I am looking for a cam that will work good with nitrous. Here are a couple of what i have found. What do you guys suggest or use?

CC-TS-224XL Comp Cams TS224XL Camshaft 224/236 duration @ .050", .536"/.555" lift with 1.6 rockers, 114lsa. Nitrous/supercharger camshaft, designed for engines running up to 150 shot N2O, 5-12psi supercharger.

OR

Comp Cams TS233XR Camshaft 233/242 duration @ .050", .569"/.576" lift with 1.6 rockers, 114lsa. Amazing top end pull, extremely lopey idle in stock displacement engine. Nitrous use 200 shot, supercharger 8-16psi.

 

Any cam with a LSA of at least 114 will be good for nitrous or boosted applications. The other specs on the cam u will just have to pick for what u want out of the car.

 

Dustin is right, anything with a 114 will LOVE nitrous.. I installed the Ts233xr in my car when I rebuilt the stock shortblock and finally got it fired up last night. Definatly a healthly sounding cam, and I'll let you know how well it pulls with stock heads after I get it on the road today hopefully. Btw, if you pick this cam, you'll love the way it sounds when you fire it up for the first time! I'm in love.

 

I don't completely agree with some of what was stated above. I think the best way to describe a good nitrous cam is that is like a good NA cam with 5-10 degrees extra exahust duration. This allows the larger volume of exhaust gasses produced by nitrous to be "exhausted". Due to the longer duration of the exhaust lobe, the LSA should be increased a couple of degrees to avoid excessive overlap. That's why the LSA of a nitrous cam is often in the 114 degree range. But just having a wider LSA per se will do nothing for nitrous operation.

Rich

 

If you were going to build a set of heads with nitrous in mind, would it be better to use a cam with more duration, or would it be better to increase the size of the exhaust valve?

 

Damn good question!!! I think that if you were designing a motor for a LARGE nitrous shot the answer would be "both". There is only so much you can do with increasing the duration on the exhaust lobe without messing up the valve events or needing an excessively large LSA. But for the usual street/strip combo I think just playing with the cam is the easiest approacjh. Just IMHO though, be glad to hear of others' thoights/experiences.

Rich

 

rskrause has hit it right on the head. Nitrous loves everything about the "exhaust" side of an engine. More exhaust duration, larger exhaust valve, opening up (porting) the exhaust side of the heads really helps a lot too on a nitrous motor. I've seen applications where the intake valve size is reduced to acommodate a larger exhaust valve. On a N/A motor this doesn't make much sense, but on a nitrous injected engine (where the extra oxygen is supplied by the nitrous, and not from outside) the intake side is not as important as the exhaust side. Getting all that nitrous in isn't as hard as getting all of the exhaust gases out of there.

When you go with a nitrous cam, and aim your engine at being a "nitrous engine" you have to make peace with yourself that N/A performance is going to suffer. It's the same concept as a forced induction engine. Superchargers and nitrous injection basically do the same thing. They supply the engine with more oxygen. People with superchargers build their engines with low compression, and with high duration cams, with super wide lobe separation. Forced induction cams almost go hand-in-hand with nitrous cams. The only difference is that the supercharged cars never see the lack of performance when N/A, because they are ALWAYS supercharged. On a nitrous motor, it's like being supercharged for about 10-12 seconds, feeling raw seat of the pants power, and then jumping out and pullin the supercharger belt off. You just have to decide which one is more important to you.... Being fast on the motor only, or all-out nitrous performance. I think it's a no-brainer.... The nitrous runs are going to be faster, so we might as well concentrate on them....

 

Everything posted above pretty much covers the contemporary thinking about nitrous cams.

Our race track findings have been different.

Much to my discomfort (he's driving me nuts with all the contradictory info), my buddy has been pushing the nitrous cam issue with Comp Cams, Lunati Cams, and other cam selection professionals. It seems everytime you call, you get a different answer on the same question, which cam maximizes nitrous operation?

It does seem as though the one thing they all do agree on: you don't need to worry about the additional exhaust duration untill you start spraying a 400 shot or more. There is very little or nothing to be had with smaller shots, concerning cam selection.

Again, it pretty well agrees with what we're seeing at the track at modest levels (75, 100, 150, and 200 shot size). All documented.

My advice is to buy a cam that maximizes all throttle performance as this is how you'll be driving it 99% of the time. You will then likely see very little to no performance loss during spray time. Unless, that is, you plan to spray 400 or more.

Prior to this last summer I'd have put in a nitrous grind just like everybody else, and in fact we did. I'll not buy another one.

 

Andy: interesting observations. But the extra exhaust duration and slightly bigger LSA does little to harm non-boosted operation on the typical street/strip motor and does have (measurable) benefit when spraying. I have seen this on the dyno (more sensitive instrument than the track). The main exception would be an NA motor set on "kill" with a valve train, induction system, and bottom end set up for very high rpm operation. In that case, the wide LSA would compromise non-boosted operation. However, that is not the kind of motor 99.99% of us have and if we did, we wouldn't be spraying it.

Rich

 

Please do not be offended. That's not my intention here. I'm just in search of the truth, as always.

If you need a "sensitive" instrument to measure the benefit, and the benefit can't be found at the track then is it worth anything to me?

My point exactly.

If anyone has reliable information regarding the huge gains attributable to nitrous cams, share them.

 

 

Perfect example of what a nitrous cammed vehicle can do.... I've got a 76 camaro that is totally built for top nitrous peformance... The cam in it @ .050 has 255 intake duration, and 262 exhaust duration... The cam is at 114 LSA, with .575 lift.... It's a power adder cam to the max.... The car has a 10:1 383 stroker in it..... On motor: runs 13.50's.... Excellent super streetable car.... 150 shot: 10.80 @ 123... The car is really un-believable when you un-cork the spray.... It launches wheels up, everytime with 1.4x 60' times every time on 150 shot..... When I squeeze the 2nd stage (additional 200) the car just goes crazy....

 

I'd like to hear from 10 more people who share similar results with a dope cam spraying a 150 kit.

Any one else who sprays a 150 that has 250 shot size results?

 

I have heard it both ways as you guys are talking. That just go N/A for small shots, but i have also heard that having the cam having 114lsa has made some really awesome performance benefits with the N20.

Good posts guys

 

I have seen one person with a 388 motor spraying a 175 shot go from a 121mph trap speed to 127mph from swapping to a Nitrous ground cam, And no it wasn't a stock cam before. (this was over a year ago so I don't know exact specs of the cams)