Right, as I need to get a new motor for the car, I have sourced a reco for a TR. I'll have it fitted and operational in about 6-8 weeks (need to save the money/pay off a few things)

But, it's not a changeover, and I will therefore have my original motor. I was going to pull it apart, and rebuild it, to learn how to do so, and to prepare it for forced induction. I was planning to go down the Supercharged route, so what will need to be changed to ensure that it'll last longer than 15 seconds?

nfi... go turbo:)

from what i hear the astrons dont work that good with supercharges as they do with turbos but ull need to fully rebuild the whole lot and look in to strenghing the internals to make sure it could handle the boost

hmmm... sell both motors and buy a EVO engine?

Definately go a turbo, astrons are true turbo champions when prepared right.

Depending on the level of boost you want to run, anything over 7psi will require forged pistons, heavy duty piston rings, stronger conrods and a stronger crank / bottom end bearings.

I would also look at replacing the valves and camshaft with a cam specific for a turbo application. compression will need to be dropped to something more boost friendly like around 9:1 or perhaps lower?

Im no expert on this but this is what i do know if you want to run high boost reliably. Best of luck :D

Definately go a turbo, astrons are true turbo champions when prepared right.

Depending on the level of boost you want to run, anything over 7psi will require forged pistons, heavy duty piston rings, stronger conrods and a stronger crank / bottom end bearings.

I would also look at replacing the valves and camshaft with a cam specific for a turbo application. compression will need to be dropped to something more boost friendly like around 9:1 or perhaps lower?

Im no expert on this but this is what i do know if you want to run high boost reliably. Best of luck :D

The astron motors are strong enough internally for 10-12psi on stock parts (So Dave told me).

The astrons are pretty strong internally, that is true. If you run a low 5-6 psi boost you'd get away without doing anything internally. By this I mean reinforcing, I dont mean do NOTHING at all, you'll still have to replace rings etc etc.

Definately go a turbo, astrons are true turbo champions when prepared right.

Depending on the level of boost you want to run, anything over 7psi will require forged pistons, heavy duty piston rings, stronger conrods and a stronger crank / bottom end bearings.

I would also look at replacing the valves and camshaft with a cam specific for a turbo application. compression will need to be dropped to something more boost friendly like around 9:1 or perhaps lower?

Im no expert on this but this is what i do know if you want to run high boost reliably. Best of luck :D
First gen. Comp ratio's already 8.8 to 1.

I'm not planning for the firebreathing route, but I'm not sure how to plumb in a turbo, that's why I was going to supercharge it (I have a better idea on how to figure that out)

Why would a turbo work well but not a supercharger? They both operate on the same principal and can be made to supply the same range of boost, but just have a different way of powering the compressor. I think the TR may have a 9.0:1 compression...I know the TS does. It would be easy to lower the compression though by using a decompression plate, which is basically a thick head gasket, but I may be wrong.

A supercharger would give a lot more low end power but will dissipate at higher revs and as a general rule requires slightly more hp to run than a turbo. A turbo will require higher revs to kick in but at what revs this happens depends on the size and design. The Lancier was released with both a supercharger and a turbo on the one engine to get the best of both worlds.

I am no expert on forced induction, the above may or may not be pure poo.

It's not that an s/c wouldn't work, it's that a turbo on the astron motors is more suited to it.

Ahk cool. Is there any reason or theory why the turbo works better on the Astron II's or is it just a given fact of life?

the astron is a torquey engine as apposed to a powerful engine. (more torque than hp). therefore, y build up something that an engine already has? the astron HAS the low down pulling power already, just lacks up in the high rev range. so y use a supercharger?

put a turbo on it, it'll add alittle bit of torque to help with low down pulling power but also increase the mid to high end dramatically. thats wat u want.

the TR/TS EFI cars has CR's of 9.0:1. the carbys still had 8.8:1. the 1st gens ALL had 8.8:1 CR's.

EDIT: i have also heard that superchargers arent suited to the astron cause of the way the pullys are setup or something. the belts keep flying off the supercharger. something about not having enough torque to use the supercharger to its potential. not totally sure, but a turbo is MUCH MUCH more suited to the astron.

brendan

That sounds right, if the SC was set up correctly the belt shouldn't come off.

Not that Im thinking of going turbo but does anyone know of a Astron II turbo set-up guide, not step by step but just a list of all the parts needed, what needs to be fabricated, some part numbers etc. I think this would help a lot of people.

My TR 2.6 4cyl has a compression of 9.2:1, it is an EFI.
How much for a small turbo that would require nearly no other mods? i just want my car to keep up with say, a stock commodore?

