Hypergear Turbochargers and High flow Services Development thread

[GTSBoy]

Smoothness of the wall inside an exhaust manifold like the RB one is going to have a very very small effect on the flow/pressure relationship, compared to the terrible, terrible aerodynamics of the bends and joins in the log itself. It is actually possible to get better flow with a rougher surface, especially on the inside of the bends, because a thicker boundary layer is less likely to seperate off the wall (or at least, it will not seperate until a higher velocity is reached). Keeping the flow attached almost always wins.

The outermost ports on the RB manifold are poorly aligned with the head's ports, and so one of the things that Stao did in that mod was to port the manifold to improve the match (and that is a long standing known improvement anyway). As to "port matching"......it is actually better if the manifold flange openings are larger than the exhaust ports on the head - by 1mm or so all around) to try to create what is known as an anti-reversion step. The idea being that the change in section does not cause a bad upset to flow when the gas is flowing out of the port into the manifold, but the step creates a place where a pressure change needs to occur to force return flow (such as when the exhaust valve is still open but there's a pressure pulse elsewhere in the manifold that drives reversion gas back in through the exhaust valve). The pressure change is sufficient to cause the pressure wave to bounce back (ie, it's the "end" of the runner, even though it's not actually the end) and reduces the amount of exhaust gas reversion into the closing valve. It works. It's probably less useful on a turbo engine where we simply have high exhaust manifold pressure anyway, and arguably less useful on a crude log than on a decent long tube manifold.... but you'd still do it if you could (and it didn't compromise any other aspect of the design) on the basis that any little help is good help.

[Dan_J]

^ aka exhaust manifold ports too small and dont line up with head ports which means theres bad flow

[Marcus89]

Have my g2.5 on the car given it a bit of a drive. Seems very good but can't get up it properly till tuned yet .

I highly recommend Hypergear to anyone interested in upgrading their turbo. My turbo was an old used one I got off another member which was stuffed. Sent it down to Stao and he replaced everything (except housings) for around $400 and he also updated the rear housing to 0.82B for no extra cost on top.

I know I wasn't the easiest customer to deal with but he was always professional and helpful so a big thumbs up from me looking forward to a safe 270rwkw

[hypergear]

Thanks for the feedback. Looking forward to see your dyno results.

Further updates with the fabricated factory exhaust manifold:

It took me 4 hours to remove brae's manifold. I believe there is a need for small alterations in design which allow tools reaching and turning manifold to head studs in a compact area. Installing the stock manifold was a piece of cake.

It still runs the SS2, I will take it back to Trent for some dyno runs on Monday. Assume no timing reduction while power and torque curves mirrors, then that would possibly confirm my $500 alteration work perform as good as some of the $1000+ hand made items.

[petero'nell]

Good work. Have you driven it on road? I might get mine done also for the ss1pu turbo.

[jet_r31]

Are you going to add a ex wastegate port to it stao?

[methz]

how many exhaust manifold gaskets do u go thru a week? lol

[hypergear]

There is a very noticeable gain in response using with this manifold. I'm very sure it has lesser volume compare to previous, plus shorter runners would've also helped. hopefully peek outputs stays the same.

The factory manifold is a twin plus log manifold.I prefer keeping it that way, refer to previous photo, note the curvature in bends of both manifold logs. if that has been milled then exhaust gas will run into a flat end, its also the reason that I didn't mill into the merging point. External gate in this case can be attached to the turbine housing since the manifold is no longer restrictive.

[GTSBoy]

Are you going to add a ex wastegate port to it stao?

He said he'd rather put it on the turbine housing.

--edit--beaten

Edited September 8, 2012 by GTSBoy

[Dan_J]

nice work

will be eagerly waiting for full boost graphs

stao, i figure your using 40mm 1 1/2" ID steam pipe ?

[hypergear]

The Tube ID is 45mm

Also an prototype actuator was made. it has adjustable rod that allows pre-loading, but also allow adjustments to spring load pressure. Similar to certain external wastegates that allows spring load adjustments. By using this prototype, I'm hopping to hold steady boost levels in upper rpms range, similar to an external waste gate result.

[hypergear]

I've finally got some results sent in from our version of billet TD06SL2 off a S13 none VCT SR20det. It made 282rwkws on 18psi with E85 , it should just touch 300rwkws at full potential. This turbo is now available for $800 brand new for any one's interested. Far as I know the car has 264 cams with every thing else standard. And that is on a high mount T3 manifold externally gated.

[hy_rpm]

Do you have them in t2 bolt on housings for s14?

[hypergear]

Think so. You need to run them externally gated to get the numbers.

Also some results about aftermarket v Stock manifolds.

Per last page referring to the modified stock exhaust manifold. I've done a back to back test today V Brae's exhaust manifold.

It is actually more responsive as I've felt, however also down on power. Pink is modified stock exhaust manifold, while the other two are from using Brae's manifold. free flow manifold produced more on lesser boost, proper manifold is very necessary for power making.

[GTSBoy]

So 2psi more boost to make 10-20 kW less across the whole top end. Not terrible.

[Cowboy1600]

You need to get hold of a stock standard manifold and compare it to that because that's what it's going to be replacing. I can't see it being attractive to someone who already has an aftermarket mani. Myself, on the other hand, would consider yours if the price is good and it compares favorably to stock.

[GeorgesR34]

I think what he meant was get a proper hand made manifold with a proper external gate system for better power.

[pipster11]

I think what he meant was get a proper hand made manifold with a proper external gate system for better power.

yeah but someone with an aftermarket manifold already won't buy one of these

someone with a stock mani would, so it would be handy to know what sort of difference vs stock there would be

[Cowboy1600]

yeah but someone with an aftermarket manifold already won't buy one of these

someone with a stock mani would, so it would be handy to know what sort of difference vs stock there would be

Eggzacery.

This manifold is targeted at people currently running stock manifolds.

The only way Stao is going to confidently say that it's a worthy ~$500 upgrade is by comparing it back to back with a stock manifold and showing the improvement, assuming there is one.

[hypergear]

Well that level of gain Its not worth the $500, a cheap china manifold would've gained better result. I won't be providing that service.

mean while we also did a power and boost comparison using the current SS2 against the T67, both on E85 and ext gate (I need harder springs in mine). this is obviously not official just some thing interesting to look at.

Red is from SS2 the rest are from T67.