this is mainly for guys like jason, Cthulhu etc etc who have got some head work done.

just curious as to what kind of gain (kw/torque) u would expect from port and polished + ralliart cams on stock ECU ...

i know it wouldnt be massive but i did a search and Cthulhu noticed u got something liek 5 kws from a fairly big port and polish on stock ecu.

also i do realise its a bit of a hard question to answer as u dont know how aressive the porting job may be.

so lets assume its a moderate job + the ralliart cams with stock TH ecu what am i looking at?

im looking at it from the point of view that the ralliarts are rated at 180kws ... and my TH is 155kws... thats a 25 kw increse with just the cams, extractors and headwork however the ecu would have a mild tune..

ill have better exhaust system, better headwork, and ralliart cams though ecu untuned.. so would it be fair to say i could gain around 20-25 kws at the fly untuned , on the basis that everything the ralliart has to make it faster from an exec i would have bettered to a degree or atleast be on par with ..?

discussion is welcomed, though please dont post if u have absolutely no clue, tis a serious thread

Since when did a TH have 155kW stock? With the rest of that work it would be foolish to not get a piggyback or at the very least a dyno tuned timing alteration.

I don't think you will get much (if any) increase with the stock ECU.

Since when did a TH have 155kW stock? With the rest of that work it would be foolish to not get a piggyback or at the very least a dyno tuned timing alteration.

lol im gettng extractors, cams and headwork done in one hit gimme a break i dont have money bags

I wasnt having a go at you. Rather that it would be a shame to spend all that money and not get the true gains by not having the right tune. Just out of interest what will the headwork be worth?

lol yeah dont worry dude i know where u was coming from

are you going to up the compresion as well??

showing my ignorance here ... how do u raise compression? .. i thought headwork contributed to this ?

im no expert, but i think you can put hi comp pistons (like the ralliart) or shave the head maybe, so as to give a smaller area for conbustion, maybe shaving the head is under head work, as i said i dont know that that much about it all. just a basic understanding

To raise compression you skim the head and effectivly lessen the combustion chamber. If by Jason, you ment me, then I would suggest just getting the cams and skimming the head for compression.

Now days with high density, high detail sand moulding, the gains from a port and polish are just uneconomic. That being because the casting techneques now days are so much better than your old 308 and 202 days where people use to port and polish for fairly solid gains. The new multivalve, high compression alloy motors are pretty much spot on and on anything other than a huge dollar buildup any head work(material wise) is not worth the bang for buck.

If you were to get a new set of cams (get regrinds or billets not just a ralliart set) which are agressive, you will really notice a difference. NA motors make power by RPM, so you just need to do whatever is possible to keep air flowing and the power up. Agressive high lift long duration cams, extractors, high compression and your usual intake and exhaust mods will get you roughly 85% of the gains of a massive dollar build up, for half/quarter the price. You'll probably get 25kw at the fly with this setup

Then later down the track you could invest in a lighter flywheel and a bigger TB to add a nice little touch of motorbike sounding revving :)

My headwork was done by me, mainly because the head was off and going to be reconditioned anyway so im simply pressed out the valve guides and detagged everything and polished the exhaust side to a mirror. The intake side is still rough, by design.

i actualkly meant JASON VRX ... but thnx for the post !!! thats the exact kind of post im after ..food for thought

reason only getting ralliart cams is cos i can get them cheap and im not looking at spending big money on the car no more ( i swear im singing that song to much on this forums now lol)

though by lowering compression wouldnt that mean that i would then need a tune or i could do serious dammage to the car?

hate to burst your bubble but TH 3.5L were only 147kw :P.

thought sports were 155 ... either way really dont bother me, had my car dyno'd and was on par with the ralliarts that were there on same day so was happy with that ...


if anything i think it shows that more of a gain could be made from the mods listed when u consider what the ralliart has power wise (factory listed) and what mods it has when compared to the TH.. i mean theres a 30 kw at the fly difference with just these mods

Raising the compression is what your after, it increases torque power and peak RPM.

