ok wus up guys,i have a b18b1 on eg dx hatch 95 and i want to go lsvtec high compression.. i have a questions.. whats the highest compression that i run on pump gas for street car. i was told i cant go higher than 12.5 to 1 is this true? im looking for the highest on pump gas 93 oct. all motor... but for the track a lil nitrous.. the nitrous will be hit on race gas only..

not looking for a poor man type r im looking for something like a fully build.

wat brand: pistons, rods, cams,ect..

im looking for a fun 200 to 250hp street car without the nitrouse all motor.

nitrous is extra 75 100 shot

thanks in advanced...

 

Static compression has little bearing on whether you can run pump gas. If you have a large cam you can run it. However, the higher compression you have the less low end torque you are going to have and the higher you are going to have to wind it out to make any power, which can making driving it on the street a hassle.

 

ok so what i gotta do to get that power i wan all motor

 

Start reading through this thread to get an idea what it take to make different power levels and then start setting some realistic goals.

http://www.google.ca/url?sa=t&source...BFkaRXNs3FyYsg

 

First I saw the title and thought this is a loaded question.
Then I saw nitrous, and thought high compression, BOOM.
Finally 200-250whp equals tons of money.

OP you are all over the place with your questions. There is a huge difference between a 200whp b series and 250whp.
If you really want nitrous, you should be planning your build around this.
Maybe a 2.0 sleeved block, 10:1 compression and nitrous plate in a GSR intake manifold. With the right parts you could get between 180-190 NA then on the NOS 280-290. Keep in mind this would need a very good tuning to accomplish.

 

i have and this web has alot of info about goal that is my goal and will hopefully acheive it i want a fully buit motor wtight a lot of power im hopping i can get 300

after that ill get me a nice daily and just put the hatch fo track use only and maybe get like a dart bolck and run some real nice numbers

 

ight thanks bout being all over the place im sorry but i like to ask insted of looking a a hole thread and not get the info iml ooking for but thanks for the info tho

abuddy of mine is running a b20 vtec with 11.5:1 compression and a 75 or 100 shot and is holding up real nice not sleeved or n e thing
he got forged rods and pistons that it

 

i'm at around 12.8~13.0 93.

 

spraying or no spray?

 

To be on the safe side WITH spray...I wouldn't go any higher than 11:9 on pump gas.

 

ok... but when imma spray ill be on race fuel ONLY... im not planning to spray on pump gas... pump gas is just to get around on daily basis.. spraying on race gas for the track or maybe and very lil hang outs...

 

i say stay bellow 12.5

 

12.5 is wat i was looking for but all the peeps that surround me say it cant be done

so that 12.5 on pump gas to drive around and with race fuel put a 75 dry shot

this is with out having to sleeve right im looking for a dart block to start building it but just for the track

 

It's not so much that high compression ratios require high octane fuel as it is the fact that the higher the compression ratio you run the higher in the rpm band you are going to start making torque. A high compression engine is not going to have much torque at low rpm. Especially on a small 4 cylinder that already has trouble making torque in the lower rpm to begin with. This makes the vehicle difficult to drive on the street. I am definitely not an expert on nitrous but the technical articles and papers I have read tend to indicate that it works better at lower rpm which would point towards using a lower compression ratio.

 

What?

 

It has to do with 'inertial supercharging'. The higher the compression ratio you have, the later you need to close the intake valves to have the proper effective compression ratio (usually about 8.5:1 on an aluminum head, 4-valve engine). At lower rpm some of the air/fuel mixture goes in the cylinder and then reverts back out the intake valve because it does not have enough inertia to stay in the cylinder. When the rpm are high enough the mixture has enough inertia to stay in the cylinder before the intake valves close. The point where the full volume of mixture stays in the cylinder will be peak torque.

 

Glad to see you've read an article on valve timing.

However your original statements are pretty misleading - basically you are stating that if we take motor, let's say 10:1 static, and we increase the compression to 12.5:1 static, all other things being equal, that we will "not have much torque at low RPM". This is absolutely not true.

Also: "A high compression engine is not going to have much torque at low rpm. Especially on a small 4 cylinder that already has trouble making torque in the lower rpm to begin with. This makes the vehicle difficult to drive on the street."

Have you ever driven a high compression Honda on the street?

Sure, when we start talking about 14:1 and 15:1 motors the game changes quite a bit, but the vast majority of Honda "high-compression" street builds will indeed make relatively substantial torque at low RPM and are not difficult to drive on the street.

 

i wouldnt run higher then 12.0:1 on pump gas just my personal opinion and im sure people are gonna say they at 13:1 and higher but i wouldnt run higher then 12.0:1 on pump gas def not on the street

 

you got access to E85?

 

same here- b18c5 with ctr pistons and supertech flatface vavles

 

they are selling me b16 pistons for my b18 for 50 bucks that will only give me 10:1 right?

if i put them in with good rings will it hold some nitrous maby 75 100 shot that will be with the ls head

im not going ls vtech till i get the eagle rods and pistons

so will it be worth putting in them pistons with the ls head?

and thanx u guys for the in put...

 

pr3 or p30 both are b16 pistons depends which one they giving you with the pr3 your compression will be 11.3:1 and with the p30 your compression will be 11.6:1 id say its worth it even with going lsvtec if your going all motor thats a very nice setup just get arp rod bolts and you will be fine by the way those compression numbers are with a ls head if you go ls vtec with those pistons with the b16 head its around 12.2:1 and with a gsr head its 12.5:1 thats the beauty of going lsvtec over b20vtec you can built a beast of a motor using all oem parts and its a lot cheaper

 

tight work good info thanks man... im going ls vtec for sure but not just yet i want to get the head ported and polished 3 angle valve job and all them lil goodies and then ill slap in the head... ill ask to see what pistons they are but i think they are pr3 not sure tho .