Forging Pistons and Billet Camshafts

FtoSam · Post by **FtoSam** » Thu Feb 01, 2007 1:19 pm

Okay Im looking at getting Forged Pistons and perhaps Billet Camshafts from RPW. Total would be a bit under $5000.
Obviously Pistons will lower my compression to 8:1 and allow me to run higher boost as well as be a lot more reliable.

What does Camshafts do? Im wanting to get some heavy power out of this engine eventually and im just worried about blowing it up.
Also someone mentioned that MIVEC Conrods Snap at around 10psi.. is that true?? I basically want my car to be running around 16-18psi and around 250kw atw next year..
To do this i am looking to spend around another $5000 or so (on top of the already finished turbo engine)
Would an engine recondition be helpfull? the engine has around 95,000kms on it and had its 100,000km service at 80,000kms.
also spent $1500 getting all the rubbers?? replaced

Post by **Bennoz** » Thu Feb 01, 2007 3:00 pm

There is no point putting forged pistons in unless you have forged rods. There is no point buying billet camshafts unless you have a grind you can put on them. The word 'billet' does not equate to strong, billet means there is no cam grind profile on the cam - ie a blank shaft.

There is no-one on the planet who has manged to come up with a grind on Mitsubishi 6A12 cams that has proved any good as opposed to the factory.

Best bet on making mivec go hard with boost - harden up the internals (forged pistons & rods, knife edge the crank, lighten the flywheel, have it all balanced up & blueprinted) lower the compression - then pump in the boost.

kid_dynamite · Post by **kid_dynamite** » Thu Feb 01, 2007 3:37 pm

How's your suspension setup Sam? For 250kw you would need something v.good (eg full Whiteline kit or equivalent) otherwise you'll find that the FTO will be tramping everywhere.

And without having rebuilt an FTO, I would respectfully disagree with dropping the CR to that extent. Going from 10:1 to 8:1 is a massive decrease. You will lose response, and have to run more boost into the car to make power. A mate has done that with his R33 (went from 9.5:1 to around 8:1) and is down about 30kw compare to a stock motor with same parts. He is regretting it now. It just doesn't make sense.

Maybe 10 years ago dropping the CR that much would have been a viable option. But these days forged pistons etc are of excellent material and quality, there is simply no need to do that. Perhaps a minor drop in compression, and a slightly thicker headgasket would suffice in my opinion.

Engine refresh is a definite though. Old rules do not apply as you are turbocharging an engine which wasn't designed for it. Pistons and rods like Ben said. Head studs are a must, as is resleeving the block - necessary for high boost.

FtoSam · Post by **FtoSam** » Thu Feb 01, 2007 4:02 pm

Well i just assumed as the forged pistons on RPWs site says they drop the compression to 8:1...

So to help me get used to all this stuff im going to put it like this..

- Forged Pistons - $2500 - Stronger and enables more boost
- Forged Conrods - $??? - Same as above?
- Knife Edge the Crank - $??? - What the?
- Lighten The Flywheel - $500??? - Obviously makes the flywheel a lot lighter. I think improves torque transfer????
- Blueprint the block - $??? - No idea. Guessing something to do with block schematics?
- Head Studs - $???? - ?????
- Resleeving The Block - $??? - ????

KD - as far as suspension I am looking at Getting a set of TEIN fully adjustables with an electronic controller in the cabin at the end of the year.
At the same time i will be doing everything else suspension wise as well.

Most of this stuff sounds like it would be smart to get done all at once..
If i got everything done that you have suggested, what boost / Power should i expect?

khunjeng · Post by **khunjeng** » Thu Feb 01, 2007 4:09 pm

man ...

after all of this u might as well just put in a new engine!

kid_dynamite · Post by **kid_dynamite** » Thu Feb 01, 2007 4:12 pm

Samson wrote: KD - as far as suspension I am looking at Getting a set of TEIN fully adjustables with an electronic controller in the cabin at the end of the year.
At the same time i will be doing everything else suspension wise as well.

Most of this stuff sounds like it would be smart to get done all at once..
If i got everything done that you have suggested, what boost / Power should i expect?

Teins - make sure they are the Aussie spec Teins (Fulcrum is the Australian Distributor). Beyond that I would think about swaybars, castor adjustment, and bushes.

An engine rebuild won't give you more power, but it will ensure that the motor can withstand the boost you push through it. I can't remember the exact specs of your GT28 (A/R?), but I think 250kw would be about the limits, provided you've sorted everything else out.

Post by **Bennoz** » Thu Feb 01, 2007 4:24 pm

khunjeng wrote:man ...

after all of this u might as well just put in a new engine!

Not such a silly idea KJ...

Sammy, why not find a 2nd hand GPX motor & go postal on that... then its just a matter of swapping them out when you got the spare bullet proofed. Turbo kit will bolt right up to another motor.

