Highest CR I can do with a shot?? - Honda Prelude Forum

Ritteri · 12-29-2002, 08:15 PM

With my NA buildup coming along nicely I need to know what the highest compression ratio I can use safely on pump gas(which is 93-94 octane in my area). I have at my disposal the AEM EMS with a wideband 02. I plan on running about 75-150 shot of NOS via DP.

Blitzbaster02 · 12-30-2002, 02:19 AM

I wouldnt go higher than 11:1. Usually anything higher than that would need higher octane.

nuro · 12-30-2002, 08:16 AM

i always thought nitrous liked high compression...

Toretto · 12-30-2002, 03:44 PM

Yea, you could run a 75shot on on pump gas with 11:1 compression ratio. Laughin and I talked about this a long time ago, we pretty much came to the conclusion that you can run 75shots with 11:1, but any shot higher than that, it becomes questionable.

Ritteri · 12-30-2002, 08:57 PM

WHat about 10.5:1 CR???? That is what I was thinkin of running. Just a tad higher than stock CR.

nuro · 12-31-2002, 12:33 AM

something isnt making sense to me... what are u afraid of with running nitrous and a high CR? detonation? wouldnt just colder plugs + retarding the timing take care of that?

point is if u go forged pistons + resleeve, can you get away with a 11:1 or 11.5:1 with nitrous? lets say a 100 shot?

Ritteri · 12-31-2002, 03:13 PM

Yeah I just want to make sure i dont go too high. I would like to do 11:1 or 11:5 to 1 if I could.

Preyluder · 12-31-2002, 06:08 PM

11:1 or below is where you wanna go!

Ritteri · 12-31-2002, 07:50 PM

Hey anyone got some links or good articles to back up this info??

NXLude · 12-31-2002, 10:59 PM

You will be hard pressed to find a nitrous can ar running on 11:1, now it is ok and i have seen 11:1 ran with a 100 shot, but it is up to you....you EMS would probably let you pull it off.....11:1 and 100 is doable....

Ritteri · 01-01-2003, 10:14 AM

What about 10.5:1?? I want to have my CR as high as possible for my NA portion of the setup.

Preyluder · 01-01-2003, 11:15 AM

Well, 10.5:1 would be better for a daily driven car...

NXLude · 01-01-2003, 02:00 PM

10.5 is way good for 100-125......perfect balance

Ritteri · 01-01-2003, 02:46 PM

Again where r u getting this info from?? Got any good links on learning about nitrous??? Help me out here.

NXLude · 01-01-2003, 05:27 PM

Where am i getting this from? Ok based on AEM's 02 RSX Type S for one....That car runs an NX DP kit at a 100 shot....it has forged pistons and iron sleeves with a stock top end and no engine management. It makes 270 whp and is daily driven real hard. It has 10.5:1 JE pistons.......On the other hand, 3 of my friends have VW GTI's with 11 and 11.5:1 CR forged pistons and shots of 100 to 125 and they all seem to be doing fine.......(actually the guy with 11.5:1 and a 125 shot is having some problems, but he is fogging in his 125...told him not to.....) If you want info on the RSX go to www.sportcompactcarweb.com ......much of what i say is based on experiences that I have seen myself.....some is based on what I have read....

Preyluder · 01-01-2003, 05:32 PM

Quote:

Originally posted by NXLude
Where am i getting this from? Ok based on AEM's 02 RSX Type S for one....That car runs an NX DP kit at a 100 shot....it has forged pistons and iron sleeves with a stock top end and no engine management. It makes 270 whp and is daily driven real hard. It has 10.5:1 JE pistons.......On the other hand, 3 of my friends have VW GTI's with 11 and 11.5:1 CR forged pistons and shots of 100 to 125 and they all seem to be doing fine.......(actually the guy with 11.5:1 and a 125 shot is having some problems, but he is fogging in his 125...told him not to.....) If you want info on the RSX go to www.sportcompactcarweb.com ......much of what i say is based on experiences that I have seen myself.....some is based on what I have read....

That's great, but none of those cars mentioned are a Prelude... entirely different engine, responds differently....

Ritteri, I'll run a search for you, but I don't know what you want answered. Is your question, "which CR is the best while running nitrous?"

NXLude · 01-01-2003, 05:54 PM

Not true.....any small dispacement honda engine will react similar....Yes they have different characteristics, but as far as N20 and CR goes, you can pretty much use their info to your advantage....its not like im comparing vs a mustang or something.....youll have a hard time finding real explicit info on a whole bunch of high powered N2o preludes......

Preyluder · 01-01-2003, 06:05 PM

So, you're saying, w/ the same setup, a 2 litre engine and a 2.2 liter engine would come out with the same dyno #'s, considering they have equal tuning? No way, besides the fact of the closed deck block on the Prelude, which I believe the RSX does not have.

nuro · 01-01-2003, 06:06 PM

the question is "i want a 100 shot of nitrous, maybe a tad more. what is the highest CR i can use on a daily driven pump-gas engine assuming it has forged pistons, beefy rods, and is resleeved correctly (and all the other stuff to hold the shot)" assume AEM EMS for engine management.

Ritteri · 01-01-2003, 07:33 PM

Yeah basically the question is: What is the highest CR I can run safely on pump gas with about a 100-150 shot of NOS?? I want the car to have the highest CR possible for maximum hp but dont want it so high its stupid hard to tune as this is a daily driver. It will be a direct port nitrous system of course.