high compression & pump gas

Does anybody know the highest compression I can safely run off 93 octane?

Does anybody know the highest compression I can safely run off 93 octane?
depends on your tuning but id say about 11.5:1 is getting pretty close. ive seen people run higher then that on 93 but thats with full engine management and knock sensors. i wouldnt push it any higher then that.

11:5:1??? The suggested octane level on a stock B16B is 103 and that's just 10:8:1 so......

Well I do know there are cars that come from the factory running higher then 11.5:1. Just an example, the F50 comes from the factory with 12:1 compression and still runs off pump gas...

This is may be *totally* different but my go-ped, running 13:1 compression, runs off 93 octane. I'm sure there is a big difference between a 25.4cc 2 stroke engine and a 1797cc 4 stroke but my go-ped still runs a 13:1 compression ratio on 93 octane with absolutely no knock.

I think I should just speak to a mechanic before I start ordering parts.

b16ej you need to understand the difference between suggested and doable. of course honda will tell you to only run 103 on the b16b but that does not mean it will not be safe on 93. i had an lsvtec motor, in case you dont remember, that was at about 11.2:1 compression running fine on 91 pump gas because thats the crap we get here in cali. a friend of mine tried pushing it with 12.3:1 but started pinging and blew the motor. so its up to you and your tuning basically.

Yeah I remember your sweet ass hatch. But I figure that suggested is better than do-able, you know what I mean?

Well I think I figured out what I'm gonna do. My friend knows this guy that has a hatch with a totally worked b18c. It makes 330hp and the guy has the dyno sheet to prove it. He runs 16:1 compression and just poors a bottle of octane booster into his tank before each fill up. 16:1 does sound a bit like overkill but he WAS making 330hp. I'm still going to talk to a mechanic before I go and do something crazy like that. It makes me happy because my horsepower goal is anything over 300hp.

I'd like to know exactly how he pulled 16:1 off. :screwy:

I'd like to know exactly how he pulled 16:1 off. :screwy:

The only reason I believe it is the dyno sheet. How many other 330hp b18's have you seen?

a bottle of octane booster is not going to make up for 16:1 compression, no way any car on the streets ever has that hgih of a cr.
you POSITIVE the dyno shet is of his car. maybe its his friends camaro with a small block V8 and he just says its his. Ive seen printoffs where it doesnt say what car, Im guessing this is the case here.

I talked to my neighbor once and he sounds like he knows his shit when it comes to engines and such, and he told me hed stay below 11.5:1 as well, but if it was him hed go with no higher than 11:1 just to not push it is how he said it. I went 11:1 but they are still in the box so I cant tell you how it worked out.

a bottle of octane booster is not going to make up for 16:1 compression, no way any car on the streets ever has that hgih of a cr.
you POSITIVE the dyno shet is of his car. maybe its his friends camaro with a small block V8 and he just says its his. Ive seen printoffs where it doesnt say what car, Im guessing this is the case here.

I talked to my neighbor once and he sounds like he knows his shit when it comes to engines and such, and he told me hed stay below 11.5:1 as well, but if it was him hed go with no higher than 11:1 just to not push it is how he said it. I went 11:1 but they are still in the box so I cant tell you how it worked out.

No, I can't be positive that it was his car...I haven't even seen it. My friend does know the guy and has ridden in it. He did say it was fast as fucking hell.

As far as only going to 11:1, b18c5's come stock with 11:1 compression. Spoon b18c's come stock with 11.3:1 compression.

What kind of cars is your neighbor into? I'm saying this because I have even read that over 11:1 compression in a muscle car is dangerous because of their pos designs.

