how to supercharge or turbo a carby motor

[SiKiD_01]

i would like to know about forced induction on any zook motor, whether it be 1.3 or 1.6.

i know most of what is needed for EFI engines, and it does seem easier, but what i would like to know, is if it can be done on a carby engine.

or has it been done before?

apparently, turbo and carby dont go together well, unless its a produced from factory set up. why? i was told the engine runs fine until the turbo is on boost, and then the engine runs real lean, and some cases, runs out of fuel. if this were to be fixed by turning up the fuel, or similar, the engine would run very rich, and then normal when on boost.

i've also heard of setups where the carby has a primary and secondary, where the secondary opens to let more fuel in when on boost.

Turbos seem to be very expensive and difficult to set up, as you also need a custom exhaust manifold made up. (for a non turbo engine)

so unless someone can shed some more light on this, i'm more interested in supercharging.

correct me if i'm wrong, but a supercharger works the same as a turbo, by forcing more air into the engine, but mechanically, runs different.

the supercharger is belt driven off the engines crank, and the amount of forced air is proportional to the revs the engine is making. if you rev harder, you get more power, and its instant, from the minute you turn the key.

as the turbo needs to spool up to speed before it can deliver its max power/ air capacity, and usually higher in the rev range, as its driven by exhaust gases.

ok, i roughly know whats going on, so how, if its possible, do you supercharge a carby motor.

i've seen newer style superchargers, in which they are half a turbo, (compressor side) and the other side is a pully, where the fan belt drives, and so mounting is similar to the alternator, as it lines up with the engines belt, but there is plumbing from air filter to inlet.

has it been done, are there links and pics?

or should i consider boring from 1.6 to 1.8?

thanks

[Beastmavster]

Turbo or supercharging can work with carbies, but carbies are limited in what we call "MAP points" (at least in EFI language)... as in where the fuelling can be mapped effectively.

Depending on your efi system and settings that can be mapped down to each RPM and THEN varied by rate of acceleration (MAP or similar sensor).

See why efi is better..... 3 load points versus 6000?

[abundance84]

Time to bring back this old thread. It seems like this guys's question was not really answered. It is clear that EFI is better than carby for turbo or supercharge but can it be done to a carbied engine to get a few more ponies?

It sounds like if you get a carby that has a primary and secondary then the fuel leaning out problem is solved for the turbo. What kind of carby is this? I'm pretty sure I already have an aftermarket carby on my 1.6 (dont know what kind, its not a weber as they didnt have any immediately in stock). 2nd hand turbos dont look that expensive to come by and given that I have a welder and a pipe bender it shouldnt be impossible to do the plumbing.

Is there a possibility of making my engine go boom by trying something like this? Do the internals need upgrading or anything like that? Am I going to need a better radiator or an intercooler???

You will have to excuse my lack of knowledge of turbos or most things mechanical for that matter!

[noelb1]

two ways you can do it blow through or suck through

[lay80n]

Here we go, i will see if i caa help here.
First, the primary and secondary you mention, take a look at your stocko zook carby. Move the throttle while looking down the throats. One will move when you twist the throttle. THats the primary. The secondays on a zook is opperated by vacum. I.E. on lower maifold vacum (therefore higher percieved engine load) the secondary opens to provide more fuel, and hence make more power (all other things being equal ). Turbo on carby can be done, and even some early factory turbo's were carby. The two comon setups and a blow through - where the turbo i located upstream of the carby - and suck through, where the rurbo is located downstream of the carby. When you run blow through, you need to pressurize the float bowl too, otherwise fuel will get forced back through the jets etc. Suck through is easier to set up, but intercooling is harder and dangerous, as when you cool the compressed fuel / air mixture in teh cooler, the fuel re-forms droplets. A backfire through the maifold turns your intercooler into a scrap allow job pretty quick. As for superchargers. There are different types. The big blowers you see on the old skool V8's are the roots style, which build up boost well at low revs, but dont like the higher revs that smaller motors work at so well. The Superchargers you are refering to Sikid are the centrifugal type, and are like the compressor housing of a turbo, but a pulley and belts turns it, not the turbine wheel. These work better at higher revs and dont produce boost as effectivlet at lower revs. Manifold designe is a complex art to make perfect, but to do a cheap job, and not trying to break world records etc, its not that hard. Look at most factory turbo manifolds, Big cast lumps of sh*t. Plenty of room for imporvement. Making a descent manifold is not that hard, just gotta think about it first.

Layto....

[Charged_ZooK]

I have superchared my zook.... the best Mod i have done !!!! i have a 4gaze blower... as for fuel i have upgraded the a electric fuel regualator and fuel pump to run 15 psi!! i also fitted a LPG safty switch just incase of a crash were to occer it will stop the pumping of the fuel pump. i had heaps of drarmas with the fuel pumping in and this was the fix!! as for intercooling i have used a air to air stock Nissan skyline R33 facotry cooler, of course modifying the air intake to suit my now beast!!!

supercharers are cheap.... i picked mine up for $250

good luck!

