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How much can standard internals take?


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The above is spot on the money - its how the power is achieved, state of tune, engine health/maintenance etc. With a well considered tune and not just an "all out all the time" mentality then good power can be made. Keeping the rpm in check is a big part and being not too aggressive with boost and timing tables helps. There has been a few builds over here that are around 300kw at the wheels on standard engines (mostly fresh rebuilds). The issue is longevity. Street driven they will probably last ok, race stressing shortens the time they last.


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The above is spot on the money - its how the power is achieved, state of tune, engine health/maintenance etc. With a well considered tune and not just an "all out all the time" mentality then good power can be made. Keeping the rpm in check is a big part and being not too aggressive with boost and timing tables helps. There has been a few builds over here that are around 300kw at the wheels on standard engines (mostly fresh rebuilds). The issue is longevity. Street driven they will probably last ok, race stressing shortens the time they last.

I see what you're saying a healthy 250 is different from a unhealthy 250

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Its wrong answers bhp these are turbo motor's so stick to max boost 1bar is safe for tdo4 size turbo after that the ring lands start failing its a lottery some had ringland failed at a bar

Posted elsewhere but tired engines don't take to boost too well!post-15273-0-64391600-1503832456.jpeg

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Correct me if im wrong but the lads in jamaica were making 300hp on stock internals ages ago back in tggt forum days.

Yup seen that. They also dismiss the myth that the gt rods are any stronger. Alot of useful information in a thread on tggt from someone from Jamaica. Information from experimenting not hearsay

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The power output is almost irrelevant and there isn't really a "safe zone", its the state of the engine, how its been setup and tuned that's key. I've seen engines with stock or even less hp let go due to a bad tune, bad setup or poor engine health.



If you are a careful and methodical tuner and you look after your engine then there is no reason why you can't run decent power reliably. The NZ record holding quarter mile of 11.75 was set 9 years ago using a 5e with stock 4e pistons and stock 5e rods. That engine is still unopened to this day albeit retired from drag racing and is a circuit car now. Saying ring lands will fail at a certain hp is not 100% true. Id be more inclined to look at the reason the ring lands have let go and you will find that in a lot of situations (granted not all) the tune or some other factor is at fault. Overly aggressive poorly planned ignition tables, or inconsistent afr's, or aggressive boost curves, or too high a rev limit, or even the type and config of the rev limit (fuel vs ignition cut and how it applies etc) etc all play their part. There will always be cases where there is no obvious reason why a piston has let go and the casting process can be a factor, but with a good tune there is no reason why you can't push some very reasonable hp numbers. I guess what i'm saying is listen to your engine as its being tuned and you will get a feel for what makes it happy. Keep it happy and it should stay reliable.

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several good points have been raised above and i'd add my two cents here as well


i'm from the Caribbean (Barbados) and I've realized over the last 18 years that starlet "tuning/development" has come a long way from its more humble beginnings. I've also realized that different places/cultures do things differently and of course nothing is wrong with that. I don't look at the limits of the stock engine in terms of bhp/boost/revs per say, though those things obviously play a critical role in what the engine can indeed take. Also, dyno figures make it hard to compare as dynos can read differently across the various regions, in fact even within the same areas as seen sometimes on this said forum.


Now i agree with the premise that tuning plays a critical role in what an engine will make and how long it will last. A freshly and properly rebuilt 4e/5e engine should be fairly reliable for some decent horse power 200 - 300hp, even more as Stu indicated and last for a long time if properly maintained and driven rationally. If you are going to blast it to the rev limiter every time you get into it and track it for 10 laps regularly then you should reasonably expect its life to be severely limited...even forged engines can be destroyed easily with that kind of usage.


A conservative/safe tune with smooth ignition curve, decent afrs, gradual boost loads over the rpms, along with a good cooling system, within spec oil clearances on a properly refreshed engine or existing healthy engine should see you make nice power on the stock engine. A proper tune inclusive of knock detection is imperative, the stock engine will not take knock very well and will break easily especially at higher rpm/boost. i've seen stock engines last long with bigger turbo set ups and supporting mods/tune and i've seen them fail spectacularly with the same set ups and no/bad tunes. It's a thin line so you have to be careful.



Similarly to the old Jamaica 300whp tread on ttgt, i've seen a fair number of local builds use stock engines over the years to make decent power. Unless chasing massive power and high rpms, persons don't usually forge from the onset here. Similar has been observed in the other Caribbean islands as well (T&T, Antigua, etc). May be its based on the premise to see how far the stock engine will go before it pops, THEN forge, who knows?!?!



http://www.toyotagtturbo.com/forums/showthread.php?52987-300whp-Jamaica-style



for sure, technology, knowledge, better gas, proven examples, etc, have given the starlet community the ability to surpass past limits---within reason

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