Nitrous? Turbo? Supercharger?

thought id ask you all about you opinions about induction. i am torn between turbo, nitrous and supercharger. they all have their upsides and they all have their downsides, maybe kicking off a debate on the forum will help me make a decision in which road to take.🤪

im running a 1776 (will eventually go bigger but i wanna see how much i can get out of this motor 1st), for arguments sake, lets assume i already have a suitable bottom end, heads and will have a cam custom ground to suit any of the 3 choices, what are/have been your experiences and which would you choose and why.

turbo. more efficent than a supercharger and not illegal like nitrous.

get this book and have a read first... http://www.amazon.com/Turbochargers-HP49-Books-Spark-Ignition-Applications/dp/0895861356/ref=sr_1_4?ie=UTF8&s=books&qid=1245221187&sr=1-4

obviously, efi/intercooled is better but drawthrough can be good too.

turbo would be better and more readily availalbe for VW applications

they all have there pros and cons as u say
ive never played with NOS and probably never will but after building turbo and supercharged vw engines i found heat was a biggest problem with the turbo
the bloke that has my turbo kit now setup an intercooler and is having a bit more luck than me but had to pull the CR down so far that its a dog off boost

I think a supercharger is more suited to a VW motor as it doesn't put such a high heat load into the exhaust ports like a turbo does. Hot exhaust ports will kill VW heads.

Porsche used a different head design on their early engines, with the exhaust valve kicked out on an angle to allow air flow between the intake and exhaust ports in the head. Then when they went turbo they used ceramic liners in the exhaust ports. VW's have none of those features.

Modern design superchargers (belt driven turbo style) are very efficient and not that far off turbos, but they cost big $$$$.

I'm no expert mate, but this is what I came up with:
I was going to try a draw through supercharger. When set up properly I think it would be a solid option. The toyota type blowers (which I was going to buy) are a positive displacement arrangement which basically means they push large volumes of air without compressing it (thus heatnig it) significantly. This really helps keep intake temps down. Drawbacks I read about were that many superchargers (the vane type) do not like to have fuel run through them and wear more quickly. Also boost is more limited but at least you have it on tap from idle. Not a great deal of fabrication required to set it up...ask Joel he did it!
I am intrigued by nitrous...is it illegal on the street? Boooo!
Finally I went with turbo efi. Reasons being that everything can be managed and controlled by a computer (ecu) and therefore if programmed correctly you will have precise control of fuel delivery, spark timing and boost for any given engine speed or load (and temperature!). I'm still setting my installation up. Obviously it is only as good as the tuning job. You should definitely also run an intercooler on an aircooled turbocharged engine. Heat is the enemy!! There are heaps of options available for efi depending on what you're after. Lowered compression ratio is a must. I use shims under the cylinders and "semi hemi" stock type 3 heads. My setup is mainly for torque and will be purely a daily driver. 12psig boost and hopefully 160hp should be achievable and be reliable. It's also a 1776 :-)
Centrifugal superchargers (basically a belt driven turbo) are just as Wes said. Efficient but they cost big $$$$!
I'm probably talking crap though...will be keeping an eye on this thread :-) Hope to learn more too!!

mmmm NOS, go nitrous you can make your fuel jet a bit bigger in the fogger to run on a safer side. you can have a well streetable engine on the street as you dont use NOS on the street but bigger power at the track.. thats my 2 cents. cheers

intercooled supercharger and EFI

supercharged it gives torque from start and dosn't ban on and load up the rods and such.i have build a supercharged 1641 and a 1600 the torque is fantastic .these ran with a 8 lb bost without causing any problems you could potter around with no worries,i used water cooling using the blowers own pressure so you only had water when you needed it and i also ran a trucks gearbox oil cooler with a 12 inch fan,this was more for oil capasity (the more oil the cooler the motor)
so whitch to go as i have used both and supercharging a simple and cost efective fit
good luck

why not go all 3 three :P 👍

space out the barrels/heads and get urself a comp ratio of 6.5:1 and go nuts lol

I have had a vortech blower on a commodore motor and after a friend built a turbo one there was no comparison. I would turbo everytime. My vortech was running twice the boost for the same result. This is double stress on components. Sure mine would get off the line harder but once his spooled there was no catching him.

