Turbo vs. Super

[sliverstorm]

Hello, I am sure this has been asked many times before, but I haven't found a comparison for the MR2. I was curious what ppl have for input on the subject, as I can't decide whether I want to improve a supercharged 4agze or switch it to turbo. Also, if I switch to turbo, I have thought about twin turbo- has anyone done that?
I am leaning towards S/C cause low end torque is real nice, but I see turbo left and right so I figured I'd ask.

[NONACK]

Generally speaking, the most ass-kicking engine you can put in you MK1 is a turbo 3sgte from the MK2 MR2 turbo. If your sticking with the 4agze, I would continue working with the supercharger, since it is already there and the engine is made for it. No one to my knowledge has twin turboed any MR2 engine (other than V6 swaps), as twin turbochargers on a 4-cylinder would be such absurd overkill and most likely produce less power than a larger single turbo for a LOT more work.

[Hellstorm]

Im pretty sure twin turbo on a four cylinder would be the dumbest idea ever. :P just my 2 cents.

[sliverstorm]

ah I never understood that TT was not intended for straight-4. I was under the impression that you could use it in the same scenarios as a twincharger (there used to be kits for the MR2 MKI for twincharging)

[MuMan]

Originally Posted by Hellstorm

Im pretty sure twin turbo on a four cylinder would be the dumbest idea ever. :P just my 2 cents.

"if it can happen, it will happen" Murphy's Law

There was a twin turbot kit available back in the mid to late 90's for the 3SGTE..just can't think of who supplied it at the moment.

[garthnet]

I'm pretty sure that if you do the math to match the correct set of turbos to the 4age's size, you could make twin turbo work. In Hugh MacIness's book called "Turbocharging" he talks about two turbos that are matched to each other - one high pressure one and one low pressure one - to somewhat eliminate turbo lag. I would guess that something like one really small turbo and a normal sized one could work if you matched their peak efficiencies looking at their compressor maps.

I might just be talking out of my ass here... correct me if I'm wrong.

Garth

[sleepermr2]

^thats called a sequential turbo setup. there have been a few cars that came from the factory that way. also some diesels have that set up. this way you have the best of both worlds as far as turbos go.

personally i would go with the turbo instead of a S/C. S/C take power to make power and a turbo makes power without any paracitic loss.

[SilverFire]

Gen3 RX-7s are like that. When I was looking at FI for my 20v, I considered getting a setup from one of the (many) guys in my area that have recently imported a jdm FD and upgraded (or are planning to) to a single, but decided that if SCing was more work than I was up for, trying to get a twin-turbo set-up working was also too much trouble. Just before I gave up on it entirely, I found out that those turbos are WAY too big for what I'd want anyway. GT22/25 here I come.

[Sang]

Originally Posted by MuMan

There was a twin turbot kit available back in the mid to late 90's for the 3SGTE..just can't think of who supplied it at the moment.

It was a very limited production (3 or so?) with only 1 still in existence from what I know, in Pouya's car. It was made by Mech-tech for the 3SGTE using two VATN turbos.

[Hellstorm]

Wow..... well.... i just dont see the point in putting a twin turbo set up on a 4 cylinder...... and the mr2 already has very little room to work with in the engine bay....so i would think another turbo wouldnt even fit. But yeah.... i can see why only 3 were made. Pointless and too much work. :P

[sliverstorm]

I wish I could do a MKI.5 but I don't have nearly the experience it seems to take to do it well. I figure if I gain the skill/expertise/friend who knows their stuff, I can later do that to a second MR2, but considering I don't want to get in over my head halfway through a swap, 4agze seems like a better plan. (it's N/A right now, I'm trying to plan a roadmap for the future) Also I have heard 3sgte changes the handling (through sheer weight), and I very much prefer mountain driving as opposed to cruising (which is why the torque of a supercharger is so enticing) I have to wonder if it might detract from it's cornering abilities.

[Sang]

Originally Posted by Hellstorm

Wow..... well.... i just dont see the point in putting a twin turbo set up on a 4 cylinder...... and the mr2 already has very little room to work with in the engine bay....so i would think another turbo wouldnt even fit. But yeah.... i can see why only 3 were made. Pointless and too much work. :P

Not to get too OT, but very few were made because they were a completely one-off (will three-off) item, lol, add to that they weren't exactly the cheapest thing to buy. True, it's not known that it not a very efficient setup on an I4, but at the time of it's inception, people were having a hard enough time getting past that majestic 300rwhp mark with the 3S. This community has come a long way since then and mods of the past are just that...in the past.

