Ok i got a b18b and if you didnt read my other post my plans are
-mill and polish cylinder head
- crower valve train
- crower 404-403 mixed spec cam regrind.
- full exhaust
- and eventually nitrous
but the thing is i was reading an article and it said that dew to the b18s low rod ratio they like long duration big overlap cams BUT on a nitrous or FI engine you want intermediate overlap cams to prevent the boost from shooting into the exhaust manifold. So if i want to have a fast b18b with nitrous im not sure what i should do. The aggressive cams would be great for the car NA but with nitrous would cause problems or not work near as well right? Or would it not make that large a difference?

 

First of all, get the 404's. You'll be disappointed otherwise. Then of course you can add nos in the future if you so desire. If you fell there is a problem, get cam gears.

 

think it would be okay. got type r with crower 403's crower valvetrain, milled head, and as soon as I put my 12.5.1 pistons in gonna run 100 shot , I have been told by many people their should be no problems. Just make sure to have some one clay test to make sure their is no clearance issues with high lift cams

 

So the overlap doesnt make a difference? Just that the article said it does but i wasnt sure wether it ment that nitrous would work fine on the engine but would work better with a cam with less over lap or wether it ment that nitrous wouldnt be a good idea at all.
So my setup would be a good idea?

 

when running a heavy shot of N2O (100-150 shot) the motor will make the most power with short to standard duration but with high lift to allow as much air in as possible. stock SI, GSR, ITR, CTR cams are nice for N2O setups, with the TypeR cams yielding the most power when tuned.

if the duration is so long that the motor sees lots of overlap then there can be problems during N2O injection. cam gears help tune the cams to the motor setup for the most reliable power output, but if the cams have such a long duration (such as aggressive N/A) cams gears may not fix that problem with tuning.

the cheapest option would be to stick with the stock cams you have and sacrifice some power. the first upgrade to get would be some good old ITR or CTR cams which work well with a lot F/I setups. or you could just dump the $$ and get some custom cams (or N2O cams for your particular setup) to achieve max power/torque while on the bottle.

tuning is needed with any aftermarket cams and N2O setup. the idle should be fine with standard duration cams even if they have a high lift. i wouldn't get aggressive N/A cams and expect them to idle fine and work great with any N2O system.

 

Thanks man thats some good info. If i regrind were could i find specs or get some info on good specs that would make my car fast NA and that would be good for nitrous. Also im prob going 75 shot.

 

the 63403's would be similar to the 62404's stage wise to non vtec. I got the 403's in my b20 and i like them. They are kinda quiet compared to what i've heard about the 404's and idle alot smoother

 

if you opt for custom ground cams instead of using cams similar to ITR/CTR cams then find someone on H-T who can get you a good price on a set. then discuss the setup you will have (block, C/R, headwork, rpm limit, fuel delivery, exhaust system, N2O injection type) with the person who'll be making the cams to insure they are made for your setup to maximize power/torque. custom cams can be pricey but will yield a nice gain if matched to your setup correctly.

you also have to ask yourself, how long will i be running this setup? will i get bored with it and want to change or upgrade it? can i even upgrade with the cams and headwork etc. that i just spent a good chunk of $$ on?? will i ever increase the injection size or switch to a VTEC or LSVTEC setup?

the fact is that most get bored with their setups and always want to uprade for more power output, so planning is important.

it's not a wise idea to get N/A cams if you want to go N2O or turbo in the future. or to install turbo cams on a N/A or N2O setup and expect to make power. each setup requires it's own range of specs to function properly and make power.


[Modified by sweet, 7:53 PM 11/5/2002]

 

Well money plays a factor here so this is all happening over time. I will get the head work done and nitrous and hopfully be in the 13s. Ill prob keep my car but if that set up gets old good chance ill be swapping teh whole engine out. Anyways thanks for the input ill have to find someone who i can discuss some custom cams with then.
thanks alot!

 

so, do you think the crower 403's with 257 duration intake and 246 exhaust. lift .472 intake, and .466 exhaust would be to agressive for 75-100 shot on built type r motor?

 

I dont know but with a b18c5 i wouldnt be running 100shot of nitrous hehe

 

seriously though does anybody know, probably thinking around maybe 75 shot now, maybe less, let me know what you guys think appreciate the help also remember highcompression like 12.5.1


[Modified by 98itr543, 12:56 AM 11/6/2002]


[Modified by 98itr543, 12:58 AM 11/6/2002]

 

A 75 shot of nos is fine. There is truth to it being better with less rather than more overlap. You can have too much and end up with a burn valve. That would suck, cause you'll have to pull the head. however some overlap isnt a problem. Also 100 shot would work but I'd only do it if the engine is built cause it wont work that long.

 

so, even with the high compression 12.5.1 I should be okay w/ 75 shot??

 

you could do that but even with premium fuel extra tuning is needed. additional ignition retard than normal will be needed to avoid detonation with a high C/R like 12.5:1. if you throw longer duration cams in the picture then even more so, though the higher lift is fine. that setup is definantly possible without a doubt, but if only using pump gas then do some good tuning to make the motor last. fuel delivery is very important as is ignition timing control. go with a wet system if you haven't decided so already and also a fuel plump and upgraded ignition system for strong spark.

 

quite a few have used 80-100+ shot N2O systems, wet or DP, on higher C/R motors such as a stock B18C5. some even go 11-13:1 C/R but use excessive tuning and race fuel to run safely. i've heard of B18C1/5's running bone stock with 100-125 DP kits and no problems. it's all in the tuning. the B18 motors can take alot when tuned and driven correctly.

 

Go with 404's if you're gonna use nitrous. I was in the same situation as you a few months ago. I emailed crower and called them and they told me to use 404's with nitrous, between 50 and 100 shot would be perfect. Brian crower actually emailed me back.

Like they said, tune the cam with cam gears if needed. ITR, GSR and B16 cams are all working well with nitrous, and they all have more overlap than the 404's

 

Seriously thats ******* great news i thought that the 403s would be better because there not as agressive.
So if i ran like 404s with new valve train slight head mill and ports all polish up i could run like 75shot of nitrous with no problems?

 

No problem at all. Just make sure you've got the right fuel cause with the new cams you will need more tuning. Get a b&m fpr and a upgrarded fuel pump for the 75 shot. You will be ok with stock injectors, i know i am.

Remember, it's better for you to get the 404's then the 403's, you'll be faster OFF the bottle first and you're only like 2% of your time ON the bottle. If it would be a BIG nitrous set up like 125 shot and more then maybe a nitrous profile cam would be better but in your case it's not...so happy revving and spraying!