so what kind of power and torque differences can i expect with a supercharger instead of a turbo with my 98 gt? any input is very appreciative!

the only thing you can expect is to keep spinning off the line with a supercharger

Superchargers are better cause there's virtually no lag, but the only kit made for the 5S is rare. A good option for an ST driver would be a 4A-GZE swap.

Supercharger!

blower for our cars = dumb

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explain please

somewhere i read said supercharger eats power.... either from the alternator or from battery.. I forgot... anyway just ignore me .... i donno what i'm talking about lol

A turbocharger will give you lag
A supercharger will will take away some torque

i prefer supercharger over turbo for our cars because of the characterists of our engines. Our engine have alot of torque in the midrange and very little on the high end.

But pound for pound of boost a turbo will make more power. Lets say we have a 5sfe running on 5 psi of boost. a supercharge 5sfe will only make 150 hp, where as a turbocharged 5sfe will make 160.

I voted supercharge because I prefer to have a constant predictable powerband.

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that depends on a lot of things, you cant just say any turbo will make more power pound for pound than a supercharger

and a turbo will easily fix the horrible top end that these cars have.

turbo is cheaper, and easier

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idk what dyno charts you have seen from the 5sfte, but id like to think that this dyno sheet im posting is pretty constant, and predictable.


i really like the supercharger option, just a shame there is virtually no options left when it comes to them

that said, i vote turbo because of the flexability of the setup.

This could go either way.

Supercharger: Overall approx 85% efficiency, near instantaneous torque depeding on blower style (roots, centrifugal), linear powerband directly related to engine RPM.

Turbo: Overall approx 95% efficiency equating to more power at a given boost point over a blower, more potential than a blower, but non-linear powerband, turbo lag, and more difficult to tune. Also, exponentially more expensive.

I owned a custom turboed car, a stock twin turoed car, and a now a supercharged car

reliability : supercharger > turbo
reason: 1 fixed boost level, 1 level to tune at, less complex boost, simpler (or self contained) oiling system, simpler control/fueling systems (no wastegates, boost controllers...etc)

power: turbo > supercharger
reason: variable boost level, racegas+moreboost+more timing option, infinitely adjustable setup (for low end or top end)


Lag is overrated... the VR4 (stock TT) could hit FULL boost @ 2300 rpms ...
Most newer S/C cars are not allowed to boost (although they are capable of making boost) before say 3k (that's how my car is) because that improves fuel effeciency ...

the mazda speed supercharged miata was like that too ... they wanted torque delivery to be linear so boost is regulated at low rpms

here's the thing

what's the point of having a 1000-4000 rpm boost band, when you have a 3000-6500 power band (as determined by your gearing)... superchargers (blowers specifically) can make boost at idle but their effeciency drops with rising CFM, rising supercharger rpm and rising boost)

example: my eaton m45 on the benz 1.8 litre consumes 30HP at redline
The supercharger temps @ redline are 25 degrees higher than they are at low rpms, and it's limited to a 10psi output (effeciently) at those rpms otherwise the temps shoot up even higher..

a properly sized turbo on teh same motor, with a good intercooler , can be at peak effeciency at redline @ 15psi ... i'd gaing 30hp in supercharger drive, the same outlet temps, and 5 more PSI of boost which translates to some 80 hp more than i have now

that's the difference between a 200hp and a 280 hp setup on a 1.8 litre

which one is better now ?

i'll tell you have to defeat lag

DOWNSHIFT

just like NuclearHappineS said, no point in having good power at torque at 2500rpm when your gearing keeps up above 3500rpm

lag is only a problem in 1st gear, and to people that are too lazy to downshift when they want to accelerate

oh and superchargering a car is not cheaper than turboing a car

but remember that a supercharger runs on a belt which will give more stress to the engine.

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no, supercharger actually takes power to make it work, a turbo is free power, so you will make more power with a turbo, and with a variable geometry turbo, there is no lag

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Huh? A turbo adds exhaust backpressure and heat.... I'd say that's not great for an engine either

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Turbos do not make 'free power'... there is generally less airflow through the motor at a given boost pressure because of the increased exhaust backpressure. The parasitic losses of a turbo are hidden from being able to be measured because they are directly related to the amount of power they are creating, instead of engine speed.

There is also no such thing as "no lag" with a turbo. There will always be some... Most of the time, its not really noticable (the boost comes up with the throttle as long as you don't slam on the gas).

Also, I dare you to find a VTN turbo out there that someone could adapt to a 'normal' car at this point. Maybe someday soon (they are already used in new diesels...).

Eh, whatever. My point is, there are no absolutes in the turbocharge/supercharge debate.

Generally though: Reliability/predicability goes to supercharging, power/tunability goes to turbocharging.

