NA, supercharger, NOS, or turbo.... which one do you think is the best setup for the 4AC?

What do you guys think the best set up for the 4ac is???? NA, supercharged, NOS, Or turbocharged???

I haven't heard of any supercharged or seen in action of the turbo yet...

so I would go with NA/NOS but reliability is not good for this set up..at least that's my 2cents.

the only supercharged enigine i've seen closest to the 4ac was a 3ac back in Naha... i didn't really examine it but it was watercooled and some other radom thing i didn't know nothing about.. i heard of a few turbo ones, and a twin turbo one in california...

For convenience and cost efficiency, nitrous would be more suitable.
A wet kit would probably be more manageable though.
Instant power via W.O.T. switch, R.P.M., or as simple as a button.
(On a side note; NOS is the name of Holley's nitrous systems.)

If you have the money, a full proof turbo set up can be achieved.
This requires a lot of trial and error so, you see where the deep pockets will come into play.
A boosted carb'd 4ac has been done and proved to be a worthy set up running on 7 psi.
Although, from what I read and saw, the owner had limited resources, thus the set up could
have been improved much more.
Just imagine what results a well refined turbo 4ac will produce

Super charger...The money and effort would not be worth it, IMO.
Lots of custom fabrication is what I assume.

same thoughts on the supercharged here...

I know the turbo one your talking..

there have been more then one twincam turbo'd ...but 4ac's a rare.

theres pics of the turbo 4ac on the forums.. I personaly talked to his guy
and i seemed to get the vibe that he was a scammer...but no dyno sheet or
word of mouth on the turbo set up ( he had no one to say it worked but his own word)


But he was nice enough to tell me all the details of how he did the set up before
he droped off the planet ....

SORRY TO JACK YOUR THREAD

I'm working on the Turbo set up myself at the moment ,
having issuses with the custom headers.

and also trying to blow my 4ac to get started

oh, no trip... your noot jacking anything, i'm just getting opinions from it.. it's going to help other people with infomation anyways so it's all good.

i was thinking on a turbo system for my 4ac, but was shot down because my turbo i have was way too big for the engine in general.... than i was thinking about a efi conversion kinda like NP75's... but that was going to cost me alot more than the turbo system( i already had alot of parts for the turbo system in hand, and my sponser supplied me with discounts), and nitrous was a no no for me.. had instant power but not lasting power and abottle refill cost 30 to 45 dollars at a time, and having a chance to blow up too... superchargers, would have to be purely custom and the block style systems i don't even know if it could be used on the 4ac, but maybe a configural supercharger might work out... but i'm not fully sure myself.

so, i'm just going with itb's, co2 chamber, free flowing headers and exhaust system, built full motor, and a few knicks and knacks... and see how it all goes out..

"I" would just get a weber carb, cam, custom intake manifold, custom headers, full rebuild, bore it out a bit, mill the head, better ignition, ect ect...have fun with it

Actually, the turbo 4ac I mentioned was from Australia.
The owner drifted it in a TE72.
If I recall correctly, it drifted pretty darn good too.

ktee wrote:

Actually, the turbo 4ac I mentioned was from Australia.
The owner drifted it in a TE72.
If I recall correctly, it drifted pretty darn good too.

are you talking about the one that was mentioned in a magazine I think i have a picture of
some of part of the article.... a orange colored one ?

Yes, that is the car.
I wish I knew the exact specifications on his build.

I believe he didn't run an intercooler thus, why he only ran on 7 PSI.

i don't have his specs but i do have some info....