Why would a turbo work well but not a supercharger? They both operate on the same principal and can be made to supply the same range of boost,

Your comments aren't poo, but I my opinion is that in order to find a s/c that can supply the same range of boost as a turbo think say, CAPA late model think RIP YOU A NEW ONE (Cost). As far as I am aware, s/c work up to around 12 psi which is just over half what you can ealisy run with a t/c. I have a car with a 1966 designed motor that runs 20psi with a t/c and it currently makes about 40kw @ the wheels more than what it would with a complimenting s/c.

I say, take a ride in a s/c and t/c car of the same make then make up your mind. You will be feeling that initial rush of power and torque with the s/c, only to realise that that is it ! No top end, plus the s/c uses hp to create power. But - little turb's have no top end too!

go the supercharger unless you want to be running like 15 or more psi go supercharger im currently in doing this myself i have a 2.6 that im supercharging only in the buy of partsstage at the moment but soon i will start to build it up

here is a list im working off this list is completly my own from my own research and im not saying that any of this is right

The List

BOTTOM END
Block
Astron 1

TOP END
Head
Astron 2
EFI of a TP magna
Ported
Polished

Pistons
Stock
hepilite pistons

Camshaft
Reground to mild/mid

Valve Springs
RPW springs

COOLING SYSTEM
Radiator
quad core radiator with twin thermal fans

Intercooler
Hybrid 280x300x76 3” inlet (maybe bigger)

Water/Ethanol Injection
D.I.Y kit

Engine management

Hawk EMS

INDUCTION
Supercharger
Toyota SC12 (pushing around 8psi)

Exhaust
Pacemakers 4-2-1 headers
Hi flow cat

umm yeah thats about all im goin to do maybe new rings aswell

Exhaust
Pacemakers 4-2-1 headers
Hi flow cat


I was under the impression that youd be better off without the extractors on a turbo/supercharger setup?

well you cant have headers on a turbo and when you goin for forced induction breathing is the aim of the game the more you push in the more thats gotta come out, the easyer it comes out the better it goes in

I was under the impression that youd be better off without the extractors on a turbo/supercharger setup?
If that were the case, why would Pacemaker have headers for the supercharged Commodore? Turbo plumbing means no 'extractors' as such. Supercharged car's can use and see gains with headers.

Weather NA or FA, getting air in and out as efficienttly as possible is the way you increase power (along with the right ammount of fuel :D )

Extractors & exhaust systems, cams, air filter, throtle bodies, port & polishing all these things are moddified to increase flow lol

, port & polishing

well from what i hear polishing isnt that good the example i was given was to think of a golf ball in the early days they use to use smooth balls they wouldnt go very far and were hard to aim well the new balls have all those little holles/dimples on them this aparently increases the airflow around the ball so putting this into practice in the head if you were to make it completely smooth it would flow as well as if it had dimples

i dont no if this is true or not just passing some info on

I think the dimples are there to create an air pocket to help suspend the ball in the air while in flight. If polishing wasn't useful, motorsport teams and companies wouldn't invest millions on extrude honing and stuff like that. Air is very responsive to flow changes. If air is following a surface and reaches a bend of 3 degrees or more, it's possible for turbulance to form behind the bend which will disrupt air flow.

I think the dimples are there to create an air pocket to help suspend the ball in the air while in flight. If polishing wasn't useful, motorsport teams and companies wouldn't invest millions on extrude honing and stuff like that. Air is very responsive to flow changes. If air is following a surface and reaches a bend of 3 degrees or more, it's possible for turbulance to form behind the bend which will disrupt air flow.

redav arguing polishing vesus cast or machine faced intake insides, is like arguing about backpressure in exhaust or arguing about religion.
imo u hit it on the head there that polishing is useful for motorsport, ultimate flow and ultimate top end hp. but for the street some swirl is better, fuel atomises and is suspended in air better at low velocity, and economy/drivability is better.

also the 2.6 is suited to turbo because it is a long stroke and thirsty engine. being thirsty there is more exhaust gases to spool up boost quickly. but if u are hell bent on s/c i would look to the little pully and belt that drives thw water pump seperately of everything else. rweplace the waterpump with a craig davie electric job and mount the s/c where the waterpump was. driving a s/c draws about 15hp so u will offset some of this loss by losing the load of the waterpump, about 3-5hp.

theres also the 2 types of s/c positive displacement eg Eaton or Rootes, or the Vortech type which is known as "belt driven turbo". Pos displacement is all bottom end grunt straight off idle but runs out of steam at higher revs. a vortech type performs more like a turbo and does not create and waste useless bottom end boost and poor economy when u r idling at the lights or in slow traffic. as the 2.6 already has great bottom end i would go for the vortech belt drive type, easier install and cheaper :cool: .

