High Compression Pistons

[Lextreme II]

Got some high compression pistons for the 1uzfe. What do u think? These are 11:1 N/A application.

 

[JustenGT8]

Sell them to me for my next high comp turbo setup

 

[Lextreme II]

Justen,

With 11:1 how many psi can it handle? 6 to 10?

 

[Jake Breyck]

I think i want to know the price.

 

[JustenGT8]

I reckon 15psi would be a good safe limit. That would give me around 400rwkw and killer boost response....not to mention off boost perf would be great as well.

Built engine though so rods, good HG and heads studs as a minimum.

 

[Lextreme II]

I am about to build a 5.2L with high compression pistons like above 11:1. Great to N/A and low boost. Massive lower end. For my LS400 of course.

 

[cribbj]

David, make sure you have enough octane to run it!

(from someone who didn't!)

 

[XR8tt]

I reckon 15psi would be a good safe limit. That would give me around 400rwkw and killer boost response....not to mention off boost perf would be great as well.

Built engine though so rods, good HG and heads studs as a minimum.

With a GOOD ECU like you already have..
Motec !!

 

[Lextreme II]

David, make sure you have enough octane to run it!

(from someone who didn't!)

John,

Would US Premium be good enouch for 11:1? My 1995 has 10.4:1 already. Perhaps .6 compression should be fine. What do u think?

 

[XR8tt]

Depends entirely on TUNE ..

 

[spf_lexus]

Either that or buy additives by the case load.

 

[Lextreme II]

from 10:1 to 11:1 will yield about 30 bhp additional. Not bad for a rebuild engine.

 

[XR8tt]

If you addded cams and good valve springs yes easy!!
The cams may bleed alittle compression off anyway??
I would fit one heat range colder spark plug also, due to combustion chamber extra heat...

 

[spf_lexus]

too bad the piston price range is not that of rods.... $400 for rods and around $1000 for pistons?

XR8 Could a cam ugrade drop the 11:1 down to a stock 10:1? meaning that if you went slightly farther and added a lightly ported head and went to say... 12:1 instead could we use this idea to "level" the comp + peformance?

 

[XR8tt]

SPF..
I guess its much like a turbo engine ??
The better the head breath's the less chance of detonation..
The better the scavenge where flame is well exhausted...
The incomeing charge has less chance of detonation..
4 valve heads can run much higher compression add a decent cam
your laughing...
The higher the piston is or over deck the better too..
No place for burning fuel to hide.. If piston bassically pushes it all out..

 

[Lextreme II]

The new LS460 is running 11.8:1 and it is generating 380 bhp. I wonder if I can run 12:1 on a 5.2L. I also wonder how does the HP from 1UZ stroke compare to the 4.6L (LS460)

 

[XR8tt]

What injector size does the LS460 have ??
It could be set up to run on part ethanol based fuels ??
Tmk high comp and much higher fuel delivery with these fuels
gives good safe power levels..

 

[stevechumo]

I wonder if these pistons can be made of magnesium. Magnesium is lighter than aluminum, about 2/3 density of aluminum, but has about the same strength of aluminum. So perhaps it can be forged or at least shot peened to increase its strength. I think Porche has used magnesium for the engine block but I'm not sure for what part. Anyway, I strongly believe these high compression pistons can be used with mild boost from 12-15 psi. 10 psi is under estimation. For the same psi, it can gain a lot more hp and tq than lower compression pistons.

 

[XR8tt]

I think a lot of them have a mixture?.Which is a little secretive.. I called into C.P pistons when in Anaheim. The silicon content is very high in them that other manufacturer's couldn't make. But what they said to me verbally was the other contents that make it work.. He rattled them off but I cannot remember and didn't say % of them either...
Certainly have silicon in them to help in wear, expansion so they can run much tighter clearances for a forged piston..
What brand are they and specs of above pistons...

 

[LEXUSA]

The new LS460 is running 11.8:1 and it is generating 380 bhp. I wonder if I can run 12:1 on a 5.2L. I also wonder how does the HP from 1UZ stroke compare to the 4.6L (LS460)

Are you serious about the LS460, 11.8:1? Wow. Technology. How similar are the pistons and combustion chamber shape/design of the LS460 and LS400?

Do you have a pic of the OEM LS400 piston for comparison?