Boost and Piston Damage

[GTS-t VSPEC]

Not quite the same, at least HKS have chosen different trims to effect the end product, the pistons are no different, just a stamp.

See'ya:burnout:

[BU5TER]

Awesome thats the part i don't understand, how do you know they're not made to different specs......Brett

[GTS-t VSPEC]

Well each company will send there specs to the factory to have there pistons made, so the pistons may have different bore size, different compression etc, but they are the same material. So if you get the same specs then there would be almost identical.

See'ya:burnout:

[Merli]

Originally posted by Sydneykid

Hi guys, just a quicky..........

As far as my research has gone to date, I have not found one Japanese tuner (HKS, Tomei, Jun, Toda, Trust etc) that make their own pistons.  I have found they all come from the piston specialty manufacturers like JE, Arias, Wiseco, TRW, Cosworth, Ross, Mahle etc.

If you want to check this out for yourself, read through the huge number of articles and videod visits to the Japanese tuning shops and see if you can find any evidence of a piston forging shop.  

Piston forging equipment and technology is very expensive and requires large quantities to be made to justify the capital cost.  I don't believe that the Japanese tuning shops would have that sort of volume now or in the foreseeable future.

Ditto conrods and crankshafts, they also appear not to be manufactured by themselves, but by the specialty houses around the world.  It is well know that Harrop's make such stuff for a number of tuning shops to brand as their own.

Bottom line, you are most likely paying for the name, not extra quality.

That might result in few more posts...............

I trust you haven't visited JUN's smelting and machining factory in Saitama, Tokyo.

JUN make parts for many of the other Japanese companies under licence, and although I may not be at liberty to say, let me just mention that I was surprised to see TRUST labelled boxes in the JUN factory. That is just one example.

I'd love to post photos and video footage that I took of JUN's massive factory, filled with CAD machines and their countless massive machines to forge, grind and polish their crankshafts, camshafts and conrods, but I promised Junichi Tanaka's daughter that I wouldn't post them publically, and the footage was only for my friends.

I did not see a machine producing pistons, as JUN uses Cosworth pistons, although I have been told that HKS produce nearly everything they sell. If you saw the massive scale that JUN operated at, and remember that HKS is even bigger, you would not be dismissing Japanese parts companies so quickly.

After saying that, I openly admit that I don't know what metal alloys each company use to produce their forged pistons. All I know is that the price varies WILDLY, with Japanese pistons usually being more expensive than their American counterparts. A set of APEXi pistons, rings, and pins will set you back 240,000 Yen (AUD$3500), whereas a set of JE or Wiseco pistons, probably around $1500.

**The following is "Merli Speculation", and is not scientific in any way, and is provided as a plausible explanation for questions asked in this thread.**

How can one forged piston be more than twice as good as another I hear you ask? I don't know. Maybe it comes from the fact that there are about 60 GTRs in America, and more than 60,000 in Japan (43,934 R32 GTR, 16,050 R33 GTR as of Oct 1998) and that the market demands a better product?

There are so many alloys available for piston manufacturers, is it hard to believe that pistons produced for two different companies originating from the same smelting house are made from two different alloys, as per manufacturer's specs?

[Steve]

Merli, I think you bring up an intersting subject. It seems to me that the japanese are so secretive, it is sometimes difficult to know what they do - which is probably the way they want it.

On the other hand, this creates rumour that is sometime hard to prove or disprove, and it would be nice to know what is going on. I have heard the same about pistons in japan as sydneykid, from BIG name performance shops in australia, but in keeping with the guidelines of this forum, I am hesitant to name them, so I suppose all you can do is take it for what it is worth - heresay.

How are you supposed to trust someone who doesnt put there cards on the table, yes they do get some fantastic results, but I really believe it borders on paranoia at times.

Just my 0.02

[Merli]

Originally posted by Steve

How are you supposed to trust someone who doesnt put there cards on the table, yes they do get some fantastic results, but I really believe it borders on paranoia at times.

Just my 0.02

The Japanese are certainly an interesting bunch Amazingly respectful, polite and extremely nice people... In fact, I want to go and live there for a year, because I feel that Japan has much more to offer me, than I was able to experience during my short two week stay there.

After saying that, the Japanese are extremely cautious, and don't like foreigners knowing all their secrets. Some leading Japanese tuning companies simply won't sell come technology to foreigners (turbochargers in particular), because they are afraid that the design will be studied and copied.

Case in point, would be Reece McGregor's "Hydraulic ATTESSA System", which amazingly looks exactly like Veilside's item which was designed about a year prior to Heat Treatment's groundbreaking invention.