[2LOW]

Can you get some pic's up of your set up Charged_ZooK?

I have the same S/C on my VR V6, but only running 3psi, any more and the internals will melt.

[lay80n]

Can you get some pic's up of your set up Charged_ZooK?

I have the same S/C on my VR V6, but only running 3psi, any more and the internals will melt.

You can go higher, but not much. 5 psi or so. Just make sure that tuning is spot on.

Layto....

[2LOW]

I have seen people on ebay say they are running 12psi on Holden reds. And they maybe are, they just don’t mention that they will last a couple of 100 kms then Time for a S/C rebuild and yes a very much needed rebuild for the 6 as well.

But yes 5psi for sixes is as high as these puppies will go. Mine on 3psi heats up after 5-10km, then I need to turn it off (Darwin weather doesn’t help).

[lay80n]

I know of one set up one to run 5psi through a fresh but standard VS V6. 5PSI no problem on a daily driver. Been almost 2 years now. Motor is fine and goes great for bugger all $$ spent. Small front mount, and a modified computer to match.

Layto....

[Rhett]

If your gunna turbo it don't go too much boost. I went 9psi and it only lasted one week it was fun while it lasted. almost doubled rwhp

[petah from oz]

Charged_ZooK , Is yours an EFI and can we get some pics.

[ado250]

You can run 8PSI through a weber 32/36 without any problems in leaking fuel. Like lay8to said though, you will need to pressurise the bowl, as simple as running a line from the intake on the carby (pressurised air) in through the top of the float bowl with some sort of fitting. Then you will also have to fill the float with foam and seal the hole you made in it (to inject the foam) with epoxy. This stops the float from crushing under pressure. You will also need to buy yourself a pressure sensing fuel regulator so that your fuel pressure goes up as your boost pressure goes up (with an electronic fuel pump). These are available on ebay.

You would really need to get a weber on the car, you can tune the primary/secondary circuit for fuel efficiency, and it's easy to re-jet (they were designed for universal tuning). You would have to work out where the super was delivering the boost - low down or high up. Some supers (I think the roots type) hit max boost at lower RPM's. You just have to know where your boost comes in and tune either the primary or secondary with bigger jets.

It can be done and it's not as hard as you might think. A weber, super, electronic fuel pump, pressure regulator and some foam/epoxy for the float and you're in business. You can also buy yourself an alloy cranskshaft (used for power steer/AC conversions) from the states for $50 US that will allow you to run a standard belt on a ribbed pulley (overcomes the Vbelt issue)

I was so close to running a super, but I have opted to hold off on that deam until I get my injected engine. I want something with low K's before I put the effort into trying to blow it up

[lay80n]

You can run 8PSI through a weber 32/36 without any problems in leaking fuel. Like lay8to said though, you will need to pressurise the bowl, as simple as running a line from the intake on the carby (pressurised air) in through the top of the float bowl with some sort of fitting. Then you will also have to fill the float with foam and seal the hole you made in it (to inject the foam) with epoxy. This stops the float from crushing under pressure. You will also need to buy yourself a pressure sensing fuel regulator so that your fuel pressure goes up as your boost pressure goes up (with an electronic fuel pump). These are available on ebay.

You would really need to get a weber on the car, you can tune the primary/secondary circuit for fuel efficiency, and it's easy to re-jet (they were designed for universal tuning). You would have to work out where the super was delivering the boost - low down or high up. Some supers (I think the roots type) hit max boost at lower RPM's. You just have to know where your boost comes in and tune either the primary or secondary with bigger jets.

It can be done and it's not as hard as you might think. A weber, super, electronic fuel pump, pressure regulator and some foam/epoxy for the float and you're in business. You can also buy yourself an alloy cranskshaft (used for power steer/AC conversions) from the states for $50 US that will allow you to run a standard belt on a ribbed pulley (overcomes the Vbelt issue)

I was so close to running a super, but I have opted to hold off on that deam until I get my injected engine. I want something with low K's before I put the effort into trying to blow it up

Correct, roots hit boost lower than centrifugal, but are not as efficient.

Layto....

[MARKx4]

There is a good book about turboing carbie cars, its writen by coorky bell (no joke). It is a good book and explains heaps, he has done one on supercharging a carbie motor aswell. Do a google search and it should come up.

