NA-T most boost with stock CR & HG

[Style]

That's a lot of compression for a turbo engine on modern junk fuel. You need knock monitoring and to mask the cooling system to see worst case temp scenarios on the dyno. The ecu needs knock fold back. It needs aggressive temp fold back. Ideally it needs the compression dropping though. Get clever and it'll bite you. Add in the fact the engine is almost certainly tired and you can see why you need to be very very conservative with the boost and mapping. I would say 550 BHP for more than a few moments is asking for trouble on stock N/A pistons.

 

I think it would be wise to drop the CR a little then to at least deal with these extremities that you've mentioned on such a high CR. I think 1bar of boost would only see just shy of 500hp on my setup so wouldn't be as close to the limits in that respect.

 

Lowered CR with TT pistons would allow you to run up to around 1.4bar of boost IIRC. It all depends on the turbo for power figures as one turbo at 1.4bar is totally different to bigger/smaller unit at the same boost.

 

But a good setup at 1.4bar would see the region of 550bhp I think.

[Chris Wilson]

With lower compression it effectively should be capable of TT power, the piston squirters do help to remove heat from the crown, but with forged pistons it should survive without.

[Nodalmighty]

I have a customer knocking on the door of about 450bhp with 0.8bar on 10.0:1 CR. Its the W58 that is more the bottle neck.

[Style]

With lower compression it effectively should be capable of TT power, the piston squirters do help to remove heat from the crown, but with forged pistons it should survive without.

 

Thanks for the info Chris, I'd probably go for the squirters down the line and do the whole coil pack ignition, tt oil pump at the same time. Then I can start pushing your 6spd clutch towards it's limits a little more

 

- - - Updated - - -

 

I have a customer knocking on the door of about 450bhp with 0.8bar on 10.0:1 CR. Its the W58 that is more the bottle neck.

 

Ooooh that sounds interesting, what's the spec of that?

[Nodalmighty]

Ooooh that sounds interesting, what's the spec of that?

 

T70 Turbo on a T3, BIG intake, 3" single box system/downpipe, 650cc HI injectors, FFIM with 70mm throttle body, FMIC, ECU Master EMU ecu with wide band, boost control and a few other small mods.

[abtin90]

Interesting thread this, it seems that the stock compression can only take you so far unless you mess with other substances, which would probably get quite costly. To go further - at which point the compression needs to be dropped via the pistons or headgasket. If you are going down the piston route, then you're essentially turning it into a TT especially if you do the CW oil squirter mod.

 

So if compression was dropped via headgasket, what kind of power is safely achievable if all supporting mods are there on a stock block NA? Actually Chris just answered that...under 550bhp.

 

How about vice versa, if TT pistons were put in with new piston rings, but without the CW oil squirter mod?

 

My Na-t made 536bhp at just 1.25 bar with a boostlogic headgasket fitted. That was with a garret t67 turbo, sp manifold, AEM ems standalone.