It is not a light mod, but the engine has is saftey factor built in, which you can sneak a little performance in but going around it. For instance compression can be raised from say 10:1 to 10.5:1 and your still in the saftey margin area but just not quite as safe you you need to listen for pinging when on regular petrol, or run PULP. Your combustion rate is also increased so the ignition timing should really be retarded a little, but will still be safe kept std.

As for cams, you could get a regrind for about 300 a stick, so 600 all up and it would end up being A LOT more powerful than just ralliart sticks thrown in, which still have to idle PERFECT for the general public, be wisper quiet, emissions etc etc.

yes but also with more agressive cams coms new lifters etc etc , cam pulleys ... adds to the cost as i said the magna is only a budget project now

turbo_charade, while your information might be useful for turbo charades' i don't think it has much relavence in relation to magna's. You can't get regrinds for magna's for $300 bucks a "stick", if you know where you can, please leave the details in your next post so we can organise a group buy.

PS. details don't include " on my old toyota you could"...., or .... " a mate said that he ..."etc.

Oh and to stonesour, i think you will find a 25 kw gain from headwork+pacies+cams is not out of the question, though it would definetly be worth waiting a month or two till you can afford an ecu, and bunging it all in at once .


later:cool:

lol im gettng extractors, cams and headwork done in one hit gimme a break i dont have money bags

Hahah thats what happened to me..:P

It started with just extractors and thinking about cams and now ive lost the plot..:P


I dont think you will get must of a change with just the stock ECU.. you will really need Piggyback or it will just not make a differance..:)



As for cams, you could get a regrind for about 300 a stick, so 600 all up and it would end up being A LOT more powerful than just ralliart sticks thrown in, which still have to idle PERFECT for the general public, be wisper quiet, emissions etc etc.

Yeah if you are gunna do the job even half right i would go down the path of a re grind.. Better off doing it right and getting new cams..

Yeah Ralliart are real mild cams but just depends what you are after..??

Here's the thread I posted my original gains from head work in: http://www.aussiemagna.com/forums/showthread.php?t=16719
Note that this was all still with the factory ECU, no piggy-back at the time.

After that I went for RPW Stage 1 cams, had the heads shaved, and tuned it all with a Haltech Interceptor. Doing that took my car from 121kW to 165kW at the wheels, aka a 44kW increase*. The RPW Stage 1 cams have more lift and longer duration than the Ralliart cams.

* on the same dyno in the same week with the same settings and atmospheric compensation for those that care.

yup this was the thread i was referring to ;)

obviously i wint expect that kind of gain ... but a noticeable gain would be nice until i am able to get a piggy back ..and more agressive cams out of the question i need to draw the line somewhere lol

thought sports were 155 ... either way really dont bother me, had my car dyno'd and was on par with the ralliarts that were there on same day so was happy with that ...
Forgot it was a TH sports, but according to carsales.com.au the 3.5L was 147kw accross the range, same with the TF sports having the same motor as the standard TF (and actually slower because it had more features LOL).
But just FYI.

turbo_charade, while your information might be useful for turbo charades' i don't think it has much relavence in relation to magna's. You can't get regrinds for magna's for $300 bucks a "stick", if you know where you can, please leave the details in your next post so we can organise a group buy.

Repco, Tighe, Crow can all offer suitable regrinds which can retain the standard lifters, or more aggressive grinds from billet which also do not require new lifters.

CB61 regrinds are 180 dollars, as there are only 6 lobes to grind lol but if you care to investigate, the general cost is setup, not per lobes. Brendans old red TM was a Crow regrind for $280 landed, so 300 isn't unreasonable at all mate.

I have recently picked up a set of 24v heads and had a good look at them. The usual detailing will work as the finish is usual production line. So 'port' means cleaning up in the valve pocket and 3 angle seats. There may not be that much in the port itself. It is fairly flat and limited to what you can do.
Piggyback is a waste of time as the ecu has been cracked and the reflash software is freeware, though the cable will cost.

I have recently picked up a set of 24v heads and had a good look at them. The usual detailing will work as the finish is usual production line. So 'port' means cleaning up in the valve pocket and 3 angle seats. There may not be that much in the port itself. It is fairly flat and limited to what you can do.
Piggyback is a waste of time as the ecu has been cracked and the reflash software is freeware, though the cable will cost.

but the question is.. does it work on the magna's.. has anyone tried it yet?

