Performance improvements (cams, nitrous, and some other thoughts)

[MaineShark]

I'm sort of considering a nitrous system. I'd like to put the engine project on hold, so I can save up some more cash to do it a little better, as well as to give me time to do some necessary work on the drivetrain and suspension, to harness that power.

Still, I'd like to do some performance improvements, in the near future (this winter, perhaps). I'm already planning on a new intake, and I may put in a higher-stall torque converter (2200 or somesuch - nothing too insane, anyway) for added fun-factor.

I'd like some advice on camshafts (figuring an auto tranny, maybe a torque converter change, probably removal of EGR, among other things).

I'm also thinking adding a small (100-hp, maybe) shot of nitrous. I'm generally more of an "all motor" kind of guy, but as a temporary measure to allow me to have a bit of fun before I am able to do the new engine, I think it might be acceptable. I'm actually tempted to keep it, even after the new engine is installed, for track/occasional use only (to allow me to build a milder engine for better street manners, but essentially change the character of the car with the flip of a switch).

Somewhere in the midst of all this, I'm also probably going to finally get off my butt and convert to EFI, since I sort of need altitude compensation...

Among the issues:

1. I really don't know what's inside my engine (it's not stock, but it makes near-stock power numbers, so it's probably close... construction materials may be different, though). This may relate to cam choice, as well as to how well the engine survives increased power production.

2. Where can a nitrous bottle be mounted? I want a "clean" install, so I was thinking about the compartment that currently houses the jack and such. I haven't done that much research on nitrous, however, so I don't know how closely any bottles will fit that space.

3. Looking at torque converter, cam, and nitrous, what order would you want to do them in?

Thanks for any advice,
Joe

 

[Edmond]

Hi Joe,

I don't have a C3, but my neighbor 2 houses down has a Shark (1979). I quote him, "Ed, I'm gonna experiment with a turbo charger for the Vette' this winter and I'm gonna put a nice little shot of nitrous in it." I said to him, "Bill, you're crazy! You're going to turbo charge it and put in a shot of nitrous?"

He did say something about changing the pistons to stronger pistons because of the nitrous.

 

[Copdogcorvettes]

Nitrous is an easy HP gain, but it is hard on the lower end and pistons. It is used a lot with turbos to make for for the lag time before the turbo get in to full boost. If you know your engine is in good condition, rod, piston and bearing things like that then you may be just fine if you only use a one shot system and not very often.
I'm running a 400 SB and a TH350 with a shift kit, mild cam, good aftermarket intake and headers in my 78. Works well for me.
Well that's my 2 Cents worth.

 

[corvettecrazy]

well some thoughts on this.
a good place for the NOs would either be a few smaller bottles under the seats, I've seen a C4 with them tucked under the rear facia or you could even tuck 1 small bottle on each side of the rear under a lip or something.

if you are going to turbocharge you will have to do a twin turbo set up unless you engine change is a change into a 4 banger. this is because if you turbo charge just 1 side the preasure on the exhaust would be uneven which is not good. therefore it would seem cheaper to add 1 large supercharger. also eliminate the turbo lag due it to the chargers linear boost.

I would do all your engine stuff at one time but you must be careful. the pistons you choose for a non turbo/supercharged engine could and probably will be different than the ones use under boost so you dont what to have to change them twice so think and plan ahead. you will eventually want cams anyways so think ahead on those also even it it will ride rough for a while.

i'm sure there is more to add but it must have slipped my mind.

 

[MaineShark]

Don't know how that got in there, but there will be no forced induction. I'm planning on sidepipes, so turbochargers are out, and there ain't much room for an intercooler in a C3, so a supercharger is out. Plus, I don't see much need for boost on a SBC, if it ain't making more than 750 hp, or so. I'd rather spend money on more cubes

I figure this will hold me over for a few years, so I can save up for a 427 or 454 small-block

Joe

 

[MoeJr]

Nitrous is not worth the hassle for a street car and if it is not perfectly set up disaster is but a shot away. Your L82 should have 9:1 CR stock which is really good for pump 93 octane. I would redo the cam first to something around 210-215 duration at .050. That will give you good torque. Free flowing exhaust and better intake than stock and the car will feel a whole lot better. A 2000 stall converter will help too.

 

[1979toy]

Decide on what camshaft you want before getting a new torque converter. The cam mfg. will have some strong opnions on what torque converter that you use based on your engine and drivtrain. Listen to them.

 

[corvettecrazy]

Don't know how that got in there, but there will be no forced induction. I'm planning on sidepipes, so turbochargers are out, and there ain't much room for an intercooler in a C3, so a supercharger is out. Plus, I don't see much need for boost on a SBC, if it ain't making more than 750 hp, or so. I'd rather spend money on more cubes

I figure this will hold me over for a few years, so I can save up for a 427 or 454 small-block

Joe

you dont have to intercool a supercharger as much as turbos because they are not run by the exhaust gasses therefore the boosted air wont be as hot. they will help but not necessary.

are you going to go with spiral or glass packs in the side exhaust? or jsut a straight pipe w/ nothing to restrict exhaust flow.(i.e. glass packs , mufflers, spiral packs.)

 

[MaineShark]

Doesn't seem to be much support for nitrous. At least, not as a first step. Actually, that doesn't really suprise me.

Your L82 should have 9:1 CR stock which is really good for pump 93 octane. I would redo the cam first to something around 210-215 duration at .050. That will give you good torque. Free flowing exhaust and better intake than stock and the car will feel a whole lot better. A 2000 stall converter will help too.

I run fine on 87 I'm not really certain what compression ratio I have, since this isn't the original engine.

I already have dual exhaust, and I'm going to install the Edelbrock Performer Air Gap intake, so that should free up some airflow.

Decide on what camshaft you want before getting a new torque converter. The cam mfg. will have some strong opnions on what torque converter that you use based on your engine and drivtrain. Listen to them.

Yeah, that's why I have the "cam and converter at the same time" option. I think that might be the best way, to guarantee a balanced pair.

you dont have to intercool a supercharger as much as turbos because they are not run by the exhaust gasses therefore the boosted air wont be as hot. they will help but not necessary.

If you're making enough power to justify boost instead of displacement (that is, if you've maxed out your displacement at 454 or so, and still want more power), then you'd need to intercool.

are you going to go with spiral or glass packs in the side exhaust? or jsut a straight pipe w/ nothing to restrict exhaust flow.(i.e. glass packs , mufflers, spiral packs.)

It's a while off, but I've heard nothing but good things about the spiral baffles, so I think I'll go that way. Current thinking is Hooker SuperComp headers, paired with STS pipes and baffles.

Joe