Turbo or Supercharged?

[mrazntre]

Okay, we've heard of this debate before. What do any of you think?

I'm only asking for fun. I was going to turbocharge my mr2, but my motor is letting go way too much to handle that kind of boost ( 1 bar or bust). Originally, I was running a supercharger, however I had to nix that because I had to get my smog done (CA test only centers sux). I was supposed to put back my supercharger, but I was unemployed and i just didn't want to deal with the gasoline bill. Imagine filling up 4 times a week on 91 octane (work was 10 miles away and school was 10 miles away -- and my driving stopped there. $2.25 a gallon !!!). Talk about poor gas mileage. *shakes head* i even ran a SuperAFC to lean out the damn thing, but it went off the charts! made me so pissed. Stupid JDM wiring harness... plus the motor rebuild wasn't done properly, ooops. (okay, remember all, next time you pop your head from your short block. DECK the shit. the gasssss is guzzzling... damn valves. oh well. whatever. good thing i have another jspec block in my stash. HOPEFULLY that will go in soon. BUT.............

here's the million dollar question. After i do my engine swap, should i go turbocharged? or supercharged? Either way, boost setting will be the same, I'm thinking of leaving boost at 8psi (what does that come to, .6 bar?) What are the downsides of either type of forced induction?

known cons

Turbocharged: Spool up time, boost spiking.
Supercharged: Parasitic drag.
*heat is detrimental to both.

known pros

Turbocharged: Crank up the boost!, after turbo lag....BOOM! outta here, the psSSSHt! sound (blow off valve, babY!.
Supercharged: Instant mash on the gas HP, no oil line needed, SC whine! (VVVWWWWWWHHHAAaa!)


Both setups are available to me, turbo will take a bit longer to do because i'll have to drill and weld an oil line for the turbo (no coolant ran in this particular turbo).

What would you do? I'm leaning towards the SC because i don't have to worry about cool down time (turbo timer).

Any experiences with either? Please share your ideas with me.

[Kevincpak]

I would choose turbo charge.

[mrazntre]

kevincpak: cool, but why would you choose turbocharged?

[karizma]

>> the psshhhhhtt sound of the blow-off valve should be reason enough to turbocharge it :D...my friend has a supra tt...people always run up to tell him that he left his car on 'cause of his turbo timer hahaha... why dont you just supercharge it if its less trouble >_<

Dunno why i said turbocharge, but i heard its the best stuff for streetracing and drag racing.

[mrazntre]

karizma: because i wanna be difficult, it's what i do best

KManfromcharlotte: OIC coooool, thanks for your input.

[IKPakI]

Wait, when i mentioned turbocharged, is it cheaper ? different models or such?

I heard Supercharger lasts longer while streetracing.

[misst0fu]

i'd rather get turbo over sc. and here's a plus
nitrous can make ur car quick. even if people say nitrous ruins your car. just get regular check up and the installation is correctly. yeah but turbo over sc

[mrazntre]

again.


why turbo over SC?

[misst0fu]

turbo- better performance

[mrazntre]

turbo has better performance how?

what's the difference between 1 bar of SC boost and turbo boost?

[misst0fu]

[quote:7112491262="mrazntre"]turbo has better performance how?

what's the difference between 1 bar of SC boost and turbo boost?[/quote:7112491262]

sighs. GEES! it's just better. i think the performance is better the sc. but depends on what car you're running it on. sorry if that doesn't answer your question lol

[mrazntre]

misstofu: uhmm okay then. so why does it depend on which car? why would i want to go turbocharged when any slight change in the weather or elevation could cause me to boost spike, resulting in detonation and blowing my piston/rings? or, how about the headache of cooling down? so that the turbo oil doesn't coke into the turbo manifold? what about the increase of ambient heat in the engine bay due to the turbocharger? don't all these symptoms apply to whatever car? more specifically motor? i'll be running 8.9:1 comp. reasonable in my eyes.

