This has probably been beaten to death, but please help another newbie here one more time because I've been hearing conflicting opinions

Does a supercharge affect the engine life and reliability?

What are the pros and cons of going Forced Induction vs Heads/Cam package? Money is an issue so I cant do both.

 

I'm a newbie to this stuff myself, but I'm pretty sure the answer is "yes", FI/nitrous does stress the engine. I think whether it is enough to break it depends on a lot of factors, which I don't understand enough to explain (but I do know that tune is important because lean = death). I've known several friends running nitrous and blowers to do engine damage.

 

Anything that increases the horsepower of the engine will have a direct effect on engine life!
However a S/C will have less of an effect then H/C because it only is there when you put your foot in it.
Let the mods begin

 

You won’t get a clear answer on this on.

H/C just swaps out existing parts of a stock motor - so it can be extremely reliable with much less to go wrong. But, to get FI levels of power from H/C you have to go with a pretty aggressive cam and bump up static compression with a smaller combustion chamber. These cams are completely different than the stock stuff and the stress on the valve train is greatly increased (even though you upgrade the springs, valves... they don't last as long as a stock configuration). This can be heard as the car idles with that sewing machine sound. This results in much more wear and tear on the top end (even in part throttle driving) and the high static compression can result in more frequent detonation (which will damage the bottom end over time). You are also going to have some reversion with an aggressive cam and this will generally make the car waste more fuel at part throttle and fail emissions. It really depends on how aggressive you go, mild H/C setups don't have these issues.

A FI setup is going to use increased dynamic compression to make power. This basically creates almost no extra stress while just cruising, but obviously puts a pretty big strain on the bottom end under boost. There are also a lot more things to go wrong with a FI setup (more parts to break or malfunction). The real beauty of FI is that you can get near stock drivability at part throttle, but have a complete monster once you get into boost.

It comes down to picking your poison. Both will reduce reliability at some level, but it depends a lot on how you are going to drive/use it.

People who beat the crap out of the car/road race... will generally get much better reliability out of a H/C setup.

Also, the things that generally go wrong with H/C packages are much easier to fix. When an FI setup goes bad you usually end up putting in a new shortblock.

Upgrading the bottom end with forged internals can eliminate a lot of the potential reliability issues with FI, but this will add about 4k to the bill.

Another important thing to consider is the tuning. NA setups are very simple to tune and it is basically difficult to screw up the WOT part of the tune. FI on the other hand, can be very tricky since the PCM was not designed to deal with boost. Low boost levels are not a big deal, but higher levels require someone who really knows what they are doing and you have to keep a close eye on it as conditions change (it won't be very adaptive unless go with some of the stuff that has just recently hit the market).

Hope that helps.

 

What's the percentage of track vs street use?

For the street:
The difference each option presents isn't enough to make stress/reliability the reason on which option you go with. NA at 450rw is nothing like FI at the same power levels and the difference becomes night and day any higher. If you want stealth w/o going big cubes or stroked then FI.

I'm sure boost stresses the bottom more but doesn't rpm when NA wear it out more?

 

 

The car will be street used most of the time with occasional few street drags. You said NA at 450rwhp is nothing like FI at the same power levels; did you mean that NA would be much more reliable at these power levels or vice versa?

 

If you had 2 motors with 500 HP each. One forced induction, and the other H/C set-up, IMO the FI would live longer. A couple reasons IMO is that a FI motor puts less stress than a Hi-compression large cam motor is, with FI you don't have to rev the motor up as high to make the same power, which takes stress off the reciprocating mass. Also I think the most stress on the rod is actually when it's on it's down stroke, not the power stroke! It's realying on the cap to pull the weight of the rod and piston, and also in air. With boost, the piston and rods goes down easier because of less or no negative pressure in the cylinder to help the crank pull the piston and rod down.
Also as Quicksilver above stated, you don't need a radical cam that will wear-out your valve train faster. You would even have better life it you could lower the compression on the LS1 down to 9.5:1 - 8.5:1.

 

sorry.. I was referring to streetability and idle or the stealth factor. FI you wouldn't know it wasn't stock driveability wise. If it were a TT you wouldn't know at all except for the BOV. If you're like most on this forum, even if you don't think so right now, 450-500 is not going to be enough and will mod it for more way before long term reliability even becomes an issue..

I agree w/ the above post.. At 450rwhp, I feel FI puts less stress on the motor. Take the time to drive a stage I TT or a mag and get a feel for how these motors don't even feel like they're sweatin it..

 

BTW, the new rear mounted turbos would work well if you're wanting to stay within a budget and they can grow with your hp needs.

If your primarily for street and don't want it to shake the walls at a light then FI is the way to go.. IMO, anyways..