I have recently picked up a set of 24v heads and had a good look at them. The usual detailing will work as the finish is usual production line. So 'port' means cleaning up in the valve pocket and 3 angle seats. There may not be that much in the port itself. It is fairly flat and limited to what you can do.
Piggyback is a waste of time as the ecu has been cracked and the reflash software is freeware, though the cable will cost.


:noway: :noway: :noway: Really? Got any links?

:noway: :noway: :noway: Really? Got any links?
yes just posted them in another thread.

I have recently picked up a set of 24v heads and had a good look at them. The usual detailing will work as the finish is usual production line. So 'port' means cleaning up in the valve pocket and 3 angle seats. There may not be that much in the port itself. It is fairly flat and limited to what you can do.
Piggyback is a waste of time as the ecu has been cracked and the reflash software is freeware, though the cable will cost.

dont count ur chickens b4 they hatch,

its general knowledge that the TH ecu can be reflashed a memebr on here already has it done succesfully a number of times, even the mitsubishi engineers from my knowlegde cant reflash a TJ ecu only the TH ecu can be

not an expert on thsi but saomeone round here is ... *waits for his arrival

dont count ur chickens b4 they hatch,

its general knowledge that the TH ecu can be reflashed a memebr on here already has it done succesfully a number of times, even the mitsubishi engineers from my knowlegde cant reflash a TJ ecu only the TH ecu can be

not an expert on th's but someone round here is ... *waits for his arrival

You referring to me jamie? :lurk:

I think this is the third thread this year on the ECU reflash question? Maybe people should use the search function so we dont all have to repeat ourselves :D

You referring to me jamie? :lurk:

I think this is the third thread this year on the ECU reflash question? Maybe people should use the search function so we dont all have to repeat ourselves :D


Well I imagine that you know more than I, I have not tried it. I've only spoke to an OEM engineer who has reflashed a 2002 ECU who indicated it could be done.

turbo charade pls stop talking out your *** about TN and old magna's, if people could get cams for 3rd gen magna's in their cars for $300 , i'm sure everyone would be running them, saving $700, and telling everyone on the forums about it.

another wuick quesation would ralliart pistons be worth chucking in while getting head work ? .... or are they really no different ?

You could put them in to bring it up to 9.4:1 but the pistons arent really that expensive, just the work to get them in. ACL will sel you them. If you were going to bother go to 10:1. You will definitely need to run 98 and will need a tune.

what do the numbers actually refer to when describing compression ? ive always wondered

If the head is off, its easier to just deck the head. Are the ralliart motors higher compression anyway?

If the head is off, its easier to just deck the head. Are the ralliart motors higher compression anyway?
Yes. 9.4:1.

9.4 is fairly low compression now days. What is the standard motor if the ralliart is that low?

9.4 is fairly low compression now days. What is the standard motor if the ralliart is that low?
9.0:1. In the reviews I've read, they made the Ralliart 9.4:1 because they found it had the best gains without needing to go to a higher RON fuel.

Stock compression is 9.0:1

what do the numbers actually refer to when describing compression ? ive always wondered

Basically, say the piston on a downward stroke sucked in 10L of air (i know thats a huge motor but this is an example). So it sucks in 10L and then on the upward stroke compresses that 10L of air in to the combustion chamber which is 1L size. The compression ratio of that motor would be 10:1. The combustion chamber is all in the head, its the domed section with the valves. If you make that larger, then the combustion would be say 10:1.2 or to invert that to keep the 1 common, 8.3:1.

http://www.well.com/~mosk/Images/CombustionChamber.jpg

Thats an image of the combustion chamber of a motor, notice how all the gas would be compressed in to the head section of the motor when the piston is all the way up(top dead centre).

If you want more compression, the easiest way is to make the combustion chamber smaller, and machining 20 to 80 thou off the face of the head does this.

it can also stuff up the timing on an OHC engine unless you adjust appropriately. It was a common fix for old pushrod engines to get a slight rise in CR. A much better solution is new pistons, but that is more expense...as long as the skimming works. Both ways need attention to piston/valve clearances etc.
Looking at the 4v heads in the workshop I am sceptical that skimming will do much at all.