"small like ct26
mine is off of a Nissan ca18det.
a t25 will be a little big for it but it will work. it'll be laggy and you must be careful as to what boost you run. this motor love i mean LOVES to pop head gaskets.
Next, you have to build an up pipe from the headers( this will become your exhaust manifold). The stock pipe that goes from the passenger side of the car over to the driver side you need to cut and route so it flows around the steering shaft up to the area where you will mount the turbo.Keep in mind you will still need space to route your downpipe.! and i suggest finding a way to keep your clutch slave line from touching any of the downpipe once you have built that side of the system. next build a collector that will mate the flange you are using for your turbo, and the extension of the up pipe. Remember your measurements. this is where you mock up the final location of the turbo. be it high low whatever. BE VERY PRECISE.
Next, build the downpipe. This is Tricky, since you have to build it in an s shape and route it to flow back to the same path that the up pipe is routed. get a little tight so clearances and presicion is key here as well. I made the downpipe till the front flange of the cat. then replaced the cat with a test pipe that was constructed as well. next.. intercooler, i have no clue where this one came from but it worked. we made some small brackets and mounted it to the front of the lower rad support. in my pics you can see the mounting location. from the charge pipe it gets routed through that triangle passage in the front right side ( standing in front of the car looking at engine bay) there is a metal cover you need to push down.
the cool side of the piping ( from the intercooler) goes through the other triangle on the left side. NEXT, you need to get a weber carb, and a few sets of jets( will use later) from that point you mount the weber and build a box to cover the inlet of the carb so you can put some boost in it. pics on my site. next, you connect the box with the cool side of the piping. furthermore, make sure you have no boost leaks. so make sure you make mounting bolts with rubber grommets that are air tight up to 5-7 psi. get a set of supercharger plugs ngk. .slap those in.
umm you need an FPR. get a holley or whatever electric fuel pump. you get rid of the fp in the 4ac and make a block off plate for it.,get a fuel filter and you gotta make a bracket for it. these things go under the car in the back near the gas tank. i have all the mounts and everything built..
By this point you should have decided to continue or to just buy my kit and save yourself an assload of hassle.
lets keep going. do the fuel pump lines, get a switch and wire in a relay for the fuel pump. next get a new dizzy cap, some header wrap and some epoxy high temp adhesive. when you have the downpipe finished you'll know where you need to put that, I'd header wrap the downpipe but that's just me. depends on the steel you used for the dp. I'd also build a heatshield for the brake master and all that. next. hm...
pull the valve cover and tighten the headbolts an additional 10lbs of tq. now see if you can start the motor but keep your charge pipe disconnected from the motor. If you boost you will blow your motor..
Go to the dyno,
this is where those jets come in. your gonna need to start to swap in in jets to tune your carb to whatever atmosphere your at up there. connect that charge pipe back up and start tuning,
keep the stock timing and you should be good.
Other than that.. if you want to just keep it N/A.. then get your crank shaft knife edged.. that's a start.. plus some custom light-weight pistons and rods.. etc etc.. The stock 4AC pistons are cast aluminum units. The basic size specs:

Diameter – 81mm

Wrist Pin – 18mm

Compression Height – 30.5mm

Compression height is the distance from the center of the wrist pin bore to the top of the piston. The piston is dished, meaning that there is cavity in the top of piston. This cavity is approximately 10cc in volume.

Stock Piston weights:

Piston with no rings – 270.8grams

Piston with rings – 295.7 grams

Wrist pin – 88.3 grams

These pictures show a used stock piston next to a new Sealed Power aftermarket stock replacement piston.







There are several small differences in the pistons. The major thing that I see is the drain holes for the oil control ring. The skirts are not connected to the rest of the piston except next to the pin bosses on the Toyota piston. It looks quite scary to me. Sealed Power did not do this, they have three small holes for the oil to drain. It looks more reasonable to do this than the slice Toyota did. Sealed Power also added an oiling groove in the pin bore which Toyota did not have. Toyota had a hole drilled through the pin boss that Sealed Power does not have. The biggest issue with the Sealed Power part is that the compression height of the piston was reduced to 30.2mm which is about 0.012” less than the standard part. They assume that you have re-machined the top of the block and perhaps the head as well, so they make the change to keep the compression ratio from increasing, and to maintain the piston to head clearance. If the block and head are not machined, your compression ratio will decrease. I imagine that this is a standard thing that all the aftermarket stock replacement pistons will have. The Toyota pistons may not be like this, buy they cost more than going to a performance piston place and having stronger and possibly lighter custom pistons made to what ever spec you want.

Think of it this way.. a 150hp.. if that's at the wheels.. is pretty damn good for a little car like yours. The 4AC engine has a single over head camshaft that operates on lift amplifying rocker arms that translate the cam motion to the valves."


and this other imformation...