[wylin]

[quote:d6091218f9="mrazntre"]misstofu: uhmm okay then. so why does it depend on which car? why would i want to go turbocharged when any slight change in the weather or elevation could cause me to boost spike, resulting in detonation and blowing my piston/rings? or, how about the headache of cooling down? so that the turbo oil doesn't coke into the turbo manifold? what about the increase of ambient heat in the engine bay due to the turbocharger? don't all these symptoms apply to whatever car? more specifically motor? i'll be running 8.9:1 comp. reasonable in my eyes.[/quote:d6091218f9]

well sy heres coming from a turbo users stand point, there is added maintenece/vigallance w/ a turbocharger from the time needed too cool down, watching for boost spikes. but superchargers also have some issues of their own mainly that its always causing some paracitic drag because of the super charger pulley, resulting in an initlal loss of power and also increase in fuel consumption. IHI's electromagentic clutch type unit is exempt from this (not like we can afford a titanium electromagenetic disengage at certian rpm and throttle imputs IHI supercharger used on mercedes SLK32 and SL55) and nessesary electronics and EMI shielding.

. there is also maintence on the supercharger unit itself you have to make sure the pulley is working well and also the volumetric effecieny of compressing air of the supercharger is inferior to the turbo-supercharger (true name of the turbocharger), a S/C generates more heat onto the compressed air and because typically its not cooled (intercooled/watercooled) its less effecient at making power also the inital cost of a super charger unit is more then a turbocharger.

turbos have their own issues as sy brought up one he failed to mention was that turbos act like an exhaust noise and heat sink making the cars exhaust quieter and colder problem is that lotsa heat is needed to start the catalystic reaction for the emission control systems main component the catalytic converter thats why alota turbo cars need pre-catalyst chamber to create enuff heat to pass startup emissions tests.

one thing gotta give sy's S/C fetish is that it has mad ass off the line pwr inspite of the parasitic drag versus the typical turbo lag (time required to produce enuff exhaust gas to spool the turbine)

[karizma]

>> everything wylin just said flew over my head so quickly it was like a streak in the sky...

>> from a highly car-retarded girl comes a retarded opinion: get the supercharger already!!! off the line power is good...turbos lag and look like snails...makes me wanna squish em...but then again i shouldnt talk cause ill be getting one in my car haha..ill shuttup now 0_o...

[mrazntre]

will:

[quote:81296fa859]IHI's electromagentic clutch type unit is exempt from this [/quote:81296fa859]

i have an electromagnetic clutch on my toyota blower. does exactly what you say it does. it can also be bypassed however. fuel efficiency is pretty much penny pinching at this point. it's been tested on the sc12 with or without magnetic clutch. the difference in fuel consumption has more to do with marketing for fuel efficiency and EPA standards than anything else. so that con has been eliminated.

[quote:81296fa859]and nessesary electronics and EMI shielding. [/quote:81296fa859]
if you were really to recreate one of these, all you would basically need is a normal 4pin relay to ground your SC, and EMI shielding! nigga. if you're buying a damn IHI supercharger unit, it better come with a fucking damn good electromagno shield, and that magnet better not be super powerful. i'm sure those engineers didn't engineer a magnet that would create a powerful EMI field that would go beyond its function of engaging the SC clutch.

SC has parasitic drag. Turbo has lag. basically we all know that cancels out.

on the point of SC maintenance, you install it. and leave it alone. remember i have a factory SC, so having the pulley work well...is a mute point. other than if you have a jacked up crank pulley or something like that. you do have to replace the SC belt, which is a given, but it's not that hard to do. it has it's own independent oil, and that you don't have to maintain so much because you are using a synthetic with a minute amount of moving parts- basically it doesn't get dirty, so the oil stays good.

as for volumetric efficiency this is a good point due to SC heat. I myself will be running a simple air to air IC. i might jump to liquid to air, but not too sure yet. this is ideal for my car. if for instance you are debating volumetric efficiency, you have to first look at what type of SC you want to use. as for me, my Toyota SC is roots type. it's basic. you have fins, it spins and compresses air and shoves it into the combustion chamber. that' where i'm at so the SC unit will not change. there are superior SC types, but we can leave that for another day (this basically challenges volumetric efficiency). there have been different fixes to the roots type to boost efficiency, by teflon coating the fins etc.