I have personally gone with turbos on all my cars because I like to tinker. If I wanted a 'set and forget' thing for 30-60k miles+, I'd try to find a supercharger option...

-Charlie

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+1 on that opinion... but like i said ...ultimate power sattisfaction imho is either turbo or centrifugal supercharger (which is still really a turbo)...

yes blowers are dumb for our cars. Theres really no reason if you want boost to go supercharger. Depending on what you expect to get power wise, 5sfte turbo is good for around 200hp unless your manny heh . Im still amazed to see what kind of power that guy puts out of his 5s motor. Getting back to the blower, After going through a 5sfte turbo setup in my 5th gen and now having a 3sgte in my 6th gen ... 3s is the way to go. Theres so much potential with that motor. Looking at what most of the mr2 guys do with 3s motors its unreal to see the kind of power they put out. You put that blower on there maybe do a little bit of bolt ons and your done. Theres really not too much aftermarket support for our cars with blowers. I know rip made a kid for a camry which should work with a 5s motor. Other than that I dont really see you getting far with a blower. Supercharger migh just be a little more reliable than a turbo but turbo always puts out more power and theres alot more tuning with a turbo. Just over all how it works, with the crank oposed to exhaust gas. Blowers are good for big domestic v8s but little 4 bangers...... not a good idea.

i want turbo,i love that blow-off sound

I have two answers. I would say for a long stroke, low reving,
high torque motor like the 7A, supercharger. Higher reving,shorter
stroke 3s, Turbo.

This is going to be an interesting post, and lets keep it drama free. Moneywise, its probably really close,
as i can guess Manny probably has 2-4 +gs in his 5sfte and somebody with the 3s swap is 4-6. Sound reasonable guys? knowledge wise, turbo, theres plenty of experience on this site. We finally got 2 superchargers coming, and it might pave the way. Its starting from scratch with both of them.One looks to be full blown with a built motor, and the other a bit mellower.
Whats better? hell I don't know. Does anybody? Have we compared both of them? Dynoed? Ran track? Rolloffs? No Were all guessing. I haven't heard of a blown celica yet. Sure some camrys. We will have to wait and see. Anytime somebody comes up with a new swap, or awd conversion, big brake setup, etc we all benefit

well put madmods we'll have to wait and see!

4-6? Where did you hear that crazy number from? With all that your experimenting with blower and being that your the first person to really get into it the little amount that your spending on putting a blower in.. with the problems you might have you could possibly spent enough to get a full 3sgte swap. Your better bet is to do a 3s swap. Once you put that blower on do the bolt ons... I meen even if you built the motor..... your still stuck at only that blower... as if you have a 3sgte you can tune the motor with so many different turbo setups. It just opens the door to so much potential.

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I looked into doing the swap awhile back. Strict smog and goverment run smog checks stopped that ideal.
Theres no way around it. I personally have two choices, turbo the 5 or put the vortech on. Bottom line is, I have to keep a 97 or higher year motor in my frame.
I wouldn't say I'm stuck with a blower. It can be upgraded in different stages with different pulleys to increase boost. I'm going with the 5psi pulley and alltrac is going all out with the upgraded kit. I actually
expect it to be easier to tune then a turbo setup.

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Actually, you want to be careful using any forced induction on a longer stroke/longer rod motor. You're slinging around more weight, and torsional effects on the crankshaft are dramatically increased. Had a LONG conversation with my engine builder about my 383 going into my Trans Am, the debate being whether to go with a 5.7" or a 6" rod with the 3.75" stroke crank. In the end it was deemed that the shorter rod would yeild the best compromise over it's strength and reliability with the longer stroke.

Not that this really applies that much to engines as small as ours. Just food for thought.

honestly a swap isnt going to cost you that much money. A 5s motor isnt going to handle a ton of boost. Yes you can get different pulleys.... but your still not going to be able to boost real high with that motor. Its only when when you have a turbo and your boosting well over 15psi.... For the amount of money you will put into upgrading a supercharger + pulleys on a 4cly... you could possibly have a 3sgte. Yes I know emissions is tough everywhere. I pay a guy to pass my car everytime. Do you know anyone who could pass your car?

aaaaaahhhhhhhhhhh i love not having emissions ha ha ha, but it doesnt matter, i have a nearly stock 7a, cept for intake, muffler, and advanced timing

thats not even right.... I wish I had my car regged in oh or michigan ... no emissions + inspections.

i like both, nut i think i wanna go with the supercharger.
i like the blow off sound but lot of people has turbo these days.
i think the turbo will be a laggy setup but with the supercharger, i thik it'll be more of a direct power. maybe it will feel more like a NA engine?