[Charged_ZooK]

hi all, yea as everyone is saying 15 psi is to much and will only last a short time if not tuned properly... i only run around 8 -10 psi depending on weather conditions. As for heating up in the summer i might change it to a big front mount.... bling it up!!! as for pics, sorry i dont have any, i will try and get some up for you guys soon..........i have spent ages on getting all this to work and have wrecked many things on the way!!!! YEAh its a 1.6 carby... i am interested in going on dyno to check everything!!!!!


thanks

[/b]

[smiley_smoke]

charged a few questions if i may?

do you have thermo fans? does it overheat in winter?
how is your s/c setup, is it a blowthrough?
i am going to go the blowthrough setup with a weber carby and up the mains so that it gets enough fuel up top without the risk of detonation.
to get around the v belt/ribbed issue i have gotten some GTI pulleys off Cruzer! on the nbs forums.. going to replace all alternator and assorted pulleys over. GTI has a twin pullet setup to run power steering (?) so no need to mod.

i will be taking pics as i go and will no doubt need some help tuning up the weber

cheers

[ado250]

Mate there are plenty of people on here (myself included ) that have tuned and can give you advice on tuning webers. You might want to consider one of these instead of the GTI conversion stuff:

http://www.rocky-road.com/zukpulley.html

A whole lot easier than changing all your pulleys over, and it remains more reliable with all the right ratios - Your decision though

You also might want to consider pressurising the throttle shaft. You do this by removing the throttle shaft (be very careful in re-inserting, need alot of oil and care to prevent damage), drilling a small hole and putting a fitting in which allows an air line to be connected. Do this to both sides of the throttle shaft and replace it. This will allow you to run as much boost as you like without risk of leaking fuel/air and going booooom!

More info here:Turbo carb modifications

I for one would love to see the progress on the buildup. Good luck!

Ado

[smiley_smoke]

cheers for the links.. after much reading and thought
i have found that the standard fuel pump is around 7psi.
i will be running the amr300 at around 6psi. this make me think that the fuel bowl should not be subjected to any pressures out of proportion to the psi be blown through it..? close to being equal in pressure the fuel bowl should be sweet??
good idea on the pulleys. i may give it a try if the gti ones dont work out. they all seem about the same diameter.. i will have to see.
as i will only be running 6psi (ish) and i have know clue about the throttle shaft mod i should hope i dont need to do that haha. :S

that turbo carb mod link i assume would be for people heading down the 15psi+ range. i may be wrong.
cheers again mate

[nicbeer]

What u pick up the amr300 for?

I may have to come have a look at it or if you are coming northwards and try it on the vit aircon bracket as i have read somewhere that they are suited.

nic

[smiley_smoke]

yeh i got it with the bracket (bit dodged to suit) from Beally off the forum.
with a GFB BOV and pipes etc 500

[ado250]

Hmmm, I'd tend to think that fuel pressure into an open space and air pressure are a different thing. Fuel pressure disipates as it fills into the bowl, air pressure doesn't. THis is in regard to crushing the float. You still need to fill the float against pressure.

When it comes to forcing air back through the jets, then you wouldn't want to risk that. Simply running a line from your charged intake tube to the fuel bowl with equalise the pressure between the float bowl and the throat, therefore no backflow.

You won't have to do the throttle shaft mod on the weber, it should be fine running 6psi. You will have to think about the choke assembly and losing air through that. You will also have to get yourself a high pressure fuel pump and a pressure sensing fuel regulator.

Ado

[Santos]

don't forget the whole thing when people say they are running 6psi they really mean 6psi on top of the 14.7psi at sea level. Which explains the high fuel pump pressure of efi.

[smiley_smoke]

lost me.. i will re read it and try make some sense.. i am new to all this so bare with me

[LTDHO]

I'm fitting one to mine.

I can't wait.

Estimate psi is 5 and I hope to make 80rwkw.

[abundance84]

Hmmm this is sounding a bit too complex for me, I might go to a turbo specialist place and pay a few my gorillas to get it done right rather than me blowing up my recond 1.6

[lay80n]

cheers for the links.. after much reading and thought
i have found that the standard fuel pump is around 7psi.
i will be running the amr300 at around 6psi. this make me think that the fuel bowl should not be subjected to any pressures out of proportion to the psi be blown through it..? close to being equal in pressure the fuel bowl should be sweet??
good idea on the pulleys. i may give it a try if the gti ones dont work out. they all seem about the same diameter.. i will have to see.
as i will only be running 6psi (ish) and i have know clue about the throttle shaft mod i should hope i dont need to do that haha. :S

that turbo carb mod link i assume would be for people heading down the 15psi+ range. i may be wrong.
cheers again mate

Wrong, the fuel pressure coming into the bowl is not what i am talking about. You mush have equal pressure in the bowl as in the inlet manifold, no the fuel inlet, the bowl pressure. The bowl must be sealed and pressureised from the inlet manifold, otherwise the fuel will get blown out the vent.


Layto....