as for the turbo acting as an exhaust dampener, i left that out because if i want a quieter exhaust, i'd just go out and buy one. a good point however is the heat sink theory of the turbo. it might serve well for your exhaust, however, since the turbo is sucking up all the heat from the exiting exhaust gases.....whaddya think happens to the exhaust manifold? orange glow. plus the heat does not stay put on thte exhaust side, it'll soak to the intake side and start to heat up your intake charge. we do know that turbos are made to dissipate heat (hah!) - (within normal working heat ranges), however that also adds to the possibilty of warpage.

emissions? WTF! do you actually care?

SC does have the turbo in terms of longevity. there is not nearly as much heat produced in an SC unit as there is in a turbo. yada yada yada.

anyway.

i usually disregard parastic drag because it factors into net horsepower output, as opposed to turbo lag, which does affect torque numbers, but not necessarily hp numbers... that's how i tend to see it. hmm... get it?

we all know that regardless of anything you do, you will always. ALWAYS. have heat soak. okay so mebbe if you live in alaska or something. heat soak always factors, but that's what a good IC is supposed to take care of right? on an SC, this is comparable to what you 'could' call boost spike. due to the increasing heat of the intake, the air molecules shrink and become more excited, thinning out the intake air and artificially creating a higher state of boost, yet effectively decreasing hp output. (same thing with turbo, however the wastegate should SHOULD SHOULD deal with the boost reading.

i know i have some fragmented thoughts (i can't be typing all this out), but Will knows what i'm talking about, and if you do too, then good for you!

okay. so here i am now. turbo makes for better freeway speeds, sc better for smoking will off the line. sc has the edge thus far because there is far less maintenance in my eyes (in terms of cool down somewhat, oil pressure/changes - definitely critical in ANY car, however the stakes are raised when the turbo is dependent on your engine oil, what if the wastegate don't work! dUmA! kaBloom.

[wylin]

kaboom, yah my wastegate works i can hear it and thats what boost guages are for.

remember turbo is better and u cant beat me!

[mrazntre]

[quote:38ca09434c]remember turbo is better[/quote:38ca09434c]


u sound like a girl!!!



If that's what boost gauges are for, then why don't you go install the boost gauge RIGHT now!!!!!!!

[wylin]

sunday biatch, i am instally the blitz Dual Turbo timer/ Boost guage sunday.

yeh boost guage is important, but what else is important i was thinking of getting a blitz SPID unit that can display speed, rpm, and 5 other random things like oil temp, oil pressure, egt etc.?

will

[mrazntre]

i know you've listed some of these, but i'm just gonna list off some of the ones i think are important.

1) fuel pressure
2) oil pressure
#) water pressure
(these would basically monitor vital functions - if all these are in good order, then that would mean your motor is running properly)

[i:5ad4486fcc][b:5ad4486fcc]In short: [/b:5ad4486fcc][/i:5ad4486fcc]
if you don't have fuel pressure, you're fucked
if you don't have oil pressure, you're fucked
if you don't have water pressure, you're fucked
All of the other gauges, in my opinion, are secondary to these three.


water temp, boost, EGT, AFM-- it's cool to see those lights flash (your EGT should be gauge enough for rich/lean conditions -- take AFM readings with a grain of salt. The readings are only as good as your 02 sensor signal.


that's all i can come up with right now. it's damn hot.

[inkpainter]

[quote:079a896652="wylin"]sunday biatch, i am instally the blitz Dual Turbo timer/ Boost guage sunday.

yeh boost guage is important, but what else is important i was thinking of getting a blitz SPID unit that can display speed, rpm, and 5 other random things like oil temp, oil pressure, egt etc.?

will[/quote:079a896652]

m/w...i think readings are important 'cause the turbo runs at around 900°C, and when the engine is switched off, it's oil supply is also stopped, meaning the bearings are not cooled, and can quickly overheat and so the engine needs to be left at idle until the turbo has cooled down sufficiently for the bearings to survive.

my take on readings...operating conditions of the engine are mapped using a Zone table formed from the engine’s Rpm And Manifold air Pressure which works great for cars that have a 1 bar map sensor (Hondas, Toyotas, etc) that needs to run under boost conditions with an afm link, cars that had 1 bar map sensors can now be programmed to run with Turbo or Superchargers utilizing larger injectors with boost fuel maps. Also has a RPM switch, which can be used to control VTEC.