FtoSam · Post by **FtoSam** » Thu Feb 01, 2007 4:41 pm

Hrmmm... Thats an idea... But would have to find a cheapo one.. Last GPX engine i bought was $2200... Which is the same as forgies. Plus i dont have a garage or anything to keep excess crap in.
Btw: only suspension is KingSpring SuperLows at the moment. Not much.

Would all this crap be overkill for a 230 Kw or so? over 230 is my magic figure.

Post by **Bennoz** » Thu Feb 01, 2007 4:45 pm

Nah, I've seen on 'em Ebay for around 6-800.

I picked up a non mivec for 186 bucks!

FtoSam · Post by **FtoSam** » Thu Feb 01, 2007 4:49 pm

Hrmm... but i still have no where to put it.
Oh and could give a guestimate to my prices on the list up a bit>?

khunjeng · Post by **khunjeng** » Thu Feb 01, 2007 11:41 pm

Samson wrote:Hrmm... but i still have no where to put it.
Oh and could give a guestimate to my prices on the list up a bit>?

its all in the 000s mate not cheap no matter which way u look at it.

Thats just for the parts...assuming u need some1 to install them...

Perosnally I dont see the point for some1 who origioanally said they only wanna run like 5psi...now we are talking big numbers.

Everything is gonna start to die mate...your going down a path which may not turn out good.

Get some ok power gains...be happy. Unless u have deep pockets or its a 2nd car for a hobby...dont bother it will be off the road more than on it.

Can your turbo take 16+psi? fuel pump upgrade etc the list will go on and on.

Then u will realise its only FWD....setup for average power...make it handle and dont try and make it a dyno king

FtoSam · Post by **FtoSam** » Fri Feb 02, 2007 10:01 am

Yes yes yes... i know im getting carried away... but i work. and i earn money.... i have nothing better to spend it on.. might just get it sprayed and kitted. Lambo doors might also be an interesting addition.. But i still want to push out the 200kw mark... by sometime next year anyway.

Nacho · Post by **Nacho** » Tue Feb 06, 2007 7:41 am

You might even better off buying that cheap GR engine in the parts for sale section and building it from the ground up. Don't know how much an engine stand will cost but they're not expensive from memory.

I would recommend looking around for pistons and conrods coz RPW prices are just overkill. You just have to get similar sized pistons to the one you have now and for a set of good conrods and pistons should only cost around the $2500-$3000 mark. Then that will leave you more $$$ to change the sump to control better oil temp, upgrade valves/valve springs and the pulleys as well.

And since you have the spare engine sitting there, your car will still be on the road.

barfy · Post by **barfy** » Tue Feb 06, 2007 12:58 pm

Dude if you want over 230 at the wheels mark and with the money your putting into it you could have sold your car bought a evo plus mods and got that sort of figure at all 4 wheels.

That sort of power at the front wheels will torque steer like a bitch and you wont enjoy it. Keep it simple stay at 5 psi so its a reliable daily driver...

Nacho · Post by **Nacho** » Wed Feb 07, 2007 7:37 am

Maybe that much power is only for dyno days?

nosman · Post by **nosman** » Wed Feb 07, 2007 9:19 am

I say we let Sam be unique..... once his project will be finished i think it will be awsome. But an Evo could have been bought kekeke.

FtoSam · Post by **FtoSam** » Thu Feb 08, 2007 10:43 am

Alright... I have been doing some thinking.
Yes.... it hurt.

I've decided to get the best out of this engine i can without going to extreames (or buying parts over $1000) if i can help it.
Instead Im putting the money i would have spent into looks. New bodykit and paint job. A bit of show for the go.
Thats not to say that when thats done i wont be looking into bigger power but for now its been put on the backburner.

RedlineGX · Post by **RedlineGX** » Thu Feb 08, 2007 3:29 pm

My advice would be to get a water injection kit, thicker head gasket and run about 9 psi. The extra cooling and sligtly lower compression will allow it. Or leave compression and run 7 with the WI.

You will be surprised how much of a difference the 2psi is.

Vaeth · Post by **Vaeth** » Wed Feb 14, 2007 12:26 pm

It has always been my understanding (perhaps wrong) that forged conrods are only a necessity if you are going for high RPM applications.

Going forged pistons alone should still provide the following benefits:

1) Lighter, hence reducing stress on internals and allowing for a slight increase in max RPM.

2) Stronger, making it more detonation proof. Though, the engine should not be detonating anyway.

3) Conducts heat better both in terms of material and oil paths, hence being less prone to heat soak and reducing combustion chamber heat buildup.

4) Generally better designed and manufactured, meaning that there are less sharp edges and casting imperfections, which subsequently mean that there will be no "hot spots" or other detonation contributing factors. (or at least less).

Lowering compression, as mentioned above, will reduce responsiveness...although I think an increase in displacement will negate this somewhat. Maybe the 8:1 compression pistons you were looking at required a bit of overboring => increase displacement.

dannyboyau · Post by **dannyboyau** » Wed Mar 14, 2007 3:26 am

drop the compression to 8.5 and then use a set of heads from the 6a13/TT