Turbo manifold on NA

[stb]

How stupid is this idea?
What is the likely result?

In my sprite project (SR20DE), I am getting pressed for exhaust manifold room. What sort of performance reduction is likely from using a turbo exhaust manifold into a single collector than into the exhaust? Room-wise it would be good. If the power is down a few hp that's not too bad, but if I'm likely to have a big flat spot or something that would be bad.

I can also pick up a 2nd hand manifold pretty cheap and do it myself, vs having customer extractors made up.

[Shifty]

Your biggest concern is not power degradation, but your engine going bang.

I can't speak for your specific situation, but a non-turbo engine will generally have higher compression and differences in the ECU & fuelling/support systems.

These need to be taken into consideration when doing the conversion, often it's cheaper to sell off your non-turbo engine and buy the turbocharged one, which also probably comes with an upgraded clutch/gearbox.

[chartreusehj]

are you talking about using a turbo ex manifold instead of an aspirated version to gain some clearance on an aspirated engine?

Im confused by shifty's post is all.

Im the above is correct, since I dont know much about anything, id figure the turbo manifold "may" be sized to suit a larger volume of ex. gas, and kill the ex gas speed on an atmo version, having said that, most factory anything is restrictive so perhaps it will work fine in your application, no idea on what itll do to the torque curve but if pushed for room even for custom piping, its going to be a compromise anyway.

If the dollar hit aint too bad, just try the cheap option first.

[stb]

OK, greenhj is on the right track - just using the turbo exhaust manifold without a turbo on the NA motor.

I think I'll give it a go, the price to result ratio is pretty good.

[Captiva Fan]

I suspect you'll find you do get flat spots etc; but it'll still go better than an A-series or whatever used to be in it.
Problem is that n/a engines do like to breathe well, and stifling one will lose you some power.

Make it a little modular, when you get the front of the exhaust-system made up; so if it doesn't work well at all, and you need a custom exhaust-manifold made-up, then you only need a relatively small bit made.

[carcrazy]

I recon you will actually pic up power, the turbo manifold is designed to flow gas to the turbo so using it as a n/a manifold couldnt be a bad thing..

[Zac]

Most turbo manifolds are designed to be cheap.

[Norbie]

Correct. Turbo manifolds also don't bother with things like exhaust scavenging, which can be worth real power on a NA engine.