"A turbo is 2 turbines connected by a shaft, on in the exhaust stream, the other in the intake. Exhaust gasses going through the exhaust turbine cause it to spin, because both turbines are connected the intake side spins too forcing air into the intake. A header brings multiple pipes together into one pipe.

SUPERCHARGING VS TURBOCHARGING
Is having a supercharger work all the time really a good thing?
Superchargers take power from the crank to turn them, which would otherwise be sent to the wheels.
Turbos use the energy of the exhaust gas to turn them, which would otherwise be sent out the tail pipe and not used.
Each has their own advantages and disadvantages. For moving larger volumes of air superchargers are better. The bigger a turbo is the longer it takes to spool up, superchargers don't have that problem.
A supercharger requires more boost to make the same amount of power as a turbo though because turbos don't drain power from the engine to turn.

AUTO VS MANUAL
It's actually better to have an auto box behind a turbo motor. Aside from the issues of the trans being able to withstand the torque the motor is putting out, the auto trans keeps the motor under load when it shifts, which keeps the turbo spooled up between shifts.
The turbo won't be spooled up at normal freeway driving. Exhaust gas volume and velocity are what spools up the turbo. Unless you drive down the freeway with the pedal to the floor the engine isn't going to have enough load on it to bring to turbo up to anywhere near full boost. As long as the turbo is properly sized to your motor then it will only take a fraction of a second to spool up anyway."

i hope all this infomation helps you guys...

I am not sure why you reposted my piston writeup, it's in the reference section.

Quote :

SUPERCHARGING VS TURBOCHARGING

Turbo's do still take power off the engine, as you have increased exhaust backpressure before the turbo. They are more efficient than a supercharger though.

Quote :

AUTO VS MANUAL

Automatics are not somehow better suited to turbo use, and I dont know how anyone can claim that they are somehow stronger than manual transmissions. One specific automatic transmission might be stronger than one specific manual transmission, but then I could come up with another manual transmission that is stronger than either. The importtant thing to keep in mind is that automatics are generally rather inefficient compared to manual tranmissions. You almost always loose more power through an automatic than a manual trans. IE a manual trans car might have a 20% loss through the powertrain, the same car with an automatic might have 30% powerloss.

hold up, hold up, hold up....

automatics hold more of a constant boost with a turbocharger.... when a stickshift lags with the boost pressure during shifting... which in turn, makes a automatic better suited for a turbo rather than stickshift, even though stickshifts could handle more of a load than automatic trans...... so it's a yes and no answer for both...

and the turbo and supercharger thing.. you got to read that part again, because it never said that turbo do not take power off the engine and it all depends on what your using the forced induction "supercharger or turbo" for efficiently...

don't try to kill the messenger, all that infomation before was from a website regarding turbo and supercharging for a engine.

First off, I was pretty sure that you were posting other peoples info. Don't think that I am singling you out. Any one that posts info that I think is incorrect or misleading will get this kind of a response. And I don't think that it was a harsh response either.

Now onto your responses:

Quote :

automatics hold more of a constant boost with a turbocharger.... when a stickshift lags with the boost pressure during shifting... which in turn, makes a automatic better suited for a turbo rather than stickshift

The only thing that I can think of here is that you don't lift off the throttle to shift with an automatic. When the throttle slams shut, it slows the turbo down. But guess what? You can do a shift with out lift kit on a manual trans and not let off the throttle when you shift. And this is only for fraction of a second anyway, if you have an automatic you have to put up with less power for the entire you time you are in gear. So what ever gains (if you actually have any) you get right after the shift will be cancelled out by the general inefficiencies of the automatic.

Quote :

even though stickshifts could handle more of a load than automatic trans......

I am not saying this either. I don't see how anyone can say that either manual trans or automatics are somehow fundamently stronger than the other.

Quote :

and the turbo and supercharger thing.. you got to read that part again, because it never said that turbo do not take power off the engine

Heres what it did say:

Quote :

Superchargers take power from the crank to turn them, which would otherwise be sent to the wheels.
Turbos use the energy of the exhaust gas to turn them, which would otherwise be sent out the tail pipe and not used.

I agree that it did not come out and say it, but the implication with "which would otherwise be sent out the tail pipe and not used" is that only wasted energy is used. Regardless of what the author meant, it could be interpreted to mean that only wasted energy was being used, which is not true. So if nothing else I am clarifying then.

