If I dropped my pistons to 9.3:1 / how much horses would be lost in the process?
Thanx

 

More details on the setup. Most likely on a turbo setup you would gain horsepower. You could run more timing and more boost.

 

ohh sorry
Je 10.2 pistons, vavletrain, head ported, crank balanced and jrsc pushing 6psi
thanks

 

not enough to make a diff. & if you do feel a diff. then just up the boost

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MaxBoost &raquo;</TD></TR><TR><TD CLASS="quote">More details on the setup. Most likely on a turbo setup you would gain horsepower. You could run more timing and more boost.</TD></TR></TABLE>

yeah, but if you have same timing and boost, just higher cr, the higher cr will yeild more power...

 

You would lose exactly 7.342 whp for every psi of boost in a mountainous region. Only about 5.893 whp if your at sea level.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93LSivic &raquo;</TD></TR><TR><TD CLASS="quote">You would lose exactly 7.342 whp for every psi of boost in a mountainous region. Only about 5.893 whp if your at sea level.</TD></TR></TABLE>

*ahem*, get your facts straight man! dont misinform him. its 7.343 whp and 5.892 whp. GEEZ. bastards.

 

where do you get that figure from if u dont mind me asking

 

If you are building the engine for a JRSC DO NOT USE LOW COMPRESSION PISTONS. you will only hurt you WHP numbers. People who make the big numbers with a JRSC use between 10:1- 11:1 pistons. the reason for this is the blowers low boost and high heat output. Now if you are going to use compound induction then it will be ok but you will still lose HP

 

A higher compression motor will make more HP on the same amount of boost than a lower compression motor. Do a search, there is a HUGE thread on this that firmly establishes this theory.

 

correct me if im wrong, but when n/a for every CR point it is a ball park average of 10hp you increase... im not sure how accurate this is for turbo applications though.

 

well on of the reasons that I wish to lower the compression is for the longtevity. i was told my a mechanic that head gaskets will blow with high *** compression like 11:1 or 12:1 w/ a blower. He does a lot of work on big block V8 motors though, are they naturally a LOT less compression than 4 bangers???
thanks

 

I have found from past experiance , 1 point is about 10 WHP . This is a rough number from what I have seen in the past.
ie, 10-1 down to 9-1.


Modified by CRVRX at 3:41 AM 4/22/2003

 

4-6% at the wheels