i was wondering what kind of boost the 04 S can handle. i have a comptech supercharger and i am thinking of getting a smaller pulley can someone advise me and also let me know if it is from experience.

 

can anybody help me?

 

i am running 8 psi so far so good

 

There is no easy answer you your question. There are to many varibles. As a general rule every 10 % increase in power will reduce the engines total life 25%. Its not a linear graph however and the more power you add the greater the rate of decrease in engine lifespan. If you go with to much power at some point you will start exceeding ultimate loads on some engine components and get immediate failure. Experienced engine builders know what will fail first and what they have to beef up. Few if any aftermarket parts companies do any real long term endurance testing so there is not a lot to go on when trying to make a guess. The only thing you can count on is that as power goes up the engine lifespan starts dropping fast. However if you take a 200,000 mile engine and reduce its lifespan 75% to 50,000 miles is that critical to you. Probably not, just keep some money in the bank for repairs if you go to far. Its something you have to expect when you start modding.

 

this is the primary reason i didn't begin heavily modding my last vehicle ('01 Lightning). It's not worth the damage it causes when it blows up. My S is bone stock and if I were to S/C it, I'd probably keep it around 6psi just for that added kick but not enough to make things go boom. Anything more, you'd better have a cash stash to pay the repair bills... or else you'll be in credit card hell.

 

I've been running 7 psi with no problems.

Tim

 

i love it when people say they run "without problems".

all that means is you are not loading it beyond the catastrophic damage point. At 7psi, you have almost certainly significantly reduced the engine's lifespan, though.

so, to answer bob's question...how long do you want the motor to last??? more boost equals less life on average. I haven't read of many Honda motors being boosted and running 100,000 miles from the time they installed forced induction. I read of many integra motors that just lose compression, often after only 30,000 miles and at low boost.

 

Hmmm, so my engine had 240hp and now that it's supercharged it has about 360 so that's 360/240 x pi, carry the one.... 50% more power!

Assuming this engine is good for 200K and for every 10% I lose 25% my engine must have blown 50K before I got it!

I realise you said it's general, but it's more like . Engine life is affected by a lot of things. A properly set up boosted engine treated well and with good maintenance will last a whole lot longer than a bone stock engine without maintence and abused on a daily basis.

My suggestion is not to boost at all unless you have good engine management. If you do have good engine management then I'd say don't go over 9psi without work. By work I mean absolute minimum of decompression (head gasket or pistons) and more probably a sleeved block and higher rated top and bottom end parts for higher boost.

 

As long as you don't get detonation then you should be fine.
Increased boost usually means increased engine temps, which can lead to detonation. Properly matched ignition/fuel systems to go with the forced induction is one of the biggest factors.

Many turbocharged cars with high boost levels run very rich systems to avoid leaning out and detonation. While this is not something I would really recommend, I gave it as an exmaple only to illustrate that it is not boost alone that causes your engine to blow up.

 

if you wanted more then 7psi of power you should have gone turbo