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Posted: Wed Apr 06, 2005 12:08 pm
by GPXXX
here's some just off the top of my head:
stroker kit
extractors
ignition advance
revised camshafts
tuned inlet runners (which IMO is unnecessary in your case, unless you can find someone competent who can make further improvements to the existing factory setup)
exhaust backpressure
Posted: Wed Apr 06, 2005 12:13 pm
by spetz
I already have all those on the list with a oversize throttle body
Stroker kit though is not really an option besides maybe the 2.5L conversion.
As far as cams go though, I am not sure as I just got a pm from RPW saying for cost V gain they aren't worth it for a street car

Posted: Wed Apr 06, 2005 12:33 pm
by GPXXX
if you intend to stick with the 2l, then you could opt for higher comp pistons (with stronger & lighter rods to suit).
Apparently there are DC2 and DC5s racing in the Super Taikyu endurance series in Japan running on 13 - 14:1 compression, and some of these cars are capable of keeping up with the Silvia and Evo lap times... (the one built by Spoon is capable of running low 13s according to a mate of mine from Japan)
having said that however, if you are going to crack the engine open to replace the pistons & rods on the 6A12, you might as well have a go at the hybrid 6A13 MIVEC setup for a 500cc increase... that's worth quite a bit of newtons there! :shock: (and to save yourself some money & hassles don't bother piss n' farting around with the 6A12 if you ARE intending to do this later)
Posted: Wed Apr 06, 2005 12:49 pm
by Black_FTOGPX
spetz wrote: But how do you recommend I increase torque but staying n/a?
You could increase the displacement of the engine, which would deffinetly give you an increase intorque.
I have heard that there is a company in the UK at the moment which is deveoping a stoker kit which will take the 6A12 to 2.6 litre. ( I dont know how true that is though.)
Posted: Wed Apr 06, 2005 12:54 pm
by dannyboyau
to increase the torque, a square stroke bore ratio is best
eg 81mm x 81mm
Posted: Wed Apr 06, 2005 12:57 pm
by FTO338
spetz wrote:No problems FTO338

If you wait a little bit longer I'll have some more work done to it.
The image is .tif
It says "Microsoft Office Document Imaging File" in the properties
Hmmm I don't remember it support .tif as a hotlink, so maybe you should convert it to jpg.
Posted: Wed Apr 06, 2005 6:44 pm
by EURO
just a question...
Obviously a turbo upgrade would give you a LOT more power... but in general would increasing your power through engine mods or having a bigger engine be a better idea for a FWD car like an FTO rather then turboing (to avoid torque steer?)
I'm not sure if that makes sense, but with a turbo that generally gives you a sudden kick, would that exagerate the torque steer more then a more liner power curve that might be generated through a bigger engine, or the other mods listed...
Something like the ALFA GT which has 300nm of torque, 176 KW and is front wheel drive - would this have problems with torque steer at that power? or if more power was given to it with mods?
Posted: Wed Apr 06, 2005 7:00 pm
by FTO338
Its all depends on the torque bandwidth, another word, how well did the guy tune your setup.
Alfa still have torque steer problem but not as bad as Volvo though

Posted: Wed Apr 06, 2005 11:13 pm
by spetz
Posted: Thu Apr 07, 2005 1:39 pm
by smorison
bumping up compression is going to cost a lot of money... i've looked into it briefly and spoken with MMC Japan regarding this, they said that it could be done to about 11:1 however the life of the engine comes into serious question.
breathing mods have a bad habit of dropping low down torque so you do need to be careful what you do and how it is designed...
CAM's are a good option but it's going to take a while before i'm prepared to spend the money to do them, so you just have to be patient...
at the end of the day MMC developed and tuned a brilliant engine, there isn't a huge amount that can be done to it cheaply once you've done the standard bolt on equipment... remember this engine is now over 11 years old and still out performs new engines.
Posted: Thu Apr 07, 2005 1:44 pm
by Black_FTOGPX
You can increase the compression a small amount by skimming the heads.
It wont be a huge jump though, probably only make it 10:2 or something
Edit
Forgot to mention that his is very cheap to do as well
Posted: Thu Apr 07, 2005 2:53 pm
by smorison
10.2:1?
Posted: Thu Apr 07, 2005 3:08 pm
by G_A_V
heheh 10:2 = 5:1 half the standard compression
anyways there was thread a while back where dannyboy informed us of the formular of gains to raising the comrpession, and it wasnt much at all
Posted: Thu Apr 07, 2005 3:12 pm
by Black_FTOGPX
smorison wrote:10.2:1?
I'm not sure on the exact compression.
A guy in the UK forum(Patt) skimmed his heads and was happy with the result.
Might want to speak to him for better details
Posted: Thu Apr 07, 2005 3:15 pm
by G_A_V
EURO wrote:just a question...
Obviously a turbo upgrade would give you a LOT more power... but in general would increasing your power through engine mods or having a bigger engine be a better idea for a FWD car like an FTO rather then turboing (to avoid torque steer?)
I'm not sure if that makes sense, but with a turbo that generally gives you a sudden kick, would that exagerate the torque steer more then a more liner power curve that might be generated through a bigger engine, or the other mods listed...
Something like the ALFA GT which has 300nm of torque, 176 KW and is front wheel drive - would this have problems with torque steer at that power? or if more power was given to it with mods?
A bigger engine means more torque down low, which means even more torque steering, the best way to avoid torque steering is to have the power increased smoothly across the rev range which is what mitsu have done for us.
With a larger capacity not only are you going to have lots of torque down low giving you lots of torque steering down low, but also the longer stroke will mean lower redline, giving again a less smother delivery of power.
with the alfa im sure it prob has an lsd, which decreases torque steering to a certain extent, also i guess the car was developed with those power figures in mind, so other modifcations would of been made to the gearbox, drivetrain, and even the steering.
Posted: Mon Apr 11, 2005 1:39 pm
by spetz
Why would 11:1 CR have serious effects on engine life?
So long as it's tuned well on 98 fuel I think it should be ok?
What sort of gains would his give? And I assume it's throughout the whole revrange isn't it?
Posted: Mon Apr 11, 2005 2:22 pm
by G_A_V
spetz wrote:Why would 11:1 CR have serious effects on engine life?
So long as it's tuned well on 98 fuel I think it should be ok?
What sort of gains would his give? And I assume it's throughout the whole revrange isn't it?
Well seals and gaskets would be the first to look out for, and then even heads and conrods i guess, though there area few cars that run stock 11:1, they were designed with stronger internals to cope with that compression.
I am not sure how dangerous 11:1 CR would be, but not only would you need to consider tunning to 98ron fuel, but what if you get a bad batch of fuel, or you suck in a whole lot of hot polluted air in the city, while revving at 8k. You cant tune for these rare events.
So just say you upgraded your internals, and tunned it, you are looking at a big bill (i would say around 8-10k) what sort of power gains would you see? thats anyones guess
Posted: Mon Apr 11, 2005 3:06 pm
by Black_FTOGPX
I have been told during the development of the 6A12 Mive, MMC tested it with a compression of 10:5 and experienced knock during high speeds.
Keep in mind that was using 100 octane fuel.
But on the other hand (I think) the 4cyl Mivec runs a compression of 11:0
Lots of people in NZ are running them on 98 octane fuel, and apparently dont have much trouble with knock.
Posted: Mon Apr 11, 2005 4:40 pm
by GPXXX
Why would 11:1 CR have serious effects on engine life?
higher compression results in stronger bang (more power) but stronger bang also means higher combustion temps (more heat), stronger bang means more physical strain being forced onto the pistons & rods... higher CR also make it more susceptible to detonation - i have seen the effects of detonation even on forged pistons first hand and I tell you it's not pretty...
So long as it's tuned well on 98 fuel I think it should be ok?
Tuning for a specific fuel octane rating is not the only answer to address reliability... once you push the limits of the hardware beyond its intended boundaries, something else will give way, somehow. It's like WRXs - it eats clutches and when you upgrade the clutch, it kills the gearbox - when you upgrade the gearbox you start breaking driveshafts and if you upgrade that too, the diffs blow so on and so forth - it never ends!
and besides, how would you know what it's like to have an engine 'tuned well on 98RON fuel'? unless you are an experienced/accredited tuner yourself, you'll never know what those timing / duty cycle figures mean and how it affects your setup - you're literally taking the tuner's words for it. If you have faith and trust in them, great - but when things go wrong (and chances are they will sooner or later) you're gonna start pointing fingers, esp once you've put in so much money into the project...
Just look at FNTSY's case - he mentioned that his FTO had been tuned to run rich with 180kw at the wheels (stock internals)... took the car to the drags not long after and then look what happened - turns out that the ignition was way too advanced. so much for 180kw...

Posted: Mon Apr 11, 2005 4:51 pm
by GPXXX
btw i think the std 6A12 ECU comes with a knock sensor and automatically retards the timing by a few degrees - that is why it is still OK to run the car even on 95RON Premium Unleaded - i don't know what is the maximum timing it can retard but i don't imagine it will be a lot... you can imagine how many degrees of timing had been taken out from factory settings with my new ECU since the turbo was installed!