The only way to do this is setup 3 exact motors and see which is best eg. reliable, useable power and outright hp.
Any volenteers?

T54

type3vw wrote:mmmm NOS, go nitrous you can make your fuel jet a bit bigger in the fogger to run on a safer side. you can have a well streetable engine on the street as you dont use NOS on the street but bigger power at the track.. thats my 2 cents. cheers

yeah iv always been a fan of nitrous, i had a wet nos system on my daily driver a few yrs back, still have it so there's most of the cost gone. since it was a new commodore ute, they generally run on the lean side of things, so i ran 1 size up jet on the fuel side and it never missed a beat for 40,000kms and god knows how many bottles of giggle gas.... but with vw motors alot of ppl have been advising me against it, dont know y, i figure if u have all the right internals it shouldnt be a problem... and with turbo and supercharger, there is the bonus of legality and not to mention the power is always there............🤪 i dont know.

greedy53 wrote:supercharged it gives torque from start and dosn't ban on and load up the rods and such.i have build a supercharged 1641 and a 1600 the torque is fantastic .these ran with a 8 lb bost without causing any problems you could potter around with no worries,i used water cooling using the blowers own pressure so you only had water when you needed it and i also ran a trucks gearbox oil cooler with a 12 inch fan,this was more for oil capasity (the more oil the cooler the motor)
so whitch to go as i have used both and supercharging a simple and cost efective fit
good luck

cooling not an issue, i struggle to get it past 80C in fairly hot weather lol, i might have used a slightly large oil cooler 😂 with all the braided lines, oil filter, deep sump and cooler i have almost 5ltrs on the dot oil capacity!🤪

if you welded water jackets round your heads you might be better off with the heat issue. i've seen it done on a few cars now.

My friend had a Sprinter with a 4AGZE. Had a 12lb boost pulley on it (I think). It went pretty hard, really grunted away at almost any rpm.

He then took the supercharger off and put a turbo on. Sure it had more HP and was ultimately faster, but only when the revs were high. It had lost the low end grunt and strong feeling that the supercharger gave.

Look at what VW do. In the 1980s, they chose to fit a supercharger - the VW 'G-lader' - to the Polo, Golf/Jetta and Passat, rather than a turbocharger. They also used a G-lader on the 'Polo Sprint', the one-off test vehicle fitted with a rear-mounted Wasserboxer flat four. The G-charger used orbiting spirals rather than rotating components.

The Mk4 and Mk5 GTIs got a turbo, but it's a high-revving performance engine.

For normal Golfs, VW now fits BOTH a supercharger (for low-down boost) AND a turbocharger (for high-up boost). This is the VW 'twin-charger' - the best of both worlds. It gives 2.0-litre performance from a 1.4-litre engine. A bit hard to adapt to a Beetle engine, though.

http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleID=40001

I'm struggling to see any advantage to nitrous. You have to keep refilling the bottle, + your mixtures are screwed up, + its illegal.

You must have too much money to waste if you're rebuilding and hotting up a temporary engine. If you're piulling an engine apart to replace a cam you should at least put 94's on. Grab a counterweighted crank and be done with it.

I wouldn't advise even contemplating forced induction without an intercooler. You're throwing horsepower out the window and adding unnecessary heat in the process.

Yeah, I can't see the point of nitrous. Where's the fun of it if you can't give it a squirt at every set of lights without having to refill something.

if it's not going to be registered do what ever,if your going to drive it on the street nitrous would be my choice you can have less of every thing cam compression head work fuel octane etc i would sugest your 1776 with a set of arp bolts and and exhaust and a non stock carb set up.Then have at it with the gas!Say it makes 60 to 90 hp at the wheels a well set up system is safe and you could end up with up to 180 hp at the flick of a switch,and you have got a car that is like jeckyl and hyde!As for it being illegal like i always say who are you a cop😂

I've driven a N/A, turbo and supercharged Fiat/Lancia twin cam and I would take the positive displacement supercharger every time. The supercharger is so much more flexible - the torque is always there.
Centrifugal superchargers are the worst of both worlds - lag at low speeds and the high power draw to spin them.

coletrickle wrote:As for it being illegal like i always say who are you a cop😂

Problem isn't the cops, it is the insurance companies. If you smash into someone/something and you have nitrous - then insurance is not going to pay out. Having to live in squalor for the rest of your life to pay back what could be millions of $$$$ would not be pleasant. Don't think it will never happen to you, as it does happen.

volumex wrote:

coletrickle wrote:As for it being illegal like i always say who are you a cop😂

Problem isn't the cops, it is the insurance companies. If you smash into someone/something and you have nitrous - then insurance is not going to pay out. Having to live in squalor for the rest of your life to pay back what could be millions of $$$$ would not be pleasant. Don't think it will never happen to you, as it does happen.

