JspecMX-6 said:
now you guys now how i feel about this one... $5000 for a turbo? for 40-100 HP? or dropping $5000 and some sweat and blood into the full engine. to gain 150+ HP. those pics of that explosion were pretty painful, and it happens but i wouldnt say its a frequent occurance.
True. But "sh*t happens":
- accidentally leaving a bottle heater on or having a relay fail "on" can lead to the type of occurence seen in those pics
- a leaking solenoid can allow the manifold to fill with N2O, which can lead to a manifold explosion if the car backfires. I've personally seen intake manifolds broken at their mounting bolts and lifted off the heads by this problem (albeit on V8s...)
- a rear-end collision can lead to a ruptured N2O tank which can make a small fire a big deal with all that liberated oxidizer around
- an ignorant mechanic working on a car can forget to install NOS jets correctly leading to potential engine damage as the driver unknowingly sprays.
Personally, I think there's just too much that can go wrong with N2O, too many avenues for something to happen that makes the long-term risk outweigh short term benefits. Having said that, there are lots of careful people out there who run N2O, and have done so for a long time, with no problems. I don't think however that their diligence & self-discipline are representative of the populace at large.
IMVHO.
i neglected the fact that he has the KL. the avenger was a 4 and i dont think the FS draws enough air to take 9 PSI. but you guys (mike and asword) know more about turbos than me so lemme know if im wrong. once you have the turbo though, how can you improve on it?
The amount of boost pressure isn't so much determined by the displacement or number of cylinders but by the turbo and control mechanisms (e.g. the wastegate). 25PSI 1.6L Honda drag motors aren't unheard-of nowadays. They run huge turbos and take a few seconds to build boost, but they do it.
As far as improvements, it depends. A stock-internal V6 is safely limited mechanically to maybe 9PSI. But at 9PSI, you're making 270HP or so at the crankshaft, giving the 2800-lb MX6/PGT the power to weight ratio of a 350HP, 3550-lb Z28. Getting that power to the ground through a FWD powertrain is the concern of course, but it'd be a lot of fun trying
That's pretty respectable output. If you still want more, then you'll have to build the motor internally. Allan Wong did this with his stroker KL03 and put over 300HP to the wheels (though the clutch was slipping badly and he aborted the run.) But he's got a ton of money, blood sweat and tears in that 626 of his. "How fast do you want to go? How much money do you have?"
With the motor built like this, the limit becomes other driveine components: lack of an LSD hurts the ability to put power down. A Quaife LSD is available but it's not cheap. The clutch and transmission is also a concern and so on down the line.
i just favor the built engine. you can drop the same amount of money for more power. and whats even better, you can build on it when you get more money. charge it, NOS it, etc. and the engine can handle it with no problems.
Well...
First, you have to decide what you're building the motor for before you can say you can "charge it, NOS it etc". A small displacement poppet valve piston engine (2.0L let's say) is never going to move alot of air on it's own unless it revs like crazy. A Honda S2000 is a good example: 240HP but near 9000RPM. You'll never hear about an engine that size making 300HP at 5500RPM without some sort of artifical respiration.
Further, if you want to start out with a high-RPM screamer making tons of HP at 7500RPM, then you'll need camshafts and compression designed for it. But those same cams and especially that compression probably won't work well for adding a blower or N2O later. High-RPM cams tend to have quite a bit of overlap which can work against forced induction (Oscar Jackson said as much about the 1.6L 160HP Civic Si motor) and high compression increases the likelihood of detonation. Most motors designed with turbocharging in mind run around 8:1, not the 10:1+ N/A high-po motors will run. You can put blowers on these engines, but you'll not be able to run alot of boost with them and they won't be optimal.
IMHO, if you're purpose building a motor, start with a definite plan: high RPM, normally aspirated, or high-pressure turbo, N2O etc and build it to optimise that plan.
but running these items on a stock engine is askin for it. like i said, respect it and it will respect you.
Definitely. Any power adder like a blower, added to a stock motor, moves the envelope of operation closer to the "red zone" of relibility of stock parts. All engine parts are designed with "safety" factors, but they're designed with the OEM power output and mass manufacturing processes in mind. Once you increase that substantially, the loading gets closer to the limits the part will take. Who knows, some KL03s might have rods with minor internal defects that will last forever at 164HP but which will break at 270HP...