Back to the point of pistons, I have no doubt that the Japanese pistons will hold as much boost and compression as you will throw at them. But for the price, I will most probably go for Wisecos or JE pistons. Why? Because for my boost levels (2bar)and requirements (500hp or 600hp with NOS), I believe that these pistons will do the job just fine. The added expense of the Japanese internals would be wasted on my relatively puny engine. You have to remember that the Japanese have MANY 1000-1300hp RB26 engines, and 600hp is considered a "light tune"...

It all depends on what your needs are.

[MIKGTR]

GTS-t Vspec: Japanese and US pistons are not made from the same material, if you have a look at the manufactures websites they all claim to use different levels of silicon, copper & magnesium in there alloys.With Alloys just as most things there is cheap shiit(TRW) and good shiit(Cosworth) And most Jap pistons are made by Cosworth or machined from elcheapo one size fits all blanks. The point I was making was don't just assume a piston is better because it is forged

Sydneykid: so motorcycle pistons are different, now it makes more sence because as I couldn't understand everyones eagerness to used forged pistons...that and the fact that I know for a fact most V8 forgies are way heavier than the standard cast pistons (learnt this building a clevo for a friend last week). But RB/SR engines along with other Japanese hi performance engines must be different. Thanks for the info

As Merli said JUN is a huge orgaisation and make just about every engine part and supply them to OEM. but they don't make there own "JUN" branded pistons, Cosworth do....go figure. it even says it in their catalog......you just have to check out what you actually buying.

HKS don't produce everything they sell in fact they are quite good at ripping off other companies designs and having copies made, a lot of people don't want to hear that!! but at the same time they do make and sell some awesome gear.

Good to see some informed technical discussion going on.

[Xeron]

Um TRW arent all cheap shit, numerous cars running around the 6 second mark use there pistons, i dont see anyone here requiring that kind of strength.

And someone said about how america has few GTR's, thus they wont have pistons as good as japan does for them. A piston isn't really a brand specific item, apart from the dimensions and sometimes a few specialised little design tricks, they are essentially all 'the same'. What im saying is, where a piston comes from dosn't affect its quality (excluding cheapo chinese made cast items and the like).

And to tell you the trueth, if i was going to be country specific, like the person saying the japanese use better alloys, i'd go for america anyway. Something about them running ALOT more 4 second drag cars than japan, im not even sure if any japanese have hit the 4's. And yes i know, that this means **** all as the technology used in 4 second cars has barely anything in common with the technology used in 9 second cars. But what country it comes from barely matters either.

[GTS-t VSPEC]

I wouldn't always believe what a website say's as far as material composition. If Cosworth are making the pistons then I'm sure that the material they use will be the same for most of there customers, they will all want the best.

See'ya:burnout:

[KAOS]

Sydney Kid and ALL.

If I want to lose the Variable cam timing, what do I have to do to the head? weld it over??????

Also I think my budget has been left by the side of the road.

I think I'll be using a microtech instead of the motec. I know motec is awesome but it costs a fortune. And I know that a lot of people will say that if you can't do it 'right', than don't do it at all. But, I still want it tough, but on a budget. So I have to prioritise.

I've got a friend who is custom making the exhaust manifold. What size pipe do you guys recommend. This has been a controversial sort of question. remember t78 33d on 3L twin cam. I want to get the bigger cams. More questions, but I'll leave it at this for now. Cheers guys.

I

[Steve]

Kaos, another option would be autronic, if I am not mistaken, it is a bit cheaper than Motec. I have seen some very tough skylines (track vehicles) using autronic with some impressive results.

Just a thougth

[Merli]

Autronics are absolutely excellent ECUs.

[Steve]

I have heard (romour mill) that the same guy who originally designed Motec computers started his own business - called it autronic.

anyone else heard of this??

Steve

[GTS-t VSPEC]

I thought the SMC's did batch firing? That's why they melt coil packs on S15's etc.

See'ya:burnout:

[Guest Peewee]

it all depends on how you wire them up and what ignitors you use. smc's have enough outputs to run sequential ignition and sequential fuel for upto (8?) cylinders i think it might even be ten i cant remember But yeh for the street i think motec is overkill with most functions in a motec only really intended for seriuos track use the autronic will shit in the job.

There is a ratio you can work out what size runners to run but can't quite remember it i think it's piston speed x stroke???i cant get tomorrow at work where it's written down but you want to aim for about 400 feet per second air speed so you will have to measure ports and everything for you to figure it out.

do you want the correct formula?

I think off top of my head 1"1/2 will be perfect but you will have to sit down and figure it out!

[GTS-t VSPEC]

Steve,

Yes you are right, I confirmed this today with Steve at SST, he knows the guy who split from Motec to found Autronic.

See'ya:burnout: