos in drag racing is a bit silly. Road racing (I.E. Autocross) really is a place where a turbo wouldn't be the best set-up to have, but again it's plenty usable with the correct set-up. I'll use this opportunity for another cheap plug of my videos, and my old car (large single-turbo Supra doing autocross: http://www.merfproductions.com/vids/autox.mpeg)

The big argument with the STS kits, like the one in my video above, is, "OMG ALL THE PIPING EQUALZ HEATZ LOSSSESSS AND LAGGG!!111!". Which I was pretty sure the physics of it all would prove to be true myself, until I saw it in action. Ok, maybe there's some lag...but it's so minor, why worry about it? That's a fairly large T76 turbo under the ass of that Formula (LT-1 stroked out to 400-something CI), with many feet of long piping and an intercooler, and you can hear that he is hitting full boost (15-18 PSI) at the 60'.

Cliffnotes: Lag is almost laughable it's so overrated. Proved by the video which shows a set-up that undergoes more scrutiny than any other for causing lag.

[TFord]

Oh MerF believe me when I say it Ive seen some insane turbo set-ups, and my unk speciliazes in they're application on Fbody's and stangs. I was merely pointing out the pros and cons of each, and if it were my money what Id do. Like I said with the boost threshold thing, there are a LOT of variables. biggest being the output of the car, and size of the turbo. thats why you see WRX's with twin turbo setup with lil baby turbo's, and ya 1000hp supra's and such have turbo's the size of trash can lids. if a TT setup is done correctly its definetly a thing to be admired. but for me, I gotta have a blower, no need for any fab work, takes a lot less time to install, not as expensive, and I love the way a blown camaro or whatever you drive feels

[MerF]

I feel yeah. The fabrication/installation factor alone, for a daily-driven weekend-warrior, I'd be SC'd. If my Camaro gets any FI at all, it would likely be a simple Vortech or Pro-Charger making 8-10 PSI at the most. If GM holds true to it's values, the LS3 should last a lifetime with that little bit of power.

[Mr. Wyndham]

1. Speaking of life, how true are the rumors that any kind of FI decreases engine life?

2. Does forced induction have a tenancy to increase or reduce fuel economy...and why? I've heard so many different things...

SIDENOTE: Even if lag isn't as big an issue as it's made out to be...S/C are just so mush simpler to install, if THAT wasn't a factor - I wouldn't care what I had...they both do the same thing...

[TFord]

Originally Posted by Dragoneye

1. Speaking of life, how true are the rumors that any kind of FI decreases engine life?

2. Does forced induction have a tenancy to increase or reduce fuel economy...and why? I've heard so many different things...

SIDENOTE: Even if lag isn't as big an issue as it's made out to be...S/C are just so mush simpler to install, if THAT wasn't a factor - I wouldn't care what I had...they both do the same thing...

Since a turbocharger increases the horsepower output of an engine, the engine will also produce increased amounts of waste heat. This can sometimes be a problem when fitting a turbocharger to a car that was not designed to cope with high heat loads. This extra waste heat combined with the higher compression ratio of turbocharged engines contributes to slightly lower thermal efficiency, which has a small but direct impact on overall fuel efficiency. Superchargers spin at the same rpm as the engine, so the output is directly proportinal to rpm so waste heat isnt as much. SC does raise compression ratio, which is why a intercooler is a must have for either application.

they both increase wear to engine internals over a period of time, but unless your driving you car pedal to the metal every day for like 30 years its not much to worry about. cars that come from the factory with FI usually have stronger internals, i.e. connecting rods, and such. but if you thinking of charging a car with high miles on it replacing engine internals is recommended. the real wear is in the SC or turbo itself. like I said SC's are almost maint free. but theres more work involved with a turbo simple be cause of the speed and heat of the internals. 60,000-100,000 rpm's is murder on any bearing. you have to make sure you use synthetic oil and before you turn off you car you need to let it idle for 10 minutes because this lets the turbo rotating assembly cool from the lower exhaust gas temperatures, and ensures that oil is supplied to the turbocharger while the turbine housing and exhaust manifold are still very hot. Otherwise coking of the lubricating oil trapped in the unit may occur when the heat soaks into the bearings, causing rapid bearing wear and failure when the car is restarted.