Well, like I said, before I spend a lot of money on 16:1 JE pistons, I'm going to talk to a mechanic.

well, a 330HP GSR would be, even a 230HP integra would be damn fast.
and maybe he means 330 at the crank which would lead to oh, say, 280 at the wheels, atainable NA, but still 16:1 aint gonna happen. maybe he puts in a half a tank of octane booster and then half a tank of race gas! I mean you wouldnt have to go that far I doubt, but no way on 93 octane with 1 bottle of octane booster would it work.

and he is into cars general, and not really cars, engines, he used to work in a shop where they did custom projects for people. hes also worked at a body shop, he has gone through school for boat maintanenece, has built lots of cars himself. 2 of those 4 dont even matter about this topic but just to show he is into cars/engines and that stuff.

and I didnt say 11 is maxed, he said he wouldnt go past 11.5:1 and if it was him hed stay at 11:1 because you wouldnt see a huge benefit over 11:1 and it wouldnt be a as reliable/easy to tune setup.


and thier pos design, sure their engines arent as hgih tech as todays, just 2 valves/cylinder pushrod type engines, but the rods bolt ot the crank, pisons on the rods, heads bolted to block, valves held shut with springs, piston moves up/down 2 times for 1 combustion, the basic "design" is the same with any internal combustion engine. so I am sure you can put a high cr in a old muscle car, probably just much easier on imports/newer cars, what do you think would be easier to tune with high cr, a new B18 with a ECU and tons of sensors and fuel injection or a 1960's small block 350 carbeurated?


and when you talk to your mechanic, youll see how right we all are.
on a B20, weak sleeved I know, 12.5 cracked this guys sleeves 2 times within like 500 miles each rebuild. so not only is it NOt going ot happen with pump gas, its not going to happen if you expect your engine to last longer than that one dyno pull that tels you you can make 330HP for 1 minute.

I run 93-94 on my B16B all the time. I can't find 103+ anywhere. I wonder what the hp difference will be?

my roommate has a '00 celica gts. their compression is 11.5-and he runs 93 octane. everything works out fine.

He runs 16:1 compression and just poors a bottle of octane booster into his tank before each fill up.
BULL-FUCKING-SHIT. There is NO way to run pump gas, even 100 octane with a 16.1:1 C/R. Period. And where did he get 330? from a dyno, no, not unless he had maybe a dynopack/rotortest and even then, I HIGHLY doubt it, since the readings would be at the wheels, and then you go on to guesstimate the whp, other than that he is pulling your chain.

one bottle of octane boost (biggest scam on the market) = about .01 octane level. So you take one bottle and add it to your 93 octane and you get 93.01. It's a complete waste. Don't go higher than 12.1:1. A buddy ran 12.?:1 on pump in a fully built b20vtec, and it ran fine, but it was tuned.

runnign higher octane doesnt give you any more power does it? I thought it was just needed if you have really high compression or lots of boost to avoide detonation? if you dont need premium, isnt it just a waste of money, another neighbor I have used to work on musclecars back in his young days, he is into imports now cuz he watches races on tv and ses the little 4 cylinders can do just what the engines twice their size and up can do. anyways he told me that running premium in an engine that only requires regular will actually run worse.????? I wouldnt have thought that but hes got more knowledge than me. but he is old and he contradicts himself sometimes and forgets where hes going when he talks sometimes. :eek7:

ok first off thanks b16ej for the compliment on my hatch. it was sweet but i sold it recently for my new car. i have a 1990 corrado g60 supercharged to 20psi. anyways this thread is perfect for me because i can not run my car without pinging on 91 pump gas. i use a 30% mixture of toluene and 91 gas to come out to about 98 octane. then i can do as i please.

i am telling you right now 16:1 is impossible for a motor that goes more then one run down the strip. it would generate an immense amount of heat that would require a cooling system that would cost as much as the engine. also i cant even imagine that race gas would be enough for 16:1 compression. race gas is 118 or 116 i think but i highly doubt that is even clean enough for that high compression. that would probably only work on methanol. not to mention that motor would need a full rebuild every mile.