If you have nothing - they cannot take it from you 😂

I always fancied trying to get a twin turbo setup working - less lag. Superchargers tend to give better low down torque - turbo's the opposite - using two smaller units should make them spin up faster and bring the useable torque down the rev range.

I've got a massive turbo (0.8 a/r) for my Ghia with a 50 shot of Nos to get the thing spooled up (Nos cuts off when it hits boost). Not got it running yet so have yet to test it out. Not 100% it is streetable without the gas, but I'm hoping that there's not massive amounts of lag (fairly large capacity engine). The gas also helps to cool the charge too.

Someone I know back in the UK was developing a cheap DIY turbo kit - basically it used a garret T03 with a re-jetted Renault 21 carby - worked really well on a stock 1600 twin port (stock cam works really well for forced induction). I think they managed to get their test bug into the 13's in this configuration. Not sure what happened to them - last time I spoke to him he was trying to get the exhausts mass produced. Used to hang out on Shop Talk Forums.

HTH

Mick.

dude i live in squalor now😂The point i was trying to make was that the speed limit is 110 max how much low end torque etc do you need the more power you have the more tempted you are to use it so a nice stockish engine that you can turn into a hot rod at off street events disconnect the bottle and drive on the street has got to be pretty hard to beat.For example i drove my brothers 73 dodge dart 440 10.1 650' solid cam pump gas etc to willowbank yesterday on street tyres thru the mufflers it ran 11.49 @119mph its got 500hp atw it's a horrible car to drive at the speed limmit its completly legal but the cops still pull it over to give you a grilling.I think i'm gonna have to ressurect my favorite engine of all time and gas it.

T-34 wrote:

volumex wrote:

coletrickle wrote:As for it being illegal like i always say who are you a cop😂

Problem isn't the cops, it is the insurance companies. If you smash into someone/something and you have nitrous - then insurance is not going to pay out. Having to live in squalor for the rest of your life to pay back what could be millions of $$$$ would not be pleasant. Don't think it will never happen to you, as it does happen.

If you have nothing - they cannot take it from you 😂

They take if from your pay, every pay, until it is all paid back. Nothing funny about it.

last to weeks total hrs worked 21 hrs might top 15 hrs this week not a lot to garnish there🙅and if i had to i recon i could live of grid doing cashies. Its not like i havent dissapeared before🥷

for ease and the abundance of information available i'd go turbo.
My stock 1641 with little TO2, SU and 6.5:1 compression ran 14's in my fat '70 beetle and was on it's way into the 12's in the current car before it torched a piston.
It was street driven didn't get too hot and the only issue was sooty plugs with the low compression.

with that said i'm now looking at supercharging but this will be for Warwick next year. Current engine with same turbo setup but some new goodies will be fitted this weekend.

If you ever saw Dave Butlers supercharged VW drag car you'll know how awesome a supercharged flat 4 can sound.

This probably doesn't apply to modifying VW engines, but it's interesting anyway.

Unlike car engines, aircraft piston engine output is not determined by the engine capacity (ie bore/stroke). It is determined only by the mass of fuel/air mixture that can be consumed efficiently, which is controlled by the supercharger. So aircraft piston engine designers improve engines in this order:
1. Improve the supercharger
2. Improve the fuel (to delay the onset of detonation)
3. Develop mechanical features in the engine to take advantage of 1 and 2.

Rolls Royce did extensive development work on the 27-litre Merlin V12 during the war, with output being raised from 700 hp in 1939 to nearly 2,300 hp by 1945. This was achieved with two-stage, two-speed superchargers. These gave the Merlin the same power output as the much larger capacity (36-litre) V12 Griffon engine, with similar reliability, and much better performance than the 28-litre Allison V12 (which only had a single stage supercharger, or a turbo supercharger, depending on the aircraft).