...just my take... :wink:

[mrazntre]

inkpainter:

re: turbo oil. That's what a turbo timer is for.

regarding your second part of your post. wylin is using the stock JDM spec wiring harness, which means that is was nissan engineered to run with turbo. so basically you're talking about NA cars that want to run boost? i am not really following what this part of you post says.. NA ecu fuel maps are quite limited and to generate any significant amount of boost, in addition to what you're saying (can you clarify? souinds interesting.) you will always need to boost fuel pressure. you can richen the fuel map in the ECU, but only to a slight degree. u will then have to manually increase flow via larger fuel pump and rising rate fuel pressure regulator.

[jizza]

bleh, its too late to jump into this argument... maybe tommorrow.

[inkpainter]

[quote:9cc17a35de="mrazntre"]ecu fuel maps are quite limited and to generate any significant amount of boost, in addition to what you're saying (can you clarify? souinds interesting.).[/quote:9cc17a35de]

Hey MrA...sorry for not responding right away...my brain's been mush the last couple of days from workin' long hrs..i enjoy reading your posts..you've got a lot of insight into hybrids..i don't play as much as i use to..i messed around when i helped my uncle at a race track in New Smyrna Beach (near Daytona Speedway..so most of my exposure is with hybrid domestics...interesting to see what u can do w/imports though..

i've seen ecu maps that can generate quite a bit of boost...but again..mostly on domestics..

[jizza]

there are several factors to deciding which is the better choice between a turbocharger and a supercharger....

for example, what type of supercharger? roots or centrifugal? another factor is the type of motor it is going on. low revving large displacement motors like on domestic cars or the high revving small displacement motors found on hondas and imports in general.

in general turbochargers are considered more efficient due to the semi-independent nature of the turbo itself. powered off of exhaust gases, a turbocharger gains its power peak when a large amount of EG is being pushed out of the motor. as a result less performance at lower rpms more at higher. whereas on a centrifugal supercharger like the vortech, there is parasitic loss due to friction and actual energy loss from the crank (as mentioned before). the SC has a terrific response, but its performance is limited due to the fact that it is belt driven.

in comparison, the compressor side of a centrigual SC is very similar in design to the compressor side of a TC, but the fact remains that one is powered by the crank itself and the other by exhaust gases.

in terms of costs and maintenance, thats all relative....

[wylin]

[quote:3aa507c993="jizza"]there are several factors to deciding which is the better choice between a turbocharger and a supercharger....

for example, what type of supercharger? roots or centrifugal? another factor is the type of motor it is going on. low revving large displacement motors like on domestic cars or the high revving small displacement motors found on hondas and imports in general.

in general turbochargers are considered more efficient due to the semi-independent nature of the turbo itself. powered off of exhaust gases, a turbocharger gains its power peak when a large amount of EG is being pushed out of the motor. as a result less performance at lower rpms more at higher. whereas on a centrifugal supercharger like the vortech, there is parasitic loss due to friction and actual energy loss from the crank (as mentioned before). the SC has a terrific response, but its performance is limited due to the fact that it is belt driven.

in comparison, the compressor side of a centrigual SC is very similar in design to the compressor side of a TC, but the fact remains that one is powered by the crank itself and the other by exhaust gases.

in terms of costs and maintenance, thats all relative....[/quote:3aa507c993]

yeh, look at my post toward the begining of the tread to see a more detailed discussion of what ur talking about.

