Pistons

[sbefar01]

What kind of boost levels (aggressive everyday driving) would likely fry-up the stock pistons/rings? If your driving the JB3 hard daily would you be at risk over say 4-5 years?

[audi2bmw1]

dont think u will get a good answer here...this engine isnt old enough to really say whats safe and wats not....im having a hard time dealing with the fact that the supra's 2jz.gte can handle around 550-650lbs torque easy..and our very adanced motor doesnt seem to...ours should handle more since everything is beefy and forged etc. both are 3.0 inline 6 cylinders twin turbo charged....they dont have the fuel system like we do but still the fact remains thats one of the best engines and transmission ever im really hoping that ours will match up

[akak1997]

^^ you brought up a good point, which I've been wondering the same thing for a very long time. Modern engines just aren't as moddable for big power as before. Some blame the electronics, but I think those electronics just keeps everything safer. Hope some engine guru can shed some light on that matter.
Sorry for the thread jack :P

[LongIslandNY135i]

I'm more worried about the turbos. With the JB3 the turbos are running close to 200% of what they are supposed to run. The turbos will be the first to go running a tune.

[thehillshavestis]

Originally Posted by akak1997

^^ you brought up a good point, which I've been wondering the same thing for a very long time. Modern engines just aren't as moddable for big power as before. Some blame the electronics, but I think those electronics just keeps everything safer. Hope some engine guru can shed some light on that matter.
Sorry for the thread jack :P

well i thinks its the fact that manufactures are building more reliable more fuel efficient cars hence the high compression and advanced computer systems. now granted the n54 motor is great with forged internals (from what i have heard from bmw techs) but the built it with really high compression for a turbo motor... beats me why but my guess is economy. but that prevents increasing boost safely. thats why 2jz motors can hold up to 750whp, cause the whole motor is forged and the compresion ratio is somewhere around 8:1 stock. just my .02 cents any body else with more info can chime in but as for the op's original question someones just gunna have to push that envelope!! haha im def curious

[sbefar01]

Originally Posted by LongIslandNY135i

I'm more worried about the turbos. With the JB3 the turbos are running close to 200% of what they are supposed to run. The turbos will be the first to go running a tune.

I might have to agree, JB3 at 14psi = 175% of stock boost, that cant be good long term. Its like asking an undersized/speedy running back in the NFL to be any every-down running back all season long . . . . they usually "hit the wall" pretty quick if over-used. Similarly, the battering on small turbos adds up eventually.

[thehillshavestis]

yep that was the case with the b5 audi s4's as well bearings go bye bye

[xantdieselx]

Very good points as I'm still on the fence about tuning. I swear everytime I read a post I change my mind again.

[Yep 135]

Also car manufactureres are making the engines out of softer material so that their engine tooling machinery (grinders, die cutters, lathe cutters etc ) last longer so as to save on costs.
They get better at it as the years roll on.
Newer chev and Ford small blocks can sometime have a problem with torque twist in higher HP motors because of this. The older blocks are better because of over engineering.
Maybe this could also be a limiting factor.

[raolc]

Its ok! Run the turbos until they die, and when they die there'll be turbo upgrades available for us!!

[sbefar01]

Originally Posted by raolc

Its ok! Run the turbos until they die, and when they die there'll be turbo upgrades available for us!!

Thats great if you have thousands to blow, and what about the poor pistons?

[jeremyc74]

Originally Posted by audi2bmw1

dont think u will get a good answer here...this engine isnt old enough to really say whats safe and wats not....im having a hard time dealing with the fact that the supra's 2jz.gte can handle around 550-650lbs torque easy..and our very adanced motor doesnt seem to...ours should handle more since everything is beefy and forged etc. both are 3.0 inline 6 cylinders twin turbo charged....they dont have the fuel system like we do but still the fact remains thats one of the best engines and transmission ever im really hoping that ours will match up

The Supra engine was overdesigned because that was a safer, cheaper alternative to extensive testing. They created a very robust design that will last forever at stock power levels and the aftermarket exploited it.

With the N54, we're several generations of engineering later, and there's enough data so that a design can be safe and robust at stock power levels without the huge safety margin that was built into engines like the 2jz.

What benefit is there for BMW to spend time and materials designing an engine that will handle 700Hp when they never intend for it to see more than 350Hp? It doesn't make sense from the manufacturer's point of view.

[audi2bmw1]

Originally Posted by jeremyc74

The Supra engine was overdesigned because that was a safer, cheaper alternative to extensive testing. They created a very robust design that will last forever at stock power levels and the aftermarket exploited it.

With the N54, we're several generations of engineering later, and there's enough data so that a design can be safe and robust at stock power levels without the huge safety margin that was built into engines like the 2jz.

What benefit is there for BMW to spend time and materials designing an engine that will handle 700Hp when they never intend for it to see more than 350Hp? It doesn't make sense from the manufacturer's point of view.

this is exactly what i was thinking....toyota meant to build a great engine but really had no idea what kind of power it could really handle and just decided to over engineer it... and the reason BMW didnt build a 700hp engine is like u put, an unintended purpose

[sbefar01]

Originally Posted by audi2bmw1

this is exactly what i was thinking....toyota meant to build a great engine but really had no idea what kind of power it could really handle and just decided to over engineer it... and the reason BMW didnt build a 700hp engine is like u put, an unintended purpose

I actually owned a 1995 Toyota Supra N/A and the engine basically blew up at 57k miles, I was shocked. I found out thru Carfax that the car was repossessed-the owner before me must have done something "shady" to car in order for that to happen- and it was a non turbo. I still scratch my head about it.

[WhiteOne]

I keep hearing about 135's with 350bhp having traction problems at dragstrips. Dragstrips with prepared surfaces.
If you can't get the power to the road isn't it useless?
My car is a daily driver. I do not get to use much of its potential.
The little bit I do get to punch it, shouldn't hurt it to much.
It will not see high boost but a fraction of the time. JMHO

[audi2bmw1]

Originally Posted by sbefar01

I actually owned a 1995 Toyota Supra N/A and the engine basically blew up at 57k miles, I was shocked. I found out thru Carfax that the car was repossessed-the owner before me must have done something "shady" to car in order for that to happen- and it was a non turbo. I still scratch my head about it.

ya thats the same engine in the lexus is300...its a 2jz not the 2jzgte...not nearly as strong because it wasnt meant to have turbos on it(no forged internals)...now some have them turbo'ed call NA-t and i think they can handle around 350 ft lbs torque but need to be upgraded a lil to handle ~500lbs and i heard quite a few spinning bearings(lexus is300 forums) i think one guy threw a rod through the block on his turbo 300 prolly had a nasty boost spike and boom

[jeremyc74]

Originally Posted by WhiteOne

I keep hearing about 135's with 350bhp having traction problems at dragstrips. Dragstrips with prepared surfaces.
If you can't get the power to the road isn't it useless?
My car is a daily driver. I do not get to use much of its potential.
The little bit I do get to punch it, shouldn't hurt it to much.
It will not see high boost but a fraction of the time. JMHO

By the time you've hit 30MPH traction really isn't an issue any more with good tires.

[BerkTechnology]

If you are mature with your mods and vigilant about maintenance I see no reason why your car would not make it to 150K (if you keep it that long).

In your case I would run the JB3 at the low boost setting and change that oil twice as much as the factory recommends. Our 135i has had 3 oil changes with ~3K on the clock (a bit excessive for a DD, but we track this car a lot). On the track with the JB3 on low boost we run 100 octane only, although the recommended octane rating is only 91. Taking good care of your stuff doesn't mean we can't have a little fun with them!