280hp is attainable on an all motor b18 but EXTREMELY hard to get and in no way streetable. it must be a dyno from another car to show 330 or fake for all i know.

again dont go any higher then 11.5:1 on a street motor. that is plenty high enough and will run fine on 93. just make sure to get some good tuning and keep your maps a little on the rich side just to be safe..

runnign higher octane doesnt give you any more power does it? I thought it was just needed if you have really high compression or lots of boost to avoide detonation? if you dont need premium, isnt it just a waste of money, another neighbor I have used to work on musclecars back in his young days, he is into imports now cuz he watches races on tv and ses the little 4 cylinders can do just what the engines twice their size and up can do. anyways he told me that running premium in an engine that only requires regular will actually run worse.????? I wouldnt have thought that but hes got more knowledge than me. but he is old and he contradicts himself sometimes and forgets where hes going when he talks sometimes. :eek7:


higher octane is a waste of money if not needed. it will not give you more power because of the octane. your combustion will be cleaner and the engine will be more efficient but the gas itself will not generate a boost in hp. a dyno might not even show a difference and if it did it would not be more then 2hp. the engine will not run worse with higher octane buts its a waste..

oh, ok,

also, on a side note, wiht 11:1 pistons meant for a b20, when swapping a B16 head on it, it will raise to about 11.2:1 right? thats what crower told me, just want to make sure.

. your combustion will be cleaner and the engine will be more efficient but the gas itself will not generate a boost in hp...
Actually, it won't even do that. Higher octane does not clean your engine, or make it run more efficiently. Higher octane resist detonation, it isn't a performance enhancer, or cleaner.

So on my jdm engine if I filled it with 103+ octane I wouldn't see any more power? I see a lot of dynocharts online of turbocharged cars, one with low octane and one with high octane, and the high octane chart showed a huge hp increase. I think it was a turbo Prelude and the difference was like 275whp to 350whp... I'll dig around for those charts and post em up here in a few min.

Well, you gave the reason in your post, TURBO. higher octane allows better tuning, and you can squeeze higher boost out of a motor running on higher octane. You can rest assured, there is no way that just adding a higher octane fuel is going to net 75hp, now if you run a nice high octane 100, 103 whatever, you can tune the motor, maybe even to the tune of 75hp if you are able to up the boost enough. And another thing is, did they say how long the motor lasted after that?

nah and to tell you the truth I don't remember the actual numbers because I saw it like a year ago. My engine is already factory-tuned for 103 octane, that's why I'm wondering if I'll see a power gain over using 93..

yah that turbo prelude made more power because with the higher octane he could use more boost without detonating which of course means more hp. but again there would be no gain even with your motor to run 100+ octane. just be happy with the b16b the way it is and dont waste 5 dollars a gallon on race gas.

Okay not a hp gain then, but a reliablility gain? Am I causing more wear and tear using only '93?

Okay not a hp gain then, but a reliablility gain? Am I causing more wear and tear using only '93?
Well, no, not really. The motor will run fine on 93, I run my B16 on 90-93 all the time, once in a while I have put in 100 just for shits and giggles, and there is no difference. If you fill it with 89 or even worse, yes you will start have some problems eventually, or if your car sits for a while, but 93 is fine for your motor. I know a guy ran a 12.1:1 crvtec (tuned as it may be) on mid to high pump with no problems.

Cool thanks for that info because every time I fill the tank with 93-94 I kind of worry. If I ever see some place selling 105 or whatever, I'll fill half a tank to see what happens though.

We only get 92 pump gas. I think I have seen race gas out here but it was some where far so that I have never seen it again. In my case it doesn't really matter but you would think we would get the same or better gas as other states considering how many cars we have on the road and how much pollution they produce...not that any of the cheap people out here would buy it... would be like $2-$3 w/ our fluxuating gas prices. Just curious what are your gas prices like?

what kind of gas should you use for a b16a?

I completely forgot about this thread. My friend is stupid. He must have been stoned when he told be 16:1 compression on octane booster and pump gas. He's running 110 octane + octane booster. He fills up at a gas station about 2 miles from here that sell the race gas.

I guess I was also an idiot for not pointing out that he was being retarded. Oh well...