At what point are aftermarket internals needed ?

Thought I'd spark a little discussion

I just wondered at what point the standard Toyota engine internals fail, ie rods, head\main bolts, bearings, main caps etc. I know its great to stand by your car at meets and reel off all the names of parts in your car But when do they become necessary ?

I doubt that the 2JZGTE was designed to run 1000hp and so some parts will reach a limit, but it is a very strong and capable unit. If you have one built and blueprinted to all the correct tolerances etc, how much power could you run before the rods fail for example ?

I know a shotpeened rod will have better tensile strenght etc, but when does it become necessary ?

I would especially like to hear of actual cases where a component failed due to too much power, NOT due to poor fitting, poor mapping, zero mechanical sympathy from the driver etc

Now a race engine is totally different, so I'm only talking about our road cars.

I have been wondering this.. Theres guys in the states that have been running 2.0 Bar on big turbo's on stock internals with few problems.. If i had a spare engine and lots of cash.. I'd sure like to try and see how far i could go....

Theres allso i guy in denmark i know of whos been running a big turbo.. on a stock HG and internals running optimax.. 2 bar all day.. and he drives it like he stole it...

It makes u wonder with the right tune how far you could really go..

Theres allso i guy in denmark i know of whos been running a big turbo.. on a stock HG and internals running optimax.. 2 bar all day.. and he drives it like he stole it...

All day? You mean he has a 2.0bar daily drive and he does tens of thousands of miles in it a year, or he can drive it for an all-day drag meet where he maybe does three or four runs?

The problem with anything vaguely related to durability is that durability means different things to different people and there is no standard way of measuring it. If your car is a weekend toy then you could probably over-stress it considerably and run it for a good while before you let go. However, coming from an OEM background, durability to me means extended running at full whack. I very much doubt that many of the big power cars on here - no matter how well engineered they are - would make it through a proper durbility test.

You can't meaningfully talk about engine durability without also stating what you want to do with the car.

I very much doubt that many of the big power cars on here - no matter how well engineered they are - would make it through a proper durbility test.

I doubt it too mate, but a big power Supra is rarely going to be used every day, and if it does then it's not at big power, it's probably below 0psig and the occasional enthusiastic blast.

I just question the need for aftermarket parts on a heavily modified road going supra.

I'm also unconvinced about the benefits of introducing a third parties components into an engine unless they are manufactured to the exact same dimensions and tolerances of OEM. Additionally, the R&D\engineering departments from the likes of Toyota et al will have put a considerable amount of time, effort and money into the design and manufacture of the engine, it's components and how they all work together as a whole, have Eagle done the same for their rods ? CP their pistons ? etc

On Pistons I accept the need for uprated parts if you are running higher boost as this is the surface in direct contact with the increased forces, but not sure on the rest.

Thank you Digsy, thank you If any engine won't reliably do two 30 minute sessions on a track like Donington, then it's not built properly. 10 second runs do not tell me an engine will handle X BHP properly.

If any engine won't reliably do two 30 minute sessions on a track like Donington, then it's not built properly. 10 second runs do not tell me an engine will handle X BHP properly.

Totally agree, but if it's built properly, does it need 'stronger' third party components ?

Its how far you go really.. and how far would u want to go on a road car... Im running 1.4 Bar max at the moment.. And really its bordering on two quick for the road.. (Hence why she's at 0.8 bar) at the moment....

Wez's car is deffo one of the best setup's i've ever been on.. Even that's insane for the road....

Our roads are very poor for quick cars....

isn't Ianc's car a good guide for this, it is stock internals, has done more miles than most without (AFAIK) any rebuilding and is (again AFAIK) 500+BHP?

So far this year my std engine has done 10 of the best, the HKS drag competition, numerous santa pod runs a week long trip to and around the Nurburgring Including long autobahn runs from the track to Dusseldorf and back as well as 6 to 7000 miles with boost on my t67 set at 1.43 and 1.65 bar:)

OIl and plug changes are all thats been done.

These std engines are good!

Although my other one made a lot more power:

If by "built propely" you mean blueprinting to get all the production tolerances as near to the middle of their bands as possible, then it will help with stufff like bearing clearances which will help reduce wear on the rotating and reciprocating parts, so its not a bad thing. Re-balancing the crankshaft will cut down on out-of balance forces (not that there are many of a straight six in any case).

As for aftermarket components, I'm pretty certain that there won't be anywhere ear as much R&D going into an aftermarket piston compared to an OE one, but the aims are different. AN OE piston will be designed to take the maximum gas loads and temperatures in the OE application. It will have a skirt profile perfectly matched to the bore and the way the piston expands as it heats up from stone cold to running temp. The rings will be matched to the gas loads and operating speed. It will have been tested at stock power and speed for several hunderd hours. If you move away from stock, then you begin to invalidate the development and durability work that Toyota did, so you can no longer say that the same piston will be reliable.

An aftermarket piston will be designed to be strong as an ox, and (hopefully) light. It will probably have a generic skirt profile and ring pack. It will probably not simply break at elevated power levels, but it may well wear badly, be slappy from cold or do any number of (probably unnoticable) things that would be unaccaptable in an OE aplication.

As for "do you ned to uprate components in a road car": Well, if the engine is capable of 600hp, then all the components need to be capable of producing that at least once, otherwise they would fail immediately - which would be a massive cock-up. But since all real-world mechanical failures are either fatigue or wear related then it once again comes down to how oftern this road car would be taken up to max power, and how long for?

Non-mechincal root cause failures might be poor lubrication, wrong oil, poor cooling, bad mapping, insufficicent fuelling, etc. These are the areas that would certainly need to be addressed before which mechanical bits will live and which will die.

The simple answer might well be that there are plenty of 500+hp cars running around on stock internals with proper mapping, being used for the occaisional track day that have not (yet) gone bang that you could be fairly confident in similar power for similar use.

robbie just for info was this a used or new/built stock engine you got when presumably a previous one let go.

Also what happen to the previous one and what in you opinion caused its demise?

Thanks Digsy, comprehensive and concise as ever And our ideas of a properly built engine are aligned, mine was blueprinted when built recently.

All day? You mean he has a 2.0bar daily drive and he does tens of thousands of miles in it a year, or he can drive it for an all-day drag meet where he maybe does three or four runs?

 

The problem with anything vaguely related to durability is that durability means different things to different people and there is no standard way of measuring it. If your car is a weekend toy then you could probably over-stress it considerably and run it for a good while before you let go. However, coming from an OEM background, durability to me means extended running at full whack. I very much doubt that many of the big power cars on here - no matter how well engineered they are - would make it through a proper durbility test.

 

You can't meaningfully talk about engine durability without also stating what you want to do with the car.

The guy does long track runs at that pressure.. can be up to 3 to 4 hours on constant runs...

He does allot of miles in it too

robbie just for info was this a used or new/built stock engine you got when presumably a previous one let go.

 

Also what happen to the previous one and what in you opinion caused its demise?

HI Scooter. The other engine let go due to a valve breaking in no 1 inlet. Lots of high revs and a dodgy spark plug helped kill it:blink:

The STD engine was a low milage j spec from a forum member. I think I payed 850 for it.