Austarion

coop1er wrote:But surely if you reduce the pressure in the exhaust manifold (which would
typically be higher than the boost pressure you are using), then airflow
through the engine must increase @ the same boost pressure.

Interestingly I got different backpressures but the same airflow (and power) with two very different turbo's TC06/TD06-17A and EVO3 big16G. This means something else is restricting it.
Which brings me back to the stock cam :D
I've done the measuments myself, looked at other peoples dyno data and the stock cam just hits a brick wall.

I agree there's no way the stock Head and Valve train will make over 200 or so rwhp, I've never said anything to the contrary . I was only talking about the cam in particular as there is a lot more to making power than just the cam , which of course can be improved on but I feel is only really worth looking at in a highly developed engine which would not be an accurate discription of most of the engines out there .

The standard pistons etc. have no trouble with such high revs PROVIDED the Valve train is in good nick ,clearances and timing are right and the Lambda is correct . However , high boost (over 16psi) will take it's toll , usually in the form of cracked ring lands .

But the motor I described did exist and it made that power ,I wish I was able to post a Dyno sheet as very few people seem willing to believe anything from QLD unless there is a "Dyno sheet" . Having said that , even if it was posted , some joker would no doubt say it was doctored or something . It's unfortunate because I thought a forum was for helping eachother out , not putting shit on people .

Mate I don't know where you are getting the idea that we don't believe things from QLD or that the forum people aim to put shit on each other.

We want dyno sheets so we can observe the power curve and so that there is actual proof. Its nothing against you, or QLD people in particular, but we have had our fair share of people on this forum who crap on and on about cars that make X amount of power with no proof to back it up. Hence why most people will ask for dyno sheets as proof.

That is all, I don't know where you are getting the idea that this only applies to QLD people though :|

Hmmm, I guess Im the only one that believes in over 210hp atw from a
stock cam/head combo. :? Thats ok though, I stil have faith.

What is the difference in exhaust backpressures between the tc/td06 and
evo turbos? I wouldnt have thought there would be a large difference.

I still think a wisely chosen turbo bolted to the stock cam/head, where
intake manifold pressure is greater than exhaust manifold pressure, can
break this 210hp barrier.

we will give you a fair trial, present the evidence. clerk where are the files LOL

OMG guys FFS, relax this is Australia btw :beer

Remember 'Nothing is impossible' if you want 250+HP from the Stock Cam/Head combo, then you can, simple as that

i mean.. shit, roger has a cordia that runs 14.4s anything is possible :P

Im pretty sure 210hp of the stock head and cams, my previous setup made 211.8 hp but then tappered off right at the end.

RiceThief wrote:Im pretty sure 210hp of the stock head and cams, my previous setup made 211.8 hp but then tappered off right at the end.

Well I'm only 1.8hp out with my 200-210hp limit :P
The tapering off is caused by the stock cam.

What durations are recommended? How do they affect the lower rpm range? Where does the peak torque shift to roughly?

I hear a lot about the DOHC cams, 264 272 and 280 etc, but can't really find any kind of guideline to the SOHC engines. I know I should just ask an engine builder, but its something I was curious about. Also the 8v inlets are quiet small, how far can you bore those bastards out?

This is totally the wrong thread for this question, but thought I'd ask since we're on the topic.

I can't promise anything because it was a couple of years ago ,I don't own the car in question and therefore the Dyno sheets , but I MAY be able to get my hands on them to post , but even if I can , it will unfortunately take maybe as much as a few weeks as , amongst other things , it's over 200 klm away but I will try my best .

Please note that I'm not going to go to the trouble just to satisfy someone who obviously just wants to stir , but I do appreciate that a lot of people have a genuine interest (that's the only reason I joined this forum) and not everyone is narrow minded and negative and some of the silent majority may be able to gain something from it .

So where were we with this piston deal? Who's the contact?

that would be me flav


*WOOO 100th post* haha

Ideally, what we want is the CP VR4 Forged Pistons without any recesses right ? Depending how they manufacture these, it may be even cheaper then the cost of them with the DOHC recesses.....you just have to check valve/piston clearances and make sure you replace your timing belt often....

What CR do people here want them at also ? remember the 50thou oversize will drop the CR a little also....

To maximise the quench area and hence detonation proness you would want the combustion process/area ultrasound tested, again expensive R&D but you would be able to run in the order of 10.5-11:1 Static CR with 20+psi of boost pressure on just 98 Ron with a reasonble timing curve :drool:

so can we get some numbers of who is interested and can afford the pistons ...