This is a lecture about the Merlin, and its supercharger development, given by Rolls Royce engineer A.C. Lovesey in 1945:

http://www.wwiiaircraftperformance.org/merlin-lovesey.pdf

blowers have that certain cool factor on a vw
but like andrew said turbos are just so much cheaper and easier to get hold of
was always good value at shows the people that thought my bug had A/C 😂, people seem to think that supercharging a vw is impossible for some reason

Agree with Wes, im a boostjunky of any descrription so a turbo spooling sounds nuts but the whine of blower is hard to beat

amazeer wrote:I'm struggling to see any advantage to nitrous. You have to keep refilling the bottle, + your mixtures are screwed up, + its illegal.

You must have too much money to waste if you're rebuilding and hotting up a temporary engine. If you're piulling an engine apart to replace a cam you should at least put 94's on. Grab a counterweighted crank and be done with it.

I wouldn't advise even contemplating forced induction without an intercooler. You're throwing horsepower out the window and adding unnecessary heat in the process.

having used it before im now quite fond of it, its litterally power on tap and the cheapest and most effective power upgrade, yes its illegal but if u keep to yourself and dont be an idiot with it there is no problem (unless u have an accident and insurance finds out 😠) All 3 systems have their advantages and disadvantages... just have to figure out what suits your car, its purpose and style ur of driving. ahhh! now im even more undecided.... lol maybe i should jus do all three 🤪😂🤪

Baja Wes wrote:Yeah, I can't see the point of nitrous. Where's the fun of it if you can't give it a squirt at every set of lights without having to refill something.

i used to run a 150hp shot on my vz storm ute and although it would be used almost every day, i used to get roughly just over a month out of a bottle and sometimes more, just depending on how long u held the button down... (10lb bottle) so i was happy with how long it lasted, only buzz kill was if u went to use it and it was empty 😬

Baja Wes wrote:If you ever saw Dave Butlers supercharged VW drag car you'll know how awesome a supercharged flat 4 can sound.

or check out "the twins" from CBB

Stanley wrote:

Baja Wes wrote:If you ever saw Dave Butlers supercharged VW drag car you'll know how awesome a supercharged flat 4 can sound.

or check out "the twins" from CBB

or even mikes old car cranky🤪

I don't really see how comparing golfs/jettas/4agze to an aircooled motor is relevant. The characteristics of the engines are completely different. all those straight fors are revy where an aircooled motor is more like a truck engine with low down torque but no top end. Check what stanley said about his cheap turboed 1600. added to that, if you could afford an ECU and an intercooler, you have a great reliable setup with excellent drivability.

what are you actually using the car for? I reckon that's the key question.

pete wood wrote:what are you actually using the car for? I reckon that's the key question.

and of course your budget

It's relevant because it illustrates how the VW company - with a lot more engineering expertise and $$ than you or me - applies modern technology to certain situations to gain certain results. You observe what they do and draw your own conclusions. The point I made, was that VW applies turbocharging to GTI engines, but twin-charging to other petrol engines. The result speaks for itself - the base Golf 90TSI (turbo only) 1.4-litre produces 200 Nm torque from 1500-4000 rpm, while the same engine in the 118TSI produces 240 Nm from 1750 to 4500 rpm using a supercharger/turbocharger combination.

Yes VW air-cooled engines have good low-rpm torque characteristics (for their day), but that's a result of their design parameters - for maximum economy, low rpm and long life - not their air-cooling. Other air-cooled motors can indeed be revvy - look at a Porsche Super 90 for example.

They take if from your pay, every pay, until it is all paid back. Nothing funny about it.

Worse than that if you're the person on the other end. The stupid cow that I used to live across the road from had an accident in her car. She didnt believe in insurance, and she actually did find it funny. She was unemployed and had to pay back something stupid like $5 or 10 per week. That was some time ago, maybe the minimum payments have been increased now, but still. $10 week would barely cover the cost of a return train ticket.

definately go NOS. ill be putting a 50hp shot of NOS on
my engine when its done, just so i can enjoy driving
my engine everyday. and only using the NOS at the track.
its only illegal if the bottle is conected. the bottle can be in
the car as long as its not connected. i say go NOS.. you
know you want to. be different..

