Unique Autosports Rb25det Exhaust Manifold

[Cubes]

Well hold your breath until we all see how sly33 goes with his nice smooth manifold.

[drgnball34]

Now that the hks is not a option....Would a standard manifold thats been extrude honed produce the same power if not better then the 6boost ones? Im from WA and havent heard of any companies here that can extrude mine. Cbf sending it over east. Rather just order a 6boost one.

[Cubes]

Spoke to the supplier of the HKs manifold. They actually do mount the turbo lower and on a slightly different angle then stock. In the case where im using a HKS GT2835 and turbinless kit...its pointless.

Longer oil and water lines need to b made

New dump pipe

Modify or Make a new intake pipe

Block off the external wastegate provision or Use an external gate and disconnect the internal gate. That sucks!

Now that the hks is not a option....Would a standard manifold thats been extrude honed produce the same power if not better then the 6boost ones? Im from WA and havent heard of any companies here that can extrude mine. Cbf sending it over east. Rather just order a 6boost one.

You do realise the 6boost manifolds are high mount...

Your going to have to make the same modifications as the turbo instead of being mounted lower will be mounted higher.

[SLY33]

You do realise the 6boost manifolds are high mount...

Your going to have to make the same modifications as the turbo instead of being mounted lower will be mounted higher.

ahh the beauty of modified OEM

Sorry to say that it may be a while before i can show you on-car results, as i am not in the same country as my car, and have to organise other people to do stuff for me..

[r33_racer]

goddamit!

what if they extrude honed it TWICE! Obviously you can only go so far with it. Yeh i wonder what a 6boost manifold would flow...and then extrude honed?

[Roy]

With turbine housings it can work very well mainly because it takes the ridges off the internal passage and reduces the depth of that boundary layer effect you get with fluid flow . Also any casting flash goes as well . The process is good for manifolds because it takes more from the constriction points ie round bends where its difficult/impossible to get at any other way .

Getting them ceramic coating does the same thing with regards to surface finish. Im interested to know if someone has had a manifold extrude honed then tried to ceramic coat them. Doesw the ceramic coating have any problem in the smoother surface?

[Duncan]

SLY33, the difference in ariflow between 2/4 (190cfm) and 1/7 (207cfm) seems pretty big, are you worried about it at all? 10% variation?

[SLY33]

Getting them ceramic coating does the same thing with regards to surface finish. Im interested to know if someone has had a manifold extrude honed then tried to ceramic coat them. Doesw the ceramic coating have any problem in the smoother surface?

I was considering ceramic coating it also! But then it really starts to add up cost wise.

The guy that did my manifold told of a stock SR manifold that whilst on the dyno would glow red, and once ex honed, it would not glow, due to the smoother passage of air and less friction/restriction. This would mean less heat radiated from the mani and lower underbonet temps, i could only imagine ceramic coating making the situation even cooler! Yet doesnt the process cost around as much as the honing process itself?

depending on how long it takes me to organise to get the manifold put back on, if some spare dollars come up i may yet do it, as id ultimately like to make the stock mani as good as it could possibly be before bolting it all back up!

Any comments on my after results? Whilst the runners dont flow as consistent as the HKS mani, the overall figures are higher than those posted for an HKS extrude honed mani. Does this mean that my stock item is now as good if not better than an HKS one, or even an ex honed HKS one??!@

HKS ex honed avg 201

Stock ex honed avg 202

[legend01]

I was going to get my HKS manifold ceramic coated after I had it honed but was advised against by both james and compition coatings as there would be a chance, how ever slight, that it might peal of the inside on the smooth surfaces but the outside no worries ,So still debating on wheather to get it done

Cheers Peter

[drgnball34]

6boost manifolds do come in low mount. Only thing is that they bolt the turbo not exactly in standard postion. Instead the turbo flange faces down rather then out 90 degree to the block. Once again no good with turbo kits. Any idea whats need/modifed to suit hks gt2835 kit?

[jnr32r]

who does extrude honing in Syd?

[drgnball34]

any1 extrude honed the inlet runners? Mite be a good mod to do at the same time as the manifold

[Beer Baron]

as per the thread title. in Sydney UAS do them (or have them done).

[ovabooster]

anyone got any results on extrude honning their manifold yet?

[ovabooster]

any1????

[blitzxtr]

Check out Shift performance Rb25 manifolds pretty could Quality I have supporting To4z & drive it most days pretty hard aswell havent had a problem as yet

[ovabooster]

check out these two manifolds, HPI on the left and x-force on the right

Seems like the HPI has a better design then the xforce...It seems to be equal length and merge smoother and in the same direction at the turbo flange..Considering the stock turbo postion is very restrictive, HPI has done not a bad job??

[STATUS]

i have tested back to back with std turbo and those styles of manifolds and found no decent increase, the HPI style on the other hand does offer a noticeable increase.

[ovabooster]

the only place i can seem to find them is directly from HPI in japan

http://web.mac.com/emihpi/iWeb/Site%2017/E...20Manifold.html

Does anyone know of any australian distributors? Are they durable or prone to crack? Do they bolt on without furthur modifications?

cheers

Edited May 16, 2007 by ovabooster

[ovabooster]

im no expert in exhaust manifold but man are the xforce crap! I only really noticed when i sat them both side by side...Just look at how the exhaust gases would flow when leaving the cylinder head...Almost at a 90 degree angle!! Not smooth at all...then look at runners 2 and 3....flow at 90 degress to the 1st runner!!! Big time turbulance...Lastly notice how all the runners merge onto the turbo flange...instead of entering directly into the turbine housing, its off to the side...Correct me if im wrong thou? Just my 2 cents