Okie dokie: Back on topic

[MRtuned]

Originally Posted by NONACK

Generally speaking, the most ass-kicking engine you can put in you MK1 is a turbo 3sgte from the MK2 MR2 turbo. If your sticking with the 4agze, I would continue working with the supercharger, since it is already there and the engine is made for it. No one to my knowledge has twin turboed any MR2 engine (other than V6 swaps), as twin turbochargers on a 4-cylinder would be such absurd overkill and most likely produce less power than a larger single turbo for a LOT more work.

the 4agze is not built for a supercharger, it is built for forced induction. many people who own buick regal gs (supercharged 3.8L) remove the supercharger and replace it with a turbocharger. both systems have advantages, so you need to look at exactly what you want out of the car. turbochargers have become very popular because the generate "free" horsepower. they do not need to be run by the engine, but rather the flow of air. superchargers require horsepower to run them. superchargers also require a lot more work to change the ammount of boost, whereas with a turbo this is very simple.

[Mista 2]

IMO i would go for a supercharged midship. all turbo midships that I have seen (in australia) have had overheating issues. i talk to a lot of MR2 owners and every one of them have had the problem. i personally like superchargers if used in a proper application such as an AW11 or ford GT40. i have seen them turboed and most of the people said they would change back if they could get the same sort of power and the same cost. if you are willing to have a car that overheats and you want all top end power then go for turbo but if overheating is an issue and want drivability got for supercharged.

just my 2c

Mista 2
Jordan

[MRtuned]

Originally Posted by Mista 2

IMO i would go for a supercharged midship. all turbo midships that I have seen (in australia) have had overheating issues. i talk to a lot of MR2 owners and every one of them have had the problem. i personally like superchargers if used in a proper application such as an AW11 or ford GT40. i have seen them turboed and most of the people said they would change back if they could get the same sort of power and the same cost. if you are willing to have a car that overheats and you want all top end power then go for turbo but if overheating is an issue and want drivability got for supercharged.

just my 2c

Mista 2
Jordan

superchargers produce more heat than turbochargers.

[MuMan]

Talking about VATN turbo's there's been a lot of development there, and they are starting to look like a smart alternative..long way from the 350HP VATN turbo that SCCA fitted to their MK2 project, and doubled the HP output in 300 RPM between 3900-4200 RPM.
S/C's are looking attractive, especially the late model stuff coming from Japan that can be had very cheap..must admit, I've been tempted.
And...hybrid S/C cross Turbo installations...all the benefits of turbo ease with off idle boost from a positive displacement S/C

Having said all that...stay stock, it'll save you a hell of a lot of headaches.

[MRtuned]

Originally Posted by MuMan

Having said all that...stay stock, it'll save you a hell of a lot of headaches.

do a v6 swap! :P

[TomsMR2]

Originally Posted by MRtuned

superchargers produce more heat than turbochargers.

ive never seen a glowing red hot supercharger.

the big problem is that the stock sc12 sucks. anyone wanting to make significant power basically must remove it.. at that point, a turbo is both cheaper and easier. superchargers are great, but the costs add up so quickly, especially for a decent new supercharger.

[sliverstorm]

so what you're saying is people w/ 4agze take off the sc12 and decide to upgrade to turbo cause it's cheaper? Ok, that would explain why so many do it. And I know peak horsepower is all a lot of ppl care about :P I think I'm gonna go S/C. Maybe just put a diff pulley on for a while, and figure out what to do from there.

I always liked the idea of turbos better (using waste exhaust to drive the turbine, instead of using engine power) but it seems like a supercharger fits my MR2 better. In any case I can't help but feel the speeds a turbo works at are not the kind of speeds I should be doing in windy hills! (and this is not in a speed limit sense, but a flying-off-the-cliff sense) I kind of enjoy the thought of S/C's being more difficult, although price could still end up forcing me to go turbo...

[sleepermr2]

Originally Posted by MRtuned

superchargers produce more heat than turbochargers.

i think what he is saying is that S/C heat up the intake air more than a turbo does. cause its constantly compressing and churning the air and making it hotter. also most S/C arent running some sort of cooling system for the intake charge.