I think the dimples are there to create an air pocket to help suspend the ball in the air while in flight. If polishing wasn't useful, motorsport teams and companies wouldn't invest millions on extrude honing and stuff like that. Air is very responsive to flow changes. If air is following a surface and reaches a bend of 3 degrees or more, it's possible for turbulance to form behind the bend which will disrupt air flow.

redav arguing polishing vesus cast or machine faced intake insides, is like arguing about backpressure in exhaust or arguing about religion.
imo u hit it on the head there that polishing is useful for motorsport, ultimate flow and ultimate top end hp. but for the street some swirl is better, fuel atomises and is suspended in air better at low velocity, and economy/drivability is better.

also the 2.6 is suited to turbo because it is a long stroke and thirsty engine. being thirsty there is more exhaust gases to spool up boost quickly. but if u are hell bent on s/c i would look to the little pully and belt that drives the water pump seperately of everything else. replace the waterpump with a craig davie electric job and mount the s/c where the waterpump was. driving a s/c draws about 15hp so u will offset some of this loss by losing the load of the waterpump, about 3-5hp.

theres also the 2 types of s/c positive displacement eg Eaton or Rootes, or the Vortech type which is known as "belt driven turbo". Pos displacement is all bottom end grunt straight off idle but runs out of steam at higher revs. a vortech type performs more like a turbo and does not create and waste useless bottom end boost and poor economy when u r idling at the lights or in slow traffic. as the 2.6 already has great bottom end i would go for the vortech belt drive type, easier install and cheaper :cool: .

I heard you the first time :D

well from what i hear polishing isnt that good the example i was given was to think of a golf ball in the early days they use to use smooth balls they wouldnt go very far and were hard to aim well the new balls have all those little holles/dimples on them this aparently increases the airflow around the ball so putting this into practice in the head if you were to make it completely smooth it would flow as well as if it had dimples

i dont no if this is true or not just passing some info on

If you where to make those same dimples on the surface of the intake manifold, you whould effectivlly reduce it's size.

I’m bored so here’s my 2c…



Extractors & exhaust systems, cams, air filter, throttle bodies, port & polishing all these things are modified to increase flow

True, but on forced induction cars – budget I am talking about, you are spending useless cash on things that boost takes car of (Like forcing air in, not relying on atmospheric pressure to draw air in. )


If polishing wasn't useful, Motorsport teams and companies wouldn't invest millions on extrude honing and stuff like that. Air is very responsive to flow changes. If air is following a surface and reaches a bend of 3 degrees or more, it's possible for turbulence to form behind the bend which will disrupt air flow.

Adding to Altera98, Formula 1, Supercar type racing (eg) is beyond everything – these guys spend $10,000’s on reducing weight by 100g or chasing 1 hp. For the average guy, polishing is a waste of money. But port matching, porting and cleaning up ports and valve stem areas does make a difference (Depending on how inefficient your motor type is to begin with).


If you were to make those same dimples on the surface of the intake manifold, you would effectively reduce it's size.

Nah, it would be increased as the surface area would enlarge. * Begin X Files music* Like a 2 stroke engine case – the fins increase it’s surface area for heat dissipation… Sorry, now I am stirring :P

True, but on forced induction cars – budget I am talking about, you are spending useless cash on things that boost takes car of (Like forcing air in, not relying on atmospheric pressure to draw air in. )

True to a point, while peak power might not increase as much as the same mods on a NA engine, they will improve the torque/power delivery as the smoother flow paths will reduce turbulance and improve cylinder fill.



Nah, it would be increased as the surface area would enlarge. * Begin X Files music* Like a 2 stroke engine case – the fins increase it’s surface area for heat dissipation… Sorry, now I am stirring :P

Hhehehe, yeah overall volume would be slighttly bigger, but once the air starts flowing the pockets of air created by the dimples will act as an added layer on the inner surface of the intake system, effectivlly reducing it's internal size :D ...now I'm just stirring

golf ball example has nothing in comparison to engine intake. The dimples on a golf ball are to trip the boundary layer early, its all fluid dynamics.

also Nomis how much is this going to cost? i thought about s/c before but from what i heard it was easier to turbo.

My new car runs 10psi boost without much modification, only strengthened rings i THINK!

Anyone with a s/c 2.6L please put up a post on what youve done and how much, etc coz im interested. Still trying to decide whether the DOHC conversion or s/c would be better. And as i feel its the low rpm torque and power im lacking maybe the s/c would be better.
Which belt does the s/c run off on the 2.6 btw?