Why cant you run a turbo everyday? I did. I drove to work and back every day. On saturday I went to coonabarabran and picked up a fastback, towed it home. On Sunday I went hillclimbing. It may not be of concern , but you cant do any racing other than drag racing with nitrous.

amazeer wrote:

They take if from your pay, every pay, until it is all paid back. Nothing funny about it.

Worse than that if you're the person on the other end. The stupid cow that I used to live across the road from had an accident in her car. She didnt believe in insurance, and she actually did find it funny. She was unemployed and had to pay back something stupid like $5 or 10 per week. That was some time ago, maybe the minimum payments have been increased now, but still. $10 week would barely cover the cost of a return train ticket.

My point exactly - If you have nothing - they can't take it from you.

amazeer wrote:Why cant you run a turbo everyday? I did. I drove to work and back every day. On saturday I went to coonabarabran and picked up a fastback, towed it home. On Sunday I went hillclimbing. It may not be of concern , but you cant do any racing other than drag racing with nitrous.

I'd listen to the voice of experience mate. But also, don't build a drag grenade, build a street motor.

nitrous is banned in the rules for pretty much every form of motorsport that i know of so that leads me to belive that if it wasn't specifically banned it would be used.The reason that drag racing engines may get a bad rap is that they allways are chasing maximum power and your going to find the weak linka lot eairler than other forms of motorsport.

nothing wrong with drag motors, but they aren't subject to the sort of long term conditions or driving style that street motors are. a monsta turbo is great on the strip but terrible in traffic. hence my qu before, what are you using the motor for? I wish I'd ask myself that question a lot more when building my car. 😢

T-34 wrote:

amazeer wrote:

They take if from your pay, every pay, until it is all paid back. Nothing funny about it.

Worse than that if you're the person on the other end. The stupid cow that I used to live across the road from had an accident in her car. She didnt believe in insurance, and she actually did find it funny. She was unemployed and had to pay back something stupid like $5 or 10 per week. That was some time ago, maybe the minimum payments have been increased now, but still. $10 week would barely cover the cost of a return train ticket.

My point exactly - If you have nothing - they can't take it from you.

I'll assume you are joking and arent completely self absorbed.

Nitrous is banned from most motorsport and the street because of the risk during fires. If fuel fires arent bad enough, you really wouldnt want to be feeding a shitload of oxygen into it as well.

I had another thought on my commute today. At either end of Wollongong there is a big ass mountain to leave town. At the southern end is Macquarie Pass which is a winding road that takes maybe 15-20 minutes to climb. You are off and on the throttle the whole time. Do you keep flicking the nitrous switch or just forget about it and use the accelerator? The other end is Mt Ousley which eventually connects with the F6 to Sydney. Would you have the nitrous button flicked for 15-20 minutes? What about the hills on the F3? I've confirmed to myself that a shot of nitrous is pretty useless for anything other than drag racing.

NOS is primarily used for wank value by people on the street. The P platers even like to install CO2 kits that make it look like they have a NOS purge.

If you really want reliable every day fast, then sell your car and buy a bike. Buy a Suzuki B-King for $19k and run 9.9s 1/4 miles completely standard.

How you can have ricers beating 400ci V8s in street drags in 2 Fast n 2 Furious without nitrous???

I agree Chris, especially since Mt Ousley has an 80 km/h limit and a speed camera half way up anyway. And Macquarie Pass is a nice drive but clogged with day trippers in their Camrys.

amazeer wrote:

T-34 wrote:

amazeer wrote:

They take if from your pay, every pay, until it is all paid back. Nothing funny about it.

Worse than that if you're the person on the other end. The stupid cow that I used to live across the road from had an accident in her car. She didnt believe in insurance, and she actually did find it funny. She was unemployed and had to pay back something stupid like $5 or 10 per week. That was some time ago, maybe the minimum payments have been increased now, but still. $10 week would barely cover the cost of a return train ticket.

My point exactly - If you have nothing - they can't take it from you.

I'll assume you are joking and arent completely self absorbed.

