If turbos give better fuel economy why don't all econobox have them

Originally Posted by atinybug

Size of the turbo doesnt have anything to do with psi, I meant to reach full boost at that low rpm the boost probably isn't that high.

A turbo is spooled by how much air is shoved through it. While a GT30 might spool at 3000rpm (fully) in an S2000, the same turbo in a mack truck will spool far faster due to the amount of air the truck motor pushes. So, if he is running a motorcycle turbo on an MR2, the airflow might be considerably greater. Having said that, I don't know too much detail in the setup, since like I said, I saw the car that one time, so I guess those that are more knowledgable in this spectrum can clarify a bit more.

Originally Posted by NFRs2000nyc

A turbo is spooled by how much air is shoved through it. While a GT30 might spool at 3000rpm (fully) in an S2000, the same turbo in a mack truck will spool far faster due to the amount of air the truck motor pushes. So, if he is running a motorcycle turbo on an MR2, the airflow might be considerably greater. Having said that, I don't know too much detail in the setup, since like I said, I saw the car that one time, so I guess those that are more knowledgable in this spectrum can clarify a bit more.

Basic concept correct, details not quite accurate.

A turbo's "spool" is referred to the RPM point at which you've achieve full boost...it's not referring to how much air, but how much pressure. Volume and pressure are two different things, which is why there are compressor maps. Turbo size and PSI are related as based on the compressor, the volume of air pushed through the turbo may not match the demands of the engine, and thus the turbo is having to work harder to maintain the target Pressure...or in many cases with small turbos, cannot maintain that pressure and you see the PSI drop towards redline.

This is why, as I stated, a small turbo is good for autocross but sucks for everything else. Being so small, it most likely cannot maintain target pressure to redline and if it can, it's so out of its efficiency range all it's doing is blowing hot air and not making good power.

They don't all have turbos because it's more expensive.

Now what's all this other talk about?

why does no good companies sells oil online?

I still want to know what atomizing air is.

Originally Posted by NFRs2000nyc

Serious question or trolling?

If srs, then it means that the desired boost/tuned boost is achieved at xxx rpm. In the case of that MR2, full boost (or full spool) is achieved at 900 rpm or so (turbo is a Gt22 I believe with a few minor modifications.)

I was trolling. Spool is generally just a term for positive pressure, as mentioned. Full boost at idle (or even near idle) is basically impossible without a major restriction at the top end. Now, I could believe the possibility that it starts to spool at idle, but that's about it.

Originally Posted by lcoleman

I was trolling. Spool is generally just a term for positive pressure, as mentioned. Full boost at idle (or even near idle) is basically impossible without a major restriction at the top end. Now, I could believe the possibility that it starts to spool at idle, but that's about it.

Not quite true. While you are right, you can't have full boost from idle to redline, you can pick which extremes you want it at. If you have full boost near idle, you sacrifice PEAK power at the top end, but you will STILL be making good power up top (although not as much). For autocross (I don't autocross, so I may be wrong) it seems like it is what you want so you can sit in 1-2 gears the whole time and have power absolutely everywhere, especially with those tiny motors.

Sigh...OK. Your buddy's MR2, with a turbo way too small, makes full boost at idle and is perfect for autocross because he only uses two gears. You win.

Originally Posted by 217Bimmer

why does no good companies sells oil online?

Originally Posted by lcoleman

Sigh...OK. Your buddy's MR2, with a turbo way too small, makes full boost at idle and is perfect for autocross because he only uses two gears. You win.

don't bother... he tried to convince me that an s2k was an upgrade from my boosted m roadster

Originally Posted by NFRs2000nyc

If you want a true go cart feel on the street the only cars are a miata, an s2000, and a boxter. The s2000 is the best to drive due to the transmission. 400whp are commonplace these days with bulletproof reliability and excellent resale. Go drive one. A boosted s2000 is quite an upgrade from a z3. One of our local guys owns both and tells us that even with 10k in suspension work, it's not even close. A 400-500whp s2k would put a bigger grin on your face then any car mentioned here, and it's nice to know that you won't be in the shop every 3 days.

Originally Posted by mash20

I still want to know what atomizing air is.

i think he just said that because it was "A" day on sesame street.

I haz a turbo

I haz two