[mrazntre]

inkpainter: with today's world of LEV and ULEV cars, there is little to be gained with a stock ECU -- mostly imports, due to the tight EPA smog restrictions most Japanese car mfg's have basically tuned out what they can in terms of peak HP and torque, THUS, on the aftermarket software side, a lot of load balancing between hp/torque takes place (we're talking strictly speaking in terms of NA imports right?). it's unlike your domestics where you have somewhat primative (ooh...!) software and uhmm. i wouldn't call it hi-tech fuel delivery and management systems. (yah yah, mustangs are fuel injected....) -- WTF was i trying to say? oh, with domestics, like with the 305, 350's, (chevy argghh!) there's a much bigger window of fuel capacity (going back to 80's ish domestics runnig carbs, i.e. irocz, mustangs, camaro's). shit. lost my train of thought again. let's just say domestics used to rely heavily/solely on displacement to create horsepower, the fuel management aspect is basically untapped with respect to domestics (until recently that is, that's most likely why you've seen some good fuel maps on domestic NA ecu's)

DONE!

jizza: good info for those who are just reading and scratching their heads!!!

i have either the choice of a roots type blower or possibly a T3 (of which i would need to rebuild + fabricate the exhaust manifold). Not gonna waste the T3/T4 on the daily. This will be on my 1.6L 4agze. high revving? uhmm 7200 redline..i dunno, it's not that high. The purpose of this car will just to get to work, in and around town, and go visit my friends, no intent on racing.

I'm leaning towards SC because I've already had one in my car, plus i have all the associated parts. I was mainly trying to see if anyone can convince me otherwise. One of the big things that I dislike about the turbo, is turbo lag. Although the SC's hp output is hampered by parasitic drag, that affect is throughout the entire power band, which basically is not noticeable (yah yah yah, i know). The major con of the turbo is something i can't stand. LAG. That's the main thing right there. Although the smaller T3 should decrease lag time, it's still there!

Okay, so taking into consideration my daily driver stuff... any more points for the turbocharger?

[inkpainter]

mr...thought this post i came across awhile back might be of interest to you..


1) Dinan, centrifugal supercharging
2) ERT, centrifugal superchargin
3) Mosselman, turbocharging
4) Active Autowerke, turbocharging

I started reading turbo magazine...(horribly written, horrible graphics, but fairly educational as far as foced induction goes)...I also subscribed to the honda performance mailing list, which caters mainly toward the drag race scene in so california (compared to them, our signal/noise ratio is great.)

My priorities, from most important to least important, were:

1) reliability
2) serviceabilty, and the related "cleanliness of the installation"
3) power increase and the associated driveability
4) cost

Here is what I found:

1) Dinan and ERT centrifugal supercharging ISN'T the same as roots supercharging, as is the case w/ the SLK, Grand PRix, T-bird. As such, these 2 supercharging kits don't really make an appreciable difference until 3500 rpm or so, and then boost starts to build quite linearly. Boost is a linear function of rpm

2) In turbocharging, boost is NOT a linear function of rpm. As long as you match the turbine housing (and some other turbocharger specs) correctly to the displacement of the engine, you'll get a turbo that spools up very quickly, and can make appreciable boost as low as 2000 rpm.

3) However, depending on the state of the motor at t - 1, planting the gas a time t will not always result in x amount of boost...I think this is turbo lag. This does not happen w/ centrifugal supercharging. You can always
predict the amount of boost you will get w/ supercharging. Supercharging wins the driveability battle.

4) Centrifugal supercharging one of the most efficient forms of supercharging..the parasitic loads are minimized in c. supercharging, but of course, it will never be as efficient as a turbo

5) The turbo kits probably make more torque under a broader range of rpms (and hence power) than the sc kits. The turbocharger wins the sheer power battle

6) compressing air always heats the air up, but the turbo kits produce more underhood temps because the turbo is mounted to the exhaust manifold, and that gets hot hot hot.

