My high compression + boost concept

[jonathan yee]

....not exactly sure what you mean. but from my exp extractors tuned for midrange feature a 4-2-1 design, and extractors design for top end have long 4-1 with the collection point under the engine .

supercharged engines run extractors for gains. extractors are to help pull the zuast gases out of the cyl.

but i'm guessing your saying that the restriction made by the turbo no matter where it's placed would cuase enough back pressure in the system to null the scavenging effect?

still i think it'd cuase less back pressure and than a conventional short length manifold to the turbo.

i have a feeling there's some crazy drag cars that run turbos almost at the back of a car. which suits them as they only drive in the top rev range.

[abently]

interesting idea but it wouldnt work, all harmonic resonant effects would be made null but the turbo. Even if this was not the case you would need primary pipes that would be stupidly long to get a primary resonance below the spool point. In theory however you could have long intake trumpets that might work for you before you hit boost.

Actually you do still see inertia tuning gains with exhaust manifold runners at the correct lengths (abit on a higher (less dominant) harmonic frequency), but you have to offset that against the heat (energy) you loose through the piping before the Turbo which affects spool.

High compression Turbo motors has been the 'in thing' to do for the last few years. Essentially if you can tune out the knock with either Timing or/and AFR's (or Fuel octane) then you will make more power everywhere.

But with the advancement of Turbo technology plodding along at a nice rate, ULP compatible VGT etc, setting up Engines on the limit of what's possible is no longer the main priority for the majority.

[Z2TT]

Have any AE111's with the 20v Blacktop been turbocharged?
I know that Blitz had a turbo kit which is no longer made.

[Sam_Q]

so what taking an eductaed guess is this "less dominant frequency" the pressure wave rebounding off the blades back up the pipes much like that off the rebound wave off the baffle in a two stroke power pipe? Other than this I see nothing else being possible.

Z2TT: plenty have, 6 boost do a manifold for the exhaust side and the intake can be made up or also bought. I suggest acl/mahle pistons with a 0.8mm trd head gasket for this job though.

[abently]

Good timing, here's the winning LeMan 24Hr Engine >

[abently]

Holy shit batman, apologies for the pic size......

[RONA]

Lol at the FAP it pipe

[Z2TT]

so what taking an eductaed guess is this "less dominant frequency" the pressure wave rebounding off the blades back up the pipes much like that off the rebound wave off the baffle in a two stroke power pipe? Other than this I see nothing else being possible.

Z2TT: plenty have, 6 boost do a manifold for the exhaust side and the intake can be made up or also bought. I suggest acl/mahle pistons with a 0.8mm trd head gasket for this job though.

Were these still running the 11 to 1 Comp Ratio ?

[Sam_Q]

thats very interesting, I have wondered what that sucker looked like. So can you explain how there is any resonace in a turbo manifold?

[Sam_Q]

Lol at the FAP it pipe

yeah funny that, I am sure some people will Fap over it

[fixeruperer]

fwoar diesel power

[The Real Roadrunner]

restrictor engines are normally also setup alot differently to unrestricted engines.

[abently]

thats very interesting, I have wondered what that sucker looked like. So can you explain how there is any resonace in a turbo manifold?

What makes you believe that inertia tuning can not occur within a Turbo exhaust manifold ?

The turbine housing itself by default allows some exhuast gas to bypass the blades which therefore means sound waves can also.

The main difference I've seen in restrictor based Engines, is just very mild cams. Which is at odds with the use of such a long runner manifold to oppose reversion, so by that logic the inertia tuning effects must be of sizable magnitude to offset the energy and space (weight gain) loss.

[Sam_Q]

well because the whole concept of harmonic tuning in an atmo application is having a pressure wave come out of the engine, down the pipe, hit the collector and then have a low pressure wave come back in time for the next exhuast stroke. With a turbo the pressure wave hits a heap of blades whic hchop them up. Unless... there is a reversion wave off the merge collector itself, but the manifold would have to be stupidly long to do this.

[PrettyCoolWagon]

Great thread for a read regardless of how old it is...
Seems there's still plenty of first time streeters buying new parts, dropping their compression ratios for a high power figure because that's the historical norm..
So many complementary variables to consider... Suprised no-one mentioned the different affects flywheels could also have on an overall system...

Personal opinion is broad torque range 'rules' for a daily streeter.