NAH2B

there are a few fuel options you can look into, but 93 octane pump is NOT one of them.

e85 would of course work well, but not the best in the winter for a couple reasons.

I am currently running 13.5:1 compression in a larger displacement motor, and I will be running VP-113 its leaded and oxygenated and will work great for n/a applications.

w/ your smaller displacement you may be able to look into VP MS109 which is unleaded, but will not protect against detonation as well.

there are also a couple other VP options, but the two i listed will likely best suite your application.

remoer

see i had kind a the simliar question not trying to thread jack.

i have a custom cut cam i obtain for free. it's a SOHC cam.. it has a 306* duration w/a .554 lift the intake is adv at 1.75* while at TDC and the ext is at 0*. i'm planing to run 12.5-13.5:1 compression w/93 octane w/itbs. i do live in SC and i can get 110 octane at the gas station "pumpers" but i don't want to. so if i do run this cam the car will be a weekend rider/DD at times.

the truth is i'm afraid to run this cam because of running ITBs, timing and 93 octane. any small advice?

Scott_Tucker

What 'math' is this?

94allmotor

iTrader: (1)

where i live i dont have E85 in my area and race gas is 10 mins from my house. i also have another question if im going to be driving the car on the highway is it safe to run straight race gas or do i mix race gas with 93 octane

PreStaged12s

I run 13:1 ish or a little over DD on 93 octane. Just no VTEC on the street, only when I use race gas. No reving over 5000 on the street on 93, its no fun, but it can be done.

jdm602

equation for static compression. you can also find out the dynamic compression in reverse order by doing a compression test for each cylinder first.

94allmotor

iTrader: (1)

would it be safe if i mix 93 and race gas for DD?

jdm602

i dont see why not. people have been doing it for years.

Bugermass

I've been tuning cars for a little over 8 years already. It can be done, I say this because I've done it.. Just like I've done a B17GSR with CTR pistons and 12PSI of boost on pump.. but whatever

94allmotor

iTrader: (1)

ok i get it..but what if im on the highway driving 4 hours and on the thruway they dont sell race gas is it safe to run 93?

jdm602

no. if its tuned for racegas or a mix, lower octane will increase the chance of detonation.

N.Y.C.E.

you guys forget the number one thing, cam selection is the most important piece of the puzzzle.

mar778c

iTrader: (1)

To achieve that level of static compression, the dome is going to be very big which would definitely reduce overlap. I honestly don't not see how you can dial up enough overlap with say a Pro2 or larger cam without having P-V issues.

Also, if you retard timing enough to get rid of detonation then you are going to heat up the exhaust valves and be right back into a problem again.

OP, how many degrees can you move the cams, intake and exhaust, before you run into problems?

Bugermass

"you guys forget the number one thing, cam selection is the most important piece of the puzzzle. "

I didn't forget I just didn't want to get into it cause no one on here listens anyways.. Everyones so quick to say things arn't possible (especially ppl who have never done it) instead of really looking at whats going on and finding a way to make it work well.

Bugermass

You know the ZX6R is 13.3:1 compression..
My ZX10R is 12.9:1 . .

The R6 is 13.0:1

All these run on 91+ octane pump gas with no problems..

While there are differences in head design and R/S and other things, it still goes to show that its totally possible.

mar778c

iTrader: (1)

Lol, you think so.

alterdcreations

the motor will run, but it will spin a bearing eventually

kgibson16

a sportbike engine is not a good comparison to a to what is being talked about.
the new bikes that have 13.1 are pretty complicated fuel system. chip controlled intake electronically varies intake funnel length,chip controlled throttle dual-injector system complements the high compression ratio. thats how its reliable from the factory. i dont think anyone running a n/a street setup would want to run 8 injectors. its awesome u can get cars to run that compression on pump but i still thinks its over kill for what he's trying to do.

94allmotor

iTrader: (1)

i have buddy club stage 5 cams and the timing is still at zero i hvant played with the cams at all i cant until i get the car tuned because we still have snow in upstate ny...the reason i ask if i can drive the car on the highway because the closest shop that can tune hondata is about an hours away and i need to get on the highway so i was wondering if it would be safe to mix 93 and race gas so i can make it there and after everything is tuned if i can still run race gas and 93 mixed because race gas aint cheap where i live its about $7 a gallon

94allmotor

iTrader: (1)

to make a long story short i just want to be able to drive my car everyday. i dont want it to be a car that i only drive on the weekends or whatever i will be going to meets and shows in the summer time and i want to be bale to get to whereever im going with the motor that i got. i know its very high compression but to end everything if i mix 93 and race gas will it be a dependable DD and will it get to shows in NYC/Boston/Virginia/Buffalo places like that. all of those places is about 4 hours from me except Virginia thats 8 hours away. but you you people understand what im trying to do

kgibson16

if this is the case why would u go with that compression? why would u want to spend so much money on mixing with race fuel plus when u drive long distances what are u gonna do bring 2 5gallon drums on the road with u? having this kind of motor to dd is pretty sick but totally not practical. good luck with what u do cause having a reliable 7 day a week car on 13.5.1 compression is gonna be pretty tough.

94allmotor

iTrader: (1)

i got the motor for dirt cheap thats why i got it...i will most likely end up driving my TSX most of the time in the summer and drive the EK or ride my CBR for fun. so i guess im limited to traveling long distances with the EK then

Scott_Tucker

You can run compression that high but you will have to have really late intake valve closing which means a cam with a lot of duration. Torque in the lower RPM will be really poor because volumetric efficiency would be really low at low RPM. That wouldn't make a good street engine.

98vtec

what do you expect? Most people on these forums now hardly practice the things they talk about.

94allmotor

iTrader: (1)

i wont be stepping on it much when im not running race gas..