How much boost on stock compression/pistons/rods

[racinstation]

We have always used low compression pistons, Carillo rods, and or a head shim along with cam timing at high boost levels (15 plus). How much boost have you guys run with a completely stock motor? At what boost and also what octane and elevation? Just trying to acquire some information for a build. Any input is appreciated.

 

[mulot30th]

its not boost as much as hp/tq and NO DETO that count with stock internals.

 

[JCLG]

I have in my MCX 180 kit in my Nytro 6 psi

 

[Tarzan]

well.. i have run 21 psi in dyno stock engine and run now 19 psi on stock engine on Ethanol mixture.
Cant say i am safe so i will turn it down to 17 psi.

 

[aja636]

I ran 18lbs on 100% stock apex motor. Ran 22-24lbs on same motor with head shim to lower compression.

I think Jannetty runs 25 plus on completely stock RX-1
just with Retorque on the head studs.

Its all about good fuel and not heat soaking the engine.

 

[zx670]

Ive been running 16-18 for the last 3 years on mine with a never been opened stock engine on av gas, but i also ride at 10,000ft so there is about 5psi less atmospheric pressure to start with up there

 

[quebecmoutainrider]

sealevel-14psi on 92 and 19psi on 110..was told I could run 94 octain at 19psi..not going to try..lol.

 

[mulot30th]

sealevel-14psi on 92 and 19psi on 110..was told I could run 94 octain at 19psi..not going to try..lol.

what head shim thickness?

19 psi pump gaz sounds crazy.

 

[TurboTime]

I've talked with a few guys on this very topic; OSP and Smith Racing. For the Nytro the engine is able run 8-10lb of boost with 93 and up to 15-16lbs with C14 - C16 race fuel
Sea level stock motor no shim...

My take its really depends on the detno and how long you WOT in specific conditions..

Hope this helps..
KI

 

[quebecmoutainrider]

You would have to ask the guys at G-Force..but I think its 10 mil.they didnt say pump.they told me 110 at 18 but its at 19.and that I could run 92-94 at 13 but its 14..There are guys running high numbers and they have had no problems..I even have a warrior rad on the back to help get rid of the extra heat.And have been told to always check the A\F after I fill it..never know if the fuel is really what they say you are buying.The sled was sappose to be 13-18psi..but it always says 14 or when up high 19 on race.

 

[FLYBYU]

You would have to ask the guys at G-Force..but I think its 10 mil.they didnt say pump.they told me 110 at 18 but its at 19.and that I could run 92-94 at 13 but its 14..There are guys running high numbers and they have had no problems..I even have a warrior rad on the back to help get rid of the extra heat.And have been told to always check the A\F after I fill it..never know if the fuel is really what they say you are buying.The sled was sappose to be 13-18psi..but it always says 14 or when up high 19 on race.

On a stock motor IMO would not take it over 8 unless I was using 116 max nos fuel.