Killashahmafia

i don't drive yet, and i havent' had the pleasure of driving in a friends car that has a turbo, but i was thinkink about the turbo lag that u get when u start accelerating. I was thinking maybe there could be a secondary air intake that went around the turbo and directly to the heads. Computer controlled and probably slowly closing as the turbo kicks in.
I have had no experience with any sort of turbo except for reading up on them. (ps. i'm only 15 so i don't own a car or drive w/o parents)

just wondering wut u guys thought...

AbusiveWombat

Turbo lag is really only a problem in 1st gear. So while you're system may help a bit it probably wouldn't be worth the added cost or complexity.

jsalicru

Well.. turbo lag can become a bit of a problem in autocross and stuff like that... but there are already ways around it. They are just not very practical and actually, quite noisy.

Rally cars have a system where basically lots of fuel gets dumped and the combustion actually happens OUTSIDE of the combustion chamber... this allows for that energy to transfer into the exhaust housing and keep the turbo spooled while off the throttle..

This is why rally cars backfire so much.

Elistan

Doubt it'll work. You're assuming the HP an engine generates on its own is greater than what it produces when turbocharged but before the turbo spools up. I'd expect that even before the turbo is fully spooled, it's sill producing some forced induction, and therefore yeilds more hp than if the engine were sucking air from the atmosphere directly.

What you really need is computer controlled nitrous to kick in during full throttle when then turbo isn't spooled up, then shut off when they've taken over. A local Ferrari Testarossa modified for this setup supposedly makes in the neighborhood of 1000hp with no lag.

Aze85

NO2 does help eliminate turbo lag but i just wouldnt get it bc it would be annoying to fill it up. My friend had a boosted EG with B18c1. the turbo was a garrett t25, so there was a very little turbo lag. his turbo would be at full boost at around i think 3k so there was never a problem.

mingster

wouldn't the T25 top out at ~6K RPMs though? that leaves quite a lot of RPMs before redline...(depends on the tune, that is)

steve c

?

AbusiveWombat

After first gear the engine (if properly shifting) will remain in a rpm where the turbo can spool.

AbusiveWombat

Before the turbo has spooled your intake has negative pressure (vaccum). So Killashamafia's idea of a valve to relieve the vacuum isn't a terrible idea and would probably yeild some power. The problem that I pointed out is that the turbo lag is really only a problem in 1st gear. After 1st with proper shifting you will remain in an rpm that the turbo can spool.

Now this is all dependant on the turbo that's attached to the engine. For instance my stock EVO starts to make positive pressure by 2500 rpms and peak boost hits at 3500 rpms. So as long as I keep my rpms around 3000 or above I don't notice any lag. But if I put a big Garrett 35R on the engine, I wouldn't hit full boost until around 4500-5000 rpms so the lag would be much more apparent. And since most people don't drive around with the engine at 4500 rpms the lag would be present all the time. On top of that, boost response would be worse because the trubo is much larger.

Aze85

well, its not like it stop boosting after 6k. it boosts 6lbs all the way up to the 8k redline. for it being such a small turbo it really didnt seem to die out at all during higher rpms. it actually boosted a bit more due to less than perfect tuning and a stupid wastegate