Anyone done this before?
I know V8 guys love doing this on their race cars.

I'm thinking of doing a 75 or 100 shot wet in my engine (12.6:1 compression)

I plan on running 110 octane. That's not a problem.

I think the only problem I see is detonation. Figure if ignition tuning is on the ball, and there's enough fuel and enough octane, I'll be in the clear.

Also, are long duration cams a bad idea with nitrous? I have JUN stage 2 cams in there right now.

Any input or comments would be appreciated. I'm just not too experienced in the field of nitrous.

BTW, the motor's putting out 212 at the wheels all motor. Wonder what a 100 shot would do!

 

Mike sorry I had to post this in your thread, but your IM is disabled and I would like to talk to you personally about somethings unrelated to your topic. Can you email me or something?

 

well if you want to wait 2 weeks i can tell you, my friend has a fully built gsr, skunk stage 2 head, 11.5 comp with a 125 shot direct port, and i think he's running 370cc's injectors, w/ a hondata stage 3. if it works i let everyone know if it doesn't i'll take pics and let everyone know!!!

 

Hey there.

I'm a V8 guy, as well as an import tuner. Here's how I see it.

Compression is not necessarly bad when running nitrous, you just need to prevent detonation and PRE IGNITION! There is a difference. You will need to really retard your ignition to prevent the preignition and damage your engine. I would say at least 5 degrees, maybe a couple more.

The lift/duration of the cam doesn't matter. But the VALVE OVERLAP/LOBE SEPERATION does. You want the valve overlap to be the same or smaller than stock. This builds good compression and utilizes the extra power from the nitrous. Also, and increase in exhaust lift/duration helps a lot too. Check out Comp Cams cams designed just for blown/nitroused motors as an example. The only make them for V8's but you will get a good idea on how they differ from other NA peformance cams.

Hope this helps.
-Brad

 

Just keep cylinder pressures as low as possible. I second the retarding of the ignition. Would personally go for more for a margin of safety though. 6-7 degrees. Go to a dyno, listen for knock. If there is none, then your fine.

You *might* not need to retard that much due to the 110, but I am one for engine longevity personally (at least in a street/daily car)

 

feeling a little fast & furious Mikey ?

 

I would second the advice on the cams, try ITR or CTR exhaust with a GSR intake cam. If thats too far apart, ITR intake pre 00-01 spec and CTR exhaust. I hear a dry setup is best on a Honda motor. You may not have to retard to much if you run a fogger with proper fuel tuning, 330 - 470 cc injectors on the stock pump will no likely be necessary due to higher pressures. I want the na car bro, good luck with the juice... I wouldnt get too greedy, chances are that engine will be reduced to industrial slag if something goes wrong. Your bottom end is already being taxed with the higher compression. Without a block guard installed to support the stock sleeve or ductile iron sleeves, the boost cannot exceed 6-10psi on a B18C1 @10:1, for you @ 12+:1 I would say 3-5 max with proper tuning. A 100 shot will more than likely be equivalent to 10-15lbs of turbo boost or more. I say you are flirting with disaster. You cant have it all, your engine was already built for NA tuning. If you can, go here: http://www.theoldone.com and read what they have to say about a boosted, higher compression engine. They have type rs with 15-17lbs of boost disabling the vtec producing +400hp.





[Modified by MikeSarr_GSR, 12:07 PM 2/28/2002]

 

mikeK,

if you were running some Toda cams then maybe you could run the gimme-NAS thing, but since its JUNs no chance

anyway, in short, yes the higher the compression the more NOS you run and keep your octane high but fuel weight low, so 112 mixed with 114 VP will do best. Put 100shot wet system and all 100 will appear at the wheels with high compression. Figure your b20 all motor now may like 14-15 degrees timing, put down 9-10 with the shot and it'll fly like Vin Disel in Fast and Furious LOL

Greg

 

I squeezed on my last Type-R with spec B's. There were no problems on 92 octane with a 50 shot. I wasn't 215 to the wheels though, but almost 190 I'd go for the smaller 75 shot versus the 100 though.

 

Fast and Furious. LOL. No.

There's a real good deal on a nitrous kit that I have access to, and I was just considering it.

I'd probably use ITR cams or maybe even bring the Toda Spec A's out of retirement and install them back in the motor.

Anyone have any idea how much lobe separation and overlap there is on Spec A cams? I realize this will all change with cam gear tuning, but a rough estimate would help.

 

The cam cards that came with the cams should have the spec's for lobe seperation and overlap.

-Brad

 

<gets onto soap box>

<ahem> A full out race motor running on high octane race gas all the time is aloud to get away with this. It can also be tuned to the ragged edge of exploding due solely to the fact it is a RACE motor and not a street motor. I'm not saying your saying this, but I hate when people quote about someone running high compression and boost and saying "well look at their results". They arent driving to work/ school/ where ever every day either. Try that on a street car and see what happens. In truth, 9:1 is too high for me.....I would much rather prefer 8.5:1 or 8:1. Turbos are much more efficient at moving air than pistons are..... Besides, boost itself is a form of compression. Less engine compression = more boost, which means you are putting MORE air/fuel into the cylinder instead of trying to get more power out of compressing the hell out of what you already have. Besides, 8:1 boosted motors are alot less knock prone, which of course is always a good thing.

<steps on soapbox>

CLIFF NOTES: high compression + boost = unreliable, yet fast race motor

 

how about running a smaller shot like around 50-65shot with 11.5:1CR and mild cams?

colder plugs? bigger injectors? retard timing? high octane fuel?

what ever happend to the saying "nitrious loves high compression" if that's so true why do we have to change a whole bunch of things to make it run safley.

 

Mike, most people who run a big shot, use a timing retard box to pull back ignition timing on the bottle, which ads a large degree of safety.

 

no **** sherlock.
i have a digital 6 w/ auto-retard feature.

 

 

wouldnt a direct port system be better for such a shot? This would better distribute the N20 to each cylinder.

However, i dont know how efficient a wet system is when considering distribution.

Just some food for thought though.


Good Luck.

Mike D

 

i'm running 12:1 in my new b16 (it's fully built to withstand what I'm doing to it, so don't nag and tell me it's going to blow up). My 1st stage of NOS is a 5o wet shot fogger system... stage 2 is a 150 wet shot direct port system. when stage 2 is activated, stage 1 is automatically deactivated. My cams are designed with NOS in mind... TODA, JUN, SKUNK2, etc... those cams are designed for an all engine application... not good with nitrous. very innefective. I'm running @ over 100% efficiency with NOS. I spray 150, i get about 160 whp... it's all about how you build the engine and the grind of your cams. by the way, the higher your compression, the more your engine will respond to the NOS... For example... HUGE difference in 11.5:1 vs 12:1 when you look at efficiency.