oufan2929

I'm curious for a # of reasons, but the main reason is, I'm going to be building an 9:1 compression motor, and then will be adding a blower towards the end of the summer. In the back of my mind, I'm wondering if I should just build an 11:1 motor and spray N20(keeping it simpler and cheap). I've really been contemplating on which setup to go with. On this thread though, I'm just wondering , for the next year, how much power am I going to have to sacrifice going w/the lesser of the two comp. ratio (9:1 vs. 11:1) considering all things equal (heads, cam, etc.). And is it just peak hp that I'm going to lose, or power throughout the entire curve? Thanks--Andy

98 Silver Bullet

iTrader: (28)

The Supercharger vs. NOS discussed here:

https://ls1tech.com/forums/nitrous-oxide/268480-s-c-vs-nitrous.html

oufan2929

I'm not wondering about s/c vs. NOS, I'm trying to get a guess on what the power output of a 11:1 vs. 9:1 motor is.

98 Silver Bullet

iTrader: (28)

Sorry man...I thought the post would help you out if you are trying to decide which route to go. It discusses the pros & cons of both. I wish I could find a post "jrp" responded to. It has been in the past couple days and he had an answer for you. That is, how HP differs based on different CR's.

LS1_PNYTAMR

iTrader: (1)

so ur saying , u want to know how much u would be giving up for a few months until u added teh blower right??? i guess ur wondering b/c if its alot ur saying u will just go ahead and spray it to save time and money.. well id spray it to begin with but that is just me..

however im going to guess u would lose at most 30 hp.. at most.. and if u could feel the difference u woudln't once u added the blower. with the blower u may add 150-200 extra hp but it will be there all the time, nitrous u want.. i know this isn't the questino u ask, but if i planned on driving it on the street a lot n2o is the way to go imo.

TNormZ28

iTrader: (9)

Isn't it like 10hp per point in the compression ratio? And the lawn boy has squeezed his fair share of n2o. That car will be bad *** with the blower set up he is after... It will be worth the wait.

oufan2929

That'd be great if you could find that post--thanks Steve

xcobra

Its quite obvious that nitroused motors are very fast and powerfull. But a blown 408.... heh heh hee. That will absoulutely destroy **** also. keepin it real weather you want to run the street or not, your building a 408. You are obviously not playing around. Why not go for the blown for its more rare and when you do hit the track............. wow.

Pro Stock John

iTrader: (34)

I've seen folks say a reduction of 3% for every point drop in compression.

xfactor_pitbulls

iTrader: (16)

John, not to chime in unwelcomed, but I thought it was 4%?

Brandon

ls1290

iTrader: (20)

3%....4%..... both are a ruff rule of thumb. There are way too many variable to give a real power loss.

Keith

Tony Mamo @ AFR

iTrader: (13)

Hot Rod Magazine did some extensive testing recently and their results back up the 4% rule....Not too mention that would be 4% of an engine dyno number, not a chassis dyno figure. I spoke personally with David Frieburger, senior Editor of HR, right after the testing which was done at the Westech facility in Mira Loma, CA.

Assuming 525 RWHP is right at 600 HP flywheel, my guess is you could see a loss in power somewhere around 45 HP, both at the wheel as well as the flywheel.

Two full points of compression drop is HUGE and your cylinder pressure, cranking compression, and torque outout would be down significantly.

Tony M.

jrp

iTrader: (16)

http://www.popularhotrodding.com/tec...power_squeeze/