Nitrous is banned from most motorsport and the street because of the risk during fires. If fuel fires arent bad enough, you really wouldnt want to be feeding a shitload of oxygen into it as well.

I had another thought on my commute today. At either end of Wollongong there is a big ass mountain to leave town. At the southern end is Macquarie Pass which is a winding road that takes maybe 15-20 minutes to climb. You are off and on the throttle the whole time. Do you keep flicking the nitrous switch or just forget about it and use the accelerator? The other end is Mt Ousley which eventually connects with the F6 to Sydney. Would you have the nitrous button flicked for 15-20 minutes? What about the hills on the F3? I've confirmed to myself that a shot of nitrous is pretty useless for anything other than drag racing.

you would only use nitrous for drag racing, obviously to run nitrous in the first place u would need to have a very stout motor (if ur doing it properly that is) so therefore hills and things of that nature are not any problem, all you would use the nitrous for is that few second boost to give u the edge over the competition. as for street use, unfortunately the majority of people running it are tossers and only use it for the wank factor. i ran it on my street car and i took the risk, but i didnt run around purging it and showing it off.... even the setup in the engine bay was hidden, the shock factor when u blew away somebody in a boxter or mildly tuned rice burner was brilliant.😂

there is an 80k limit on Ousley itself, and then theres the other hills over the back that are 100. They are all pretty steep hills. One of them probably use 70% throttle in a 4 litre falcon to simply maintain 100kmh. The question probably doesnt involve a kombi but the scenario is the same. If you have a 2 litre kombi you dont have any chance of doing these hills in top gear. You could do them in third and rev the guts out of your engine. Or you drop down to 80km and cruise up doing 20kmh less than the speed limit in third. Alternatively you can fit a small turbo to your internally standard 2 litre kombi and effortlessly cruise up the hill in 4th gear with about 4psi boost.

I've been doing the daily commute up Macquarie for the last week. I've got sore kidneys from my mate's seat bashing me around the corners. You just need to go up on a weekday Phil, not a Sunday.

There's plenty of shock factor in not being able to pass a kombi going up a hill. Not that you should speed up to stop someone passing you if you are holding them up. But for whatever reason most people in other cars seem to want to be in front of a VW no matter what speed its doing and then slow back to your speed or less once past.

If we're not worried about the car being streetable then it doesnt really matter what method of supercharging you use, either mechanical or chemical. All of them will work. Use them together. Use nitrous injected straight into the the compressor housing. Use the shot to spool the turbo. Not sure why you would use the small 1776 engine to start with though.

anyone can throw cubes at it and make power, which i will eventually do, but for the time being, i have set myself a little challenge of seeing how much power i can get out of the little 1776. even now with stock heads and in need of the 2nd dyno tune (only a brand new engine) its putting out 74.6hp at the wheels which is more than some ppl i know are putting out with a 1916... not mentioning any names..... im hoping with another run on the dyno, ill crack 80's. hoping to have the bigger heads, counterweight crank and h-beam rods in for warwick, then when we get back ill be looking at the induction side of it.

Ask Daimo about his dyno figures for his 1776. Cost alot of dosh to get to that stage! (NA)

Dyno figures are ok, 1/4 mile times are a better indicator.

Mick058 wrote:Ask Daimo about his dyno figures for his 1776. Cost alot of dosh to get to that stage! (NA)

Dyno figures are ok, 1/4 mile times are a better indicator.

yeah i havent run it down the 1/4 yet, so i dont know what to even shoot for, im just waiting till i get another dyno tune done (only got 1200-ish miles on it since i built it) and then ill take it out.... hopefully a couple of weeks...... wanna get alot of runs to get used to the car and see what it responds to the best before warwick. Im not expecting any low ET's for the moment, but i did enjoy the look on a guys face when i torched him off the lights on the way back from the nationals 😂😂 he had a VE SV6 and although iv been a holden man from day one, i didnt seem to have any conflicting feelings about just beating one in a VW🤪😂

Just curious, but where would you run the 1/4 mile now? Aren't the Warwick and Portland drags 1/8 mile, like Oran Park once was?

Or does WSID do street car drags?

wsid does street drags every wed night and sometimes fridays too.... other then that there is bracket racing almost every weekend (atleast there used to be)