So just how much boost can our stock 3.8 take?

[Mighty Thor]

Six years ago I was told to never go above 8psi because it will ruin the engine.

At read once at ZZperf. that L36 can't take no more than 9psi. And should get L67 if you want to go higher.

Now I'm hearing people doing 10 psi with no problem. I've even heard people doing 12 psi with an intercooler and doing just fine.

Could 14 psi. with an intercooler be really our limit? [img]graemlins/popcorn.gif[/img] Entertain ME

[Turbo V6 Camaro]

umm well.

alot of poeple with the powerdyne have the 10lb pully and there running w/out proplems. see is really if you have tunning or not, and your a 1998 so you have tunning every were, there is a breaking point but, i would say you can do 12 PSI tuned and 14PSI with bigger injectors tuned and a cam. but im NOT a pro
see what Tiago says

[Shane]

i ran 7-8 for a while....now recently im at 10psi....once my L67 is together im going to up it to how ever it will hold.

[Tiago]

we ran 14 psi for a long time without any side effects. I think you will need injectors though.

[nocutt]

It is really hard to say...I use to run 11psi on a stock bottom end...you have to compromise here...too big a turbo and you run the chance to lift the heads, 14psi is nothing on the stock bottom end and stock rev-limiter. The question is how long can you sustain this since your tunning window has been reduced...
The question should be...how long can you run 14psi with an efficient turbo and a good tune...

[Ironman24]

I think some important factors are: intercooler, injectors, and most important, tuning. I'm going to push the limit with an ATI D1. I should be starting around 10psi and work up from there. We'll see how long it lasts. [img]smile.gif[/img]

[Die Ford V8]

shane could you tell me the differences in the L67 block and L36
r they the same bolt patterns is one stronger, i was told it was just the heads but I don't know if i can trust many junkyard salesman

[RedAudiomobile]

10 PSI since 9/24/03 with minimal problems, roughly 6K miles on the system.

[Radcat]

I ran 14psi for about a week. Since nobody really knew what the limits were I didn't want to find out the hard way so I turned it back down to 10psi. It ran fine at 14psi though :D

[nocutt]

You will always get varying views, however the constant will be the mechanical limits and longevity...the L36 bottom end is strong...FACT! However the design of the pistons and it rings make it prone to popping if too much detonation is present...The stock cam will be another problem at this boost level especially on a big turbo...(one can literally lift the heads)...Timing or rather tunning is also critical at the this boost level ...(the stock timing tables will have to retarded, even too much octane won't help because you still have to drive the car un-boosted)...
So everyone will have that...I ran a billion psi and nothing went wrong story...
Shoving 14psi with the stock cam...will start to yield you "the point of NO-RETURN"...the gains will be minimal if no head work or different spec'd cam is present...
The L67 block is different MAINLY at the bottom end and therefore can hold more boost than an L36 will want to... for example, everything else remaining equal...to get 400hp from an L36 one will theoretically need ~about 14psi, while on an L67 in theory, one will need an excess of 18psi...of course TQ will be different on both apps, but you get my drift...

[NSolano]

so wait, what if he rebuilds the engine?? what will the max boost be?? I don't know much about bottom ends but I know you don't rebuild that part, so even with a rebuilt engine is the max still only at 14psi??

[imported_admin]

Harsh truth is nobody knows. To my knowledge, no L36 owner has ever destroyed an engine due to excessive boost.

I ran 12 psi (intercooled) on the stock block for a few months with no problems. We dissected the engine afterward and found no damage to the piston assemblies.

10 psi (also intercooled) on Jenn's setup hasn't seemed to cause any engine problems yet.

[Turbo V6 Camaro]

dont for get the L67 can take a little more b/c the c/r is only 8.5 to our 9.4 so to make same power you do need more boost

but yes there bottom end is stronger on the L67

[imported_admin]

Originally posted by Shane:
once my L67 is together im going to up it to how ever it will hold.

Eh, that's kind of what I'm doing.

I suspect the tranny will die before the motor. Not a very comforting thought, though...

[nocutt]

Originally posted by Stefan:
</font><blockquote>quote:</font><hr />Originally posted by Shane:
once my L67 is together im going to up it to how ever it will hold.

Eh, that's kind of what I'm doing.

I suspect the tranny will die before the motor. Not a very comforting thought, though... </font>[/QUOTE]I concor!! To answer the question above...you see every DIY or tuner will have their limits, which I beleive will be directly dependent on the design of their respective kits...as you can see, tunning and efficiency remain the constant. You rebuild the bottom end and "Realistically" keep things in percpective...I don't see why an L67 cannot be ran at 20psi...but now we are going to be dealing with a different animal altogether...