stealth turbo

[frank]

a thread on cisco,s (au) gives food for thought
http://www.micra.com.au/community/message.php?messageid=36873

 

[joesouthgate]

Interesting concept, but i'm sure it would have been done a few more times if the pros outweighed the cons.

 

[ollie240585]

I would have throught that a turbo on the manifold will be more efficient than a turbo on the backbox.

If you wanted the stealth turbo, then surely then just behind the engine would be best suited (roughly where the 2nd cat is) rather than the backbox.

No one with a Micra is ever going to try this though.

 

[superls]

i cant see why this wouldnt work, theres the same volume of air passing through the tail pipe as there is at the manifold so that isnt an issue, unless there is a leak obviously. and it will hve cooled as it gets to the back of the car.

 

[ollie240585]

It should theoretically work, but it wont be as effiecient as a manifold mounted turbo.

Also you'll need to consider the possible turbo lag, you'd need to run this straight to the inlet manifold as it'll just be too ridiculous to run this through an inter cooler.

Also the oil would be ridiculous. You'd need a seperate oil cooler and pump to allow a flow through the turbo.

I just think its a crap idea

 

[Craig]

Sounds appealing in theory, but when you think it through pretty much ludacrous - where would you run the piping to the throttlebody, nest to the exhaust pipe? Where will the exhaust pipe go post turbo exit, out the side of the car? What happens if you go over a speed hump and rip the whole thing off? What if the turbo gets really hot and melts the floor of your car? How are you going to get the air to the turbo inlet in the first place? How are you going to get the oil from the turbo back into the sump?
Regardless of lag issues, this is surely much more work than doing it normally, the only effort that you save on is sorting out a manifold....

Craig

 

[frank]

craig

personally, i think it would work ok, if you fitted the turbo where the 2nd cat was, with the air filter inside the car, also the induction piping inside the car, which would be about 4 foot long (about the same as an intercooler setup).
a topmount manifold puts the turbo inches from the bonnet (which does,nt burn) and i doubt the turbo would get any hotter than the 2nd cat, which just leaves the fitment of an oil scavenge pump

 

[richj]

hmmm i guess the advantage would be that the exhast gas will have lost alot of heat by the time it reaches the turbo, thus decreasing the maximum temperature that the oil in the turbo would reach. Increasing the amount of gas to be compressed is going to lead to very bad lag. The intercooler analogy seems redundant to me, as the air is already compressed. I wouldn't be suprised if a small turbo like a T2 took 5-6k to spool. No doubt it would work, although not very well.

 

[Craig]

Yeah, but topmount manifold is nassssssssteeeeeeee

I've never seen a cat get red hot (although the only cats I have seen have fur )

The 2nd cat is basically below the gearstick so you're gonna have fun getting all the pipework through the floor, through the dash and then through the bulkhead. Also, oil which comes from the turbo exit isn't fluid, it's a kind of aerated foam so dunno how effective a pump would be at getting that out?

Craig

 

[whipit]

All points seem valid, although lets be honest since most standard designs of turboed micras don't get finished i wouldn't see anyone finishing one of these.

Also one more thing if the reason for doing so is purely to have the gases cool off before they reach the engine then does all the extra weightof having the turbo at the back make up for it.