Quote :

and it all depends on what your using the forced induction "supercharger or turbo" for efficiently...

Not sure what this part is supposed to mean. When I said that the turbo was more efficient, I was agreeing with the general gist of that Supercharger vs Turbo bit, so you probably don't need to argue with me there.

I didn't read all this day-dream stuff, but here's my take: manual is better than auto. I am used to driving turbo cars, so I don't completely let off throttle when shifting anyways.

Supercharger won't happen for under a couple grand, unless you can modify a 4AGZE SC12 to work.
Procharger is do-able, but gains would be limited.
Turbochargers have been done and there's a complete kit for sale on Club 4AG for $700 shipped.
NOS works on everything, but I wouldn't run more than a 50 shot and not hit it very often.
NA is always best for reliability's sake. If God wanted this car to be turbo, it would have come from Japan already boosted.

Honesly kid, build the shiz out of a 7-rib block. Then wait for one of the 3 HKS twin carb manifolds to come up for sale. I saw one availible from a cat in Hawaii for $300. Grab a pair of Weber DCOE 40's. Get your cam reground and new springs from Schneider. That's really the extent of a reliable 4AC build.

honestly, has anybody ever drove a aftermarket turbocharged car with a automatic trans? if not, well go find one and see the diff... i'm not trying to bicker, so please don't quote me.


actually.... right now everybody is right and wrong at the same time. and it's a great thing that this thread is getting input, but serious guys, we were complaining to each other transmissions on a completely diff thread topic??? bump the rest on something else, and keep this one simple... no quote please..


and i kinda forgot i'm the youngest over here "the kid thing...", and the NA build would work but the only reason i'm swaying from the build is because i'm kinda am doing something similar to that but not exactly like that... and coming across one of those HKS manifolds would that me longer than expected. but i'm personally going NA anyway because the turbo i got is just too damm big for the 4ac " and that those dreams already got shot down by somebody, no qoute".. but thankyou Eric for the advice


lets all be happy and keep the topic straight, all you old guys... "just kidding with the old guy part, or am i "

ktee wrote:

Yes, that is the car.
I wish I knew the exact specifications on his build.

I believe he didn't run an intercooler thus, why he only ran on 7 PSI.

HE ran a stock motor with just the suck thru style turbo... I read the article a while
ago but I still can recall most of the info..

do you know how much power he was pushing out?

inagawa wrote:

do you know how much power he was pushing out?

I'll let you know tonite I gotta find the article and see if it says it in there.

not0riouskid wrote:

inagawa wrote:

do you know how much power he was pushing out?

I'll let you know tonite I gotta find the article and see if it says it in there.

read the article again and no metion of how much he made but says
"more then enough to let twincams know of a sleeper"

not0riouskid wrote:

not0riouskid wrote:

inagawa wrote:

do you know how much power he was pushing out?

I'll let you know tonite I gotta find the article and see if it says it in there.

read the article again and no metion of how much he made but says
"more then enough to let twincams know of a sleeper"

lol
60whp to 145whp
so

at least 100hp from a turbo to beat twincams

about 10psi max with no stronger internals?

could be possible
but probably with a frankenstein 4ac

I'm quite satisfied with a N/A build like what Eric said earlier 4AC with Webers give great throttle response, and overall engine responsiveness. Sure, boosting (Turbo, supercharger) may yield more power but you sacrafice reliability, in addition to more mechcanical complexity, N/A is simpler to work with.

Btw, theres a turbo kit for sale on club 4ag.

http://forums.club4ag.com/zerothread?id=63253

The guy claims that the turbo will put out 130whp on stock internals..with 7psi. I do have my doubts.

from a small turbo like that? correct me if i'm wrong but i personally think that in wasn't going past 130 hp... i was looking at the pictures and it just all look dull to me "sorry that was the only word that i could think of".... unless he was running mild internals.... tuned right with just a camshaft, double valve springs, and a weber adds 40 hp " at least that's what paradise racing said it makes", with the engine at 50 hp in total na"d it would make 90 hp..... and that's not the case most of the time either, but maybe he was pulling that much from the turbo... who knows. all i know is that i'd be proud to tell people that i'm running that much power from a unloved small engine... but that's me...