i have an ls vtec with usdm b16 pistons running bout 11.7:1 compression. i talked to a local race shop and they told me nitrous takes well to compression and i researched it on here a bit. what im wondering is what kind of shot would be safe at this compression. the set up i have is a nos direct port system currently only 75 shot jets, for what its worth.

 

I have heard to high of compression and some nos..it will melt your pistons or blow it out of your motor...not sure if it is true though.. I am runnin 11.5:1...as much money I spent in my motor..I am too chicken to try it..

 

well im for sure not running the 75 shot, i was thinkin like a 35 shot and since its direct port it shouldnt be to dangerous.

 

in for answer.

 

 

i was currently running 12:5:1 comp with a 150 shot on a h22

 

nos loves high compression. direct port yes, wet shot yes, leaning out is what is bad,bad,bad wide band is very helpful. you could spray 75 on a stock motor all day. just from experince we tried

 

WTF?! Nitrous donesn't melt pistons!!!! not having fuel to burn melts pistons!! Size your injectors properly and you can run as big of a "Shot" as you want. I ran a 100 shot on my h22 daily driver and never had a problem. After 7 bottles and 5 months I decided to go turbo. If you need some 411 on picking the right injector see the RC's website for some education. Just keep in mind that a good rule of thumb is to retard your timing 1 degree for every 50hp you shoot and step it down on your plugs, keep it cool in there. Make sure you caculate your injector sizing based off of FLYWHEEL hp not whp if you don't know then guess high-its better to run rich than not run at all.

 

well i might be getting some cams so i dont know if im still gonna try running nitrous on this set up. i read that all motor-ish cams dont mix well with nitrous.

 

what is all motor-ish cam's?

 

cams that arnt made for turbo or nitrous lol

 

Yeah, nitrious and cams don't really produce results. Nitrous doesn't like alot of Cam activity so you if have a big lumpy cam that would be great for N/A it won't have great results for nitrious. You'll find that the if your running a nitrous car and its set up properly it'll run like crap when your not on the juice but when you are on it you'll feel untouchable. I think if you keep it small (under 50) you'll be able to keep your N/A setup potent and have a bit of juice without retarding the timing and taking away from your N/A power.

 

if you do decide with nitrous, proper fuel and timing management is a must. a 2 timer would work great because it would allow you to run 2 different maps

 

yea get hondata so you can get a good tune! also we have some what close set up's my compression on the piston's is rated at 11.7:1 but ls/v pop's it up to 12.?:1 also 1.8L, i have sk2 s2 but gonna change over to pro 2's and drop some weight and get into the 12's on the juice push for 11's

 

yea ive heard of nitrous and high compression doing bad to your motor but never melting any pistons that will diffinaltly not happen. you will be putting alot of stress to your motor though. i wouldnt do that to my daily driver, but if its not it will be fine i would keep it under a 100 shot to keep it on the safe side.

 

just cuz its a smaller shot dont mean it wont pop but as long as you tune right and everything perfect when you tune you should be fine no matter what its a power adder just like turbo, super charge .... but if you tune right you should be safe my brother has a 16:1(closer to 17:1) and a friend want the same set up so we built the motor he tuned and when tuning decided he want to put the juice so took a kit put it on tuned and went to pomona(where the nhra final's happen) and the car ran fine and even shaved a second off his time so its safe(er) if you tune and dont beat on it.

 

i appreciate all the replys, i might just go straight all motor. i acquired the nitrous kit in a trade so i was just curious. this is my daily so nitrous would put alot of stress and cut down the life of the engine.

 

I'm actually running the same setup as the OP. Compression is around 11.9:1 with plans of a 75 shot. It will be tuned on crome pro for the NA maps; and fiddling around with the fuel jet for the spray on a wideband and dyno.

 

i agree with many of you, a good tune for nitrous will make it last sum time. higher compression plus nitrous puts more stress on the motor if its not properly tuned but proper tune will even out the odds against it. my last motor i ran 12.5:1 pistons on a stock LS block with H beam and arias pistons and a 150 shot direct port and it lasted some time after getting it tuned. the worst possible thing to do is not get it tuned.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DSRacing &raquo;</TD></TR><TR><TD CLASS="quote"> my brother has a 16:1(closer to 17:1) </TD></TR></TABLE>

 

its all motor tho i was just making a point that even a high comp motor tuned with nitrous can be just as self a turbo car tuned and you live kinda near the 626 if you go to irwindale its the jakespec crx black the one runin 7.4's ALL MOTOR

 

compression and nitrous are friends