7) More air to burn means you need more fuel to burn it with.....
a) The Mosselman kits use a variable fuel pressure regulator to provide for more fuel...this doesn't seem like a very accurate way of providing for more fuel..in fact its very INaccurate.. compared with changing the fuel injection curve, this is like comparing carbs to fuel injection. I want engineered accuracy, not ball park correct. Mosselman out.

b) The Active Autowerke kit mounts two additional fuel injectors upstream of the original fuel injectors and controls these injectors with a combination of HKS/GReddy computer parts and revised motronic programming. How can I be sure than all six cylinders receive an equal amount of fuel from the additional two injectors if they are mounted upstream of the original injectors? I can't. I don't like this "adding 2 more injectors in the vicinity of the intake manifold" idea. I don't like using HKS/Greddy computer parts to control these injectors...IMHO its kinda like a band aid...Its kinda like cadillac, when they say, "Our front wheel drive cannot cope w/ the 300hp from our Northstar engine, so we will use traction control, ABS, computer adjustable shock valving, and the like to 'control" the chassis as much as possible" If the factory tubocharged the M3, I'm sure they wouldn't add two more injectors and use more computers to control them. Plus, I don't like the turbo heat probelms, and the fact that a turbo literally cooks your engine oil. That's why AA suggests you use a HKS turbo timer, to keep
your engine idling for a few minutes AFTER you have left the car, to let the oil circulate thru the turbo...I don't like this either...more bandaids IMHO!!!!
Note: intercooling standard.

c) Dinan supercharging...The powerdyne sc uses a self contained lubricant...no cooking engine oil. The sc's had also been redesigned (by powerdyne) as of November 1996 to account for internal sc belt/bearing failure experienced under high stress track conditions. no more failures with the new units...quieter too! Now, Dinan replaces the stock fuel injectors with bigger ones (the factory would have done it this way) I like this... Now, under boost, the HFM air sensor reads an "out of range" reading (too much air being pushed thru!) so Dinan gets around this by incorporating another black box to intercept this signal and spit out a correct reading to the motronic computer so the reporgrammed motronic will shoot out the
correct amount of fuel to the injectors. This is good. Very factory like, except Dinan is a little pricey...
Note: Intercooling an option.

d) ERT supercharging...same thing as Dinan, except instead of the black box affair,they replace the HFM completely with a bigger european HFM that can correctly read the amount of air passing thru under boost, and reprogram the motronic to control the bigger injectors correctly. EVEN CLEANER! EVEN BETTER! They are cheaper than Dinan too.
Note Intercooling an option.

[jizza]

i'd just like to point out that TC'ing or SC'ing a beemer is a world of difference from doing it to a honda. a friend of mine was actually running a SC on his m3 for a while until he realized that it wasn't much faster than his non-FI motor. i've also heard that the FPR on the e36s are volatile and don't take kindly to changes in pressure.

on the flip side of things, in comparison i would have to say jap. imports are much more FI friendly. as for the hks AIC, i haven't seen to many people running this setup but i haven't seen anything bad from the ones who do. i've got a buddy running a built ka24 motor on a garret t3/t4 running a HKS VPC, GCC, and AIC. everything seems to run fine on his car.

on the 4ag motor i would probably go with a turbo setup. its a matter of preference but i believe that if ur willing to compromise a little bit of the reliability, the payoff in terms of net power is worth it. issues with lag can be compensated with a smaller turbo setup (t3 or a t28?) and driving style.
i haven't had too much experience with the 4ag, but from what i've seen the 4ag is capable of some power both on and off FI. a few years back i used to work with a guy who drove an older mr2 with the NA 4ag, milled head, cams, etc. etc., and that thing hauled ass... ran a high 13 in the 1/4 mile.

[mrazntre]

jizza: i'm not really willing to give up on reliability, because i use my car for work, and i drive around everywhere! i'm pretty much stop and go, so it's important for me to just be able to start the motor, and then stop it. i do mostly city driving. true the smaller turbo can cut down on lag time, but there will still probably a noticeable amount of lag ~2500-3500rpms (SC hits full boost at 1K), at least that's what i'm thinking. the reason i'm not going to twincharge is because of reliability issues. so it's either one or the other.

thanks for everyone's input, but i'm probably just going to stay with the SC for now. motor will drop tomorrow night, and hopefully be up and running by sunday (i have to work on fri, and on sat. i need to help my gf look for a car ---argh!! anyone selling a decent Civic *cringe*) *barf* *barf*

ink: neat post.

wow this forum is getting so much better. we need more car people in here.